Effect of four levels of added fat on broiler breeder performance.

Broiler breeders were fed corn-soybean diets and reared under 8 h of incandescent light. Birds were photostimulated with a mixture of incandescent light and daylight at 20 wk of age. Corn-soybean breeder diets with 0, 2, 4, and 6% added poultry fat were fed from 24 to 64 wk of age. Daily feed allocations were adjusted to provide comparable calculated protein intake at peak egg production; calculated ME intake was 413, 437, 461, and 484 kcal per bird per day for the 0, 2, 4, and 6% added fat diets, respectively. Feed was gradually reduced such that ME intake reached 400, 415, 429, and 422 kcal ME per bird per day from 57 to 64 wk of age for the respective diets. When compared with 0%, all levels of added fat significantly increased egg production and feed conversion. Fertility was increased significantly with the 4% added fat when compared with fertility at 2%; fertility with 0 or 6% added fat was intermediate. Female body weight increased in a dose-related manner in response to added fat. Chicks per hen was maximized at 4% added fat. Taken together, the data are interpreted to mean that 4% added fat is near the optimum for broiler breeders.