Submitted to: Poultry Science Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 8, 2005
Publication Date: January 1, 2006
Citation: Chen, S.E., McMurtry, J.P., Walzem, R.L. 2006. Overfeeding-induced ovarian dysfunction in broiler breeder hens is associated with lipotoxicity. Poultry Science. 85.70-81. Interpretive Summary: Genetic selection for rapid growth in modern broiler strains is collaterally associated with specific undesirable traits, including skeletal deformities and metabolic diseases such as ascites, fatty liver and kidney syndrome. In females, the capacity for rapid early growth coupled with free access to feed leads to enhanced adult fatness and poor reproductive performance. These undesirable outcomes appear to arise from increases in feed intake that occurred concomitantly with genetic selection for rapid early growth. In adulthood, persistence of the trait of increased voluntary feed intake results in actual food intakes in excess of the requirement for optimal adult health and performance. These genetic traits impact adult animal health and as a result, nutritional management plays a large role in adult broiler breeder performance. Restriction of feed intake to approximately 50 to 60% of ad libitum feeding is an effective and practical management technique to reduce metabolic disease and improve egg production in broiler breeder hens. Leptin is the best understood of the adipose tissue hormones. Impaired leptin signaling is known to cause increased feed intake, massive obesity, and reproductive failure in mammals. This study was done to test whether lipotoxicity could drive the altered hormonal signals and metabolic homeostasis leading to ovarian dysfunction and reduced egg production in feed satiated broiler breeder hens. The results in the present study strongly indicate that unregulated feed intake and genetic divergence converge to influence reproductive function of broiler breeder hens. These effects appear to be mediated through lipopenic dysregulations and lipotoxic mechanisms. The genetic divergence in the sensitivity of ovarian function in response to feed intake suggests a potential for further improvement in current broiler strains. The results of this study will be of interest to other scientists.