Deterministic simulations to determine the impacts of economic and non-economic breeding objectives on sustainable intensification of developing smallholder dairy farms

Abstract

Dairy cattle farming in developing countries is mainly by resource poor smallholder farmers. Intensification of production within smallholder production systems is being driven by increasing demand for animal products. Current intensification is driven by importation of high-input high-output genotypes. This puts in question the sustainability of these resource constrained systems under harsh environmental conditions. Sustainability of production systems can be defined as long-term resilience and productivity. We use deterministic simulations to compare the impacts of three criteria to define breeding objectives i.e., economic, desired gains and non-market value, on annual genetic and monetary gains in production (market) and functional (non-market) traits for a small-sized nucleus genomic selection breeding program under developing country conditions. Market traits considered were milk yield (MY) and mature body weight (MBW). Non-market traits were calving interval (CI) and production lifetime (PLT). Fat yield (FY) was also considered a non-market trait as it had no market value. With the economic objective, traits were weighted on economic values. Weights for desired gains and non-market (NM) values were derived iteratively. Economic objectives placed highest emphasis on MY with very little gains in non-market traits but had the highest returns on investment. For desired gains objective, maximal achievable gains in PLT, CI and FY were lower than the indicated desired gains. The non-market value objective achieved the best compromise between gains in MY and other traits. We conclude that non-market value objectives can be applied to direct selection towards more robust genotypes but with loss in monetary gain. Breeding robust genotypes can contribute to sustainable intensification in developing small-holder dairy systems. However, for such objectives to be satisfactory, a sound criterion is required to determine declines in genetic gains for market traits that are acceptable by producers.