Growth performance, nutrient digestibility and haematological response of Captive grasscutters (Thryonomys swinderianus) to dietary bitter leaf (Vernonia amygdalina) meal

Abstract

A feeding trial was conducted to determine the effects of dietary bitter leaf meal (BLM) supplementation on the growth performance, nutrient digestibility and haematological indices of weaner grasscutters. Forty grasscutters of mixed sexes weighing between 391.5g and 400.5g were assigned to four dietary treatments consisting of ten grasscutters per treatment in a completely randomized design. BLM was incorporated into the experimental diet at varying levels of 0, 20, 40, and 60g/kg representing T1 (control), T2, T3 and T4 respectively. Data collected were analyzed using one-way Analysis of Variance (ANOVA) Mean differences were significant at p<0.05. Growth performance of weaner grasscutters was significantly (P<0.05) improved by BLM at 40g/kg as indicated by highest final live weight, average daily weight gain and better feed conversion ratio (1037.9g, 9.11g/day and 4.09) respectively (P<0.05), while those on 20g/kg had the highest average daily diet feed intake (40.17g). Animals on 20g/kg BLM had significantly (P<0.05) improved nutrient digestibility. All haematological parameters were significantly (P<0.05) affected by dietary BLM except granulocytes and platelets. Packed cell volume,
haemoglobin concentration, and red blood cells of the grasscutters increased across the dietary treatments as graded levels of BLM increased. Total leukocytes count significantly reduced with lowest value (7.53×109 /L) at 60g/kg while the lymphocytes were significantly (P<0.05) higher than the control. It was concluded that feeding grasscutters diets supplemented with BLM at 40g/kg improved their growth and health status as could be observed from their growth and haematological parameters, hence BLM can be used a natural growth promoting feed additives in grasscutter production.