New concepts and objectives for protein-amino acid nutrition in rabbits: a review.

Abstract

ABSTRACT:In the European context, the new legislation to avoid mineral contamination and the ban on antibiotics as growth promoters has led to the defi nition of new objectives in respect of nitrogen supply. The present study summarizes the state of nitrogen nutrition in rabbits and reviews the role of protein and amino acids in rabbit health and the new nitrogen value of protein sources based on true ileal digestibility (TID) for future recommendations. The main sources of nitrogen for microbial growth are ammonia, urea and protein (endogenous and dietary). The surplus of nitrogen fl ow to the caecum increases mortality rates during fattening by favouring the growth of potential pathogenic bacteria. Accordingly, feeding strategies to reduce ileal nitrogen fl ow have been reviewed. A large reduction of dietary protein level might have negative consequences on growth performances and mortality. In order to formulate balanced lowprotein diets, data on ileal and faecal amino acid digestibility of 14 raw materials is summarized. The use of this different unit for amino acid digestibility is also discussed.

Effect of decreasing dietary protein level and replacing starch with soluble fibre on digestive physiology and performance of growing rabbits

“…Nor the changes in dietary CP concentration or the dietary supplementation with specific amino acids (glutamine and arginine; Chamorro et al, 2010), which may directly promote gastrointestinal integrity, modified mucosal histology of early-weaned rabbits. On the basis of current knowledge, we could hypothesise that the CP level and the concentration and characteristics of dietary fibre interact and modify both the amount of undigested protein reaching the caecum and the contribution of the endogenous nitrogen to the total ileal flux (García et al, 1995;Carabañ o et al, 2009). However, the role of this interaction on rabbit health needs to be elucidated.…”

“…In addition, a high dietary protein (DP) level, besides affecting growth performance and nitrogen excretion of rabbits , may impair caecal fermentations and alter gut microflora composition and thus is considered to be among the causes of increased mortality in rabbits (De Blas et al, 1981;Carabañ o et al, 2009). Possible interactions between the protein level and the soluble fibreto-starch ratio may be hypothesised (Gidenne et al, 2001;Carabañ o et al, 2009), but needs to be proven.…”

“…Possible interactions between the protein level and the soluble fibreto-starch ratio may be hypothesised (Gidenne et al, 2001;Carabañ o et al, 2009), but needs to be proven.…”

Transfer of blood urea nitrogen to cecal microbial nitrogen is increased by mannitol feeding in growing rabbits fed timothy hay diet

“…Most of the blood urea is eliminated in the urine and the remainder enters the digestive tract (Jackson et al, 1984;Lobley et al, 2000;Stewart and Smith, 2005), where it can be hydrolyzed to ammonia by the intestinal microflora activity. Ammonia derived from nitrogenous residues (endogenous and undigested food) and urea is the major N source for bacterial growth (Viallard, 1984;Younes et al, 1995b;Carabañ o et al, 2009). It has been well documented that the presence of fermentable materials can stimulate bacterial proliferation -E-mail: eisakag@cc.…”

Effect of dietary soluble fibre level and protein source on growth, digestion, caecal activity and health of fattening rabbits

“…In addition, as stated by Carabaño et al (2009), the role of protein in digestive health level need to be further investigated because little is known about the interaction between dietary fibre composition and the protein level and source. As occurs with protein excess, the use of less digestible protein sources may increase the nitrogen flux at caecum and favour the development of pathogenic strains of E. coli and Clostridium spp., thus impairing animal health and performance (Gutiérrez et al, 2003;García-Ruiz et al, 2006;Chamorro et al, 2007).…”