title: The effects of shade on performance, carcass classes and behaviour of heat-stressed feedlot cattle at the finisher phase.
abstract: The study aimed to determine the impact of shade on the performance, carcass class and behaviour using 146 crossbred steers and bulls during the finishing phase on a commercial feedlot in February. Treatments were (1) shade and (2) no shade. Average daily gain (ADG), DMI, and feed efficiency were measured, and hot carcass weight (HCW) and grades were collected at slaughter. The proportion of animals within a pen engaged in various behavioural activities (standing, lying, feeding and panting) was recorded. Five randomly selected individual animals per treatment were monitored every 2 min between 0700 and 1600 hours to determine the time spent on each of the above activities. Shade improved the final body weight (P < 0.0001), ADG (P = 0.079), and HCW by 8.33 kg (P < 0.05). Shade increased (P < 0.05) the feeding activity but decreased (P < 0.05) panting behaviour. Shade conferred an economic benefit of R2.03 head(-1)week(-1), and thus would reduce heat stress and increase the feedlot profitability.
authors.affiliation: Crafcor Farming PTY Ltd, Dundee, KwaZulu-Natal, South Africa.
authors.forename: K L
authors.initials: KL
authors.lastname: Blaine
authors.forename: Ignatius Verla
authors.initials: IV
authors.lastname: Nsahlai
mesh_terms: D000822:Animal Husbandry / Q000379:methods*; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D001835:Body Weight / Q000502:physiology; D002417:Cattle / Q000254:growth & development* / Q000502:physiology; D004435:Eating / Q000502:physiology; D016014:Linear Models; D008297:Male; D011897:Random Allocation; D013019:South Africa; D013312:Stress, Physiological / Q000502:physiology*; D013696:Temperature