Broiler Breeder Diet Enriched in Omega-3 Fatty Acids Programs Chicks for Reduced Fatness

Maternal consumption of n-3 long chain polyunsaturated fatty acids (n-3 LCPUFA) in mammals has been associated with reduced adiposity in offspring, suggesting the ability to developmentally program adipose deposition with dietary lipids. We hypothesized that enriching developing adipose tissue in n-3 LCPUFA would reduce fatness in young broiler chicks. Cobb500 broiler breeders were fed diets containing either 5% fish oil (FO) or corn oil (CO) for four weeks, after which fertilized eggs were collected and hatched. After hatch, all chicks were fed CO-based diet until 7 or 14 days of age. Phospholipid species in brain, breast, and liver at hatch were significantly enriched in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) relative to CO-chicks, with reductions in n-6 LCPUFA (e.g., arachidonic acid) (p<0.05). Hen fat source did not compromise lean growth. However, FO exposure during development reduced adiposity (fat pad wt/body wt) in abdominal and subcutaneous depots at both ages (p<0.05). Despite all post-hatch lipids being derived from corn oil, adipose tissue of FO-chicks was significantly enriched in EPA, DHA, and their metabolites (p<0.05) at 7 and 14 days of age. Hen FO consumption impacted adipogenesis, significantly increasing numbers of small adipocytes associated with efficient glucose metabolism, while attenuating numbers of large adipocytes. Genes controlling adipocyte differentiation (peroxisome proliferator-activated receptor-γ) and mitochondrial biogenesis (PPARγ coactivator 1B) were upregulated by FO, while those controlling hypertrophy (e.g., lipoprotein lipase) were significantly down-regulated. Manipulating the diet of hen therefore is a potential strategy to program reduced fat deposition while maintaining performance in broilers.

Keywords: Dietary enrichment, PUFA, adipose