Shorter Grazing Time and Supplementation Are Beneficial for Gastrointestinal Tract Development and Carcass Traits of Growing Lambs

Abstract

The effects of restricted grazing durations on the gastrointestinal development and carcass quality of growing lambs are poorly understood. In this study, 32 lambs were randomly assigned to four groups (n = 8, body weight = 21.86 kg) corresponding to 2, 4, 8 and 12 h of grazing per day. When off-pasture, all lambs were housed and fed concentrate and hay. When the grazing time decreased from 12 h to 2 h, the abomasum weight and large intestine length decreased (p = 0.019; p = 0.069). Compared to lambs grazed for 12 h, animals grazed for 2–4 h had a greater villus height and villus-to-crypt ratio in the duodenum, jejunum and ileum segments (p < 0.05); the 2 h lambs had superior carcass quality and a smaller diameter and area of the gluteus medium muscle fibers (p < 0.05), with no significant change after 4 h of grazing. The results indicated that shorter grazing times and supplementation were beneficial for the gastrointestinal tract development and carcass quality of growing lambs. Therefore, a better grazing management approach in Inner Mongolia could be to restrict the grazing of lambs to 4 h per day instead of grazing for more extended periods.

Different feeding strategies can affect growth performance and rumen functions in Gangba sheep as revealed by integrated transcriptome and microbiome analyses

“…Under the same physiological conditions (breed, age, and initial body weight), the G group had lower ADG compared to the T and F groups, due to less DMI and higher ADF content in the diet resulting in the reduced nutrient intake or absorption efficiency. Similar results were also observed in small-tailed Han sheep and Ujumuqin lambs that the final body weight or carcass weight was significantly higher in the confinement group compared to that in the grazing group (Wang et al, 2020;Jin et al, 2022). Our results indicated that the barn feeding strategy can significantly improve the growth performance of Gangba sheep in the F group through the systemic ruminal microbiota-host interactions.…”