Determinants of Remittances: The Case of the South Asian Community in Manchester

Keywords: JEL Classification: E21, F22, C25, D10 remittances, international migration, household data, Manchester

This paper investigates the remittance behaviour of the South Asian community using new data from Indian, Pakistani and Bangladeshi households in Manchester. The findings show that standard variables such as income, employment, education, linkages to the home country and host country are important determinants of remittances. Although remittances are sent mainly for consumption purposes, those sent for land acquisition and savings have stronger association with the amount of remittances. In addition, we find strong evidence for the remittance decay hypothesis for Indian and Pakistani migrants, but not for Bangladeshi migrants.

I. Introduction

Recent debates on development finance have drawn attention to the role of remittances in achieving the MDGs (Millennium Development Goals) target of fostering growth and alleviating poverty in developing and less developed countries. Recent estimates suggest that a 10 percent increase in remittances as a percentage of GDP can decrease the poverty gap in Asian countries by about 0.7-1.4 percent (Vargas-Silva et al., 2009). In addition to their role in development, remittances have become a source of concern since 9/11 because of the possibility that, when sent through informal channels as they often are, they could be used to finance terrorism and money laundering.

According to [START_REF] Sander | Migrant remittances to developing countries: a scoping study overview and introduction to issues for pro-poor financial services[END_REF], in 2002 the estimated amount of informal remittances to developing countries was between 25 and 125 percent of official remittances. Although these developments have prompted academic research on remittances, there are only a few studies on the determinants of the remittances of the South Asian community in the UK, one of the largest migrant groups both in the UK and worldwide. Thus, this study aims to contribute to the literature by providing an indepth statistical and econometric analysis of the remittances of three major South Asian communities of Indian, Pakistani and Bangladeshi origins in Manchester using a new, comprehensive household database. 1 The South Asian community is well established both professionally and politically in the United States and Western Europe. The immigration of South Asian people to the UK started in the colonial period and continued after independence. The expulsion of Indian communities from East Africa also contributed to the strong presence of the South Asian population in the UK. The migration from Pakistan and Bangladesh was male-led with many migrants coming from poor rural areas such as Mirpur and Syllhet, and settling in the industrial areas of North West England as well [START_REF] Dale | Migration, marriage and employment amongst Indian, Pakistani and Bangladeshi residents in the UK[END_REF]. The official remittance inflows to South Asia have increased continuously over the past decade from $5.6 billion (1.4% of GDP) in 1990 to $43.8 billion (3.2 percent of GDP) in 2007 (World Bank, 2008). In 2007, the top recipient countries of recorded remittances in South Asia were India ($27.0 billion), Bangladesh ($6.4 billion) and Pakistan ($6.1 billion), collectively making the South Asia region the third largest regional recipient of remittances in the world (World Bank, 2008). According to a recent survey by DFID (2006), a typical South Asian family in the UK sent an average of over £1,000 back home, and South Asian countries are among the five largest recipients of remittances from the UK.

Notwithstanding their significant presence in the UK, only [START_REF] Clark | An investigation of household remittance behaviour: evidence from the United Kingdom[END_REF] provides an econometric analysis of the determinants of the remittances of the South Asian community, and only a few studies, such as [START_REF] Ballard | The South Asian presence in Britain and its transnational connections[END_REF], [START_REF] Seddon | South Asian remittances: Implications for development[END_REF], [START_REF] Boon | BME remittance survey[END_REF], provide some information about their socio-economic background and remittances. [START_REF] Clark | An investigation of household remittance behaviour: evidence from the United Kingdom[END_REF] use nationwide household data to examine the remittance incidence of the major migrant groups in the UK, including the Pakistani, Indian and Bangladeshi communities. According to the findings of [START_REF] Clark | An investigation of household remittance behaviour: evidence from the United Kingdom[END_REF] income is the main determinant of the remittance incidence of all three South Asian communities, Pakistani migrants are most likely to send remittances, and years since migration and education do not have a significant effect on the remittance incidence, although having foreign qualifications promotes the remittance incidence of Indian community. Different from [START_REF] Clark | An investigation of household remittance behaviour: evidence from the United Kingdom[END_REF], we use household data from Manchester, examine the amount of remittances, instead of remittance incidence, and incorporate the use of remittances into our econometric model. In line with [START_REF] Clark | An investigation of household remittance behaviour: evidence from the United Kingdom[END_REF], our findings show that income is the main determinant of the amount of remittances, and Pakistani migrants send the largest amount of reveal that the remittances sent for savings and land acquisition tend to be larger than those sent for consumption and loan payments.

The rest of this paper is structured as follows. The next section reviews the theoretical and empirical background of the determinants of remittances; section three provides information on data and methodology; section four presents the recent trends in the socio-economic background and remittance profile of three South Asian communities in Manchester; section five reports the findings of econometric analysis; and section six concludes.

II. Determinants of Remittances -Theory and Evidence

Broadly, the main theories on remittances fall into three categories: altruism, self-interest, and intertemporal contractual agreement. The last category includes all kinds of contractual arrangements between the migrant and the household left behind, such as insurance and risk sharing, exchange, and implicit loan agreements. Self-interested remittances generally arise from the desire to secure an inheritance, fixed assets or income from one's parents, or to obtain social or financial services from relatives. Purely altruistic remittances involve transfers to the home country to aid the recipient without any expectation of reciprocity. As [START_REF] Lucas | Motivations to remit: evidence from Botswana[END_REF] point out, 'altruistic' remittances often include an element of self-interest and so may be better regarded as tempered altruism or enlightened self-interest. In other cases, altruistic remittances may be accompanied by an element of contractual agreement. [START_REF] Johnson | Urban-rural income transfers in Kenya: an estimatedremittances function[END_REF], involves a set of factors that determines remittance behaviour irrespective of the economic situation of the migrants.

In many cultures and religions, selfless concern for the welfare of others is paramount, which is different from moral obligations. Specifically, migrants care about the well-being of their family because their utility function embodies the utility function of their family members [START_REF] Agarwal | Are international remittances altruism or insurance? Evidence from Guyana using multiple-migrant households[END_REF]. The main indicators of altruistic remittances cited in [START_REF] Funkhouser | Remittances from international migration: A comparison of El Salvador and Nicaragua[END_REF] are that remittances are inversely related to the recipient's income; they tend to decrease with the number of other migrants from the same family and decrease with the time spent in the host country.

Contractual agreement basically refers to mutual agreement between the migrant and his/her family that they will help each other in difficult times (for example, insurance and risk sharing) and that the migrant will at some point pay back the costs of education and migration incurred by his/her family (implicit loan agreement). [START_REF] Lucas | Motivations to remit: evidence from Botswana[END_REF] explain the implicit contractual arrangement between the migrant and the home country household as being based on investment and risk. The notion of risk sharing appears to be self-enforcing and cooperative [START_REF] Agarwal | Are international remittances altruism or insurance? Evidence from Guyana using multiple-migrant households[END_REF], and arises from both self-interest and mutually beneficial arrangements [START_REF] Lianos | Factors determining migrant remittances: the case of Greece[END_REF]. In the case of an implicit loan agreement, the migrant repays the family's human capital investment either in cash or by financing other migrant family numbers [START_REF] Poirine | A Theory of remittances as an implicit family loan arrangement[END_REF]. Selfinterested remittance is mainly associated with the exchange motive put forward by [START_REF] Rapoport | The economics of migrants' remittances[END_REF]. This explains the remittance behaviour as being driven by the migrants' intention to return home. However, exchange motivation can also take place within the mutual contractual agreement. Although the motivational models provide a structured framework to explain the remittance behaviour of migrants, they are unlikely to provide a holistic picture of this complex issue since many other factors can influence migrants' decisions to transfer remittances to their home country.

For instance, [START_REF] Lianos | Factors determining migrant remittances: the case of Greece[END_REF] argues that remittance behaviour can be the result of a complex decision-making framework of a migrant seeking to maximise his/her economic welfare through various rational behaviours. The argument here is that migrants' savings and investment behaviours and the flow of remittances are somewhat difficult to predict because of the many different possible objectives of the migrant, which might include permanent settlement in the home country, minimising the time to be spent in the home country, or maximising wealth within a specific period of time.

The nature and patterns of various economic and social factors appear to play a crucial role in determining the size of remittances. [START_REF] Sander | Migrant remittances to developing countries: a scoping study overview and introduction to issues for pro-poor financial services[END_REF] specifies several factors such as the migrant's profile and salary level, the cost of living in the host country, political and economic volatility in the home country, the migration period, and generational patterns. Based on a review of various empirical studies, [START_REF] Rapoport | The economics of migrants' remittances[END_REF] conclude that familial inter-temporal contracts appear to have more explanatory power than individualistic considerations. Even though some individualistic considerations such as altruism, an intention to return, and inheritance prospects may explain remittance behaviour, their influence generally takes place within a familial context.

In accordance with the theoretical predictions of altruism and mutual contractual agreement, [START_REF] Osili | Remittances and savings from international migration: theory and evidence using a matched sample[END_REF] finds that the remittances of Nigerian migrants in the US are determined by altruism, as the [START_REF] Clark | An investigation of household remittance behaviour: evidence from the United Kingdom[END_REF] show that the stronger family ties and the repayment of contributions received earlier by the migrant are significant drivers of the remittances of migrants in the UK, as they are more likely to remit than their native-born counterparts. [START_REF] Glytsos | Remitting behaviour of 'temporary' and 'permanent' migrants: the case of Greeks in Germany and Australia[END_REF] put forward that the remittance behaviour of temporary migrants is driven by an obligation to meet the needs of close family back home coupled with an endogenous decision-making process by which the migrant's own higher consumption is postponed for future comfort at home after an early return.

III. Data and Methodology

Data for this analysis was collected mainly through random sampling strategy from 700 Indian, Pakistani and Bangladeshi households in the districts of the City of Manchester that hold the largest South Asian communities in Manchester. According to 2001 census data, among all minorities, Pakistanis and Indians constitute the largest share of the total population of Manchester followed by Chinese and Bangladeshis, 5.9, 1.5, 1.3 and 0.9 percent respectively, (Manchester City Council, 2001). The largest concentration of these three communities is in Longsight constituting 41 percent of Longsight's total population, followed by Cheetham (30%), Whalley Range (26%), and Rusholme (24%), Levenshulme (17%), Crumpsall (14%), Fallowfield (12%) and Withington (10%). Our data covers the first four wards where the majority of South Asians reside and Withington, which together hold half of all three communities in Manchester (see Table 1).

Face to face interviews were carried out with individuals of Indian, Pakistani and Bangladeshi origins, who were approached in ordinary public places such as streets, shops, parks, in front of houses, offices, community-based organisations, mosques, cafes, bus stops, and where possible in houses. We are aware that this strategy might lead to under-representation of some groups such as females and the elderly. However, given the high rate of non-response from the households in their residency, it was not possible to conduct interviews in pre-assigned residencies, as true random sampling strategy requires. Nonetheless, to cover the main parts of a ward, prior to the interviews we identified all the main streets and public places in each ward with a high concentration of the South Asian community. In addition, to make sure that each South Asian group was fairly represented, all three communities are over sampled and the number of interviews is determined in line with the relative size of each community in the wards (Table 1).

Although we mostly followed random sampling strategy, in very few cases, leads from other interviewees were used to find the areas of a ward with high concentrations of a particular South Asian community to reach our target number from each group. This was necessary because even though these three groups tend to work or reside in the same areas in the dynamic parts of the wards, which we first covered without any difficulty, in other parts local knowledge was necessary to find out the whereabouts of those individuals from each group.

A final point about our methodology concerns the fact that we interviewed only those respondents sending remittances, as the central focus of the study is to examine the determinants of the amount of remittances and our funding was not sufficient to cover both remitters and non-remitters. We understand that employing such a strategy might cause sample selection bias. However, many studies examining the determinants of remittances have employed a similar strategy (i.e. [START_REF] Knowles | An analysis of income transfers in a developing country: the case of Kenya[END_REF][START_REF] Blue | State policy, economic crisis, gender, and family ties: determinants of family remittances to Cuba[END_REF][START_REF] Durand | International migration and development in Mexican communities[END_REF]. As explained in [START_REF] Knowles | An analysis of income transfers in a developing country: the case of Kenya[END_REF], 2, even though almost all statistics from our data are somewhat larger than those from the national and local census, they are entirely consistent with the latter in terms of their relative values across the three South Asian communities. For example, in both our data and census data, Indian migrants have the highest income, followed by Pakistani and Bangladeshi migrants, while Pakistani migrants send the largest amount of remittances, send them more regularly, and are more likely to remit to their parents.

The age, religious background, and the fraction of each group in self-employment, owning a house in the UK, and sending remittances to their children, are similar in both sources. Although there are some differences between the two sources with regards to the full-time and part-time employment positions of the three communities, considering that our data is collected five years after the census data reported in Table 2, they are not alarmingly disparate. The only major difference is that our data seem to over-represent the married and highly educated individuals in all three communities compared to the census data, which should be kept in mind when interpreting the findings. In fact, On the whole, our data deviates slightly from census data, and in almost all cases it overestimates the statistics by about a third in relation to the census data, meaning that there will not be a serious bias in the regression analysis. In addition, our data is fully in line with the census data in terms of the relative values of the key variables across the three South Asian communities, implying that the comparative statistical analysis in our paper can largely be representative of these three groups.

Finally, since this is the only data providing methodical information about the remittances of the three major South Asian communities in Manchester, we strongly believe that it will contribute greatly to our understanding of the remittance behaviour of these groups, which have significant presence in the UK.

IV. Socio-Economic Characteristics and Remittance Patterns of the South Asian

Community in Manchester

This section provides an overview of the social, economic and demographic characteristics of the South Asian community in Manchester as well as their remittance patterns. The summary statistics and the frequencies of the main indicators for the full sample are reported in Table 3. As the table shows, the average age of a respondent is 37; 68 percent are married, and 84 percent of the married respondents have their spouses in the UK (Table 3). 3 Given that Pakistani and Bangladeshi migrants constitute the largest portion of our data, it is not surprising that 74 percent of all respondents are Muslims, followed by Hindus (26%). 84 percent of all respondents work full time percent intend to return to their home country. In addition, 65 percent of all respondents use informal channels to send remittances, providing support for the view that the majority of the South Asian migrants use informal channels, named as hawala or hindu, for money transfers.

As seen from Table 3, on average, a South Asian individual in Manchester in our data has a university degree, earns £1,378 per month gross, and remits £1,672 a year. In addition, 42 percent of respondents own their accommodation, 88 percent have fixed assets in their home country and the parents of 18 percent of the respondents live in the UK. In terms of the characteristics of recipients, we find that the average monthly income is £238, and the main recipient groups are the parents of the remitters (59% sent money to their parents) followed by siblings (28%), cousins/aunts/uncles (20%), spouse/children (11%) and close family friends (8%). The most common use of remittances is to finance consumption, followed by savings, education, land acquisition and loan payment.

To examine the differences in terms of the key social, economic and demographic indicators across Pakistani, Indian and Bangladeshi communities, we also report the statistics for each group in Table 4. As observed, Indian respondents have the highest monthly income (£1,784) followed by Bangladeshi and Pakistani migrants, £1,286 and £1,206, respectively; while Pakistani migrants send the largest amount of remittances (£1,817), followed by Indian and Bangladeshi migrants (£1,559 and £1,486, respectively). The average age and education levels of respondents are close 4 reveals that the Bangladeshi community is the most established South Asian community in Manchester in that a larger proportion of Bangladeshis has UK citizenship, own their house, and have their parents in the UK. They also have more siblings and children in the UK and have been residing in the UK much longer than the migrants in the other two communities. In all communities, parents seem to be the main recipients of the remittances, and the remittances of all three communities are used mainly for consumption followed by savings.

Since the remittances literature indicates differences between temporary and permanent migrants' remittances (i.e. [START_REF] Dustmann | Remittances and temporary migration[END_REF]Ulku, 2010;2004;[START_REF] Glytsos | Remitting behaviour of 'temporary' and 'permanent' migrants: the case of Greeks in Germany and Australia[END_REF], in Table 5 we also present the data for permanent and temporary migrants separately. 4 As seen from the table, there are differences between these two groups in terms of their age, income, remittances, education level and the duration of their stay in the UK. On average, temporary migrants seem to be 10 years younger, earn £355 less, are more educated, have spent 15 years less time in the UK, and send £213 more remittances than permanent migrants. In addition, a smaller proportion of temporary migrants own their house in the UK and hold a full-time employment position.

Finally, in Figure 1 we report the pattern of remittances against the key variables such as the duration of residence in the UK, age and education level, for the full sample and for the three decline at about the age of 44, whereas those of Bangladeshi migrants stay stable until the age of 54, after which they increase sharply. In addition, the relationship between remittances and the level of education is highly positive for both Indian and Pakistani migrants, while it is slightly negative for Bangladeshi migrants.

From the findings of Figure 1, we infer that the remittances of Indian and Pakistani migrants might be influenced by both altruistic and mutual contractual agreement motivations given that their remittances decay with their age and the duration of their residence in the UK, providing evidence for altruistic motivation [START_REF] Funkhouser | Remittances from international migration: A comparison of El Salvador and Nicaragua[END_REF], and increase with education, indicating the presence of mutual contractual agreement motivation [START_REF] Poirine | A Theory of remittances as an implicit family loan arrangement[END_REF]. The remittances of Bangladeshi migrants, on the other hand, seem to be motivated mainly by self interest, given that their remittances do not decay throughout the duration of their residence and age, and start to increase after the age of 54, suggesting that they might be sending large amounts of money to invest for their retirement. In addition, their remittances are not highly correlated with their education level, weakening the presence of the contractual agreement motivation.

V. Econometric Analysis of the Determinants of Remittances

After providing the analysis of the remittances and socio-economic characteristics of the South Asian community in Manchester based on descriptive statistics, in this section we will examine the determinants of the amount of their remittances using Ordinary Least Squares (OLS) and Seemingly Unrelated Regression (SUR) techniques. OLS is an appropriate estimator given that all However, in addition to the main regression, we estimate a model that includes the different end uses of remittances as explanatory variables, which could be endogenous to the amount of remittances. To mitigate the potential endogeneity problem between these variables, we employ SUR analysis in which we simultaneously run six regression equations, consisting of the amount of remittances and their five end uses, namely, consumption, savings, education, land acquisition and loan payments.

We are aware that employing instrumental variable analysis would be the most appropriate technique to control for the endogeneity problem. However, due to lack of appropriate instruments for the different uses of remittances, we employed the SUR technique that controls for the correlations across the error terms of the equations, mitigating the potential endogeneity problem.

Our econometric model is based on a standard remittances model as shown below:

i i i i i i i i X X X X X ces mit ε λ β β β β β α + + ′ + ′ + ′ + ′ + ′ + = , 5 5 , 4 4 , 3 3 , 2 2 , 1 1 0 tan Re (1)
where, X 1: standard variables on the demographic and socio-economic characteristics of the household head; X 2 : rootedness in the UK; X 3 : linkages to home country; X 4 : recipient households' characteristics; X 5 : use of remittances; λ: district dummies. The regression includes the respondents who are either the head of household or the spouse of the head of the household.

The findings of the regression analyses are reported in Table 6. As the first column of the table shows, most of the standard variables on the socio-economic and demographic characteristics of the remitters are significant and have the expected sign. More specifically, income, full-time employment and education are all positive and significant in all regressions, with respective coefficients in the range of 0.60-0.75, 0.20-0.30, and 0.07-0.12. Although the theoretical impact of education on remittances is ambiguous, as it can affect remittances through different channels, there is extensive empirical evidence for its positive impact on remittances. For example, using comprehensive micro data from surveys of immigrants in eleven major destination countries, [START_REF] Bollard | Remittances and the Brain Drain Revisited: The Microdata Show That More Educated Migrants Remit More[END_REF] find strong evidence that education has a positive effect on remittances. Age, being married and being female are not significant. Interestingly, being Muslim and having rural origins are significant in all regressions with a positive sign, implying that the migrants from rural areas and who are Muslims send more remittances than others. An interesting observation from these finding is that, once we control for religion, being from Bangladesh or Pakistan does not have an impact on the amount of remittances.

The second column of Table 6 reports the findings of the analysis, which in addition to the standard variables includes the indicators about the rootedness of the migrants in the UK. As seen from this column, only duration of residence in the UK and having parents in the UK are significant in all regressions, while having a spouse in the UK is significant only in some of the regressions. The remaining variables, such as having permanent migrant status, number of children and siblings in the UK, are not significant in any of the regressions. As expected, having a UK-based spouse and duration of residence in the UK have a negative impact on remittances, which is consistent with the findings of earlier studies such as those by [START_REF] Massey | Determinants of savings, remittances, and spending patterns among Mexican Migrants to the United States[END_REF] and [START_REF] Brown | Estimating Remittance Functions for Pacific Island Migrants[END_REF]. The evidence that the duration of the residence in the UK is negatively related to remittances is consistent with the remittance decay theory, which suggests that the longer the time spent away from the home the weaker will become the social linkages of the migrants to their home country, leading to a decrease in remittances over time. Studies such as those of Stark and [START_REF] Lucas | Motivations to remit: evidence from Botswana[END_REF] and [START_REF] Funkhouser | Remittances from international migration: A comparison of El Salvador and Nicaragua[END_REF] assert a close relationship between remittance decay and remittances motivated by altruism. According to these studies, if migrants are motivated by self-interest or by mutual inter-temporal agreement, remittances will not decrease over time because migrants have a future self-interest in the home country or are tied into an implicit contract with the family. In the case of altruism, however, they generally decline over time, given that the social connectedness weakens as the time spent away from the home country increases. When interpreting these results, we should keep in mind that, although as a whole South Asian migrants' remittances decrease with the duration of their residence, remittances by the Bangladeshi community have a tendency to increase throughout their stay in the UK as shown in Figure 1.

In the third column of Table 6, we add the frequency of visits to the home country as an indicator of the social linkages of the migrants to their home countries. We find that the lower the frequency of the visits to the home country (the negative sign on the coefficient comes from the fact that high numbers refer to low frequency of visits) the smaller the amount of remittances the migrants send back to their countries, implying the importance of social linkages to the home country in the amount of remittances. Column 4 presents the findings of the analysis that includes the nature of the relationship between recipient and remitter in the model. As observed, only the remittances sent to spouse or children are significantly higher. Being parents, siblings or extended family does not have a significant impact on the amount of remittances. Finally, in column 5, we incorporate the However, because the use of remittances might also be affected by the amount of remittances themselves, for robustness check we also report the findings of SUR analysis that estimates the amount of remittances and all five different uses of remittances simultaneously, to control for the contemporaneous correlations among these six variables. The last column of Table 6 reports the results of the SUR analysis of the amount of remittances. 5 As seen from the last column, the findings of the SUR analysis are very close to those obtained from the OLS, the only exception being that the use of remittances for consumption becomes significant with a positive sign. Thus we conclude that savings have the strongest association with the amount of remittances, followed by land acquisition, loan payments and consumption, in that order. The use of remittances for education does not seem to be a significant determinant of the amount of remittances.

In addition to the analysis of the full sample, we have estimated the amount of remittances separately for permanent and temporary migrants and for the remitters using informal and formal channels. However, the results of the Chow test revealed no differences between the remittance behaviour of these groups, although there are differences in the income and remittance amounts of temporary and permanent migrants when we do not control for other factors.

To sum up, the findings of the econometric analysis suggest that the standard variables of remittance models such as income, full employment, education, rootedness in the host country and

VI. Conclusion

This paper attempted to analyse the remittance behaviour of the South Asian community residing in Manchester using newly developed household-level data collected from 700 households residing in different districts of Manchester. To the best of our knowledge, this is the second study after [START_REF] Clark | An investigation of household remittance behaviour: evidence from the United Kingdom[END_REF] assessing the remittance behaviour of South Asian community in the UK using econometric analysis.

The analysis of the descriptive statistics revealed that the average South Asian individual in our study holds a university degree, earns about £1,375 per month sends 10 percent of his or her annual income to the home country, which is higher than those of some other migrant groups, such as Turkish migrants in Germany (Ulku, 2010). Consistent with the UK census data in 2001, we also find that Indian migrants are the highest earners, while the Pakistani migrants send the largest amount of remittances on a more regular basis. In addition, 42 percent of the South Asian According to the findings of the econometric analysis, remittances of the South Asian community are primarily determined by income, employment status, education level of the remitter as well as his/her rootedness in the UK and linkages to the home country. These results are somewhat different from those of [START_REF] Clark | An investigation of household remittance behaviour: evidence from the United Kingdom[END_REF] in that they do not find a significant effect of education and rootedness in the UK (measured as years from migration) on the remittance incidence of the South Asian communities. This could be due to the fact that they investigate the remittance incidence while we investigate the size of remittances. Among the different uses of remittances, our results show that savings have the strongest association with the amount of remittances, followed by land acquisition, loan payments and consumption.

Contrary to the previous studies, such as those by [START_REF] Glytsos | Remitting behaviour of 'temporary' and 'permanent' migrants: the case of Greeks in Germany and Australia[END_REF] and [START_REF] Dustmann | Remittances and temporary migration[END_REF], we find no difference in the remittance behaviour of temporary and permanent South Asian migrants, though temporary migrants tend to earn less and send more remittances than do permanent migrants. Similarly, there is no difference between the remittance behaviour of informal and formal remitters. Finally, remittances of the South Asian community in Manchester seem to be driven by a mix of altruistic, inter-temporal contractual agreements and self-interest motivations, in that their remittances decay overtime, are used mainly for consumption, and are positively associated with the education level of the remitter and the use of remittances for savings, land acquisition and loan payments. The main implications of our analysis in terms of the potential developmental impacts of the remittances of South Asian migrants in their home countries are that, first, the average amount of remittances and their share in the incomes of the remitters are higher than those of many other migrant groups, making the remittances a significant financial source for development. Second, that the remittances of Bangladeshi migrants do not decrease with the duration of their residency in the UK, increase towards their retirement age, and a significant proportion of their remittances is spent on land acquisition implies that, compared to the other two groups, the remittances of this group might be more effective in promoting development. Finally, although consumption is the main area where remittances are used, remitters seem to send more money for land acquisition, savings and loan payments, implying that they can promote development not only by relaxing liquidity constraints of the poor but also by creating income generating activities through their impact on savings in the home country. However, considering the relative importance of the remittances as a stable source of development finance, the receiving country governments yet to implement significant strategic interventions and formulate appropriate mechanisms to enhance the impact of remittances on growth and development. 7.7 7.5 6.8 5.0 2.0 0.0 1. [START_REF] Boon | BME remittance survey[END_REF]; 2. [START_REF] Clark | An investigation of household remittance behaviour: evidence from the United Kingdom[END_REF]3. Manchester City Council (2001). Sources 1 and 2 use national, 3 uses local data. parentheses * significant at 10%; ** significant at 5%; *** significant at 1%. Note: Both country and district dummies are included in all regressions. Country dummies are not significant in any regressions. a/Age bracket: 1: 20-30; 2: 31-40; 3: 41-50; 4: 51 and above; b/Permanent migrants are those who have UK citizenship or permanent residency in UK; c/Higher numbers refer to lower frequency of visits; d/This is a dummy variable which takes on one if remittances are sent to the respective relative, zero otherwise; e/Importance of the use of remittances in different areas is measured as an index number, higher values refer to the higher level of importance. Manchester is a multi-cultural city in the UK which has a very long relationship with South Asia. The growth of the city of Manchester from the mid-18 th century onward went hand in hand with the arrival of people of many nationalities and ethnic groups. Many workers from South Asian countries (Bangladesh, Pakistan and India) came to Manchester from the 1950s to work in the mills.

F

2 Our findings show that there is no difference between OLS/SUR and the Tobit analysis. Thus we reported the findings of OLS and SUR only. 3 Only the individuals at and above 18 years of age are interviewed as we targeted those who are economically active and send remittances to their home country. This naturally raises the average age in our data. 4 Those who have UK citizenship or permanent residence are referred to as permanent migrants while those who are on work permit/HSMP, short-term stay, student visa or asylum seekers are referred to as temporary migrants. 5 The explanatory variables included in the SUR regression model of the five different uses of remittances are: log remittances, age bracket, education, rural background, time spent in the UK, permanent migration status, frequency of visits to home country, relationship of the recipients to the remitter, the country dummies and district dummies in the UK and home countries. We did not report the results of the regression analyses of the different uses of remittances, as their determinants are not the focus of this study.

  , in our model education has a positive and years since migration has a negative impact on the amount of remittances of South Asian community. Furthermore, our results

  to receive lower amount of remittances.

  remitters in the analysis could cause bias in the estimations towards zero if the majority of the migrants are non-remitters. In addition, our data include any amount of remittances that is different from zero, i.e. annual remittances in our data are as low as £100. Thus the sample selection bias could easily be corrected by employing Tobit analysis which censors the remittances data at a lower level of remittance amount.2 Next, we compare the descriptive statistics of the key variables from our data collected in 2006 with those obtained from 2001 national and local census, in order to assess whether or not our data are representative of the three South Asian communities in Manchester and in the UK. As seen from Table

  could explain the higher income and remittance levels of the three communities compared to those from the national census.

  -time employment or self-employment), 37 percent are UK citizens, 25 percent are permanent residents, 26 percent are on a work permit visa or highly skilled migration programme, and 27 percent are on a student visa. The average time of residency in the UK is 12 years, and 31

  communities, although Indians have marginally higher levels of education. A closer look at Table

  communities separately. As the figure shows, although the patterns of remittances of the three migrant groups exhibit different trends until about the 28 th year of their residence in the UK, they all decline substantially afterwards. We observe a gradual decline in the remittances of Indian and Pakistani migrants throughout the first twenty-eight years, while the remittances of Bangladeshi this time. Similarly, remittances of Indian and Pakistani migrants start to

  in the main regression model are exogenous to the amount of remittances.

  of remittances in the regression model, and find that among these five uses, only the remittances sent for savings, land acquisition and loan payments have significant impact on the amount of remittances.

  community linkages to the home country, are all important determinants of the amount of remittances of the South Asian community in the UK. Furthermore, among the different areas of the use of remittances, savings seems to have the strongest association with the amount of remittances, followed by land acquisition, loan payments and consumption. From the viewpoint of the motivational models, we can infer that the South Asian community's remittances are influenced by a combination of altruism, mutual contractual agreement and self-interest motivations, given that their remittances decay overtime, and are positively associated with education level of the remitters and the use of remittances for savings, land acquisition and loan payments.

  owns a house in the UK, while 88 percent own fixed assets in their home country.

  Figure 1. Patterns of Remittances According to the Key Variables a. Full Sample

  . (2010) Remitting behaviour of Turkish migrants: evidence from household data in Germany. Brook World Poverty Institute (BWPI) Working Paper No. 115, University of Manchester. Vargas-Silva, C, Jha, S. and Sugiyarto, G. (2009) Remittances in Asia: Implications for the fight against poverty and the pursuit of economic growth, ADB Economics Working Paper No.182, Asian Development Bank. World Bank (2008) Migration and Remittances Fact Book. World Bank: Washington, DC.

Table 1 .

 1 Distribution of South Asian Community and Household Surveys in Manchester Metropolitan Area Distribution of SA Community in Manchester, 2001 Census Data (percent of total population) a Manchester City Council derived from 2001 Census CAS Theme Table 3; b/Authors' data and calculations.

						Distribution of Household Surveys in
							Manchester in 2006 b
							(percent of total surveys)
		All Population	Indian	Pakistani	Bangladeshi	Indian	Pakistani	Bangladeshi
	Cheetham	13,121	2.7	27.0	0.4	21.5	29.9	14.4
	Longsight	12,249	3.0	29.7	8.1	22.5	28.2	38.6
	W.Range	11,965	3.7	21.8	0.6	20.4	28.5	11.1
	Rusholme	12,275	4.2	12.7	7.5	18.3	13.2	35.9
	Withington	11,201	3.1	5.9	0.9	15.7	0.3	0.0
	Manchester Total	392,799	5892	23175	3535	191	355	153
	Source: a/
		o
		r
		P
		e e r
			R e v i e w
					O n
							l y
								21

Table 2 .

 2 Comparison of Our Statistics with those from National and Local Government

	National and Local Government Data	Our Data

Table 3 .

 3 Full Sample Summary Statistics, N. 691 Education level: 2: A level; 3: university; 4 postgraduate; b/ high values refer to low frequency of visit, i.e. 1: every 3 months, 3: yearly c/ higher values indicate higher level of importance; d/Full time employment includes full time employees and self employed. See Table2for the description of some of the variables. HC stands for home country

	Variable	Mean	Median	Variable	Percentage of Respondents
	Remittances amount (annual)	1672	1500 Fulltime employment d	84
	Income (monthly gross)	1378	1250 Female	10
	Recipient's income (monthly gross)	238	150 Married	68
	Age	36.5	1 Muslim	74
	Education level a	2.94	35 UK citizen	37
	Duration of residency in UK (years)	12.4	3 Permanent resident	25
	Number of children in UK	1.29	7 Rural background	23
	Number of siblings in UK	0.89	1 Spouse in UK	84
	Frequency of visits to home country b	3.47	0 Parents in UK	18
	Importance of remittances for consumption c	0.77	3 Remittances sent to spouse/children	11
	Importance of remittances for saving c	0.25	1 Remittances sent to aunt/uncle/cous.	20
	Importance of remittances for land c	0.10	0 Remittances sent to siblings	28
	Importance of remittances for education c	0.19	0 Remittances sent to parents	59
	Importance of remittances for loans c	0.07	0 Own accommodation	42
				Fixed assets in HC	88
				Informal remittances	65
	a/

Table 5 .

 5 Summary Statistics for Permanent and Temporary Migrants See Table2for the description of some of the variables.

			Temp		Perm		Temp	Perm
		N=259	N: 432		N:259	N:432
		Mean	Median	Mean	Median		percent percent
	Remittances amount (annual)	1805	1500	1592	1500	Full time employment	76	89
	Income (monthly gross)	1156	750	1511	1250	Female	10	10
	Recipient's income (monthly gross)	280	250	208	150	Married	41	84
	Age	29.53	28	40.64	39	Muslim	70	76
	Education level	3.32	4	2.70	3	UK citizen	0	60
	Time spent in the UK	3.10	2.5	18.16	15	Rural	20	24
	Number of children in UK	0.20	0	1.94	2	Spouse in UK	25	79
	Number of siblings in UK	0.13	0	1.34	0	Parents in UK	2	28
	Frequency of visits to home country	3.30	3	3.55	3	Rem. sent to spouse	15	5
	Imp. of rem. for consumption	0.75	1	0.78	1	Rem. sent to children	3	4
	Imp. of rem. for saving	0.33	0	0.20	0	Rem. sent to siblings	20	33
	Imp. of rem. for land	0.03	0	0.14	0	Rem. sent to parents	84	45
	Imp. of rem. for education	0.20	0	0.18	0	Own accommodation	8	63
	Imp. of rem. for loans	0.16	0	0.02	0	Fixed assets in HC	91	85
	Source: Authors' data and calculations.
	Note:

Table 6 .

 6 OLS and SUR Regression of Log of Remittances Basic Variables

	Rootedness in UK	Linkages to HC	Recipient's Characteristics	Use of Remittances	SUR

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Peter Hekman

Gerrit Johan

Dr G J Schefferlie
email: gj.schefferlie@cbg-meb.nl

Kinetic Modelling and Residue Depletion of Drugs in Eggs

Keywords: Egg, Modelling, Pharmacology

come

the egg albumin(albumen) and yolk could be described using rate constants. 5 3. Using datasets from the literature, the model was used to describe concentrations in 6 albumin and yolk of sulphanilamide, sulphaquinoxaline and pyrimethamine as a function of 7 time. 8 4. The model could be used as a tool to obtain an insight into those properties of a drug which 9 are responsible for the amount of residue in eggs, and could help in the design of critical 10 studies for determining withdrawal periods for eggs. 11 Veterinary drugs are therapeutically used in laying hens. The residues of these drugs and their 13 metabolites are to some extent deposited in the eggs laid by the birds. Withdrawal periods are 14 set to ensure consumer safety; only eggs laid after the withdrawal period may be designated 15 for human consumption. In order to set safe withdrawal periods for eggs, residue depletion 16 studies are performed. The disposition and depletion of a wide range of veterinary drugs in 17 the egg albumin and yolk have been studied and described by many authors. Kan and Petz 18 (2000) studied the factors that determine the distribution of residues between egg albumin and 19 yolk of a wide range of drugs. They found that pKa values, lipid solubility or binding to 20 albumen macromolecules could not be used to predict the distribution between the albumin 21 and the yolk. The processes governing drug disposition in albumin and yolk are still not well 22 understood. Some authors have proposed kinetic models to describe the residue concentration 23 profiles in eggs laid after drug treatment. [START_REF] Donoghue | Modelling residue uptake by eggs. 1. Similar drug residue 206 patterns in developing yolks following injection with ampicillin or oxytetracyclin[END_REF][START_REF] Donoghue | Modelling drug residue uptake by eggs: yolks contain ampicillin 210 Page 10 of 21[END_REF] showed that the 24 residue uptake by developing yolks showed a particular pattern following single drug 25 administration which depended on the stage of development in the follicles. Based on their 26 findings, they proposed a model to predict the residue concentration in yolks of laid eggs after 27 multiple drug administration. 28

Although the authors recognised that plasma profiles will have an important influence 29 on drug disposition in eggs, they did not include plasma profiles in their models. It is often 30 reported that the residue profiles are different between albumin and yolk (Laurencot et al., 31 1972;[START_REF] Blom | Plasma half-lives and the excretion into egg-white-and -yolk of three 199 sulphonamides and pyrimethamine after medication to laying hens[END_REF][START_REF] Oikawa | Clearance of 229 sulfamethoxazole in eggs and tissues of chickens[END_REF][START_REF] Rodaut | Residues of aminoglicoside antibiotics in eggs after medication of 231 laying hens[END_REF][START_REF] Rodaut | Residues of macrolide antibiotics in eggs 233 following medication of laying hens[END_REF]Rodaut et 32 al., 1987;[START_REF] Nagata | Transfer of dietary 223 sulfadimethoxine and sulfamonomethoxine into eggs and their disappearance from eggs[END_REF][START_REF] Nagata | Residue studies in 226 egg on pyrimethamine given with feed[END_REF][START_REF] Chu | Determination of total 14 C residues of 202 sarafloxacin in eggs of laying hens[END_REF][START_REF] Giorgi | Determination of 216 thiamphenicol residues in albumin and yolk of hen eggs[END_REF]. Typically, the 33 residue concentrations in the yolk peak later than in the albumin. This is due to the fact that 34 [START_REF] Geertsma | Residues of sulphadimidine and its metabolites in eggs following oral 214 sulphadimidine medication of hens[END_REF]. Therefore, the relationship 38 between these three variables must be studied in order to understand the processes governing 39 the drug residue profiles in eggs. However, the current models of residues in eggs do not 40 include plasma drug concentration profiles. In this paper, we present a physiologically-based 41 pharmacokinetic (PBPK) model that can be used to describe or predict the drug residue 42 profiles of certain veterinary drugs in eggs based on their plasma kinetics. Published data 43 were used to illustrate the applicability of the model, it was however noted that very few 44 authors presented residue concentration data in plasma along with residue data in eggs. 45

Insights into the relationship between plasma concentration of a drug and its excretion 46 via the egg could help in the design of critical residue studies. Furthermore, such a 47 mathematical model could contribute to the study of the processes governing the deposition of 48 chemicals in eggs, for example by relating the fitted model parameters to the physico-49 chemical properties of the substance. 50

MATERIALS AND METHODS 52

Experimental method 53

All data for the calibration and testing of the model were obtained from the literature (Blom, 54 1975;Geertsema et al., 1987;[START_REF] Kan | Residues of veterinary drugs in eggs and their distribution 219 between yolk and albumin[END_REF]. The simulations were made using 55 The PBPK-model used to describe the relationship between the plasma concentration of a 62 drug and its deposition in the egg is depicted in Figure 1. 63

The formation of yolk and albumin are two distinct physiological processes. 64 Therefore, the disposition of a drug into one compartment is described independently from the 65 other. It is assumed that the nature of the process that governs the disposition of drugs into 66 egg yolk and egg albumin is that of a filtration-process rather than that of a concentration-67 gradient driven process. This concept is introduced into the present PBPK-model. A number of papers describe the rate of yolk formation (Geertsema et al., 1987;Kan and Petz, 84 2000). It can be deduced from these papers that the formation rate of the egg yolk is not 85 linear. Geertsema et al. (1987) characterised the rapid growth phase as an exponential growth 86 The average follicle develops over an 8-11 d period before the egg is laid (Geertsma et 104 al., 1987). The maximum growth rate is achieved at a time point (tsig), which is 105 approximately 1-3 d before ovulation. From the fitted data, it could be estimated that Ay is 106 approximately 25 g, tsig = 2 d and s = 1 per d. It is clear that these variables may change with 107 the breed and the production phase of the birds used in a particular experiment. 108

The rate of yolk formation can therefore be described as the first derivative of the 109 In the simulations the average weight of the albumin, Ww(tlay), was assumed to be 34 g, and 148 the period of formation, talbumin, was assumed to be 10 h. 149 150

RESULTS AND DISCUSSION 151

In order to test the mathematical model described above, a number of simulations was 152 performed using data obtained from the literature [START_REF] Blom | Plasma half-lives and the excretion into egg-white-and -yolk of three 199 sulphonamides and pyrimethamine after medication to laying hens[END_REF]. In his paper on the residues 153 of drugs in eggs after medication of laying hens, Blom described the results of an experiment 154 in which groups of laying hens (n = 12) were given medicated drinking water ad libitum over 155 8 consecutive d. A number of drugs were administered in that way (three sulphonamides and 156 pyrimethamine). Throughout the treatment and after its cessation, blood samples and eggs 157 were collected at various times and subsequently analysed for residues. The results were 158 reported in tabulated format. Using the model as described above, attempts were made to fit the time-dependent courses of 162 the concentrations of sulphanilamide, pyrimethamine and sulphaquinoxaline in egg yolk and 163 egg albumin as measured by [START_REF] Blom | Plasma half-lives and the excretion into egg-white-and -yolk of three 199 sulphonamides and pyrimethamine after medication to laying hens[END_REF]. In order to calculate the time dependent courses of 164 the plasma concentrations of the drugs, which are necessary input functions, the t1/2 values of 165 the three compounds were estimated from the graphs. Next, the plasma curves were calculated 166 assuming a relatively constant concentration during treatment (0-8 d), and a mono-167 exponential decay after cessation of the treatment. 168

The following values could be derived from the tabulated data in the article of Blom 169 (1975) 3 and4 show the obtained data points and the simulations according to 174 the model. 175

The only parameters used as variables in the 'fitting' of the data points according to the 176 model were ky (for the egg yolk data) and kw (for the egg albumin data). These variables 177 obviously depend, among other things, on plasma protein binding, pKa-value and/or the 178 lipophilic affinity of a drug. The Table shows the values of ky and kw calculated from the fits. 179

These results show that where the value of kw (rate constant for deposition in egg-180 albumin) is relatively constant, the values for ky (rate constant for deposition in egg-yolk) are 181 strongly drug related. 182

Limitations to the model 183

Egg production is not uniform with regard to development time, the number of oocytes in the 184 fast-growing stage, egg weight and the proportional weights of the yolk and albumin 185 [START_REF] Laurencot | The deposition and 221 clearance of Rofenaid® in chicken and turkey eggs[END_REF]. Therefore, in some cases the fixed values in the model (for example, 186 However, in studying a number of drugs using the same experimental conditions these values 188 could be considered constant. Also the data used did not allow the establishment of the exact 189 times of egg lay after dosing, and only rough estimates of the actual time-dependent course of 190 the plasma concentrations could be calculated, because the experimental data sets did not 191 focus specifically on all these aspects. Therefore, further experimental studiesfocusing on 192 these aspects, would help to further validate the model. 193

In conclusion, the model offers a generally-applicable tool that can be used to further 194 investigate the properties of a drug that determine its residues in eggs which is independent of 195 the physiological circumstances such as breed and egg production. 196 residues in egg albumin and yolk using data points from [START_REF] Blom | Plasma half-lives and the excretion into egg-white-and -yolk of three 199 sulphonamides and pyrimethamine after medication to laying hens[END_REF]. residues in egg albumin and yolk using data points from [START_REF] Blom | Plasma half-lives and the excretion into egg-white-and -yolk of three 199 sulphonamides and pyrimethamine after medication to laying hens[END_REF].

  For the purpose of describing the relationship between plasma concentration of 1 drugs and their deposition into eggs, a physiologically-based pharmacokinetic model was 2 developed. 3 2. By incorporating the physiology of egg formation into the model, the transfer of drugs into 4

  yolk and albumin develop at different stages of egg production, where the formation of yolk 35 takes 8-11 d and the formation of albumin approximately 10 h. The drug disposition in the 36 the development stage of the oocyte, the plasma drug concentration and the 37 physico-chemical properties of the drug

  Multisim, a visual basic programme developed at the Medicines Evaluation Board, Veterinary 56 Medicinal Products Unit, Den Haag, and based on the algorithms of Yamaoka, K. and 57 Nakagawa, T.(1983). The programme is capable of solving sets of predefined differential 58 equations in which time acts as an independent variable.

  In this 68 model ky and kw represent constants determining the amount of the administered drug from 69 the central compartment into the yolk and the albumin respectively. The concentration of the 70 drug in the central compartment (plasma) is a function of time itself, and should be provided 71 as an input to the model. 72 Using the concepts described above, the general equations describing the transport rate 73 of drug into the egg yolk and egg albumin are therefore: 74 dQy/dt = C1(t). Ky.dWy/dt [1] 75 dQw/dt = C1(t). Kw.dWw/dt [2] 76 where: 77 dQy/dt and dQw/dt = the rates of drug deposition into yolk and albumin (mg/day), 78 dWy/dt and dWw/dt = the formation rates of yolk and albumin (g/day), Ky and Kw 79 = transport constants into yolk and albumin, 80 C1 = plasma concentration (mg/L). 81 82 Time dependent concentration in egg yolk 83

Figure

  Figure 1 near here

  Figure 2 near here

Figure 1 .Figure 2 .Figure 3 .

 123 Figure 1. Schematic representation of the physiologically-based pharmacokinetic -model. 247 248

  254

Figure 4 .

 4 Figure 4. Simulation according to the model of the time dependent course of pyrimethamine 256

  257

Figure 1 :Figure 3 .Figure 4 .

 134 Figure 1: Schematic representation of the PBPK-model 118x47mm (100 x 100 DPI)

E-mail: br.poultsci@bbsrc.ac.uk URL: http://mc.manuscriptcentral.com/cbps British Poultry Science


Chamari Devika

M W C D Palliyeguru
email: mpalliyeguru@harper-adams.ac.uk

S P Rose

A M Mackenzie

Mrs M W C D Palliyeguru

Effect of trypsin inhibitor activity in soya bean on growth performance, protein digestibility and incidence of sub-clinical necrotic enteritis in broiler chicken flocks

Keywords: Biochemistry, Broilers, Nutrition, Growth, Digestion, Protein

Effect of trypsin inhibitor activity in soybean on the growth performance, protein digestibility and incidence of sub-clinical necrotic enteritis in broiler chicken flocks

M. W.

broiler chickens was compared. A fourth dietary treatment compared the effect of a diet that used potato protein concentrate as the major protein source. The determined trypsin inhibitor activity increased with the increasing content of non-toasted soya bean: 1.90, 6.21, 8.46 and 3.72 mg/g for the three soya bean diets (0, 100 and 200 g of non-toasted soya bean/kg) and the potato protein diet respectively.

2. Although increasing amounts of the non-toasted full-fat soya bean increased the feed intakes of the birds, there was a marked reduction in protein digestibility, weight gain and feed conversion efficiency.

3. There was a linear increase in sub-clinical NE lesions in the duodenum, jejunum, mid small intestine and ileum with increasing non-toasted soya bean. Caecal Clostridium perfringens counts increased with the increasing dietary content of non-toasted soya bean.

Serum α-toxin antibodies were higher in the birds fed the 200 g non-toasted soya bean/kg diet compared with the other diets.

4. The results demonstrated that variation in the amount of non-toasted dietary soya bean not only affects growth performance of broilers but also affects the incidence of sub-clinical necrotic enteritis in the flock. Ensuring the lowest possible trypsin-inhibitor activity in soya bean samples is a valuable tool to improve the health and welfare of birds and in reducing the financial losses from this disease.

INTRODUCTION 23

Subclinical necrotic enteritis (NE) is an economically important bacterial disease in modern 24 broiler flocks [START_REF] Kaldhusdal | Necrotic enteritis as affected by dietary ingredients[END_REF]. The condition is not usually detected owing to the absence 25 of clear clinical signs and persitsunnoticed and untreated. However, the disease may be 26 suspected when there are poor growth [START_REF] Lovland | Severely impaired production performance 434 in broiler flocks with high incidence of Clostridium perfringens-associated hepatitis[END_REF] and wet litter 27 conditions [START_REF] Williams | Review: Intercurrent coccidiosis and necrotic enteritis of chickens: 492 rational, integrated disease management by maintenance of gut integrity[END_REF]. Sub-clinical NE also increases the risk of contamination of 28 poultry products for human consumption [START_REF] Craven | Incidence of Clostridium 374 perfringens in broiler chickens and their environment during production and processing[END_REF]. The financial cost of the 29 disease to the world's poultry industry has been estimated as US$2.6 billion per year (van der 30 Sluis, 2000). The causative organism, C. perfringens, is ubiquitous in the environment and the 31 intestines of most healthy animals and humans [START_REF] Wages | Necrotic Enteritis[END_REF]. C. perfringens is 32 also a commensal bacterium of chicken intestines [START_REF] Ewing | Micro-flora of the gastro-intestinal tract, in: The 384 living gut -An introduction to microorganisms in nutrition[END_REF] and there are 33 further predisposing factors that alter the intestinal balance to favour its proliferation and 34 toxin production. Intestinal C.perfringens and alpha-toxin levels (Hofshagen and Stenwig, 35 1992;[START_REF] Si | 471 Quantification of cell proliferation and alpha-toxin gene expression of Clostridium 472 perfringens in the development of necrotic enteritis in broiler chickens[END_REF] are increased in the disease, so causing major pathological changes in 36 the small intestine (Gholamiandehkordi et al., 2007) and liver (Lovland and Kaldhusdal, 37 2001). 38 NE has been reproduced experimentally by oral or intra-duodenal administration of 39 birds with pathogenic strains of C. perfringens isolated from clinically diseased birds 40 (Gholamiandehkordi et al., 2007;[START_REF] Pedersen | Reproducible infection model for Clostridium perfringens in broiler chickens[END_REF]. The majority of these experiments 41 have involved regular administration of the pathogen into a small number of birds kept in 42 cages [START_REF] Drew | Effect of dietary protein source and level on intestinal populations of Clostridium 378 perfringens in broiler chickens[END_REF]Gholamiandehkordi et al., 2007). These conditions are different 43 from practical broiler production methods. However, [START_REF] Lovland | Diagnosing Clostridium 437 perfringens-associated necrotic enteritis in broiler flocks by an immunoglobulin G anti-alpha-438 toxin enzyme-linked immunosorbent assay[END_REF] clinical NE provides the possibility of studying the effects of production variables under 48 conditions that are directly related to commercial production methods. 49 [START_REF] Apajalathi | 355 Percent G+C profiling accurately reveals diet-related differences in gastrointestinal microbial 356 community of broiler chickens[END_REF] identified the diet as the strongest determinant of the caecal 50 bacterial community, so diet composition may influence the susceptibility of broilers to sub-51 clinical NE. There is evidence that different dietary protein sources affect the proliferation of 52 C. perfringens within the caecum [START_REF] Drew | Effect of dietary protein source and level on intestinal populations of Clostridium 378 perfringens in broiler chickens[END_REF] and in the ileum [START_REF] Wilkie | 499 Dietary amino acids affect intestinal Clostridium perfringens populations in broiler chickens[END_REF] 53 when birds are orally dosed with these bacteria. The effect of different protein concentrates on 54 the incidence of spontaneously-occurring sub-clinical NE was studied in an earlier experiment 55 and there was a higher incidence of NE in birds fed potato protein-based diets compared with 56 soya bean-based diets [START_REF] Palliyeguru | Effect of dietary 446 protein concentrates on the incidence of necrotic enteritis and growth performance of broiler 447 chickens[END_REF]. High trypsin inhibitor activity (TIA) in this 57 diet was identified as a probable causative factor. 58 Soya bean meal is the most common protein concentrate used in proprietary poultry 59 feeds. Soya bean must be heat-treated to improve protein digestibility due to the presence of a 60 heat-labile trypsin inhibitor. Heat denatures the trypsin inhibitor, but the process has a 61 variable efficiency that depends on the initial concentration of TIA, the moisture content of 62 the seeds, the temperature and time of heating [START_REF] Liener | Implications of antinutritional components in soya bean feeds[END_REF]. Precise control of heating 63 conditions is needed to prevent under or over-heating of the soya bean (Liener and Kakade, 64 1980). TIA has been identified as the best in vitro predictor of the nutritional value of 65 processed full-fat soya bean for chickens [START_REF] Perilla | Effect of 456 temperature of wet extrusion on the nutritional value of full-fat soya beans for broiler 457 chickens[END_REF]. 66

A survey of commercially-available soya bean meals found there to be varying levels 67 of TIA (0.4-6.8 mg/g) [START_REF] Probert | Role of enzymes in increasing protein digestibility in soya bean and 461 other oil seeds[END_REF] even though there is a European Union import 68 threshold of TIA for soya bean meal of 4 mg/g. Therefore, the quality of soya bean meal is a 69 factor that could affect the protein digestibility of the overall diet. [START_REF] Perilla | Effect of 456 temperature of wet extrusion on the nutritional value of full-fat soya beans for broiler 457 chickens[END_REF] showed 70 that a TIA of 2.8 mg/kg of diet was associated with poor growth performance in broilers. Hill 71 et al. (1957) demonstrated that the lower growth performance of broilers fed an unheated soya 72 bean (100 g/kg of diet) could be eliminated by the addition of dietary antibiotics. This 73 indicates that small changes in TIA may affect the gut microflora of broiler chickens. 74

The objective of this experiment was to compare the effect of three different levels of 75 TIA (achieved by varying the amount of unheated full fat soya bean in replacement for heat-76 treated full fat soya bean of the same original source) in nutritionally-complete diets, on the 77 incidence of spontaneously-occurring, sub-clinical NE. A fourth dietary treatment compared 78 the effect of a diet that used potato protein concentrate as the major protein source. All 4 diets 79 had nutrient compositions typical of those fed to commercial broilers. 80 81

MATERIALS AND METHODS 82

Dietary treatments and experimental design 83

Four nutritionally complete [START_REF] Aviagen | Broiler Nutrition Specification[END_REF] maize-based, broiler-grower diets were 84 formulated. All 4 diets were formulated to have similar calculated contents of metabolisable 85 energy (13.1 MJ/kg), crude protein (210 g/kg), lysine (13 g/kg), methionine and cysteine (10 86 g/kg) and threonine (10 g/kg) (Table 1). Celite (20 g/kg) was included in each diet as an 87 indigestible marker for determining nutrient digestibility. Three increasing inclusion rates (0, 88 100 or 200 g/kg) of unheated full-fat soya bean (with high TIA) were included in replacement 89 for a toasted full fat soya bean (from the same batch and with the same proximate 90 composition). A nutritionally-complete diet that included potato protein concentrate was also 91 formulated (Table 1). No antibiotic growth promoters or anti-coccidial drugs were used in the 92 diets. The formulated diets were mixed and steam-pelleted (3 mm diameter pellets). Chemical 93 analysis of representative samples of the prepared diets indicated that there were only 94 relatively small differences in dry matter, ash, protein and amino acid contents. The dietary treatments were fed to 6 replicate pens of male broilers. Twenty four pens 97 were used within the environmentally controlled house. The dietary treatments were randomly 98 allocated to pens within positional blocks. 99 100

Broiler chicken management and feeding 101

The experiment was conducted under the guidance of the Research Ethics Committee of 102

Harper Adams University College. A total of 1900 1-d-old male Ross 308 broilers was reared 103 as a single flock in a solid-floored pen in an environmentally-controlled house. The birds 104 were fed a proprietary, nutritionally-complete, broiler-starter diet that contained no antibiotic 105 or anticoccidial drugs for the first 16 d and provided with adequate feeders and drinkers for 106 the age and the number of birds. 107

At 16 d of age, the birds were weighed and 74 were randomly allocated to each of 24 108 pens within an environmentally-controlled house, so that 1776 birds were used in the 109 experimental design (24 pens x 74 birds). Each of the 24 pens had a solid concrete floor with 110 an area of 1.5 m x 3 m covered with a bedding of 4 parts new wood shavings to one part 111 reused litter material. The reused litter was from a previous flock reared on the same poultry 112 unit. This flock had no clinical NE but some sub-clinical NE and sub-clinical coccidiosis 113 would have been expected. 114

For the following 16 d, the birds were fed the experimental diets. Ad libitum feed and 115 water were provided during the experimental period. Feed was provided in hanging tube 116 feeders and the levels were managed to minimise wastage. House temperatures and humidity 117 were controlled to provide optimum growing conditions for the age of bird using the current 118 (online) Management Guide for Ross 308 broilers [START_REF] Aviagen | Broiler Management Manual[END_REF]. Light was provided for 23 119 h/d. Over the experimental period, the growth and feed intakes of the birds were recorded. In 120 addition, the birds in each pen were inspected daily and mortalities recorded.

Data collection 123

Lesion scoring 124

Randomly-selected birds were sampled from each of the 24 pens on d 5 and at the end of the 125 feeding period (d 12, 13, 14 and 15). On d 5, 4 birds from each pen were killed by cervical 126 dislocation and 5 ml of blood collected from the jugular vein and transferred into glass tubes, 127 and ileal contents were collected and pooled for each pen. At 12, 13, 14 and 15 d, 8 birds 128 from each replicate pen (two birds per day) were randomly selected, killed by cervical 129 dislocation and 5 ml of blood collected from the jugular vein and transferred into glass tubes. 130

The intestinal tract and liver were removed and the ileal contents collected from individual 131 birds. Each liver was inspected for the lesions of hepatitis or cholangiohepatitis which are 132 consistent with the pathological changes of NE [START_REF] Lovland | Liver lesions seen at slaughter as an 431 indicator of necrotic enteritis in broiler flocks[END_REF]Sasaki et al., 133 2000). Four 8-cm intestinal sections were taken; the first of these sections was the duodenal 134 loop, the second was proximal jejunum beginning immediately after the distal end of the 135 duodenal loop, the third was either side of Meckel's diverticulum (mid small intestine) and 136 the fourth terminated at the ileo-caecal junction (distal ileum). All 4 sections were 137 immediately incised, washed in normal saline and the mucosal surfaces were inspected and 138 any necrotic lesions recorded. A scoring system originally established by Truscott and Al-139 Sheikhly (1977), but modified by Gholamiandehkordi et al. (2007) of bovine trypsin per 1 g of sample using the method described by Smith et al. (1980). 197 Dietary amino acid samples were determined by ion exchange chromatography (Biochrom 20 198 analyser, Amersham Pharmacia Biotech, Pittsburgh, PA) with post-column ninhydrin reaction 199 as previously described [START_REF] Palliyeguru | Effect of dietary 446 protein concentrates on the incidence of necrotic enteritis and growth performance of broiler 447 chickens[END_REF]. 200

Ash and acid insoluble ash contents in feed and digesta samples were measured using a 201 modified method described by [START_REF] Atkinson | Evaluation of acid insoluble ash 361 as an indicator of feed digestibility in Rainbow trout (Salmo gairdneri)[END_REF]. Approximately 5 g of diet (dry) or 1.0 g 202 of digesta (dry) was placed into a previously-weighed crucible and ashed at 610°C for 13 h. 203

The contents of the cooled crucibles were weighed and washed into a glass tube with 50 ml of 204 4M HCl. The tubes were boiled at 110°C for 30 min. The cooled contents were filtered and 205 washed with de-ionised water through an ash-less filter paper and the filter paper was again 206 ashed in the same crucible at 610°C for 13 h. Subsequently the crucibles were cooled in a 207 desiccator and weighed. 208

Crude protein content in each feed sample was measured in 6 replicate samples and the 209 crude protein content in ileal digesta and the acid insoluble ash (indigestible marker) contents 210 in both feed and ileal digesta were measured in duplicate samples and the protein digestibility 211 coefficient of the lieal digesta calculated. 212

213

Statistical analysis 214

The variables of growth performance, necrotic lesion scores in the intestinal sections, 215 proportion of birds that had liver and gall bladder lesions, C. perfringens in the caecal 216 contents and duodenal mucosa, serum antibody levels for alpha toxin and the number of 217 coccidial oocysts on the duodenal mucosa were compared using a randomised block analysis 218 of variance. The 24 pens were used as the experimental units and individual bird or sample 219 data from within a pen were pooled before statistical analysis. The treatment sums of squares 220 of the three soya bean diets were partitioned using a polynomial contrast with the determined 221 There were no major differences in the determined nutrient compositions of the three soya 226 bean diets (Table 1). The determined TIA of the non-toasted full fat soya bean was 27.62 227 mg/g. The TIA of the treatment diets increased with increasing inclusion rate of non-toasted 228 soya bean (0, 100 and 200 g/kg). Determined TIA with the three increasing non-toasted soya 229 bean diets and the potato protein diet were 1.90, 6.21, 8.46 and 3.72 mg/g respectively. 230 Although increasing the content of non-toasted full-fat soya bean significantly increased feed 231 intake, there was a marked reduction (P <0.001) in protein digestibility, weight gain and feed 232 conversion efficiency. Mortality was not significantly affected (Table 2). 233

There was a linear increase (P <0.001) of sub-clinical NE lesions in the duodenum, 234 jejunum, mid small intestine and ileum with increasing dietary non-toasted soya bean (Table 235 3). There was a significant increase in the number of liver lesions in the birds fed all other 236 dietary treatments compared with the toasted soya bean diet. Caecal C. perfringens counts 237 increased with the increasing dietary non-toasted soya bean. Serum α-toxin antibodies were 238 higher (P <0.001), on d 5 in the birds fed the 200 g/kg non-toasted soya bean diet compared 239 with the other two soya bean diets, although there were no significant treatment differences at 240 the end of the feeding period. Dietary treatment had no significant effect on the number of C. 241 perfringens colonised on the duodenal mucosa. Coccidial oocyst counts decreased (P <0.01) 242 with increasing dietary non-toasted soya bean (Table 3). 243

There was a strong negative correlation (P <0.001) between the necrotic lesion scores 244 of the intestine and the growth and protein digestibility coefficient of the broilers. Although the toasting may have had other effects on the chemical composition of the full fat 248 soya bean, the high levels of TIA were probably the major cause of the reduced protein 249 digestibility in the non-toasted soya bean diets; [START_REF] Perilla | Effect of 456 temperature of wet extrusion on the nutritional value of full-fat soya beans for broiler 457 chickens[END_REF] concluded that TIA gave 250 the best prediction of the feeding value of soya beans. The growth performance responses of 251 the broilers to the dietary treatments in the present experiment were expected, but the size of 252 the reduction in growth was relatively large in comparison with the results of Perilla et al. 253 (1997), who observed a 6.5% increase in feed intake and a 4.9% decrease in growth rates for 254 an increase in dietary TIA from 0 to 9.4 mg/g. In the present experiment, there was a 4.3% 255 increase in feed intake but a 22% decrease in growth rate from the low to high TIA diets. 256

When the non-toasted soya bean was fed to the broilers, the effect of trypsin inhibitors 257 on protein digestibility did not fully explain the reduction in growth performance, as reported 258 by [START_REF] Liener | Protease Inhibitors In[END_REF]. Dietary antibiotics have beneficial effects on the growth 259 performances of birds fed non-toasted soya bean diets [START_REF] Hill | Studies on the effect of antibiotics on 397 the intestinal weights of chicks[END_REF], and there is a lack of 260 growth depression in germ-free birds fed dietary trypsin inhibitors [START_REF] Coates | A comparison of the effects of raw and 371 heated soya bean-bean meal in diets for germ-free and conventional chicks[END_REF]261 Hewitt and Coates, 1973); all these experiments indicated that microbial activity in the 262 intestine may exacerbate the negative effects on growth performances caused by poor protein 263 digestion. However, in the present experiment, the broilers were reared in conditions that 264 predisposed sub-clinical NE and it is possible that the increased severity of sub-clinical NE in 265 these dietary treatments further contributed to the poor growth rate and feed conversion 266

efficiency. 267

The results (Table 3) are clear evidence that dietary non-toasted soya bean produced 268 an increased incidence and severity of sub-clinical NE, although there was no significant 269 increase in the C. perfringens numbers in the duodenum. Proliferation of this causative 270 organism can be restricted to localised sites in the small intestine, so it is difficult to 271 [START_REF] Ewing | Micro-flora of the gastro-intestinal tract, in: The 384 living gut -An introduction to microorganisms in nutrition[END_REF]. When 297 protein digestibility is low, the ileal contents will have a relatively high content of protein. 298The growth of C. perfringens under in vitro conditions needs 11 amino acids (Sebald and 299 Costilow 1975). C. perfringens that are producing α-toxin need specific amino acids and 300 peptides for their proliferation [START_REF] Nakamura | Lecithinase production by 443 Clostridium perfringens in chemically defined media[END_REF], so it is possible that the low protein 301 digestibility in the small intestine directly predisposed the more rapid multiplication of C. 302 perfringens. There is also a possibility that trypsin inhibitors may stabilise the C. perfringens 303 toxins and so increase the severity of their toxigenic effects. 304 Soya beans contain lectins that are known anti-nutritive factors [START_REF] Probert | Role of enzymes in increasing protein digestibility in soya bean and 461 other oil seeds[END_REF] which 305 have the ability to damage the intestinal epithelial cells (van Dijk et al., 2002) and also 306 possibly mediate the adhesion of pathogenic bacteria on to the epithelial cell membrane. 307

Lectin concentration can be 10-20 mg/g of non-toasted soya bean (Clarke and Wiseman, 308 2000). However, the lectins are heat labile and [START_REF] Armour | Protease 358 inhibitors and lectins in soya beans and effects on aqueous heat-treatment[END_REF] and [START_REF] Probert | Role of enzymes in increasing protein digestibility in soya bean and 461 other oil seeds[END_REF] found 309 that lectins in soya bean denature more readily than trypsin inhibitors. 310

A negative correlation of coccidial oocysts counts in the duodenal mucosa with the 311 severity of lesion scores was found in this experiment and also in an earlier experiment 312 [START_REF] Palliyeguru | Effect of dietary 446 protein concentrates on the incidence of necrotic enteritis and growth performance of broiler 447 chickens[END_REF]. This may be due to their exclusion from the proliferation sites when 313 C. perfringens invade the damaged intestinal epithelium [START_REF] Williams | A 495 new method for the experimental production of necrotic enteritis and its use for studies on the 496 relationships between necrotic enteritis, coccidiosis and anticoccidial vaccination of chickens[END_REF]. It is therefore 314 possible that the coccidial oocysts in the mucosa of the small intestine reduced with an 315 increasing severity of NE, even though the initial coccidial damage in the mucosal epithelium 316 may have predisposed [START_REF] Al-Saieg | Role of coccidiosis in the occurrence of 350 necrotic enteritis of chickens[END_REF][START_REF] Shane | Aetiology 469 and pathogenesis of necrotic enteritis[END_REF] and aggravated 317 [START_REF] Park | Immunopathology and cytokine responses in broiler chickens 450 coinfected with Eimeria maxima and Clostridium perfringens with the use of an animal model 451 of necrotic enteritis[END_REF] the C. perfringens damage. 318

The birds fed the potato protein diet had significantly poorer growth performance 319 (weight gain, feed intake and gain:feed) than the birds fed the soya bean diet with the lowest 320 TIA. The non-significant trend of lower protein digestibility of the potato protein diet was 321 consistent with the determined TIA of this diet, even though it was not as low as the two soya 322 bean diets that contained some non-toasted soya bean and had much higher trypsin inhibitor 323 activities. The relatively low TIA in the potato protein diet was not expected, despite the 324 trypsin inhibitor activities of different samples of potato protein concentrate being known to 325 vary with the variety [START_REF] Jadhav | Potato[END_REF] and the method of processing [START_REF] Knorr | Effect of recovery methods on yield, quality and functional properties of 414 potato protein concentrates[END_REF](Knorr, , 326 1982)). There were no significant differences in caecal C. perfringens counts and serum α-327 toxin antibody concentrations between the potato protein and the soya bean diet with the 328 lowest TIA. This was consistent with the relatively small difference between these two diets 329 in protein digestibility and TIA. However, the birds fed the potato protein diet had a 330 significantly higher incidence of liver lesions, increased severity of duodenal lesions and a 331 lower feed intake compared with the low trypsin inhibitor soya bean diet. The heat-resistant 332 glycoalkaloids [START_REF] Jadhav | Potato[END_REF] that are also contained within potato protein (Lokra 333 et al., 2008) may have contributed to the severity of the disease in the potato protein fed birds. 334

The results of this experiment have demonstrated that variation in the amount of non-335 toasted dietary soya bean not only affects growth performance of broilers but also affects the 336 incidence of sub-clinical NE in the flock. Although the maximum recommended TIA of soya 337 bean is 4 mg/g, there is considerable variation in activity below this level in commercially-338 available samples [START_REF] Probert | Role of enzymes in increasing protein digestibility in soya bean and 461 other oil seeds[END_REF]. Many countries have now adopted a complete ban on the 339 use of antimicrobial growth promoters and so there is potential for an increase in the 340 incidence of sub-clinical NE in their commercial broiler flocks. Ensuring the lowest possible 341 TIA in soya bean samples would appear to be a valuable tool for improving bird health and 342 welfare and reducing the risk of serious financial losses from NE.

Abstract. 1 .

 1 Effect of trypsin inhibitor activity in soybean on the growth performance, protein digestibility and incidence of subclinical necrotic enteritis in broiler chicken flocks The effect of three different levels of dietary trypsin inhibitor activity (achieved by varying the amount of non-toasted full fat soya bean in replacement for toasted full fat soya bean) on the incidence of spontaneously-occurring sub-clinical necrotic enteritis (NE) in

  121

  , was further slightly 140 modified to score intestinal lesions. The scoring system was: score 0: no lesions, score 1: 141 focal necroses (1-10 mm diameter), score 2: necrotic patches (1-2 cm diameter), score 3: 142 coalesced necroses and score 4: pseudo-membrane covering the whole epithelial surface. The 143 mucosal surfaces of each of the 4 gut wall samples were scored for necrotic lesions. 144 145 Enumeration of Clostridium perfringens and coccidial oocysts 146 The duodenal sections were used for the quantification of C. perfringens and coccidial 147 oocysts. Each duodenal sample was washed 4 times in sterile Phosphate Buffered Saline 148 (PBS) at pH 7.2, weighed, added to the same weight of dilution buffer (Bio-X Diagnostics, 149 Jemelle, Belgium), stomachised in a sterile stomacher bag and the resulting liquid frozen at -150 20°C. Duodenal extracts were subsequently thawed at room temperature and vortexed for the 151 quantification of coccidial oocysts. The extracts were diluted (x 6) with saturated NaCl, 152 placed into both sides of a McMaster counting chamber and allowed to settle for 5 min. The 153 number of coccidial oocysts (all species found in the sample) was counted at 10-times 154 magnification. 155 C. perfringens in the caecal contents and in the duodenal mucosal sample were 156 quantified with a double antibody sandwich ELISA (McCourt et al., 2005), using the BIO K 157 086 -Closridium perfringens antigen detection kit (Bio-X Diagnostics, Jemelle, Belgium). 158 Caecal contents were collected in a sterile container and diluted (x2) with dilution buffer 159 (Bio-X Diagnostics, Jemelle, Belgium), vortexed and frozen at -20°C before analysis. Both 160 duodenal extracts and diluted caecal contents were thawed and vortexed before being allowed 161 to settle for 10 min for the enumeration of C. perfringens. Standardisation of the ELISA was 162 done as described previously (Palliyeguru et al., 2010). 163 164 Quantification of serum α-toxin antibodies 165 The blood collected from each bird was allowed to clot for 8-10 h at room temperature. The 166 serum was separated from the coagulum and stored at -20 o C. Twelve serum samples from 167 each pen were compared for antibody levels developed against the alpha toxin of C. 168 perfringens using an indirect ELISA according to the method described by Heier et al. (2001) 169 and Lovland et al. (2003) with slight modifications as described below. Each well of the antigen, phospholipase C type XIV (Sigma-Aldrich P 4039, St. Louis, MO) 172 10 µg/ml in sodium carbonate and bicarbonate coating buffer (pH 9.6) by incubating the 100 173 µl of antigen in each well overnight at 4 o C. The plates were washed three times with PBS at 174 pH 7.2 with 0.05% Tween 20 (PBST). A volume of 150 µl of 1% bovine serum albumin in 175 PBST was added into each well as a blocking buffer and incubated for 2 h. The plates were 176 washed again three times with PBST. 177 Serum samples were diluted 1:250 in PBST and 50 ml of each sample was added into 178 duplicate wells. After leaving the plates at 4 o C overnight, the contents were washed with 179 PBST. Rabbit anti-chicken immunoglobulin IgY (IgG) whole molecule conjugated with 180 alkaline phosphatase (Sigma-Aldrich A9171, St. Louis, MO) was diluted (10 -4 ) in blocking 181 buffer and 50 µl of diluted anti-chicken antibodies were added to each well and the plates 182 incubated at 37 o C. After 2 h, the plates were washed with PBST and tapped on absorbent 183 paper to remove all droplets. 184 The plates were incubated with 150 µl of para-nitrophenyl phosphate (Sigma-Aldrich P 185 7998, St. Louis, MO) for 1 h at 37 o C, and the reaction stopped with 50 µl of 2M NaOH. The 186 optical density (OD) was determined at 405 nm using a microplate reader (Bench Mark 170-187 6850, Bio-Rad, Hercules, CA). Resulting OD values were pooled for each pen. The indirect 188 ELISA was not standardised using chicken α-toxin antibodies, so the pooled OD values were 189 compared instead of the antibody titres. 190 191 Feed and digesta analyses 192 The experimental feed samples were oven dried to a constant weight at 105°C to determine 193 the dry matter content. Nitrogen (N) was determined with an automatic analyser (LECO FP-194 528 N; LECO Corp. St Joseph, MI) by AOAC 968.06 (Dumas method) using EDTA as the 195 standard (AOAC International, 2000). TIA was determined by measuring the inhibition of mg 196

  a commensal bacterium of chicken intestines

Table 2 .

 2 Financial support provided by the Commonwealth Scholarship Commission in the UK is 346 Growth performance1 and protein digestibility 2 in male broiler chickens fed nutritionally complete diets with different protein concentrates for 16 d (16-32 d of age) Data are means of 6 pens of 74 broilers per pen. 2 Data are means of 6 replicate pens of 12 sampled broilers per each pen. NS=not significant.

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	344
	345	ACKNOWLEDGEMENTS

1

Table 3 .

 3 Necrotic lesion scores, Clostridium perfringens counts cocidial oocyst counts and serum antibody levels for Clostridium perfringens alpha-toxin 1 in male broiler chickens fed nutritionally complete diets with different protein concentrates for 16 d (16-32 d of age)

		Soya bean diets Level of un-heated soya bean (g/kg) 0 100 200	Potato protein diet		Probability of differences
		Trypsin inhibitor activity		SED		Linear
			mg/g (TIA)					effect of
					(TIA		Treatment	non-
		1.90	6.21	8.46	3.72)		differences	toasted soya
								bean
	Necrotic lesion scores
	Duodenum	2.38	2.92	3.19	2.63	0.078	< 0.001	< 0.001
	Jejunum	2.13	2.44	2.58	2.27	0.085	< 0.001	< 0.001
	Mid small intestine	2.02	2.19	2.25	1.97	0.064	< 0.01	< 0.01
	Ileum	1.65	1.88	2.02	1.71	0.096	< 0.05	< 0.01
	Proportion of birds with liver
	or gall bladder lesions	0.69	0.85	0.88	0.88	0.062	< 0.05	< 0.01
	C.perfringens counts
	(log 10 cfu/g)
	Caecum	7.82	7.99	8.32	7.91	0.138	< 0.01	< 0.01
	Duodenum	7.53	7.71	7.60	7.62	0.152	NS	NS
	Serum α-toxin antibody
	(OD 405 ) in the feeding period
	Intermediate (d 5) 2, 3	0.357	0.354 0.509 0.340 0.0370	< 0.01	< 0.001
	End (d 12-15) 4	0.554	0.584 0.509 0.582 0.0691	NS	NS
	Coccidial oocyst counts
	induodenal mucosa (n/g) 2	4564	3193	2530	3188	456.7	< 0.01	< 0.001

E-mail: br.poultsci@bbsrc.ac.uk URL: http://mc.manuscriptcentral.com/cbps British Poultry Science

 Thermo Fisher Scientific, Rochester, NY)

Data are means of 6 replicate pens with 8 broilers sampled from each pen.

Data are means of 6 replicate pens with 4 broilers sampled from each pen.

Birds were sampled on d 5 of the feeding period (20 d of age)

Birds were sampled for 4 consecutive days; from d 12-15 of the feeding period (28-31 d of age).