Effects of Sunflower Hulls on Productive Performance, Digestibility Indices and Rumen Morphology of Growing Awassi Lambs Fed with Total Mixed Rations

Forty-eight growing Awassi lambs were used in a 70-day trial to investigate the effects of different levels of dietary sunflower hulls (SFH) on growth, rumen morphology, fiber digestibility and meat characteristics of lambs. Animals were randomly allocated to 4 groups with 3 replicates of 4 lambs each. The diet was composed of total mixed ration (TMR) without SFH (control group), and the TMR diet supplemented with SFH at a level of 5% (SFH5), 10% (SFH10) and 15% (SFH15). Lambs in the treatment groups had greater BW changes (p = 0.04) and ADG (p = 0.04) than the lambs in the control group. Intake of dry matter, acid detergent fiber (ADF) and neutral detergent fiber (NDF) were also significantly (p < 0.05) higher in SFH15 compared to SFH10. Digestibility of ADL and empty stomach weight were also significantly (p < 0.05) higher in SFH10 and SFH15, respectively. Cooking loss, blood total cholesterol and total protein decreased significantly (p < 0.05) in SFH15. Ruminal lightness (L) and yellowness (b) also increased significantly (p < 0.05) in SFH15. We concluded that the TMR diet supplemented with up to 15% SFH improved weight gain, digestibility, meat cooking loss and rumen color in Awassi lambs.