|Coon, Craig -|
Submitted to: Journal of Applied Poultry Research
Publication Type: Review Article
Publication Acceptance Date: February 19, 2010
Publication Date: June 1, 2010
Citation: Richards, M.P., Rosebrough, R.W., Coon, C.N., Mcmurtry, J.P. 2010. Feed intake regulation for the female broiler breeder: In theory and in practice. Journal of Applied Poultry Research. 19(2):182-193. Interpretive Summary: Commercial poultry breeders and producers continually work to improve the efficiency and profitability of meat production. To meet these goals, poultry breeders have placed a major emphasis on the selection of new broiler chicken strains that grow faster and produce more meat than previous generations. Unfortunately, improvements in such economically important traits have been accompanied by some unintended changes in feed intake and body composition. Modern commercial lines of broiler chickens now tend to over-eat because they cannot adequately self-regulate the amount of feed consumed to match their nutritional requirements. Proper feed allocation is especially critical for successfully raising the adult bird or broiler breeder which is responsible for producing the next generation of broiler chickens. Unregulated feeding of these birds leads to excessive accumulation of fat and a variety of health-related problems due to the progressive development of obesity in the adult bird. Thus, the amount of feed provided must be strictly controlled throughout the entire lifecycle to ensure efficient egg and chick production by the female broiler breeder hen. In order to mitigate or eliminate the need for feed restriction, it is important to first understand the underlying mechanisms that regulate feed intake and energy balance in poultry. This manuscript discusses what we currently know about the regulation of feed intake, energy balance, and body weight in poultry and some of the physiological consequences arising from different feed restriction regimens commonly employed in the management of commercial broiler breeders. A better understanding of the genes associated with controlling appetite and energy balance and how their expression is regulated by nutritional and hormonal stimuli will offer new insights into current poultry breeding and management practices. This information is intended for use by researchers studying the control of appetite and body weight in avian species, as well as, poultry producers in formulating new genetic selection and feeding strategies for commercial poultry flocks.
Technical Abstract: The modern commercial broiler is the product of intensive genetic selection for rapid and efficient growth. An unintended consequence of this selective breeding has been the loss of the ability for self-regulation of feed intake to closely match the requirements for maintenance, growth and reproduction. Thus, the broiler tends to over consume feed resulting in a range of metabolic and health problems related to the development of obesity. These problems progress with age and become a significant impediment to the production of parent stock. To manage this situation, broiler breeder birds must be subjected to severe feed restriction, beginning early in life, to assure that appropriate body weight and composition are achieved at critical phases of the production cycle. This review focuses on the female broiler breeder since this bird requires the most intensive management with respect to feed allocation throughout production to attain targeted body weights that ensure good livability and efficient egg and chick production. Background information is provided on the cellular and molecular mechanisms that regulate feed intake and energy expenditure in poultry. Also, several examples are discussed with regard to the endocrine and metabolic consequences of different feeding regimens commonly used in the management of the female breeder during rearing and egg laying phases of production.