Improving roughage sources in ewes' diets: Effect of replacing wheat straw with Date palm leaves on productive and physiological performance and economic efficiency

This study aimed to evaluate the effect of replacing wheat straw with date palm leaves on nutrient intake, physiological status, and economic efficiency of lactating ewes exposed to heat stress. Ewes (N = 15) were equally allocated into three experimental groups (5 per group). All experimental rations were formulated to meet the nutritional needs of ewes (NRC, 2007). The control group fed a conventional diet containing 50% concentrate feed mixture (CFM), 20% Pearl millet and 30% wheat straw (WS); a partially replaced group fed 50% CFM, 20% Pearl millet and 15% WS, and 15% date palm leaves (DPL) (T1); and a totally replaced group fed 50% CFM, 20% Pearl millet and 30% DPL (T2). Total protein, albumin, globulin, glucose, total cholesterol, AST, ALT, urea-N, and creatinine concentrations remained within the normal physiological range and showed no significant differences among groups. Moreover, thyroid hormone levels (T3 and T4) did not differ significantly among treatments, indicating that metabolic and endocrine functions were not influenced by the type of roughage used. Similarly, no significant (p > 0.05) differences were observed among the treatment groups in terms of body weight, total dry matter intake, or milk yield. However, the cost of feeding was reduced by 4.818% in the partial replacement group and by 8.713% in the total replacement group, indicating a clear economic benefit. These findings suggest that date palm leaves can be used as a low-cost roughage alternative to wheat straw in lactating ewe diets without negatively affecting animal performance or health.