Submitted to: British Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/15/2004
Publication Date: 4/25/2005
Citation: Kidd, M.T., Mcdaniel, C.D., Peebles, E.D., Barber, S.J., Corzo, A., Branton, S.L., Woodworth, J.C. 2005. Breeder hen dietary l-carnitine affects progeny carcase trait. British Poultry Science. 46:97-103. Interpretive Summary: Carnitine is a nutritionally essential compound that is necessary for the movement of fats in poultry. While carnitine has been shown to improve the hatching rate of eggs when it is fortified to the diets of commercial layers, its impact on the carcass characteristics of chicks hatched from eggs laid by those hens is unknown. This study was conducted with commercial broiler breeders fed carnitine fortified diets to assess the impact on chick growth and carcass traits including body weight, carcass fat and breast meat. The research demonstrated that hen diets fortified with carnitine can impact some carcass traits of their chicks: specifically males had more relative fat and breast meat when their parents received added carnitine; however, the effects of carnitine were not observed in chicks until the parent hens had received the test diets for 16 weeks and therefore research to further evaluate chick carcass traits with higher levels (above 25 mg/kg of diet) of carnitine in hen diets and in older broiler breeders is warranted.
Technical Abstract: Ross 308 broiler breeder hens were fed 0 to 25 mg L-carnitine/kg of diet (eight replications each) from 21 wk of age and onward. Hens were inseminated with semen from Ross broiler breeder males and subsequent progeny growth performance and carcass traits, obtained from hatches on 30, 35, and 37 wk of age, were evaluated. Progeny were hatched in a common facility and separated by gender. Experimental treatments employed for the 30, 35, and 37 wk hatches, respectively, were: hen diet and progeny gender (16 replications with two subplots); hen diet, progeny diet (0 and 50 mg L-carnitine/kg of diet), and progeny gender (16 replications with four subplots; and hen diet and progeny diet (high and low density; 16 replications with two subplots). Females had less growth and breast meat, but more relative carcass fat and breast meat than males. Growth performance measurements of progeny were not impacted by hen carnitine, but hen carnitine decreased abdominal fat in progeny. Increasing diet density in the chick diets increased growth and carcass weights. Hen and progeny dietary carnitine interacted to increase male mortality. However, dietary hen carnitine decreased carcass fat and increased breast meat in progeny fed high nutrient dense diets. In conclusion, dietary carnitine impacted carcass traits of progeny.