Abstract
This study investigates the impact of neutral detergent fiber (NDF) content in pelleted complete diets on the weight gain, carcass characteristics, and meat quality of lambs. A total of 72 lambs (12±1 weeks old) were randomly assigned to three dietary groups: Diet 1 (20.98% NDF), Diet 2 (28.23% NDF), and Diet 3 (32.82% NDF), with 8 replicates as the experimental unit. Weight gain parameters were recorded over 84 days. At the end of the trial, carcass characteristics, body components, wholesale cuts, fat depot metrics, and physical separation were evaluated. In addition, the physical, chemical, and fatty acid profiles of the meat and the qualitative meat characteristics were assessed. All data were analyzed using one-way ANOVA and regression analysis. Lambs fed Diet 2 exhibited superior overall weight gain and improved carcass characteristics, including higher slaughter weight, empty weight, hot carcass weight, cold carcass weight, and carcass compactness index. The amounts of back fat, omental fat, mesenteric fat, meat percentage, and trimmings were also higher in Diet 2 than in the other groups. In terms of meat quality, Diet 2 resulted in lower shear force and a higher myofibril fragmentation index, indicating higher tenderness, along with substantially reduced cooking loss indicating improved meat quality. In addition, lambs fed Diet 2 had higher crude protein and polyunsaturated fatty acids content, while saturated fatty acid content decreased. In conclusion, these findings suggest that an NDF level of 28.23% in lamb diets optimizes weight gain, improves carcass characteristics, and enhances meat quality.