Effect of dietary protein intake during the pullet-to-breeder transition period on early egg weight and production in broiler breeders

Abstract

The effects of CP intake on broiler breeder hen performance were evaluated. A flock of pullets was reared in floor pens from 0 d to 20 wk of age. At 20 wk of age, 96 pullets were randomly assigned to one of three feeding regimens with 14, 16, or 18% dietary CP. Daily feed allocation from 20 to 29 wk of age was identical for all three treatments and was based on the BW of the birds fed the 16% CP diet. Photostimulation occurred at 22 wk of age. At 29 wk of age, the hens were killed for determination of carcass characteristics. Dietary protein intake did not influence BW or BW gain throughout the trial. There were no differences in age at sexual maturity among treatments. From 25 to 28 wk of age, the hens on the 16 and 18% CP treatments had a significantly greater egg weight than did hens in the 14% CP group. The 14% CP treatment was unable to sustain as high a level of egg production as the other two treatments at 29 wk of age. The number of settable eggs was also lowest for the 14% CP treatment. The CP level in the diet did not affect the weights of the Pectoralis major or minor. Carcass composition was also not different among the treatments. Increased levels of CP in the prelay and early lay diets increased egg size and production rate although had minimal effect on carcass and ovarian parameters.