Influence of adding fibrolytic enzymes to olive cake on feed intake, nutrient digestibility, growth performance of lambs

This research evaluated the effects of the addition of a blend of exogenous fibrolytic enzymes composed of a mixture of cellulase and xylanase (CX) to a high-fibre diet on growth performance of meat lambs. The diet contained olive cake (OC), and CX was added to this fibrous by-product at 0 (control, no addition of CX), 4 (CX04) or 16 (CX16) ml of the enzyme preparation per kg OC dry matter. The study was planned according to a quintuplicated 3 × 3 Latin square design, with three experimental treatments (control, CX04, CX16), three 21-day periods (14-day adaptation plus 7-day collection period) and 15 weaned male lambs (Queue Fine de l'Ouest) randomly assigned to the 5 replicates (3 lambs in each replicate). Intake of both dry matter and organic matter were increased (P < 0.05) by 4 % with CX addition. Fibre digestibility was increased (P < 0.05) by 6 % (CX04) and 8 % (CX16) as compared with control. Blood serum biochemistry were not affected (P > 0.05) by CX, except cholesterol concentration that was increased (P < 0.05). As compared with lambs fed the control diet, average daily weight gain was increased (P < 0.05) by 6 and 10 % when lambs were fed CX04 and CX16 diets, respectively. These results indicate that the supplementation of OC-based lamb diets with CX, even at relative low concentrations, improves lamb growth performance as a result of increasing feed intake and enhancing fibre digestibility with no adverse effects on animal health.