Effect of nutrient level and feed form on the performance of heavy breeder turkey toms

Abstract

Nicholas male-line breeder toms were given either nutrient levels recommended by the National Research Council (NRC) or a reduced plane of nutrition (LOW) in either pellet (P) or crumble (C) form. Treatments were arranged factorially and imposed from 1 day of age until 57 weeks. The LOW diets were formulated by replacing portions of the maize, soya-bean meal and fat in the NRC feeds with wheat, oats and barley, such that the energy-to-protein ratio and the essential amino acid profile were similar. Management was similar to that of commercial practice. Toms receiving C until week 29 had reduced body weight gain and poorer feed conversion than birds receiving P; NRC led to better feed conversion than LOW. Evaluation of breast muscle yields and intestinal depot fat from sample birds indicated that a greater proportion of body weight in birds given NRC was attributable to adipose tissue accrual than for birds given LOW. Carcass composition differences were greatest at 16 weeks of age, and declined thereafter such that no differences existed by the end of the experiment. Semen yield and sperm concentration were not affected by the feed treatments.