J M ; Codron

M ; Fares

E Rouvière

From public to private safety regulation ? The case of negotiated agreements in the French fresh produce import industry

Introduction

The growing number of crises related to food safety has led public authorities to strengthen food safety regulations, in particular in developed countries. The law increases the responsibility of the actors in the food supply chain and obliges them to monitor the safety of the products they market. This article deals with the safety control devices on the French import markets for fresh fruit and vegetables for three reasons: i) the nature of the safety risk in the fruit and vegetables industry; ii) the specific legal status of the French importer; and iii) the original organisation of safety controls on the import markets. First, the safety risk in the fruit and vegetables sector demonstrates two particularities which make the analysis of safety control devices of great interest. On the one hand, the fruit and vegetables sector is primarily confronted with a problem of pesticide residues. Pesticides are used during production or post-harvest to treat fresh produce and residues may be found in or on the produce prior to consumption. There is, however, a lack of sound scientific proof concerning the potential risks related to the daily intake of fresh produce containing pesticides [START_REF] Wilson | To spray or not to spray: pesticides, banana exports, and food safety[END_REF]. The pesticide risk can, therefore be qualified as being a "minor" risk in comparison to the pathogenic risk present in the meat and fish sectors. This qualification of risk can be explained by the very low probability of serious and immediate consequences for human health after consumption of fresh produce. On the other hand, the nature of the products makes safety controls difficult to implement. Fruit and vegetables are sensitive and perishable products and thus generally have short delivery deadlines which, more often than not, do not fit in with the time required for analysing pesticides.

Second, we undertake our analysis in the French import sector due to the particular legal status of French importers. The importer is the first supplier to introduce the product onto the market. He can, therefore, be compared to a producer and is responsible for the products which he brings into the country. He is liable under criminal law if the products do not satisfy the regulations in force. The importer is therefore confronted by a legal risk when he introduces products onto the national market.

Third, changes in food safety regulations have given rise to an original organisation of safety controls in the import markets. Since 1998, French importers of fresh fruit and vegetables have been obliged to undertake their own safety controls in firms. These controls aim to check that imported fruit and vegetables respect the Maximum Residue Limits (MRL) for pesticides defined by French law. In order to satisfy this new regulation, importers * on the two French import markets, located in Perpignan and Rungis, have established safety self-monitoring agreements with the public authorities.

These safety self-monitoring agreements are negotiated between the DGCCRF (General Service for Consumption, Competition and the Repression of Fraud.), the public authority responsible for safety controls in the import markets, and a group of importers. The original nature of these agreements is to be found in their organisation. The agreements are organised on the basis of a model which is not completely decentralised. The importers are not committed to the public authorities directly, but instead are responsible to their "representative body". The "representative body" is in turn responsible to the public authorities, acting on behalf of importers during negotiations. The central position of the "representative body" gives it the status of guarantor of the importers' commitment.

This article aims to analyse these safety self-monitoring agreements and to characterise the importers' incentives which might explain the emergence and development of these agreements. We have undertaken this analysis using the case of the self-monitoring safety agreement in force in Perpignan for which we have adopted a two-step approach. First, we attempt to characterise the incentive mechanisms involved in the agreement, basing our analysis on the literature concerning incentive schemes in teams [START_REF] Okuno | Corporate Loyalty and Bonus Payments: An Analysis of Work Incentives in Japan[END_REF][START_REF] Aoki | Toward an Economic Model of the Japanese Firm[END_REF][START_REF] Greif | Contract Enforceability and Economic Institutions in Earlier Trade: The Maghribi Traders' Coalition[END_REF][START_REF] Milgrom | The Role of Institutions in the Revival of Trade: The Law Merchant, Private Judges, and the Champagne Fair[END_REF]. We demonstrate that the theoretical conditions for implementing the system do not exist in the agreement. Second, we endeavour to characterise the incentive schemes outside the agreement by employing the analytical framework of voluntary approaches to food safety developed by [START_REF] Segerson | Mandatory Versus Voluntary Approaches to Food Safety[END_REF] and [START_REF] Venturini | Public Regulation and Voluntary Approaches to Food Safety Credence Good[END_REF]. We thus demonstrate that alternative hypotheses must be put forward in order to characterise the importers' incentives to commit themselves to the agreement voluntarily and to provide the resources necessary for safety controls of imported fresh produce. The introduction of a third party, namely supermarkets, may create the incentives necessary for the adoption of voluntary approaches to food safety by firms upstream. The private incentives created by supermarkets are primarily incentives in terms of market access, sales volumes and reputation.

To the best of our knowledge, no research has yet considered the French case for products such as fresh fruit and vegetables which present a safety risk that is still not wholly understood [START_REF] Wilson | To spray or not to spray: pesticides, banana exports, and food safety[END_REF]. However, the existing literature has given extensive coverage to the English case, the organisational consequences of regulatory change and, in particular, the implementation of the principle of "due diligence" via the "Food Safety Act" (cf. [START_REF] Hobbs | Costs of Monitoring Food Safety and Vertical Coordination in Agribusiness: What Can Be Learned from the British Food Safety Act 1990?[END_REF][START_REF] Henson | Food Safety Regulation: An Overview of Contemporary Issues[END_REF][START_REF] Loader | Strategic Responses to Food Safety Legislation[END_REF][START_REF] Holleran | Private Incentives for Adopting Food Safety and Quality Assurance[END_REF]. According to the principle of "due diligence" downstream firms are fully liable. They must therefore check that the products they market are safe. To do so they must monitor the safety practices of their upstream suppliers. In the United Kingdom, this principle of liability has led modern retailers to create quality assurance schemes and to impose them on their suppliers for improved monitoring of their food supply [START_REF] Henson | Private Sector Management of Food Safety: Public Regulation and the Role of Private Controls[END_REF][START_REF] Holleran | Private Incentives for Adopting Food Safety and Quality Assurance[END_REF]. Furthermore, most of this research has focussed on sectors where the risk can be qualified as "major" due to the immediate and serious consequences for consumers which may result from contamination [START_REF] Northen | Using Farm Assurance Schemes to Signal Food Safety to Multiple Food Retailers in the U.K[END_REF].

The article is organised as follows: section 2 presents the agreement and analyses the internal incentives mechanisms with regard to its organisation; section 3 deals with the external incentives for importers which might help to explain the emergence and development of these new mechanisms; section 4 concludes.

Self-monitoring safety agreement for the fresh produce import industry in Perpignan.

Changes in the French food safety regulations are characterised by an increased involvement and responsibility of the private actors with regard to food safety controls. Since 1998, importers of fruit and vegetables have been responsible for safety controls within their firms and must therefore implement a system of self-monitoring. Safety self-monitoring is aimed at checking that the imported products satisfy the MRLs for pesticides defined by French law.

The importer is, in fact, the first supplier to introduce the fresh produce onto the market and is held liable under criminal law if the fresh produce which he imports does not comply with the MRLs for pesticides. They can be held if fruit and vegetables tested are over the MRLs.

Self-monitoring agreement: a case study.

On the Perpignan market, the self-monitoring safety agreement has been drafted on the initiative of the importers, negotiated then approved by the public authorities. It is, then, a negotiated agreement between the public authorities and the importers aimed at enabling the importers to respect collectively their new obligations with regard to self-monitoring. It characterises the coordination between public and private actors in the process of drafting new regulations for safety controls and consolidates the wish of the two parts to cooperate. It can, therefore, be considered as a tool of co-regulation [START_REF] Eijlander | Possibilities and constraints in the use of self-regulation and coregulation in legislative policy. Experiences in the Netherlands-Lessons to be learned for the EU?[END_REF].

The organisation of the agreement is not based on an entirely decentralised model (cf. figure 1). The agreement comprises two sub-agreements. A first sub-agreement exists between the importers and their "representative body", while a second sub-agreement links the "representative body" to the public authorities. The importers do not commit directly to the public authorities. They first form a collective group and then commit to their "representative body".

The importers committed to the agreement represent about 80% of the firms present on the market in Perpignan. The cost of committing to the agreement is twofold: the firms must pay a subscription fee of 1,000 € per year while at the same time allocating human and financial resources for implementing, monitoring and completing the safety self-monitoring. The firms who do not adhere to the agreement are either small firms which are new to the sector of activity, or large highly-organised firms. The former, for whom the safety aspect of the fresh produce is of secondary importance, find commitment to the agreement too costly whilst the latter already have their own provisions for safety self-monitoring.

The importers' "representative body" is an administrative organisation. The constituent

Comment citer ce document : Codron, J. M., Fares, M., Rouviere, E. ( 2007). From public to private safety regulation? The case of negotiated agreements in the French fresh produce import industry. International Journal of Agricultural Resources Governance andEcology, 6 (3), 415-427 members are not involved in the import sector. They are paid by the importers and therefore assume an administrative role of representing these importers. The central position of the "representative body" in the organisation of the agreement gives it the status of guarantor of the agreement. On the one hand, it is the spokesperson for the importers: the representative body negotiated the agreement with the public authorities on behalf of the importers. On the other hand, it is the dedicated contact for the public authorities and must therefore ensure close control of the importers' group. The "representative body" must, then, ensure that the importers undertake the safety self-monitoring and respect their commitment.

The DGCCRF is the public authority responsible for public safety controls on the import markets. Historically speaking, the mission of the public authorities was to control the public norms which were, more often than not, accompanied by sanctions. The introduction of the agreement has caused its function to change from that of controller to a more preventive role.

In the agreement, the official control is a second-level control which consists of checking that the firms undertake their safety self-monitoring correctly. Implementing the agreement thus means that the delegation of the imported produce safety controls to the importers is official.

For the public authorities, delegation of safety controls has two main objectives. First, the safety self-monitoring undertaken by the importers increases the number of controls on the market and thus facilitates an increase in the number of analyses undertaken. Second, it reduces the costs of public control by transferring the control and analysis costs to the importers. This transfer allows a reallocation of resources provided to public control in those sectors where the level of risk seems higher. In sectors such as the meat sector, public intervention is still inescapable and is related to the recent food outbreaks.

The agreement is a code of conduct for controlling the safety level of supplies, enabling importers as a group to satisfy the requirement of self-monitoring. The code of conduct, therefore, defines the procedure for collective safety self-monitoring. By adhering to the agreement, the importers undertake to: i) assign one person to quality control; ii) implement the common self-monitoring safety procedure; and iii) carry out laboratory analyses. The collective safety self-monitoring procedure is based on the principles of the HACCP method (Hazard Analysis Critical Control Point.). In light of the information available to them (production practices, relations with foreign suppliers, etc.), the importers must identify fruits and vegetables which might present an excess of MRLs in relation to pesticides used in production and post-harvest. At the start of the campaign, the importers define a sampling plan for fresh produce to be controlled and determine the number of analyses to be carried out during the campaign. Laboratory pesticide analyses must therefore be carried out on a regular basis. These pesticide analyses are costly and must be carried out for all produce provided for in the sampling plan. A standard multi-residues analysis costs more than 200€ for one sample of a given product. The fact that the importers form a group which adheres to the agreement enables them to take advantage of economies of scale. The agreement means that they can share both the costs of implementing self-monitoring in the firms and the cost of the analyses.

The definition and negotiation of the safety self-monitoring procedure are common to all the importers in the group and the pesticide analyses are undertaken by a single laboratory at a preferential rate. The results of the analyses remain at the discretion of the importers. In the event of a safety anomaly, the importers must alert the "representative body" voluntarily, which then conveys the information to the public authorities. As long as the results are not over the MRL they do not have to report them. Moreover, in order to be cleared through customs when entering the French market, fresh produce must pass through a series of controls (customs, phytosanitary services and DGCCRF). Membership of the collective agreement allows importers to avoid the DGCCRF control and thus to save time.

The success of the agreement lies in the definition of the control and enforcement mechanisms which must force the importers to respect their commitment. In the agreement, these functions fall to the "representative body. The "representative body", ensures that the safety self-monitoring undertaken by the importers is realised. Monitoring is effected by means of random visits and reminders when the importers do not respect the established sampling plan. The mechanisms for enforcing the agreement rely on principles of exclusion.

The representative body decides whether or not to exclude importers who do not undertake their safety self-monitoring. Exclusion can be temporary or permanent. Those importers who are excluded can no longer benefit from the advantages provided by the agreement: i) costsharing for the controls; ii) reduction of resources required in implementing the common procedure.

With regard to public control, the authorities made considerable concessions during the negotiation of the agreement. First, their controls have become a second-level control, that is, the authorities rely on the record-keeping of self-monitoring provided by the importers.

Second, the frequency of official controls has been greatly reduced within the group. Third, in the event of an established safety anomaly, the authorities assume that the importers act in good faith. If the inspectors of the DGCCRF believe that the resources mobilised by the firms in the context of the safety self-monitoring are sufficient, the importer will not be held liable under criminal law. In this context, joining the agreement can be perceived as a means for the importers to reduce the scope of the controls of public norms within the group. It also allows them to reduce the extent of their own legal liability in the event of a safety issue.

The agreement, in its current organisational structure, poses a problem in terms of incentives, as we will see below. Implementing the self-monitoring safety agreement requires two conditions: first, the public authorities must ensure that the "representative body" carries out its control and enforcement functions; and second, the "representative body" must create sufficient incentives to make the collective discipline mechanisms effective within the group.

Internal incentive schemes in the self-monitoring agreement.

To study the incentive question within the agreement, we compare the "representative body" to a supervisor of a team (the group of importers). This comparison leads us to consider the literature concerning incentive schemes in decentralised systems and, in particular, the approaches developed by Aoki and Okuno [START_REF] Aoki | Toward an Economic Model of the Japanese Firm[END_REF][START_REF] Okuno | Corporate Loyalty and Bonus Payments: An Analysis of Work Incentives in Japan[END_REF]. [START_REF] Aoki | Toward an Economic Model of the Japanese Firm[END_REF] establishes that two conditions exist in a team game with a supervisor so that each member of the team and the supervisor have an interest in complying with the rules of the agreement. The first condition concerns the supervisor's incentive while the second condition concerns the existence of an incentive mechanism within the team.

How to supervise the supervisor? The literature suggests two types of solution: either the implementation of a traditional incentive system or the introduction of a principle of supervisor responsibility. First, the implementation of a "traditional" incentive system assumes that there is the possibility of rewarding the supervisor when he controls his team efficiently and the desired level of effort within the group is achieved. However, the selfmonitoring agreement signed with the public authorities generates neither positive incentives (subsidies) nor negative incentives (taxes). Second, [START_REF] Aoki | Toward an Economic Model of the Japanese Firm[END_REF] suggests the introduction of a principle of awareness of his responsibility by the supervisor. On the one hand, the supervisor can be "relieved" of his functions if the level of effort produced by the team does not reach the desired level. The introduction of such a principle assumes that the supervisor's effort is monitored alongside that of the team as a whole. This option has a cost and was not envisaged during the development and negotiation of the agreement. On the other hand, it should be possible to make the supervisor legally liable. If the team does not perform correctly, the supervisor should be held liable. While negotiating the agreement, the public authorities suggested introducing a principle whereby the representative body would have greater responsibility. This principle of responsibility was rejected because the threat appeared too strong for the "representative body" and it did not satisfy its participation constraints.

The second condition concerns the introduction of a collective discipline mechanism within the team. Each member of the team must, then, not only find an economic advantage in undertaking such an effort, but also be encouraged to maintain his place in the team. The literature concerning decentralised systems has developed this aspect, in particular by establishing that the existence of a mechanism of ostracism within the team can force members to respect their commitment [START_REF] Okuno | Corporate Loyalty and Bonus Payments: An Analysis of Work Incentives in Japan[END_REF][START_REF] Milgrom | The Role of Institutions in the Revival of Trade: The Law Merchant, Private Judges, and the Champagne Fair[END_REF]Weingast, 1990, Greif, 1994). For this to be successful, it must be possible to identify free riding behaviour, a fact which requires the existence of a third party or system responsible for this function. The agreement provides for exclusion mechanisms and the enforcement of such mechanisms is the responsibility of the "representative body". We demonstrated above that the "representative body" is in no way encouraged to fulfil its role of controller. Just as the "representative body" is not encouraged to assume its responsibility, nor is it encouraged to fulfil its role of enforcement. Moreover, the representative body is not fully neutral. Thus, the collective discipline mechanisms cannot, then, be effective in light of the current agreement.

We have demonstrated that the theoretical conditions for implementing the system do not exist in the current agreement. The importers are encouraged neither to allocate resources for safety controls nor to commit themselves voluntarily to the agreement. Nor do the concessions made by the public authorities with regard to public controls, and in particular to reducing the extent of legal responsibility, appear to be credible incentive mechanisms. Indeed, on the import markets, public safety control is hindered by the gradual reduction of the budgets and personnel allocated to public control. For importers, the probability of their being liable in the event of a safety anomaly is low, at least in the current period. The same is true for importers who are not bound by the agreement. Commitment to the agreement cannot, then, be seen as a means of protection against legal risk. Commitment to the agreement as a protection against legal risk is a less-than-satisfactory explanation. However, changes in public intervention and an increase in the legal risk for importers could occur in the long term. For example, if French consumer associations become more active on such safety issues as they are in some Northern European countries, they could exert more pressure on the legal system. In its current state, the agreement does not create incentives and we have to seek for other incentives in the short term which could explain the voluntary adhesion of importers to the agreement and the respect for their commitments. To answer this question, we turn to the literature on voluntary approaches to food safety.

Voluntary approach to food safety: new insights.

The safety self-monitoring agreement: a voluntary approach to food safety?

Numerous papers have analysed the introduction of voluntary approaches in an environmental context (cf. [START_REF] Khanna | Non Mandatory Approaches to Environmental Protection[END_REF] for a review of the literature). In this context, voluntary approaches aim to introduce protective measures to preserve the environment through auto-regulation by the firms [START_REF] Segerson | Voluntary Environmental Agreements: Goods or Bads News for Environmental Protection?[END_REF]. In the field of food safety, voluntary approaches are the measures taken by firms with a view to increasing or controlling the safety of the products they market. Recently, certain authors have analysed the emergence of voluntary approaches to food safety [START_REF] Segerson | Mandatory Versus Voluntary Approaches to Food Safety[END_REF][START_REF] Venturini | Public Regulation and Voluntary Approaches to Food Safety Credence Good[END_REF]. In this section, we will refer to these researches to characterise the external incentives for importers which could help us to explain their voluntary commitment to the agreement.

The self-monitoring safety agreement corresponds to one of the three broad categories of voluntary approaches identified in the literature: i) unilateral initiatives, ii) negotiated agreements, iii) non-obligatory public programmes. They differ as to the extent of the public authorities' commitment to their implementation [START_REF] Khanna | Non Mandatory Approaches to Environmental Protection[END_REF]. The first category is that of unilateral initiatives. These involve measures taken by firms in response to the demand or pressure of the market in which the regulator does not intervene. The second category is that of negotiated agreements. These are agreements which characterise a bilateral commitment between the firms on the one hand and the public authorities on the other with regard to the definition and negotiation of the new protective measures to be introduced. The third category is that of public programmes introduced by the public authorities. These programmes are nonobligatory and the firms have the option of participating or not.

The research concerning voluntary approaches to food safety primarily considers the decision of firms to adopt such safety measures [START_REF] Segerson | Mandatory Versus Voluntary Approaches to Food Safety[END_REF][START_REF] Venturini | Public Regulation and Voluntary Approaches to Food Safety Credence Good[END_REF][START_REF] Noelke | A Model of the Implementation of Quality Management Systems for Credence Attributes[END_REF][START_REF] Caswell | How Quality Management Metasystems Version postprint Comment citer ce document[END_REF]. Sergerson (1999) provides a decisionmaking model where, faced with the regulator, the firm opts to implement voluntary safety measures or to remain passive. If the firm remains passive, the regulator may impose the introduction of mandatory measures. Segerson hypothesises that a voluntary system is less costly to implement than a mandatory system. She shows that a strong mandatory threat (i.e. a high probability of a more costly system being imposed) is a necessary and sufficient condition for firms to adopt safety measures voluntarily. However, by relaxing the assumption concerning costs, [START_REF] Venturini | Public Regulation and Voluntary Approaches to Food Safety Credence Good[END_REF] demonstrates that the mandatory threat is no longer a sufficient condition for the adoption of voluntary measures to ensure food safety. The firm must be able to promote or value the voluntary nature of its initiative with the consumer. Furthermore, Venturini adds that, as the safety quality of produce is a credence attribute, the firm needs to promote its initiative to consumers indirectly. For example, introducing independent certification, supported by the government, should serve to increase the credibility of voluntary approaches vis-à-vis the consumers.

In the agreement, the theoretical conditions for adopting voluntary approaches to food safety suggested in the literature above do not exist. First, the mandatory threat is weak. As we have seen before, the resources allocated to public control in the fresh produce sector are diminishing. Thus, the definition and imposition of a more stringent system of control are highly unlikely. In addition, the conditions for promoting the effort vis-à-vis the consumers are absent. First of all, the importer is not in direct contact with the consumers, most volumes are bought by the supermarkets. Second, promotion vis-à-vis the consumers is difficult to envisage with regard to the safety attributes of fruit and vegetables, except for organic produce which is still a "niche" market. In France, firms which communicate concerning the attributes of a product must provide proof of their claims. They are severely punished under criminal law in the event of false or unfounded claims. As the cost of proof concerning fresh fruit and vegetables is high, sellers generally refrain from communicating directly with regard to pesticide residues [START_REF] Codron | Minimum Quality Standards, Premium Private Labels, and European Meat and Fresh Produce Retailing[END_REF].

In light of the absence of a strong mandatory threat, and taking into account the literature studied, we should conclude that it is impossible to implement the voluntary commitment of importers to the agreement. The question of incentives for importers therefore remains unanswered.

New proposals for voluntary approaches to food safety.

We underline here the interest in changing our mind in analysing the decision of firms to adopt voluntary approaches within the supply chain. We should indeed consider that firms do not only take decisions with regard to the regulator, but also to private firms operating downstream. Alternative hypotheses to those suggested by [START_REF] Segerson | Mandatory Versus Voluntary Approaches to Food Safety[END_REF] and [START_REF] Venturini | Public Regulation and Voluntary Approaches to Food Safety Credence Good[END_REF] should thus be put forward to characterise firms' incentives to adopt voluntary safety measures within the supply chain. To the best of our knowledge, only a small number of papers have highlighted the impact of introducing a quality management system within the supply chain. [START_REF] Noelke | A Model of the Implementation of Quality Management Systems for Credence Attributes[END_REF], for example, suggest a model which identifies the interactions relating to the introduction of these systems in a simplified supply chain and to the consumer interface. [START_REF] Caswell | How Quality Management Metasystems Version postprint Comment citer ce document[END_REF] suggest a model which introduces the costs and benefits relative to the introduction of these systems at firm level. However, we have just established that the analysis of firms' decisions to adopt voluntary approaches cannot be generalised and thus specified depending on the firm's position in the supply chain.

Other research [START_REF] Codron | Minimum Quality Standards, Premium Private Labels, and European Meat and Fresh Produce Retailing[END_REF] shows that the incentive may come not from the consumer but from the supermarkets. The latter have an interest in strengthening food safety controls carried out by the state through the application of their own methods. One of the ways of implementing this private control is to give the supplier strong incentives to undertake these controls himself. With regard to fruit and vegetables, delegation of safety controls upstream is possible in so far as the effort made to monitor the residues can be undertaken at different levels in the chain. The introduction of a third party, namely the supermarkets, can thus create the incentives necessary for the adoption of voluntary approaches to food safety by firms upstream.

For firms upstream, the private incentives created by the supermarkets are primarily incentives in terms of market access, sales volumes and reputation. These incentives thus characterise the commercial risk faced by the supermarkets' suppliers. Indeed, the supermarkets represent a real commercial stake for firms in the food-supply chain because they are the dominant outlets for selling large volumes. The incentives generated by the supermarkets can also be positive. They might take the form of price premiums paid to the suppliers. The supermarkets can then attempt to transfer these premiums to the consumers by using private label strategies to promote or to value indirectly the safety attributes of products.

The commercial risk and a possible promotion of voluntary approaches to food safety within the supply chain are important and should be considered in theoretical analyses. Today, for fruit and vegetables, the safety aspect of fresh produce is still not a predominant factor in the commercial relationships between the suppliers and the French supermarkets [START_REF] Garcìa Martinez | The development of private fresh produce safety standards: implications for developing Mediterranean exporting countries[END_REF]. The emergence of a self-monitoring safety agreement could, then, be explained by an attempt on the part of importers to offer the supermarkets a collective safety control system for imported fruit and vegetables. The implicit objective of the importers is thus to make the collective self-monitoring safety agreement credible for the supermarkets. [START_REF] Northen | Using Farm Assurance Schemes to Signal Food Safety to Multiple Food Retailers in the U.K[END_REF] notes the same effect among English meat producers. The aim of implementing a collective system of quality control directed by producers was to act as a credible sign of the food safety attributes of the products vis-à-vis the English supermarkets.

Henceforth, to maintain their market access, the importers must make sure that their collective self-monitoring procedure is credible in complying with the supermarkets' private safety standards. The emergence and development of the self-monitoring agreement could be considered as an attempt by importers to position themselves vis-à-vis the supermarkets and to protect themselves against commercial risk. The importers have, then, foreseen the role that the safety aspect of fruit and vegetables should play in the future in their commercial relations with the French supermarkets.

The commercial risk ** represented by the supermarkets therefore constitutes a strong, private incentive against which the firms try to protect themselves and this can explain the adoption and the development of safety voluntary approaches within the food supply chain. The incentives within the supply chain are not the same as those in the analyses of the firm/consumer interface. For firms upstream in the supply chain, there is a need to consider both the commercial risk and the legal risk. Firms are usually more adverse to commercial risk than to legal risk.

Conclusion

In this article, the analysis of the Perpignan agreement allows us to demonstrate two results.

First, the organisation of the agreement requires the introduction of internal incentive mechanisms so that each member respects his commitment. However, there is no means of implementing a collective discipline mechanism within the group. The fact that the "representative body" has no legal responsibility means that the latter is in no way encouraged to fulfil its functions of control and enforcement. Furthermore, commitment to the agreement does not appear to be a means for the importers to protect themselves against legal risk. The probability of being held liable in the event of a safety anomaly is low, irrespective of whether the importers adhere to the agreement or not. The legal risk is too insignificant in the current period for importers to care about protecting themselves by voluntarily committing to the agreement and allocating resources for safety controls.

Second, by suggesting alternative hypotheses to those presented by [START_REF] Segerson | Mandatory Versus Voluntary Approaches to Food Safety[END_REF] and [START_REF] Venturini | Public Regulation and Voluntary Approaches to Food Safety Credence Good[END_REF], we demonstrate that the commitment of the importers to the agreement can represent a means of protecting themselves against commercial risk in their relations with the supermarkets, their most important customers. The importers thus initiated the agreement in order to offer distributors a credible collective system for controlling the safety of imported fruit and vegetables. Commitment to the agreement is a means of satisfying the increasing demands of the latter. In this way, we emphasise the interest in considering both commercial risk and legal risk in the firms' decision to adopt voluntary approaches to food safety within the supply chain.

To conclude, the agreement has considerable consequences for the French import sector. On the one hand, the agreement has allowed a highly-fragmented sector to become more structured. On the other hand, it has facilitated the organisation of a group of importers

  . DOI : 10.1504/IJARGE.2007.012845

  Comment citer ce document : Codron, J. M., Fares, M., Rouviere, E. (2007). From public to private safety regulation? The case of negotiated agreements in the French fresh produce import industry. International Journal of Agricultural Resources Governance and Ecology, 6 (3), 415-427. DOI : 10.1504/IJARGE.2007.012845

  Comment citer ce document : Codron, J. M., Fares, M., Rouviere, E. (2007). From public to private safety regulation? The case of negotiated agreements in the French fresh produce import industry. International Journal of Agricultural Resources Governance and Ecology, 6 (3), 415-427. DOI : 10.1504/IJARGE.2007.012845

  Comment citer ce document : Codron, J. M., Fares, M., Rouviere, E. (2007). From public to private safety regulation? The case of negotiated agreements in the French fresh produce import industry. International Journal of Agricultural Resources Governance and Ecology, 6 (3), 415-427. DOI : 10.1504/IJARGE.2007.012845

Acknowledgments:

The authors ARE VERY GRATEFUL TO Céline Bignebat and three anonymous referees for their comments and very helpful suggestions. This research was supported by the Ecoponics program (www.ecoponics.de) a project of the European Union under the INCO-MED2 (Shared Cost Action) Research Programme within the 5th framework programme (FP5RTD) (www.cordis.lu/fp5).

Version postprint

Comment citer ce document : Codron, J. M., Fares, M., Rouviere, E. (2007). From public to private safety regulation? The case of negotiated agreements in the French fresh produce import industry. International Journal of Agricultural Resources Governance and Ecology, 6 (3), 415-427. DOI : 10.1504/IJARGE.2007.012845 through the emergence of a cooperation procedure in a highly-competitive sector. The agreement is, then, considered by importers as an opportunity granted by the state to create a pool of importers capable of offering a collective system of food safety controls which they will endeavour to make credible vis-à-vis the supermarkets. Indeed, at this level, the major issue is the credibility of the agreement vis-à-vis the supermarkets. Today, the supermarkets act as private regulators which promote food safety controls in the supply chain through their own incentives and sanctions. Further research will be necessary to assess whether this new form of regulation is a substitute for or a complement to public regulations. At present, it would appear to be a substitute. Indeed, both ex-ante public control and ex-post legal risk seem to have little effect on the decisions of private actors. A change in public intervention could occur for instance if French consumer associations were to become more active bodies, thereby exerting more pressure on the legal system as is already the case in some Northern European countries such as the Netherlands and the United Kingdom.

Notes:

* Importers who are members of the collective agreements are not only located in Rungis and Perpignan but nevertheless depend on the collective agreements with Perpignan and Rungis as registration centres.

** We distinguish commercial risk from legal risk for two reasons. First, these two risks are not linked. The legal risk depends on public control and on the ability of public authorities to monitor and then sanction firms which fail. The commercial risk relies on a private contract between firm and retailer. The retailer can undertake safety tests; if the firm fails it faces a commercial sanction but never legal proceedings. Second, if a firm fails a public test, the customer (the retailer) is never informed, either by the public agency or by the firm.


J C Bambou

R Arquet

H Archimède

G Alexandre

N Mandonnet

E González-García

Intake and digestibility of naïve kids differing in genetic resistance and experimentally parasitized (indoors) with Haemonchus contortus in two successive challenges 1

Keywords: digestibility, goat, Haemonchus, immunity, intake, resistance

ABSTRACT:

We evaluated the effects of infection with Haemonchus contortus on feed intake, digestibility, fecal egg count, circulating eosinophils, and packed cell volume in Creole kids differing in genetic resistance (susceptible, S; resistant, R) to gastrointestinal parasitism and maintained on a similar level of nutrition. The experiment was carried out during 2 periods of 6 wk each differing in immunity development stage. In the first period (acquisition of immunity; period I), 22 naïve male kids (23.4 ± 0.65 kg of BW) were housed in individual boxes and fed a hay-based diet, and a primary infection was induced. In the second period (expression of immunity; period II), 15 of the initial 22 kids (28.4 ± 0.77 kg of BW) were submitted to a secondary infection. Housing and management were uniform throughout the experiment. For each period, measurements of intake and digestibility were made at 0, 2, and 4 wk postinfection (WPI) with a single dose of 10,000 infective larvae (L 3 ). The DMI and total-tract DM, OM, CP, NDF, and ADF digestibilities were determined using the total feces collection and ad libitum forage supply method. Fecal and blood samples were collected weekly to measure fecal egg count, circulating eosinophils, and packed cell volume. Infection with Haemonchus contortus decreased feed intake during period I. The absence of anorexia in period II was probably due to the acquired immunity of kids. The DMI was affected (P = 0.05) by genetic predisposition to resistance (626 vs. 583 ± 26 g/d, for R vs. S) and WPI, being greatest in the second WPI (693 vs. 614 and 657 g/d, for WPI-2 vs. WPI-0 and WPI-4, respectively). The latter was related to worm establishment phase and was linked to the lower total tract digestibilities at this point. Digestibilities were least at WPI-2. The fecal egg counts were greater (P < 0.001) in period I than II, and differences between S and R were evident after the fifth WPI in period II. Circulating eosinophils were greater (P < 0.001) in S vs. R. The results suggest that effects of these parasites on intake and digestibility are influenced by the individual genetic resistance and the immunological stage, and the strongest impact occurs between the second and the third WPI, a period during which the immune response is more pronounced, probably due to parasite maturation.

INTRODUCTION

Few published papers are available about effects of gastrointestinal parasitism on feed intake, digestibility, and their relationship with the immunological system in ruminants. Most of our understanding about the impact on ruminant nutrition has been derived from infections in sheep [START_REF] Coop | Nutrition-parasite interaction[END_REF][START_REF] Hoste | Nutrition-parasite interactions in goats: Is immunoregulation involved in the control of gastrointestinal nematodes?[END_REF]. In goats, data on this topic remain scarce and there is little clarity about mechanisms underlying the relationship between nutrition and gastrointestinal parasitism. However, compared with sheep, goats seem to develop a reduced immune response against nema-todes, which has implications for epidemiology, pathology, and control of infections [START_REF] Hoste | Nutrition-parasite interactions in goats: Is immunoregulation involved in the control of gastrointestinal nematodes?[END_REF]. [START_REF] Mandonnet | Assessment of genetic variability of resistance to gastrointestinal nematode parasites in Creole goats in the humid tropics[END_REF] demonstrated intrabreed variability in resistance to gastrointestinal parasitism in Creole kids, ensuring that this factor must be considered when evaluating impacts on this breed. Their work [START_REF] Mandonnet | Résistance aux strongles gastrointestinaux des caprins. Influence de différents environnements tropicaux sur l'expression du potentiel génétique de résistance[END_REF][START_REF] Mandonnet | Mortality of Creole kids during infection with gastrointestinal strongyles: A survival analysis[END_REF][START_REF] Mandonnet | Impact on productivity of periparturient rise in fecal egg counts in Creole goats in the humid tropics[END_REF]) constitutes 1 of 2 attempts at the international level to select goats based on response to gastrointestinal parasitism; the other was in Scotland with Cashmere goats [START_REF] Vagenas | Genetic control of resistance to gastro-intestinal parasites in crossbred cashmere-producing goats: Responses to selection, genetic parameters and relationships with production traits[END_REF].

Response to gastrointestinal parasitism is dependent on immunity stage, physiological condition, nutritional status, and nutrient requirements of the host at the time infection occurs; therefore, different reactions would be expected among breeds of the same species (sheep; [START_REF] Zaralis | Changes in food intake and circulating leptin due to gastrointestinal parasitism in lambs of two breeds[END_REF] or between naïve and previously infected animals, even when subject to the same nutrition and parasite burden.

Our hypothesis was that genetic predisposition (GP) to gastrointestinal parasites and the immunity stage of the host at the beginning of the infection affects the magnitude of the effects of parasites on feed intake and diet digestibility of Creole kids. This hypothesis was tested in resistant (R) and susceptible (S) kids, and during a primary (period I) and secondary (period II) challenge with infective larvae (L 3 ) of Haemonchus contortus (HC).

MATERIALS AND METHODS

The experiment was conducted at Institut National de la Recherche Agronomique (INRA) Animal Re-search Unit, Guadeloupe (French West Indies). All animal care, handling techniques, and procedures as well as the license for experimental infection and blood sampling were approved by INRA, according to the certificate of authorization (number A-971-18-01) to experiment on living animals issued by the French Ministry of Agriculture, before the initiation of the research.

Animals, Management, and Experimental Design

The study was carried out with growing male Creole kids during 2 consecutive periods of 6 wk each, the first (period I) from October 8 to November 19, 2007 and the second (period II) from December 17, 2007 to January 28, 2008; there was a lapse of 4 wk between finishing period I and beginning period II. Although the acquisition of immunity is a continuous process, the 2 periods were considered as separate according to our objectives and taking into account previously established criteria and definitions for the development of the nutrient partitioning framework [START_REF] Coop | Nutrition-parasite interaction[END_REF][START_REF] Athanasiadou | Exploiting synergisms and interactions in the nutritional approaches to parasite control in sheep production systems[END_REF]. Thus, period I and period II were respectively associated with the acquisition and expression of immunity phases. The expression of immunity after the second challenge was confirmed by the decreased fecal egg count (FEC) compared with FEC values after the first challenge (see Figure 1; compare period I vs. II).

All kids were born indoors at INRA-Domaine Gardel (north of Guadeloupe) during the summer season of 2006 and were brought into a naturally illuminated and ventilated shed in INRA-Domaine Duclos (South) 1 mo before the beginning of the experiment; kids were housed in individual pens (2.0 × 1.0 m) until the end of the study.

In the flock at INRA Domaine Gardel, the pedigree of each animal was available since the foundation generation was established in 1979. Fecal samples were collected regularly (during wk 6 and 7 after drenching) at 7 and 11 mo of age for genetic evaluation on the average of 2 FEC measures. Thus, the breeding value for FEC of each kid of the flock at 11 mo of age, under natural mixed infection on pasture conditions, was regularly estimated. Such estimation was made taking into account their own individual performances, the performances of their ascendants, and their pedigree. The records used were then back-transformed value logarithm of parasite eggs/g of feces. The 11 R and 11 S kids initially used in the current study were selected on basis of their extreme breeding value (see Table 1) with regard to their cohorts. The average breeding value of the 2 groups was distant (P < 0.0001) at 2.99 genetic SD of FEC at 11 mo of age.

Period I started with 22 male worm-free (naïve) Creole kids (23.8 ± 0.65 kg of BW; 15 mo old), selected on the basis of their genetic index [START_REF] Mandonnet | Assessment of genetic variability of resistance to gastrointestinal nematode parasites in Creole goats in the humid tropics[END_REF] as R (n = 11; 24.3 ± 0.93 kg of BW) or S (n = 11; 23.4 ± 1.25 kg of BW). Period II continued with 15 kids (28.4 ± 0.77 kg of BW; 17 mo old; R, n = 8, 28.2 ± 1.02 kg of BW; S, n = 7, 28.5 ± 1.24 kg of BW) from the initial 22; 7 kids were slaughtered for in vitro studies about parasite balance and morphology at abomasum (results not corresponding to the objectives of this paper). The selection criterion for slaughter of kids was their FEC values; kids were categorized as low, average, and high FEC, and we selected 2 or 3 animals per group.

On the first day of each period and before the morning meal (0730 h), we individually challenged all kids with a single dose of 10,000 L 3 of HC to monitor the effects of induced infection on feed intake and diet digestibility during the subsequent weeks. The L 3 were obtained 42 d before the challenge. Cultures of feces taken from anthelmintic-susceptible strain were har-vested from feces of donor Creole goats monospecifically infected [START_REF] Bambou | Serum antibody responses in Creole kids experimentally infected with Haemonchus contortus[END_REF] with isolates previously obtained from Creole goats reared on pasture in different farms in Guadeloupe [START_REF] Aumont | Etude comparée du succès reproductif du nématode parasite Haemonchus contortus, en situation de co-évolution chez des hôtes petits ruminants sensibles et résistants en zone tropicale[END_REF]. A standard Baerman procedure [START_REF] Urquhart | Veterinary Parasitology[END_REF] was used. After harvesting, L 3 were stored at 4°C in tap water (1,000 L 3 /mL) and used within 3 wk of collection. Each infective dose was suspended in 10 mL of water and was administered orally using a syringe.

During the entire experiment, animals received a diet composed of ad libitum access to 75-d-old Dichantium spp. hay and restricted concentrate (100 g/d). Measurements of intake and digestibility were made at 0, 2, and 4 wk post-oral infection (WPI); feed intake, BW changes, FEC, and blood variables were measured weekly throughout the experiment.

Feed Intake and In Vivo Total Tract Digestibility

The total feces collection (with fecal trays placed behind the kids) and ad libitum forage supply method was used. Pooled samples of hay, supplementary concentrate, and feces (10% per day of the wet weight) were also collected daily for chemical analyses (Table 2). Each digestibility measurement was based on a 5-d period for sample collection. Offered and refused feed were individually recorded weekly to determine voluntary DMI and to enable 115% of that respective value to be offered the following week. The in vivo apparent total tract DM, OM, CP, NDF, and ADF digestibilities were determined.

FEC and Blood Sampling

Fecal and blood samples were collected before challenge in WPI-0. To determine FEC, fecal samples of approximately 10 g were collected weekly after experimental infection directly from the rectum of each kid. The feces were kept in plastic tubes to avoid contamination and immediately transported to the laboratory in refrigerated vials. All samples were individually analyzed [START_REF] Aumont | Le dénombrement des éléments parasitaires: Un outil pour l'étude de la résistance génétique aux endo-parasites chez les petits ruminants[END_REF], and FEC was expressed as the number of eggs/gram of feces. Blood samples (4 mL) were individually collected once weekly by jugular venipuncture from each Creole kid using disposable syringes and 20-gauge needles. A 2.5-mL aliquot of each blood sample was placed in commercial anticoagulant tubes (EDTA tubes, Becton Dickinson, Plymouth, UK); the remainder was placed in a tube without additive, left to clot at room temperature for 1 h, and then centrifuged for 5 min at 5,000 × g (4°C). Serum was then frozen at -20°C until analysis. Blood samples previously placed in EDTA-coated tubes were used to measure the number of circulating eosinophils (EOS) according to the method of [START_REF] Dawkins | Eosinophil responses in sheep selected for high and low respon-siveness to Trichostrongylus colubriformis[END_REF] and counted with a Malassez cell counter. The packed cell volume (PCV) was measured using the capillary microhematocrit method.

Chemical Analyses of Feeds, Orts, and Feces

The DM contents of feeds, orts, and feces were determined by oven drying (type SE-79, Le Matériel Physic Chimique Flam et Cie, MPC, Neuily S/Marine, France) to a constant weight at 60°C for 48 h (AOAC, 1997), and ash content was determined by heating samples at 550°C for 4 h according to AOAC (1997). The OM content was calculated by difference. Dry samples were obtained for further chemical analyses and were ground (model SK100 confort Gußeisen, F. Kurt Retsch GmbH & Co., Haan, Germany) to pass through a 1-mm stainless steel screen. The CP content was calculated after N determination by combustion using the micro-Dumas method (NA2100 Protein, CE Instruments, Thermo-Quest S.p.A., Milano, Italy).

The methods of [START_REF] Van Soest | Methods for dietary fiber, neutral detergent fiber and nonstarch polysaccharides in relation to animal nutrition[END_REF] were followed to determine NDF, ADF, and ADL (sequentially) on an ash-free basis using the Ankom 200 Fiber Analyzer incubator (Ankom Technology, Fairport, NY). The hemicellulose and cellulose contents of ingredients were calculated as the differences between NDF and ADF, and between ADF and ADL, respectively.

Statistical Analysis

Data were analyzed by repeated measures ANOVA (PROC MIXED, SAS Inst. Inc., Cary, NC), considering the immunity period, the GP to gastrointestinal parasitism, the WPI, and their interactions as fixed effects. This was done for the whole data set (including data from both periods). Second, because of the significant effect of period in the statistical analysis conducted on the entire data set, subsequent analyses were performed on each period separately. For all traits, kid was the experimental unit because they were individually fed and managed, and was included in the model as a random effect. Significance was declared at P ≤ 0.05; comparisons between means were tested by the least squares means procedure with adjustment for multiple comparisons (Tukey-Kramer test; compound symmetry covariance parameter).

RESULTS

The chemical composition of the hay and concentrate for both experimental periods is shown in Table 2. During period II hay quality changed with a greater content of CP and decreased values of cell wall components (NDF, ADF, ADL), which may have influenced feed intake and digestibility compared with period I. Primary infection; considered as acquisition of immunity period (period I) for the naïve kids; 6 wk in length.

However, differences in total DMI between periods were likely to be linked to the progressive natural increase in feed intake capacity with growth (kids were 5.2 kg heavier in period II).

There were significant effects of GP (P = 0.02), WPI (P < 0.001), and period (P < 0.001) for total DMI, whereas no significant interactions between these variables were observed. Greater average DMI were recorded for R kids compared with S kids and during the second WPI in both periods (Tables 3 and4).

There were interactive effects (P < 0.01) between period and WPI for total tract apparent digestibilities. Such differences for OM, CP, NDF, and ADF digestibilities may be checked by comparing values of Tables 3 and4.

The FEC and PCV were also affected (P < 0.001 and P = 0.009, respectively) by the interaction of period × WPI with the FEC being greater from 28 d postinfection (DPI) in period I, whereas the PCV was greater at 7 and 14 DPI in period II (Figures 1 and2). The EOS were greater (P = 0.03) in S kids when compared with R during period II (125 vs. 100 ± 9.0; Figure 3).

Acquisition of Immunity Period (Period I)

Table 3 presents the results from the analysis of period I, after a primary infection of the naïve kids. The DMI were affected by WPI, (P = 0.01) being greater at WPI-2, whereas GP influenced (P = 0.05) DMI with R kids demonstrating less effect on appetite depression compared with S kids. There were no GP effects nor an interaction of GP × WPI for nutrient digestibility, indicating that effects on this variable during period I were more dependent on the evolution of parasite establishment in the gastrointestinal tract (WPI), irrespective of the genetic resistance in individual kids. Except for CP (P = 0.15), all digestibility values were less at WPI-2 than at WPI-0 and WPI-4.

The FEC remained at zero during the first 2 wk of measurement and were greater (P = 0.04) in period I for S vs. R. The PCV decreased with time (P < 0.001) without being affected by GP. The EOS were not affected in period I by GP with the exception of 14 DPI (P < 0.001) on which S kids had greater values (Figure 3). Genetic predisposition (GP) to gastrointestinal nematode resistance: kids indexed by pedigree as resistant (R) or susceptible (S).

Expression of Immunity Period (Period II)

The results from period II are presented in Table 4. There were no differences in the performance of R and S kids for any variable, except for circulating EOS, which were significantly greater (P < 0.001) in S than in R kids.

In contrast to period I, there was no effect of GP, WPI, or their interactions on DMI. The digestibilities of DM, OM, CP (P < 0.001), and ADF differed accord- ing to WPI, consistently decreasing as WPI advanced (WPI-0 > WPI-2 > WPI-4).

In period II, FEC was not affected (P = 0.24) by GP and remained at zero until 14 DPI, afterwards increasing with time in both lines with a lesser slope than period I. There were differences (P = 0.03) between S and R kids in PCV (Figure 2) with S showing greater values. The PCV also decreased (P < 0.001) with time after infection in period II. The EOS were greater (P < 0.03) in S kids and showed a peak between 21 and 28 DPI (Figure 3).

DISCUSSION

Information about the variability in response to gastrointestinal parasitism that could be linked to genetic components is still scarce in goats [START_REF] Hoste | Nutrition-parasite interactions in goats: Is immunoregulation involved in the control of gastrointestinal nematodes?[END_REF]. Including resistance to these pathologies as an objective of genetic improvement schemes for Creole goats has been one of the main research goals for the INRA Animal Research Unit (URZ) team over the last several decades [START_REF] Aumont | Gastrointestinal strongyloses in small ruminants in the French West Indies[END_REF][START_REF] Aumont | Le dénombrement des éléments parasitaires: Un outil pour l'étude de la résistance génétique aux endo-parasites chez les petits ruminants[END_REF][START_REF] Mahieu | Intensive grazing system for small ruminants in the Tropics: The French West Indies experience and perspectives[END_REF]. Thus, the Creole goat is now considered a good model for highlighting mechanisms and genes of resistance to gastrointestinal strongyles in small ruminants.

Our results support findings by [START_REF] Mandonnet | Assessment of genetic variability of resistance to gastrointestinal nematode parasites in Creole goats in the humid tropics[END_REF], who demonstrated the heritability of resistance to strongyles and the feasibility of increasing resistance through a selection program in Creole goats. Such genetic differences related to the immune response characteristics (GP) had significant effects on feed intake and immune effectors after the artificial infection implemented in our study. Thus, the hypothesis that GP influences the magnitude of negative effects of gastrointestinal parasitism, when the kids were categorized as R or S according to their pedigree, was confirmed. However, differences in FEC were only evident after 35 DPI in both periods, being greater at this point in S kids. We think that such differences in FEC only after this point are probably related to the delay for the immune response effects on the worm population. Also, it remains a possibility that an effect on female prolificacy occurs. Thus, a possible modulation of genetic resistance against adult worms rather than against the incoming parasites could be hypothesized. This may also reflect the necessity for a longer monitoring period (>6 wk) in future infection protocols with similar aims, if we want to check effects from the incoming L 3 until the last phases of adult worms.

Possible inconsistency in our findings with the difference between R and S, normally found at 6 to 7 WPI at grazing (selection criteria) in Domaine Gardel, must be carefully interpreted because the different prevailing conditions, which could make the comparison irrelevant. During the selection process, the genetic evaluation is performed on grazing and with 7-mo-old nonnaïve animals that were naturally exposed to HC infection since they began to eat grass. In contrast, in the current study the first challenge was conducted in naïve kids.

In other traits, differences were more evident in period I during which R kids experienced greater DMI and less FEC after 35 DPI. An explanation could be that similar FEC before 35 DPI do not necessarily reflect that animals have similar worm burdens. It is possible that, during the first challenge, R kids limit worm establishment in the abomasum but not the female prolificacy. Thus, a smaller number of worms established in the abomasum may have a smaller effect on intake.

The results of this experiment are in general agreement with our previous findings obtained under natural grazing conditions. [START_REF] Bambou | Characterization of blood immunoglobulin responses to Haemonchus contortus in resistant and susceptible Creole kids naturally infected with gastrointestinal strongyles[END_REF] observed a more intensive immune response against HC in R kids that had greater immunoglobulin response than S at 49 DPI, when FEC were relatively small. Surprisingly, they found that, whereas R presented less FEC than S at 49 and 56 DPI, the FEC were not correlated to the parasite (female) prolificacy at 56 DPI. Furthermore, R harbored 20 times more L 4 than S, and their young/ adult ratio was 15 times greater. Such results may indicate that resistance occurred by controlling worm maturation, but a question still remains on the precise function of immunoglobulin response in this process.

Despite the lack of clarity of such mechanisms for depressing appetite and DMI during infection, [START_REF] Dakkar | Conséquences nutritionelles du parasitisme gastrointestinal chez les ruminants[END_REF] tried to describe other possible factors that could be implicated in the process. Local inflammation and pain in sites of the gastrointestinal tract affected by the infection, changes in absorption sites, and the decrease of availability for absorption of AA, as well as problems of motility in the GIT and of digesta transit may all be correlated to the depression of voluntary feed intake (anorexia) experienced in S kids. A more integrated approach to the occurrence of anorexia in parasitic diseases has been recommended by [START_REF] Kyriazakis | Towards a functional explanation for the occurrence of anorexia during parasitic infections[END_REF]. Its duration perhaps depends on the rate of development of the immunity, which can be from a few days in protozoan infections or up to several weeks in helminthes parasitism. Its extent is independent of the nutrition of the host (i.e., feed quality and quantity), which does not seem to affect the rate of establishment or development of parasites in nonimmune hosts. This is consistent with the approach of our experimental design looking for genetic effects while maintaining a similar level of nutrition. [START_REF] Kyriazakis | Towards a functional explanation for the occurrence of anorexia during parasitic infections[END_REF] also refers to a host-specific, perhaps genetically determined, response to parasitic infections in terms of a reduction in their feed intake that could also be related to a decrease in energetic efficiency. They highlighted the untested but attractive possible role of anorexia to enhance the immune response of the host.

The relatively high level of nutrition applied in our experiment could help to emphasize the relevance of the individual genetic factors in this tropical breed. However, as our kids were advancing in age (from 15 to 17 mo old), an increase in genetic variability of the resistance to HC could be expected, as has been reported after 10 mo of age [START_REF] Mandonnet | Assessment of genetic variability of resistance to gastrointestinal nematode parasites in Creole goats in the humid tropics[END_REF], thus making it more difficult to perceive differences between the experimental groups. Also, a better regulation and development of the mechanisms of resistance is thought to develop with age and repeated contacts with parasites [START_REF] Baker | Genetic resistance to gastrointestinal nematode parasites in Red Maasaı¨ sheep in Kenya[END_REF][START_REF] Baker | Genetic resistance to gastrointestinal nematode parasites in some indigenous breeds of sheep and goats in east Africa[END_REF]. This was demonstrated by [START_REF] Mandonnet | Assessment of genetic variability of resistance to gastrointestinal nematode parasites in Creole goats in the humid tropics[END_REF] with the high genetic correlations obtained between 2 adjacent measurements of FEC or PCV in Creole goats. Inter-and intrabreed differences in the immune responses to gastrointestinal parasitism, and especially with HC infections, have been also demonstrated in several studies with sheep [START_REF] Terefe | Immune response to Haemonchus contortus infection in susceptible (INRA 401) and resistant (Barbados Black Belly) breeds of lambs[END_REF].

The lack of effects on DMI during period II remains unclear. An interpretation could be that S kids had developed immunity, thus diminishing the possible negative effects of parasitism on appetite and intake during period II. However, the fact that a single-challenge protocol was used and that anorexia was reported to last for weeks makes this hypothesis doubtful. Nevertheless, apparent nutrient digestibilities, which were greater than in period I (with the exception of CP digestibility), continued to be influenced by WPI, with the least values being obtained at WPI-2, the phase of establishment of parasites in the digestive tract.

The increase in DMI observed in the second WPI was consistent with the decrease in nutrient digestibility in the same week. We speculate that this may be because it is at this moment that animals start to suffer the strongest negative effects of the establishment of the HC population in the abomasum leading to competition for nutrients between host and parasites that momentarily could enhance feed intake to compensate for the depression in nutrient digestibility. This may have occurred in our experiment, in contrast to the criterion of depression in intake, because of the high level of nutrition used. The peak of such a process is likely to occur around 2 or 3 wk after infection [START_REF] Dakkar | Conséquences nutritionelles du parasitisme gastrointestinal chez les ruminants[END_REF][START_REF] Coop | Nutrition-parasite interaction[END_REF], and the result would depend on the immunity status of the host, leading to a resilient (maintaining productivity while still infected) or an acutely infected animal [START_REF] Kyriazakis | Immunonutrition: Nutritional control of parasites[END_REF].

Because circulating EOS were greater in S than in R kids, our results are in some ways contradictory with the available literature. In a previous study [START_REF] Bambou | Serum antibody responses in Creole kids experimentally infected with Haemonchus contortus[END_REF] we did not observe correlation between EOS and resistance. In the present study, we confirmed this observation. In our model (Creole kids), EOS seems to perform more as a marker of the level of infection rather than a trait associated with resistance. In agreement with this suggestion [START_REF] Wildblood | Production of eosinophil chemoattractant activity by ovine gastrointestinal nematodes[END_REF] demonstrated in vitro that HC produced EOSchemoattractant activity (with identity that remains unknown), challenging the hypothesis that EOS are host-protective effector cells. They raised the possibility that nematodes (i.e., HC, Teladorsagia circumcinc-ta, Ostertagia ostertagi, or Trichostrongylus) actively encourage recruitment of EOS. The magnitude of the chemotactic response was also directly related to larval numbers. Such results provide evidence that pathogenic gastrointestinal nematodes produce factor(s) that directly influence EOS migration. This may be important for in vivo pathogenesis and could provide novel targets for future control strategies. The chemoattractant activity could derive either from constitutively expressed worm products or indirectly through interactions with other cell types present in the mixed bone marrow cell populations. Thus, the precise nature of the interaction between parasite and EOS remains an enigma that will require new research efforts.

It was also noticeable that CP digestibility did not differ between GP or among WPI during period I. According to [START_REF] Dakkar | Conséquences nutritionelles du parasitisme gastrointestinal chez les ruminants[END_REF], parasitism of the abomasum (i.e., with HC) reduces rumen fermentation by almost 30% and generates an important depression in OM digestibility and CP digestibility, more so than intestinal parasitism, the maximum intensity being around 2 to 3 wk after infection, as in our study. In contrast, the infestation site did not seem to influence DM, energy, and sugar digestibilities. Nutrient absorption problems are difficult to identify due to the relevant capacity of intestines in ruminants to compensate for losses at the site of infection by increasing nutrient absorption in distal sites. The effects are influenced by the level of CP in the diet; at greater CP concentrations, less negative effects of parasitism on DMI are expected. A suitable level of CP in the diet could help to avoid negative effects on DMI, so it would be interesting to replicate the study but offering different levels of CP. The different trend observed for the digestibility of CP is likely to be influenced by the already known modifications of nitrogen metabolism in infected animals. The CP is the most critical nutrient because many components of the immune system, such as immunoglobulins and mucoproteins, and cellular products, such as leukotrienes, are proteinaceous in nature; they would be expected to use protein resources, especially in quantitative terms [START_REF] Coop | Nutrition-parasite interaction[END_REF]. In HC infections these losses can represent as much as 10% of the circulating blood volume per day.

Dietary CP and the increase in the catabolism of proteins from muscles, bone medulla, wool, and skin, to satisfy the increase in the metabolic demands, are expected to be used to replace cells in the epithelium and to produce a large quantity of mucus at the infection site, leading to increases in endogenous N losses into the gut (apparent absorption of CP can fall to 25% in sheep; [START_REF] Dakkar | Conséquences nutritionelles du parasitisme gastrointestinal chez les ruminants[END_REF]. The amount of nonreabsorbed endogenous N may be considerable and a proportion will be excreted in feces, but the majority will be fermented in the hind-gut and absorbed as ammonia or just excreted as urea, and will not be available for metabolic processes. Such reduction in absorption in addition to the endogenous losses results an increase in CP proportion in the digestive contents and in the

Figure 1 .

 1 Figure 1. Weekly evolution of fecal egg counts (FEC) in resistant (R) and susceptible (S) Creole kids after 2 single experimental infections with 10,000 infective Haemonchus contortus larvae. Period I = first challenge, corresponding to the acquisition of immunity stage; period II = second challenge, corresponding to the expression of immunity stage. Periods differed at P < 0.001. GP = genetic predisposition to gastrointestinal parasitism; DPI = days postinfection. Error bars represent the SE at each point for R or S kids.

Figure 2 .

 2 Figure 2. Weekly evolution of pack cell volumes (PCV) in resistant (R) and susceptible (S) Creole kids after 2 single experimental infections with 10,000 infective Haemonchus contortus larvae. Period I = first challenge, corresponding to the acquisition of immunity stage; period II = second challenge, corresponding to the expression of immunity stage. Periods differed at P < 0.001. GP = genetic predisposition to gastrointestinal parasitism; DPI = days postinfection. Error bars represent the SE at each point for R or S kids.

Figure 3 .

 3 Figure 3. Weekly evolution of eosinophils (EOS) in resistant (R) and susceptible (S) Creole kids after 2 single experimental infections with 10,000 infective Haemonchus contortus larvae. Period I = first challenge, corresponding to the acquisition of immunity stage; period II = second challenge, corresponding to the expression of immunity stage. Periods did not differ, P = 0.42. GP = genetic predisposition to gastrointestinal parasitism; DPI = days postinfection. Error bars represent the SE at each point for R or S kids.

Table 1 .

 1 Genetic resistance indexes of the kids selected for the experiment and classified as resistant (n = 11) or susceptible (n = 11) to gastrointestinal parasitism according to their breeding value

		Breeding value for
	Animal classification	[log (FEC, eggs/g + 15)] 1
	Susceptible	0.156
	Resistant	-0.286
	SEM	0.08
	P-value 2	<0.0001
	Distance between susceptible and resistant, genetic SD	2.99

Table 2 .

 2 Average determined chemical composition (DM basis) of diet components Dichantium spp. grass, with forage grown with irrigation and inorganic fertilization.

				Hay 1
			Period I 3		Period II 4
	Item, %	WPI-0 5	WPI-2 6	WPI-4 7	WPI-0	WPI-2	WPI-4	Concentrate 2
	DM	92.7	92.3	91.2	90.2	90.5	90.4	93.4
	OM	93.7	93.7	93.0	95.8	94.5	95.3	97.0
	CP	4.4	5.3	5.5	8.1	8.3	8.1	16.5
	NDF	76.5	76.3	79.2	72.1	73.6	73.8	17.6
	ADF	45.6	41.8	44.3	37.7	37.5	38.8	4.8
	ADL	7.0	5.3	7.0	5.1	4.5	4.7	0.7
	Hemicellulose	30.9	34.5	34.8	34.4	36.1	35.0	-
	Cellulose	38.6	36.5	37.3	32.6	33.0	34.1	-
	1 Hay of 75-d-old 2 Offered daily in a fixed individual amount (100 g/d) as supplement.

3

Table 3 .

 3 Least squares means of DMI, apparent total tract digestibility, and BW of Creole kids during the acquisition of immunity period (period I) after a primary oral infection with a single dose of 10,000 third-larvae stage (L 3 ) Haemonchus contortus

		WPI-0 1	WPI-2 2	WPI-4 3			P-value
	Item	R 4	S 4	R	S	R	S	SEM	WPI	GP 4	GP × WPI
	DMI, g/d	579	552	671	617	628	581	26.0	0.01	0.05	0.87
	Digestibility, g/kg of DM
	DM	630	620	600	610	621	630	9.8	0.03	0.62	0.71
	OM	649	645	620	627	638	646	9.5	0.04	0.61	0.79
	CP	582	577	542	573	578	580	12.5	0.15	0.34	0.31
	NDF	547	519	504	500	559	565	9.9	<0.001	0.33	0.22
	ADF	535	520	456	440	520	529	12.0	<0.001	0.46	0.52
	BW, kg	24.3	23.4	25.9	24.1	24.3	23.4	0.76	0.46	0.19	0.87
	1 Week postinfection (WPI) number 0: beginning week immediately after experimental challenge with 10,000 infective H. contortus larvae.
	2 WPI 2: second week after experimental challenge with 10,000 infective H. contortus larvae.
	3 WPI 4: fourth week after experimental challenge with 10,000 infective H. contortus larvae.
	4 Genetic predisposition (GP) to gastrointestinal nematode resistance: kids indexed by pedigree as resistant (R) or susceptible (S).

Table 4 .

 4 Least squares means of DMI, apparent total tract digestibility, and BW of Creole kids during the expression of immunity period (period II) after a secondary oral infection with a single dose of 10,000 third-larvae stage (L 3 ) Haemonchus contortus

		WPI-0 1	WPI-2 2	WPI-4 3			P-value
	Item	R 4	S 4	R	S	R	S	SEM	WPI	GP 4	GP × WPI
	DMI, g/d	666	659	767	718	742	676	33.7	0.07	0.15	0.67
	Digestibility, g/kg of DM
	DM	701	701	662	682	657	660	7.5	<0.001	0.23	0.37
	OM	707	707	673	693	664	669	7.9	<0.001	0.21	0.41
	CP	578	573	514	557	508	513	11.1	<0.001	0.13	0.10
	NDF	687	689	661	676	663	660	11.4	0.07	0.65	0.72
	ADF	698	700	663	685	669	674	10.5	0.02	0.26	0.61
	BW, kg	29.3	28.7	31.4	31.0	32.7	31.7	0.78	0.02	0.47	0.98

1

Week postinfection (WPI) number 0: beginning week immediately after experimental challenge with 10,000 infective H. contortus larvae.

2 WPI 2: second week after experimental challenge with 10,000 infective H. contortus larvae.

3 WPI 4: fourth week after experimental challenge with 10,000 infective H. contortus larvae. 4

at INRA Institut National de la Recherche Agronomique on August 16, 2013 www.journalofanimalscience.org Downloaded from

FEC = fecal egg count. Breeding value based on individual, ascendants, and pedigree historical performance. The breeding value for FEC of the Creole goat flock in Guadeloupe has been estimated since 1979 at Institut National de la Recherche Agronomique, Domaine Gardel, under natural mixed infection under grazing conditions.

2Kruskal-Wallis test.Intake and digestibility in parasitized kids

Secondary infection; considered as expression of immunity period (period II); 6 wk in length.

Week postinfection number 0: beginning week immediately after experimental challenge with 10,000 infective Haemonchus contortus larvae.

6Second week after experimental challenge with 10,000 infective H. contortus larvae

.7 Fourth week after experimental challenge with 10,000 infective H. contortus larvae.Bambou et al.

Plateform Tropical de Experimentation Animal, INRA-Domaine Duclos, for their technical support. This study was financed by La Région Guadeloupe.