Effects of Feed Restriction and Refeeding Period on Productive Performance and Digestive Efficiency in Goats and Sheep

In semiarid regions, seasonal forage scarcity often leads to feed restriction in small ruminants. Although restriction can impair metabolism and growth performance, animals may exhibit compensatory growth during subsequent refeeding. Although compensatory growth has been extensively investigated in sheep, evidence regarding this response in goats remains comparatively limited. This study evaluated the nutritional efficiency and productive performance of sheep and goats subjected to 15% or 30% feed restriction, followed by a refeeding period A total of 36 young growing animals were used, including 18 Santa Inês sheep (initial body weight [iBW] 17.9 ± 1.69 kg) and 18 Boer goats (iBW 18.35 ± 3.46 kg), all uncastrated males aged four months. Animals were selected to have comparable initial body weights to facilitate comparisons between species. Animals were assigned to a completely randomized design in a 3 × 2 factorial arrangement, with three feeding levels (ad libitum, 15% restriction, and 30% restriction) and two species (sheep and goats). During the restriction period (days 1–28), sheep showed higher intake of dry matter, organic matter, crude protein, ether extract, and neutral detergent fiber than goats (p < 0.05). Feed restriction did not affect growth performance; however, sheep presented greater final body weight (26.6 vs. 23.1 kg), average daily gain (157 vs. 85 g/day), and carcass yield (p < 0.01). During the refeeding period (days 29–56), previously restricted animals exhibited increased nutrient digestibility (p < 0.01), indicating compensatory adaptation. Intake remained higher in sheep, whereas ether extract digestibility was greater in goats (p < 0.01). Both species showed compensatory growth after restriction, with sheep achieving greater weight gain (4.1 kg) due to higher energy intake. These findings indicate that moderate feed restriction (up to 30% for 28 days) does not compromise long-term productivity in growing sheep and goats when followed by a refeeding period.