Partial substitution of concentrate with Parkia biglobosa foliage improves feed utilisation and performance of goats

Abstract This study investigated the response of intake, ruminal fermentation, digestibility, N utilisation and growth performance in goats fed concentrate partially substituted with Parkia biglobosa foliage (PBF). Fifteen goats were randomly assigned to a control concentrate diet (PBF0) which was partially substituted with 25% PBF (PBF25) or 50% PBF (PBF50) on dry matter (DM) basis. Concentrate, TST and non-fibre carbohydrates intakes (linear and quadratic, P<0.001), digestible organic matter (DOM; linear, P=0.001) and urinary N (linear, P=0.039) decreased with increased PBF level. Condensed tannins intake, fibre fractions and cellulose digestibility, faecal N (linear and quadratic, P<0.05) and ruminal pH (quadratic, P=0.001) increased with increasing PBF level. Average daily gain, DM and crude protein (CP) digestibility, N intake and retention (quadratic, P<0.05), organic matter and hemicellulose digestibility, DM and nutrient intakes, energy concentration, ruminally-fermented DOM and microbial protein synthesis (linear and quadratic, P<0.05), and digestible CP and volatile fatty acids (linear, P<0.05) increased as PBF level increased. Feed:gain ratio and total N excretion (quadratic, P<0.05), and ruminal total N and ammonia N (linear and quadratic, P<0.05) decreased in PBF25. It is concluded that PBF is a cost-effective alternative supplement which could reduce the quantity of concentrate for goat feeding by 50%.