Effects of enzyme additive on haematological and serum biochemical parameters of calves fed fresh grass and hay based diets
This study was conducted to determine the effects of an exogenous fibrolytic enzyme (ROXAZYME G®) on blood parameters of calves fed fresh grass and grass hay-based diets. Chemical composition of concentrate, fresh grass and grass-hay were determined. Sixteen crossbred (N’dama × Muturu) calves were subjected to two feeding trials that lasted 84 days each in the wet season and dry season. Fresh grass (Panicum maximum) was the basal diet in the wet season while, the hay was the basal diet in the dry season. Four concentrate diets were formulated with enzyme inclusion at 0, 50, 100 and 150 mg/kg to form four dietary treatments (T1, T2, T3, T4), with four animals per treatment in a completely randomized design. Results showed that fresh grass had higher crude protein (CP), ether extract and ash than hay. However, the hay had higher dry matter, crude fibre, neutral detergent fibre (NDF), acid detergent fibre (ADF) and acid detergent lignin (ADL) contents. The calcium and phosphorus contents of the concentrate diets were higher than that of fresh grass and hay. At the end of the first experiment, Packed cell volume (PCV), Haemoglobin (Hb) and Red blood cell (RBC) values were highest (P<0.05) in T3 and lowest in T1 (control). White blood cell (WBC) and neutrophil counts were highest in T1. Transaminase enzymes: AST and ALT were highest (P<0.05) in T4. In the second trial, the diets influenced (P<0.05) the WBC, lymphocyte, total protein and AST. The WBC was also highest in T1 while, lymphocyte was highest in T2. Total protein was highest in T3 and AST was highest in T4. It was therefore, concluded that the inclusion of ROXAZYME G® up to 150 mg/kg DM in the diets of calves improved their blood parameters without any deleterious effect.
Keywords: blood parameters, dry season Panicum maximum, ROXAZYME G®, wet season