The Haematological and Biochemical Responses of Goat Bucks to Range Grazing and Indoor Concentrate-Based Feeding Systems.

BACKGROUND: Range grazing remains the principal feed resource for goats in smallholder production systems, particularly in regions where range grazing and intensive concentrate-based systems coexist. However, expanding cropland has reduced the availability of grazing lands and shifted production toward concentrate-based feeding systems. OBJECTIVE: This study aimed to evaluate the haematological and biochemical responses of goat bucks managed under range grazing and indoor concentrate-based feeding systems. METHODS: Forty yearling bucks (10 bucks/treatment) were randomly allocated to one of four 90-day feeding groups: range grazing (T1) or three treatments with roughage-to-concentrate ratios of: 60:40 (T2), 50:50 (T3) and 40:60 (T4) on a DM basis. Blood samples (10 mL/animal) were collected every fortnight via jugular vein from all bucks and were subjected to haematological and biochemical analysis. RESULTS: Bucks in T3 and T4 had significantly (p < 0.05) greater haemoglobin, red blood cell and packed cell volume compared to T1; nevertheless, the difference between T1 and T2 was not significant. Serum protein, albumin, glucose and testosterone concentrations were also higher in bucks fed concentrate diets (p < 0.05). White blood cells, mean corpuscular volume, mean corpuscular haemoglobin concentration, the red blood cell distribution widths, globulin, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, urea and creatinine remained unaffected (p > 0.05). Calcium level was significantly higher in T4 than T1 (p < 0.05), while K, Na, Cl and P remained unchanged (p > 0.05). CONCLUSION: Bucks kept indoors on concentrate-based diets showed better oxygen-carrying capacity, iron status, nitrogen balance and body protein reserves than bucks reared under range grazing.