EARLY DIETARY-PROTEIN RESTRICTION AND INTERMITTENT LIGHTING .2. EFFECTS ON CARCASS CHARACTERISTICS OF MALE TURKEYS

A trial was conducted to determine the effects of dietary protein restriction at an early age and intermittent lighting, designed for curtain-sided houses, on the carcass characteristics of Nicholas commercial male turkeys (sired by male Line 88). Four isocaloric diets containing various levels of protein (100, 90,80, or 70% of control values) were fed ad libitum from 8 to 56 days of age. All birds were fed control diets from 1 to 7 days of age and from 57 to 124 days of age. Two lighting regimens, a control of 15 h light (L):9 h dark (D), and intermittent (15L:2D:1.5L:2D:1.5L:2D), were each assigned randomly to two rooms from Day 8 until the end of the study. Turkeys reared in intermittent lighting had heavier weights for whole breast (muscle and bone, P < .06) and breast muscle (without bone, P < .07) than those of the control (15L:9D) photoperiod. Toms fed the 90% protein diet in both lighting regimens had carcass part weights and yields similar to the controls. The weight of the breast and breast muscle and the percentage yield of breast and breast muscle decreased in birds fed the 80 and 70% CP diets. It is concluded that Nicholas commercial male turkeys can be reared in intermittent lighting and can be fed dietary protein levels at 90% of the control level from 8 to 56 days of age without negatively affecting the weights or yields of carcass parts.