New insights into the potential effects of date palm seed powder supplementation on the growth, hemato-biochemical indices, organ histology, and gene expression in Rahmani sheep.

Globally, the utilization of agricultural waste in animal production is gaining significant attention. Despite the widespread cultivation of date palm seeds (Phoenix dactylifera), they generate substantial byproducts that pose environmental challenges. Incorporating these byproducts into animal feed offers a dual benefit: mitigating environmental issues and enhancing the sustainability of sheep production. Consequently, this study investigated the effects of dietary supplementation with date palm seed powder (DPS) on Rahmani lamb growth, carcass characteristics, hematology, biochemical parameters, antioxidant status, and the expression of growth and immune-related genes. Four groups of 6-month-old male Rahmani lambs (n = 5 each) were randomly assigned to one of four diets: a basal diet (control), or the basal diet supplemented with DPS at 100 g/kg (DPS100), 150 g/kg (DPS150), and 200 g/kg (DPS200) for 3 months. The results indicated that dietary supplementation with varying levels of DPS significantly improved final body weight (FBW), and average body weight (ABW), dry matter intake (DMI) in sheep (P < 0.001), while feed conversion ratio (FCR) remained unaffected (P > 0.05). Dry matter intake (DMI) was higher in the DSP100 group compared to the control group (P < 0.05). Hot carcass weight dressing percentage, heart weight, and liver weight were significantly increased in all DPS-supplemented groups (P < 0.05). Supplementation with 150 g DPS /kg significantly increased hemoglobin levels compared to the control group (P < 0.01). Furthermore, DPS inclusion significantly improved red blood cell (RBC) count, white blood cell (WBC) count, and hematocrit (Ht), with the highest value observed in lambs fed 200 g DPS /kg. Glucose levels were also improved with DPS supplementation, with the most significant increases at 150 and 200 g/kg (P < 0.001). However, albumin, globulin, and creatinine levels were not significantly altered by DPS across the groups (P > 0.05). Notably, superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities were significantly elevated in all DPS-supplemented diets. Including DSP at 100–150 g/kg significantly upregulated the growth hormone (GH), insuin growth factor-1 (IGF1), and growth hormone receptor (GHR) genes compared to the other groups. Moreover, increasing levels of dietary DPS (100, 150, and 200 g/kg) significantly upregulated Toll-like receptor 7 (TLR7), interleukin-6 (IL-6), and Interleukin-1beta (IL-1β) in a dose-dependent manner (P < 0.05). Muscle architecture also showed improvement in all lambs fed DPS. These findings collectively indicate that supplementing lamb diets with date palm seed powder at a concentration of 150 g/kg is an effective strategy. This inclusion significantly enhances blood health, improves antioxidant status, and boosts growth performance, making the 150 g/kg inclusion level highly recommended for improving overall lamb health and productivity.