Urea and citrus by-product supplementation of straw-based diets for goats: effect on barley straw digestibility

Abstract

Voluntary intake and in vivo digestibility of barley straw based diets supplemented with citrus by-product and urea were determined in 24 castrated male goats of the Murciano-Granadina breed in a digestion trial. Daily DM and digestible OM intake of diets increased ( P < 0.05) with increasing levels of energy supplement. ME daily intake was improved ( P < 0.01) by supplementation ranging from 411.0 to 611.1 kJ kg −1 LW 0.75 as higher levels of citrus by-product were included in the diets. DM and OM digestibilities of the diets increased ( P < 0.01) when citrus by-product was added. Citrus by-product supplementation caused a quadratic increase ( P < 0.001) in DM and CP digestibilities of the diets. DM, CP and crude fibre digestibilities of the straw increased ( P < 0.05) as higher levels of dried citrus by-product were incorporated in the diet. These results suggest that digestibility and intake of barley straw are improved when urea and citrus by-product were included in the diets.