Soil Pollution, Animal Contamination and Safe Food Production: The Case of the French West Indies

Abstract

This article presents a new model to manage the provision of healthy food despite incomplete information about exposure of natural resources to a persistent pollutant (chlordecone). This toxic molecule has contaminated both terrestrial and aquatic resources for several decades in the French West Indies. As a consequence, the threat of exposing humans to contaminated food jeopardises local agricultural and livestock activities. We address the problem that breeders face: producing healthy food with incomplete information on the animals’ contamination. We examine the compatibility of respecting health-production constraints with the timing of animal management. We consider the dual set of constraints that breeders face: (i) they must achieve a target contamination rate that complies with the regulation on the maximum residue limits (MRL), and (ii) they must comply with a production calendar that tells them at what age the animals are to be sold. We also discuss the economic and biotechnical consequences that changes in the MRL impose on meat production. We compute the time required to decontaminate the animals and analyse the cost for farmers to adapt to (i) the regulation in place and to (ii) the more stringent health-related targets that are expected in the future. Our results are sensitive to the choice of species (cattle, goats, sheep and pigs), the rearing practices, the information setting and the initial contamination rate. This paper opens strategic windows for breeders to guarantee their economic sustainability and their ability to produce healthy meat despite the incomplete information on pollution at their disposal.

Appendix. Rearing Costs and Benefits

Few data exist on breeding practices in Guadeloupe. [26] usually produces monographs on the functioning of livestock systems based on a small number of cases. Since the data produced by [26], the work of [21] is the most comprehensive work with a qualitative survey based on 37 livestock farmers. In this appendix, we provide further details on rearing costs and benefits that are integrated in the economic calculation (see Table 4).

1.1 Cattle

Rearing practices implies both fixed costs and variable costs. In this section, we list all the costs that intervene in the rearing of an animal (a male cow).

The fixed rearing costs for cattle include the purchase price, various fees (subscriptions) and animal’s identification tags.

• Purchase price: The cost of buying a male cow at 8 months of age is expressed in EUR/animal. The price depends on its weight. The average weight of a male cow after weaning (at 8 months of age) is 175 kg [23]. The average price per cow equals 910 EUR/animal.

• EDE contribution (in French, subscription to the Établissement de l’Élevage): The EDE is a development institute in charge of the identification and the traceability of animals. The subscription cost equals 8 EUR per animal to be paid once a year (on the month in which the animal is bought and every 12 months thereafter).

• GDS contribution (subscription to the Groupement de Défense Sanitaire - GDS): The GDS is a development institute that advises breeders on the animal’s health status. The subscription cost equals 3 EUR to be paid once a year (1 month after the animal is bought and then every 12 months).

• Animal’s identification tags: The cost of these tags amounts to 9 EUR and is paid once, 2 months after the animal is bought.

All the fixed costs noted above apply to all animals, regardless of whether they graze or they are kept in stalls. These costs amount to 930 EUR within the first year and 11 EUR for each subsequent year.

1.1.1 Fixed Decontamination Costs

• Animals’ enclosure: The breeder bears specific costs such as electric fences. They are equal to 608.21 EUR. One such structure lasts at least 10 years, which means that several cows may benefit from the same structure, although not at the same time. For each animal, the stabling cost is at most equal to 60.82 EUR. We attribute one tenth of the total cost to each animal.

If an animal is decontaminated in a stall, additional costs are paid. In practice, since the production units are small, farmers design rudimentary stalls with recovery material whose costs are not evaluated.

Two types of costs are distinguished: the monthly rearing cost and the additional monthly decontamination costs.

1.1.2 Variable Costs (per Month)

These cover all the basics (i.e. fodder, feed concentrate, veterinary costs). It amounts to 14.58 EUR per month. When the animal is undergoing the decontamination phase in a stall, food must be bought. Two supplementary costs are considered in this case: the cost of fodder and the cost of feed concentrate.

• Cost of fodder: An animal placed in a stall eats 2 kg of fodder per day. A 240 kg fodder bale costs 80 EUR (i.e. 0.33 EUR $\cdot$ kg^-1). For an average month (30.5 days), this represents 20.3 EUR per animal and month.

• Cost of feed concentrate: The average animal needs 0.6 kg of concentrate per day (i.e. 18.3 kg per month). A bag of animal concentrate (25 kg) costs 13.2 EUR. The cost of feed concentrate amounts to 9.7 EUR per month.

The variable rearing costs are thus 14.58 EUR per month when the animal is not undergoing decontamination and 44.58 EUR per month (14.58+20.3+9.7) when the animal is undergoing decontamination.

1.1.3 Financial Inputs

The technical-economic schedule also includes financial inputs for the breeder. These are the turnover, the slaughter premium, a marketing premium, a transport premium and European financial help (Programme of Options Specifically Relating to Remoteness and Insularity - POSEI).

• The turnover is computed as the product between the weight (measured in kg of carcass) and the price (measured in EUR/kg). The average carcass weight of a male cow after 22 months of fattening is 500 kg. The average sale price of male cows is estimated at 5.2 EUR $\cdot$ kg^-1 of carcass.

• Slaughter premium: 210 EUR/animal.

• Marketing premium: 300 EUR/animal.

• Transport premium: 40 EUR/animal.

• POSEI: 0.55 EUR $\cdot$ kg^-1 of carcass.

Following the same structure of decomposition of cost and benefits, the subsequent appendixes inform about the other animal species.

1.2 Sheep

• Purchase price: The cost of buying a male sheep at 2.5 months of age is expressed in EUR/animal. The price depends on the weight of the animal. The average weight of a male sheep after weaning (at 2.5 months of age) is 13.7 kg [26]. The average price per sheep equals 4.8 EUR $\cdot$ kg^-1 that corresponds to 66 EUR/animal.

• EDE contribution: The subscription equals 8 EUR per animal and year. This cost is paid once a year, on the month in which the animal is bought and every 12 months thereafter.

• GDS contribution: This subscription amounts to 3 EUR/year. To be paid once a year, 1 month after the animal is bought and once every 12 months.

• Animal’s identification tags: This cost equals 9 EUR to be paid once, 2 months after the animal is bought.

All the fixed costs above apply to all animals. They amount to 123.76 EUR within the first year and 11 EUR for each subsequent year.

1.2.1 Fixed Decontamination Costs

• Animals’ enclosure: The breeder supports specific costs (e.g. stall). They are equal to 50 EUR/animal. One such structure lasts at least 5 years, which means that several animals may profit from the same structure.

If an animal is decontaminated in a stall, additional costs are paid. We distinguish two types of costs: the monthly rearing cost and the monthly decontamination costs.

1.2.2 Variable Costs (per Month)

These cover all the basics (i.e. fodder, feed concentrate, veterinary costs). It amounts to 15.74 EUR per month.

When the animal is undergoing the decontamination phase in a stall, its food is bought. This adds cost of fodder and cost of feed concentrate.

• Cost of fodder: An animal placed in a stall eats 2.5 kg of fodder per day. A 240-kg fodder bale costs 80 EUR (i.e. 0.33 EUR $\cdot$ kg^-1). For an average month (30.5 days), this represents 10.17 EUR per animal.

• Cost of feed concentrate: After weaning, the average animal needs 0.1 kg of concentrate per day during 3 months. After this period, the animal is fattened during 3.5 months and eats concentrate and fodder at the rate of 0.3 kg of concentrate per day and 2.5 kg of fodder per day.

The variable rearing costs are thus 9.09 EUR/month when the animal is not undergoing decontamination and 15.74 EUR/month when the animal is undergoing decontamination.

1.2.3 Financial Inputs

• The turnover is computed as the product between the weight (measured in kg of carcass) and the price (measured in EUR/kg). The average weight gain for animals kept in stalls is estimated at a level of 188 g/day. The average weight at the end of fattening is 33 kg. The average carcass weighs 14.6 kg. Fattening sheep are sold at the age of 9 months.

The average sale price is estimated at 9.6 EUR $\cdot$ kg^-1 of carcass according to the data provided by the Réseau de références.

Contrary to breeders that rear cows, there is no other premium except:

• POSEI at a rate of 9 EUR $\cdot$ kg^-1 of carcass.

1.3 Goats

• Purchase price: The cost of buying a male goat at 2.5 to 3 months of age is expressed in EUR/animal. The price depends on the weight of the animal. The average weight of a male goat after weaning, at 2.5 months of age, is 7.87 kg [26]. The average price per goat equals 4.8 EUR $\cdot$ kg^-1 that corresponds to 55.09 EUR/animal.

The following costs are strictly identical for goats and sheep (refer to Appendix on sheep for detailed figures): EDE contribution, GDS contribution, animal’s identification tags and animals’ enclosure.

All the fixed costs above apply to every animal. They amount to 113.09 EUR within the first year and 11 EUR for each subsequent year.

If an animal is decontaminated in a stall, additional costs are to be paid. We distinguish two types of costs: the monthly rearing cost and the monthly decontamination costs.

1.3.1 Variable Costs (per Month)

These cover all the basics (i.e. fodder, feed concentrate, veterinary costs). They amount to 2.64 EUR per month.

When the animal is undergoing the decontamination phase in a stall, fodder and feed concentrate must be bought.

• Cost of fodder: An animal placed in a stall eats 2.5 kg of fodder per day. A 240-kg fodder bale costs 80 EUR (i.e. 0.33 EUR $\cdot$ kg^-1). For an average month (30.5 days), this represents 10.17 EUR per animal.

• Cost of feed concentrate: After weaning, the average animal needs 0.1 kg of concentrate per day during 3 months. After this period, the animal is being fattened for 3 months and eats concentrate and fodder at the rate of 0.2 kg of concentrate/day and 2.5 kg of fodder/day.

Once they are 6 months old, goats are supplemented with concentrate and fodder at a rate of 0.3 kg of concentrate/day and 2.5 kg of fodder/day.

The variable rearing costs are thus 5 EUR/month when the animal is not undergoing decontamination and 7.51 EUR/month when the animal is undergoing decontamination.

1.3.2 Financial Inputs

• The turnover is computed as the product between the weight (measured in kg of carcass) and the price (measured in EUR/kg). The average weight gain for animals kept in stalls is estimated at 84 g/day. The average weight at the end of fattening is 23 kg, for an average carcass weight estimated at 10.5 kg. Fattening goats are sold at the age of 12 months.

The average selling price is estimated at 12.1 EUR $\cdot$ kg^-1 of carcass.

The other financial inputs are strictly identical for goats and sheep: POSEI at a rate of 9 EUR $\cdot$ kg^-1 of carcass.

1.4 Pigs

Considering that pigs are not viable from a health-related viewpoint, economic computation is not worthwhile. That is the reason why no further details are provided for this species.