DefinePK

Abstract

Heat stress poses a significant challenge to small ruminant production, particularly in arid and semi-arid regions. This study aimed to evaluate the effects of different grazing durations on growth performance, carcass traits, and meat quality of Kachhi lambs under heat stress conditions. Fifteen lambs were randomly assigned to three groups (n=5): morning grazing (KMG; 7:00 AM–11:00 AM), hot hours grazing (KHG; 11:00 AM–3:00 PM), and evening grazing (KEG; 3:00 PM–7:00 PM). All lambs received a basal diet in addition to grazing. Body weight and conformational traits were recorded biweekly. At the end of the experiment, lambs were slaughtered to estimate carcass characteristics and meat quality. Lambs grazed during cooler periods (morning and evening) showed improved growth, carcass yield, and meat quality compared to those grazed during peak heat hours. Morning grazing lambs exhibited higher body weight gain (8.7 vs. 5.5 kg), heavier dressed carcass (8.04 vs. 6.14 kg), and higher water holding capacity (69.2 % vs. 65.4 %) compared to hot-hour grazing. Favorable grazing schedules also improved meat quality by increasing nutritional components. Lambs in the morning grazing group had higher protein content (20.6 % vs. 17.6 %) and ether extract (fat) content (2.74% vs. 2.50%) compared to those grazing during hot hours. Morning or evening grazing regimes are therefore recommended to mitigate heat stress and enhance productivity and meat quality, offering practical strategies for sustainable sheep management in hot climates.
Keywords: Carcass traits; Grazing duration; Heat stress; Kachhi lambs; Meat quality
http://dx.doi.org/10.19045/bspab.2025.140084