CONTROLLING OVARIAN FOLLICULAR RECRUITMENT TO IMPROVE BROILER BREEDER REPRODUCTION EFFICIENCY

The US Poultry industry produced 53 billion pounds of broiler meat in the year 2015 valued at $28.7 billion by rearing 9.0 billion broiler chickens (http://usda.mannlib.cornell.edu/usda/current/PoulProdVa/PoulProdVa-04-28-2016.pdf). The commercial broiler chickens are hatched from eggs laid by broiler breeder hens that are among the poorest in reproductive efficiency of any commercial avian species. The broiler breeder chickens are genetically selected for faster growth, higher feed intake, and muscle yield. Consequently, the breeder chickens eat voraciously leading to aberrant follicular recruitment in the ovary and low egg production efficiency. A lack of thorough understanding of ovarian dysfunction encountered in broiler breeder hens remains as a critical gap in our knowledge in our efforts to improve egg production. The rationale for conducting the proposed experiments is that it will advance our understanding of the cellular and molecular mechanisms in the ovary that are likely to be involved in aberrant follicular recruitment. The overall hypothesis is that activation of adenosine monophosphate-activated protein kinase and extracellular signal-regulated kinase pathways in the broiler breeder ovary will prevent aberrant follicular recruitment and increase both egg production (without affecting fertility or hatchability), and meat yield in broiler progenies. The objectives of the proposed research are 1) to determine the endocrine and molecular mechanisms by which metformin affects ovarian follicular recruitment, steroidogenesis, and metabolism, 2) to determine the extent to which dietary supplementation of an anti-diabetic drug affects egg production in broiler breeder hens, and 3) to determine the extent to which dietary supplementation of an anti-diabetic drug affects fertility and hatchability in broiler breeder hens and meat yield in their broiler progenies. We expect to elucidate the molecular mechanisms underlying ovarian follicular recruitment and thus providing specific targets for selecting future generations of broiler breeder hens with superior egg production efficiency.