Coat colour's studies in relation to the productive variables of crossbred sheep under heat stress

Abstract

The aim of this research was to evaluate the yield responses of crossbred sheep Santa Ines with Dorper, with an average age of four months, 15 of dark coat and 15 of white coat, under heat stress. The animals were exposed to solar radiation for one hour per week (14.00 - 15.00) for eight weeks. Measurements of height of the dorsum, rump height, chest width, rump width, thoracic perimeter, thigh perimeter, hind perimeter and scrotal perimeter were made. The animals were slaughtered and were weighed the following components: blood, skin, liver, heart, kidneys, head, legs, lungs, testicles and penis / urethra. The gastrointestinal tract was weighed full and empty. The hot carcass weight and cold carcass weight and calculated cooling losses and hot carcass yield and cold were evaluated; beyond of the commercial cuts: palette, leg, neck, loin and rib. Finishing and carcass conformation and color assessment, marbling, texture and subcutaneous fat thickness were also evaluated. Black sheeps had heavier kidneys than the white sheeps. Testicles, the hot carcass, palette, leg, rib and rump width of black sheeps were lighter towards animals white fur. Heat stress can cause disturbances in the metabolism of sheep, affecting their body condition and altering its development.