Environmental impacts of different innovative feeding strategies in pig and broiler farms

Visuels d'intervention de Sandrine Espagnol et al., 68th Annual Meeting of the European Federation of Animal Science, Tallinn, Estonie, 28 août-01 septembre 2017, Session 11 : LFS efficiency : indicators and scales

Optimization of feeding strategies (S) is an effective option to reduce the environmental impacts of livestock. It can be performed, by using multi-objective feed formulation (MOF) to select feedstuffs according to their price and environmental impacts, and by adapting dietary composition to animal requirements during the rearing period. This study investigates the combination of those feeding strategies on the environmental impacts of pig (P) and broiler (B) productions. Different S for conventional farms were specified in B and for fattening period in P. In P, the S were: 2-phases feeding (S1); multiphase feeding with two (S2) or four (S3) pre-diets, mixed together in different proportions during time; and 2-phases feeding with a reduction of energy (S4) or amino acid (S5) content. In B, the S were: 3-phases feeding (S6) and 3-phases feeding with lysine and energy contents respectively increased and decreased (S7). For each S, feeds were formulated using least-cost optimization (LC) and MOF. The environmental impacts of the kg of BW at farm gate were assessed by Life Cycle Assessment and compared to the reference scenarios: LC-S1 and LC-S6 for P and B, respectively. S with LC formulation showed impacts between -19% and +13% compared to the reference impacts. MOF reduced impacts per kg of feed by up to 30%, and final impacts per kg of BW by 1 to 20%, except for Acidification and Climate Change (S4), and for Land Occupation (S7). Three criteria explain these contrasted results among S and LCA impacts at the kg of BW scale. The first one is the contribution of feed to impacts per kg of BW (34% to 98%). The second one is feed conversion ratio as it reflects the overall efficiency of the system, and thus impacts nutrient excretion and manure gas emission. The last one is nutritional balance of feed (protein, amino acids composition), explaining nitrogen excretion (S2, S3). This study underlines the need for optimizing S while considering simultaneously the consequences on economics and environmental performances at animal scale.