Effects of replacing a concentrate-based regimen with low-value date fruit on growth performance, meat quality, and fatty acid composition in Hamra lambs

Abstract. This research investigates the effects of two different dietary regimes on body weight, fatty acid composition, vitamin E levels, and meat color attributes. The research involved two groups of Hamra breed lambs raised on pasture at the same farm in the El Bayadh area. The first group was supplemented with date fruit from two varieties, whole pitted date and Degla-Beida, while the second group was fed a concentrate diet. At the end of experiments, the lambs' weight gain was recorded, and Longissimus thoracis muscles were excised from each carcass. The results showed significantly higher weight gain (p<0.05) in lambs fed a concentrate diet (Group 2) compared to the group fed date fruit (Group 1) (34.83 kg vs. 29.15 kg). However, the latter group displayed significant improvements in meat quality parameters, including a healthier fatty acid profile, with higher levels of polyunsaturated fatty acids and omega-3 fatty acids (16.38 %), particularly alpha-linolenic acid (0.30 %). Meat from lambs fed date fruit also showed elevated vitamin E content (1.47 mg/100 g) and stronger antioxidant capacity (1.14 mg TE/100 g), reducing lipid oxidation (0.05 mg MDA per kg meat) and enhancing meat stability. Group 1 also exhibited darker meat coloration and lower lipid oxidation rates. It is critical to highlight the unique advantages of the El Bayadh ecosystem for outdoor sheep breeding, which produces healthier meat that is rich in vitamin E and possesses an appealing color that could potentially enhance its marketability.