Effect of varying concentrate level on voluntary intake and haematochemical indices of goats fed Piliostigma thonningii basal diet

Abstract

The effects of feeding different levels of concentrate supplement to Red Sokoto goats (body weight (BW), 6.64±0.28), fed basal tannin-containing Piliostigma thonningii foliage on voluntary intake, haematological and biochemical parameters, were evaluated. Fifteen goats were stratified into three groups of homogenous BW and randomly assigned to one of three treatment diets in a completely randomized experiment in a 70-d assay. One concentrate ration was formulated and fed at varying levels of 1.5 or 2.5% BW and ad libitum. Intakes of dry matter and crude protein, and serum urea nitrogen and glucose concentrations increased (P < 0.05) with increasing level of concentrate supplementation. Intake of condensed tannins was highest and lowest (P < 0.05) for 2.5% BW and ad libitum concentrate allowance respectively. Red blood cell counts were higher (P < 0.05) for ad libitum concentrate feeding than for 1.5 and 2.5% BW concentrate allowances. Serum total protein and albumin were intermediate for 2.5% BW concentrate feeding but higher (P < 0.05) for ad libitum concentrate allowance than for 1.5% BW concentrate supplementation. Values of all blood and serum measurements were within normal ranges for goats. The results indicate that low or high concentrate supplementation level did impair the health status of the animals, and tannin-containing Piliostigma thonningii foliage can used as a basal forage without inducing tannic acid toxicity, metabolic disorders and compromising the nutritional and health status of goats. However, for superior health and nutritional status, ad libitum concentrate allowance may be preferred.