Whole white lupin (Lupinus albus cv. Amiga) seeds as a source of protein for growing-fattening rabbits

The purpose of this study was to evaluate the effect of substituting 100 g soybean meal (SBM) for 150 g whole white lupin seeds (WL, Lupinus albus cv. Amiga) or 170 g sunflower meal (SFM)/kg diet as protein source for growing-fattening rabbits. The SFM diet contained more cellulose and lignin, and less digestible energy than the other diets whereas the WL diet contained more oligosaccharides of the raffinose series. In the performance trial, 90 weaned Hyplus rabbits (30 per treatment) were individually housed and fed one of the three experimental diets for 42 days (37–79 days of age). At the end of the trial period, 18 rabbits per treatment were slaughtered and used for the evaluation of carcass traits. In addition, the coefficient of total tract apparent digestibility (CTTAD) of the diets and caecal traits were determined from 48 to 52 days of age in 13 rabbits per treatment. Diet did not affect weight gain or feed conversion ratio but feed intake was higher with the SFM diet (P<0.05). Dressing-out percentage was higher in rabbits fed the WL diet than in rabbits fed the other diets (P=0.006). Diet did not affect CTTAD of organic matter, crude protein or ether extract. Rabbits fed the SFM diet had lower neutral detergent fibre digestibility (P<0.05) and tended to have lower gross energy and acid detergent fibre digestibility than rabbits fed the other diets. In addition, pH, volatile fatty acid and ammonia concentration in the caecum were not affected by diet; however, lactic acid concentration was increased with WL feeding (P<0.05). It is concluded that whole white lupin seeds can replace satisfactorily soybean meal and sunflower meal in diets for growing-fattening rabbits.