Effects of substitution of soybean meal-alfalfa-maize by a combination of field bean or pea with hard wheat bran on digestion and growth performance in rabbits in Algeria

Abstract

[EN] The aim of the trial was to study the effects of replacement of a soybean meal-alfalfa-maize based diet by a mixture of field bean (g/kg as fed: 257 crude protein [CP], 139 neutral detergent fibre [NDF]) or pea (g/kg as fed: 203 CP, 122 NDF) combined with hard wheat bran (g/kg as fed: 140 CP, 396 NDF) and without supplementation of synthetic DL-methionine, on diet digestibility, growth and slaughter traits of growing rabbits. Three diets were formulated: a control diet mainly consisting of 15% of soybean meal, alfalfa and maize (SBM15 diet; g/kg as fed: 161 CP and 267 NDF) and 2 experimental diets based on 26% of field bean (FB26 diet; g/kg as fed: 167 CP and 250 NDF) or 30% of pea (P30 diet; g/kg as fed: 167 CP and 255 NDF) as main protein source, and completed with hard wheat bran (34 and 40%, respectively for FB26 and P30 diets) partly replacing alfalfa and maize. Diets were distributed ad libitum to 3 groups of 40 mixed-sex growing rabbits of Algerian white population, placed in collective cages (4 rabbits/cage) from weaning (28 d, mean weight: 614±112 g) until 77 d of age (slaughter). Faecal digestibility was measured between 42 and 46 d of age in 7 rabbits/group. Gross energy and crude protein digestibility coefficients were similar for SBM15 and FB26 diets (78.6 and 86.4%, respectively) and lower for P30 diet (75.1 and 83.6%, respectively; P≤0.03). Treatments had no effect (P=0.12) on mortality rate, which was on av. 9.2%. Treatments did not affect growth performance from 28 to 77 d of age (30.8 g/d) or feed intake (mean 94.6 g/d), but feed conversion ratio was higher for rabbits fed FB26 and P30 diets compared to those fed SBM15 diet (3.13 vs. 2.94; P=0.006). The dressing out percentages (mean 66.6%) and the muscle/bone ratio (6.8) were similar for the 3 groups of rabbits. In conclusion, the substitution of soybean meal-alfalfa-maize by a combination of field bean or pea with hard wheat bran, without methionine supplementation, does not seem to affect growth, nor the slaughter performances of the local growing rabbits. However, digestion of pea diet was reduced and feed efficiency of FB26 and P30 diets was impaired.