Emmanuel Anaso
This study investigated the effects of Piliostigma thonningii essential oil (PTEO) supplementation on feed intake and hematological parameters of growing sheep. Twenty-one healthy Yankassa ram lambs (6–7 months old; average weight: 10.55 ± 0.60 kg) were randomly assigned to three treatment groups in a completely randomized design. Each group received the same basal diet with different levels of PTEO: 0 ml/kg (T1 – control), 5 ml/kg (T2), and 10 ml/kg (T3), over a 16-week feeding period. Dry matter (DM), ether extract (EE), organic matter (OM), acid detergent fibre (ADF), and hemicellulose intake increased significantly (p < 0.05) across treatments, with the highest values observed in T3. Similarly, crude protein (CP), non-structural carbohydrates (NSC), neutral detergent fibre (NDF), and cellulose intakes were higher in PTEO-supplemented groups compared to the control. The highest DM intake in T3 indicated that PTEO at 10 ml/kg diet did not compromise palatability. Hematological parameters followed a consistent ly positive trend with increasing PTEO supplementation. Packed cell volume (PCV) ranged from 35.55% to 41.29%, hemoglobin (Hb) from 11.76 to 13.04 g/dL, mean corpuscular hemoglobin concentration (MCHC) from 31.43% to 33.52%, neutrophils from 39.33% to 44.30%, and eosinophils from 5.00% to 7.51%, all increasing in the order T3 > T2 > T1. Red blood cells (RBC), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), white blood cells (WBC), and lymphocyte counts were also higher in the PTEO-supplemented groups. Conversely, the neutrophil-to-lymphocyte ratio was highest in the control group (T1), while basophils and monocytes showed no significant differences among treatments. In conclusion, dietary supplementation of PTEO at 10 ml/kg improved nutrient intake and supported favorable hematological responses, indicating enhanced health and performance. PTEO may serve as a safe, sustainable alternative to synthetic feed additives in sheep production