THE USE OF FEED RESTRICTION FOR IMPROVING REPRODUCTIVE TRAITS IN MALE-LINE LARGE WHITE TURKEY HENS .1. GROWTH AND CARCASS CHARACTERISTICS

The influence of feed allowance during rearing was investigated in mal e-line Large White breeder hens. A flock of 200 poults was reared from 4 to 28 wk of age under four treatments as follows: full-fed controls (FF), low-protein diet (12% CP from 12 to 28 wk; LP), and reduced BW (10 or 20% lower BW than FF; R10 and R20). At photostimulation (28 wk) , all birds consumed a commercial breeder diet ad libitum for the rema inder of the study (48 wk of age). Body weight differed among treatmen ts during most of rearing. The LP birds were similar in BW to the R10 birds at 28 wk of age. By 40 wk of age, growth curves of all treatment s became similar, with the R20 group having lower BW. Feed restriction reduced frame size during rearing. Flock uniformity in the R10 and R2 0 treatment hens was reduced during rearing, but improved early in the breeder period. Feed restriction reduced breast muscle and abdominal fat pad weight early in lay, except for the LP group. Liver lipid cont ent increased throughout the breeder period. Changes in liver weight f ollowed the pattern of BW changes. Total carcass protein content chang es in time reflected breast muscle mass changes. In R20 hens, carcass lipid content was reduced and protein content increased. Sexual maturi ty was delayed in the R20 hens. Body weight at first egg was negativel y correlated with settable egg production (r=-.37, P less than or equa l to.0015). The R20 treatment is recommended for male-line turkey bree der hen candidates during rearing.