Body Composition of Chicks as Influenced by Environmental Temperature and Selected Dietary Factors

Abstract

Four trials were conducted to study the effects of environmental temperature in relation to selected dietary factors and age on the carcass composition of broilers. The temperatures used in these trials were 7.2°, 10.0°, 18.3°, 21.1°, 29.4°, and 32.2°C. Total carcasses were analyzed for moisture, ether extract and protein. There was a significant decrease in carcass ether extract with a concomitant increase in moisture content with decreasing temperature. Carcasses from birds reared at 18.3° and 29.4°C. receiving a diet containing 2877 kilocalories of metabolizable energy per kilogram contained significantly less ether extract than carcasses of birds receiving the higher energy diets. Carcasses from birds reared at 18.3 °C. receiving a 16.5 percent protein diet contained significantly more ether extract than carcasses of birds receiving the higher protein diets. Protein levels did not significantly affect carcass composition at 29.4°C. Temperature effects on carcass protein content varied between trials, but there appeared to be a trend toward decreasing carcass protein content with increasing temperatures. Carcasses of chicks fed a diet deficient in lysine contained significantly more ether extract than those fed diets adequate or in excess of the lysine requirement. Protein and ether extract content of carcasses increased with the age of the birds and the moisture content decreased.