Influence of exogenous enzymes ensiled with orange pulp on digestion and growth performance in lambs

Twenty-four Ossimi male lambs were used to evaluate effects of inclusion of ensiled orange pulp (EOP) in lamb diets either with or without addition of exogenous enzymes (ENZ) of ZADO (R) on digestion and growth performance. Lambs (21.1 +/- 1.01 kg body weight (BW)) were assigned to one of three groups of 8 animals/group in a randomized complete block design being: Control (basal diet with 0 g/kg EOP), EOP (Control with 150 g/kg EOP) or EOP + ENZ (EOP with 5 g/kg of ZADO (R)) in a 90-day experiment. Ensiling the orange pulp increased the crude protein, ether extract and metabolizable energy of the silage by 29, 46 and 8%, respectively, and reduced the secondary metabolites, such as total phenolics, saponins and alkaloids. Silage lactic acid and ethanol were increased by 35% and 54%, respectively for EOP and EOP with ENZ, but all silage quality parameters were in the normal range. Concentration of NH(3)-N before feeding was decreased (P < 0.05) by 11 and 13% in EOP and EOP + ENZ, respectively, whereas at 3 and 6 h after feeding ruminal VFA concentration was increased (P < 0.05) by 23 and 9% respectively, only in EOP + ENZ lambs. NDFom intake was increased (P=0.036) by 52 and 59%, whereas the ADFom increased (P=0.032) by 8 and 11% in EOP and EOP + ENZ lambs, respectively. Nutrients digestion were higher (P < 0.05) in EOP + ENZ than EOP lambs. Digestible DM was increased by 18%, whereas the fiber fractions (NDFom and ADFom) were increased by 93 and 47% with similar EOP + ENZ. DM intake among groups, whereas feed efficiency was higher (P=0.042) by 19 and 31% in EOP and EOP + ENZ lambs compared to control diet. Live weight gain increased (P=0.038) by 92% in EOP + ENZ lambs whereas it increased by 54% in EOP lambs. Addition of EOP to the diet improved feed efficiency and live weight gain suggesting a good quality feed, which could probably be used to replace a part of the concentrate in ruminant diets. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.