Thermal comfort, ingestive behavior, feed intake, and productive performance of shorn and unshorn Texel and Corriedale ewe lambs finished in a feedlot system

Context Feedlot finishing can improve sheep productivity, while fleece cover may influence thermoregulation, feed intake, and productive performance. Aims This study aimed to evaluate physiological parameters, feed intake, ingestive behavior, and productive performance of Corriedale and Texel ewe lambs, shorn and unshorn, finished in a feedlot system. Methods Forty-four ewe lambs (22 Corriedale and 22 Texel) were evaluated. Within each breed, 11 animals were shorn and 11 remained unshorn, and all animals received the same diet throughout the experimental period. Key results Regarding physiological parameters, Texel ewe lambs exhibited higher ocular and skin temperatures, whereas unshorn animals showed higher respiratory rates than shorn animals. Regarding ingestive behavior, Texel ewe lambs spent more time ruminating and chewing than Corriedale ewe lambs. Shorn ewe lambs spent more time standing than unshorn animals. Regarding feed intake, shorn ewe lambs showed higher dry matter and nutrient intake. Regarding productive performance, Texel ewe lambs showed higher average daily gain and final body condition score. Shorn ewe lambs also exhibited a higher final body condition score than unshorn animals. Conclusions Under feedlot finishing conditions, Texel ewe lambs showed better finishing than Corriedale ewe lambs. Shearing was associated with a lower respiratory rate, suggesting greater ease in maintaining thermal homeostasis, as well as greater feed intake. Implications Shearing at the beginning of the feedlot finishing period may be a useful management strategy for ewe lambs with meat- and wool-producing potential because it was associated with greater nutrient intake and improved final body condition without compromising thermal homeostasis under the environmental conditions of this study. Differences in productive performance between breeds also indicated that breed choice may be relevant in feedlot finishing systems.