Carcass Composition Studies

Abstract

Studies were conducted to determine the effect of age and sex on the carcass composition of broiler type chickens and to determine the influence of feeding various fats such as cottonseed oil, acidulated cottonseed soapstock, beef tallow, and poultry fat on carcass composition and fatty acid composition of broilers. These studies show the tremendous differences in body composition that develop between male and female chickens with age and at what age these changes take place. The types of fat fed did not influence gross body composition but had a very large effect on fatty acid composition of whole carcass and adipose tissue fatty acids. The feeding of beef tallow produced a bird with increased stearic acid and oleic acid levels at the expense of linoleic acid, thus producing a bird that feels much firmer to the touch. Data is presented on the amount and composition of feathers from male and female chickens from 2 to 10 weeks of age. The quantity of feathers on the carcass increased with age. The protein content of the feathers also increased with age from a low of 37.2% in feathers from 2 weeks old females to 68.6% in feathers from 8 weeks old females. Linear regression equations for relationship between N/H2 O ratios vs. age and lipid vs. protein (dry matter basis) were utilized to calculate protein, lipid and ash content of carcass from moisture.