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

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) LW0.75 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. (C) 1997 Elsevier Science B.V.