A dose–response meta-analysis of grape by-product effects on lamb growth performance, nutrient digestibility, and blood parameters

作者：J Bahrampour, Ali Hossein Piray, Amir Mousaie, Mohtasham Ghaffari · 发表于：animal · 年份：2025 · DOI：10.1016/j.animal.2025.101449 · 被引用次数：3 · 研究领域：Horticultural and Viticultural Research、Ruminant Nutrition and Digestive Physiology、Animal Nutrition and Physiology

Previous studies on feeding grape by-products (GBP) to lambs have shown conflicting results regarding performance, nutrient digestibility, nitrogen metabolism, and blood constituents. To clarify these uncertainties, we conducted a systematic review and dose-response meta-analysis to evaluate the efficacy and dose-dependent effects of GBP in lamb diets. Sensitivity analyses were performed to assess the robustness of the results, including the localisation of knots, leave-one-out tests and the exclusion of data points with high GBP addition (more than 600 g/kg). The results showed that GBP addition had no statistically significant effect on DMI (P = 0.92), average daily gain (P = 0.21) or final live weight (P = 0.36). However, GBP inclusion had a significant effect on feed conversion ratio (P = 0.002), with lambs fed up to 450 g/kg GBP showing an improved feed conversion ratio, which peaked at 200 g/kg. ADF digestibility was not significantly affected by GBP inclusion (P = 0.08). Conversely, significant negative linear correlations were observed between the consumption of GBP and the digestibility of OM (P = 0.03), CP (P = 0.002), DM (P = 0.001) and NDF (P = 0.004). In contrast, the intake of GBP was positively associated with fat digestibility (P = 0.001). The meta-analysis revealed no significant association between GBP intake and urinary nitrogen excretion, nitrogen consumed, faecal nitrogen excretion, or nitrogen retained. Blood analysis also showed no significant correlati...