Replacing crude fiber content of berseem hay by wheat straw with or without probiotics or enzymes in the diets of growing rabbits

Abstract

The goal of the current study was to assess the impact of partial or complete substitution of crude fiber content of berseem hay by wheat straw with or without probiotics or enzymes on growth performance, caecal contents parameters, nutrients digestibility and economic efficiency of growing rabbits. Eighty-four weaned New Zealand White rabbits of both sexes (at 30 days of age) were randomly assigned to seven groups, each consisting of twelve rabbits. The same feed ingredients as the control diet (D1) were used to create two experimental pelleted diets, but one source of roughage (wheat straw) was added in diets 2 (D2) and 3 (D3) which replaced 50 & 100% of the crude fiber content of berseem hay with or without probiotics or enzymes. The first group (control group) was given a basal control pelleted diet (D1) that included berseem hay as the primary source of crude fiber without additives. The second, third and fourth groups fed on the second pelleted experimental diet (D2) in which fiber content of wheat straw replaced 50% of berseem hay without (group 2) or with probiotics (group 3) or enzymes (group 4). The fifth, sixth and seventh groups fed on the third pelleted experimental diet (D3) in which fiber content of wheat straw replaced 100% of berseem hay without (group 5) or with probiotics (group 6) or enzymes (group 7). Experimental period extended for 42 days from weaning (at 30 days) to slaughter age (at 72 days). The results showed that replacing of 50 or 100% of berseem hay fiber by wheat straw with probiotics or enzymes in the diets of growing rabbits increased the final weight of the body, gaining in weight, the cumulative feed consumption and economical feed efficiency as well as improved the feed conversion ratio, performance index, the coefficients of digestion for all nutrient and also feeding criteria including DCP & TDN in comparison with control. During the entire trial, there was no mortality among rabbits fed diets made with wheat straw supplemented with probitoics or enzymes, while those fed the same diets without additives had a lower mortality rate than the control group, which had the highest mortality rate. Compared to other treatment groups and the control, rabbits fed diets containing wheat straw supplemented with enzymes, had the highest values of total bacterial count and total volatile fatty acids of the cecal content. In conclusion, it is cost-effective to replace 50 or 100% of the fiber in berseem hay with wheat straw fiber, either without or with probiotics or enzyme supplements, and the feed additives will enhance the growth performance metrics for growing New Zealand White rabbits.