The Effects of Varying Levels of Hydrolyzed Animal and Vegetable Fat Upon Growth and Carcass Characteristics of Broilers

DURING recent years the use of animal and vegetable fats in broiler rations has increased. Marion and Woodroof (1965) reported that body weights and feed efficiency were greater at higher levels of protein when fat was added to the diets. They also reported that the degree of rancidity, measured as “TBA Numbers,” was higher in tissues from birds reared on Menhaden oil diets. Essary et al. (1965) reported that different levels of added fat (2, 4, 6, and 8%) and protein fed to broilers did not appreciably influence dressing percentages but did significantly influence live weight. Stephenson et al. (1960) reported that added dietary fat at levels from 0 to 10 percent did not affect the breast blister condition of broilers. In this study the factors which appeared to significantly affect the breast blisters were market age, sex and breed. Gyles et al. (1957) reported that differences in incidence of . . .