Emmanuel and Benoît Bretaudeau are breeders in Torfou, in Maine-et-Loire. In Gaec on 72 ha, the two brothers raise 610 Alpine goats and produce 500,000 liters of milk per year. A suckling herd of 30 Charolais mothers completes the activity. Overall, “the farm stores 0.7 tonnes of CO2 equivalent/ha of UAA. But it also emits greenhouse gases (GHG): 14.5 tonnes of CO2 equivalent/ha” explains Emmanuel. In detail, these GHGs are 63% methane from animals and excrement, 17% nitrous oxide from excrement, crops, meadows and fertilization and 20% CO2 linked to manufacturing. and transport of inputs.
All of this data is extracted from Cap'2ER (1). From this diagnosis carried out in 2023, “we worked on technical adjustments. The idea is to activate levers to reduce CO2 emissions without destabilizing the system in place.” On a farm, the quantity of GHGs emitted directly depends on the number of animals present. Benoît and Emmanuel therefore sought to reduce it while maintaining the level of production.
Increase production per animal
Concerning the goats' diet, consideration focused on nitrogen intake. Livestock is on a “corn silage” ration. In addition, the goats receive alfalfa hay: 350 gr/day/animal in 2023. “The disadvantage of hay is that the goats sort it and leave the long strands behind.” At the end of Cap'2ER, it was therefore decided to replace it with alfalfa caps from this winter. “Better valued, the ration should make it possible to increase production per goat.” To maintain good rumination, breeders have opted for a partially dehydrated commercial product. It contains strands of 10 to 15 cm in length.
Reform management is another lever to reduce the number of females. On the farm, goats have an average of five lactations. The average age at first birth is one year. The culling rate barely reaches 20% while Benoît and Emmanuel bring 25% of kids into the herd each year. “We tend to let it get old and could reform more.” The breeders calculated that by removing 10% of the least productive goats, they would have to increase the production of the others by 50 liters/year to maintain the 500,000 liters per year. The objective is to go from an average of 860 kg to a minimum of 900 kg/goat/year. “Quantitatively, it’s playable but we have to pay attention to the rates.” With a TB of 41.7, a TP of 35 and 950,000 cells/ml on average, Bretaudeau breeding is now well placed. To maintain this level, genetics has its role to play. For natural control, the farm buys three or four young goats each year. They are reserved before their birth to be put with the doelings in August.
Anne Mabire
(1) Automated calculation of environmental performance for responsible operations.
