Breaking strength and composition of the skin of broiler chicks: response to dietary calorie-protein ratios.

Skin breaking strength and protein, fat moisture, and total collagen concentrations of skin from the breast, thigh, and back of male and female commercial broilers were measured in response to diets containing relatively wide or narrow ratios of calories to protein (C:P). Comparisons were made at 28, 42, and 56 days of age. Chicks fed diets containing relatively wide C:P ratios had weaker skin than those fed diets with narrower C:P ratios, with differences being greater at 56 days than at younger ages. Regardless of diet, males had stronger skin than females. Although the magnitude of the differences varied with age, breast skin was stronger than thigh skin, with skin from the back being intermediate in strength. The observed differences in breaking strength were not consistently associated with fat, protein, moisture, or collagen concentrations of the skin.