Effect of arginine and glutamine supplementation on performance, health and nitrogen and energy balance in growing rabbits

Abstract

The aim of this work was to study the effect of supplementation with arginine and glutamine and its interaction on growth performance, chemical composition of body and carcass, and digestible nitrogen and energy body and carcass retention efficiency in growing rabbits. A Basal diet (B) was formulated to contain 29.8 g N/kg DM and 313 g aNDFom-cp/kg DM and with an amino acid level enough to meet rabbits post-weaning requirements, and further three diets were obtained by adding to the B diet as-fed basis 4 g arginine/kg (Arg), 4 g glutamine/kg (Gln) and a mixture of 4 g arginine and 4 g glutamine/kg (Arg + Gln). To determine growth performance and mortality (from 25 to 55 d of age), 1223 rabbits were studied in three consecutive fattening periods Moreover, 104 rabbits were chosen to determine their chemical corporal and carcass composition at weaning (25 d of age) and at 55 d of age using the bioelectrical impedance analysis (BIA). Another 96 rabbits were blocked by litter and assigned at random to the experimental diets to determine apparent ileal digestibility of DM, N and amino acids at 35 d of age and 44 of them were used to determine faecal digestibility of DM, N, gross energy and aNDFom-cp from 32 to 35 d of age. All the trials were executed under common Epizootic Rabbit Enteropathy circumstances. Rabbits fed with Gln supplementation from 25 to 35 d of age showed lower mortality during the whole fattening period than those unsupplemented (41.3% vs. 25.6%; P = 0.042). However, supplementation with arginine and glutamine during the whole fattening period did not affect the mortality. Arginine supplementation increased total and digestible nitrogen intake by 10 and 8%, respectively (P < 0.002), without affecting nitrogen and energy retention. Therefore, the retention efficiency of digestible nitrogen and digestible energy decreased by 8 and 7% (P < 0.001), respectively. This led to an increase of urine nitrogen excretion (by 23%; P = 0.030) and energy losses as urine + heat production (P = 0.003).