Protein recycling in growing rabbits: contribution of microbial lysine to amino acid metabolism
Data de publicació2005
MetadadesMostra el registre d'unitat complet
To study the absorption of microbial lysine in growing rabbits, a labelled diet (supplemented with 15NH4Cl) was administered to six animals (group ISOT); a control group (CTRL, four rabbits) received a similar, but unlabelled, diet. Diets were administered for 30 d. An additional group of six animals were fed the unlabelled diet for 20 d and then the labelled diet for 10 d while wearing a neck collar to avoid caecotrophy (group COLL), in order to discriminate it from direct intestinal absorption. At day 30 animals were slaughtered and caecal bacteria and liver samples taken. The 15N enrichment in amino acids of caecal bacteria and liver were determined by GC–combustion/isotope ratio MS. Lysine showed a higher enrichment in caecal microflora (0·925 atom% excess, APE) than liver (0·215 APE) in group ISOT animals, confirming the double origin of body lysine: microbial and dietary. The COLL group showed a much lower enrichment in tissue lysine (0·007 (SE 0·0029) APE for liver). Any enrichment in the latter animals was due to direct absorption of microbial lysine along the digestive tract, since recycling of microbial protein (caecotrophy) was avoided. In such conditions liver enrichment was low, indicating a small direct intestinal absorption. From the ratio of [15N]lysine enrichment between liver and bacteria the contribution of microbes to body lysine was estimated at 23 %, with 97% of this arising through caecotrophy. Absorption of microbial lysine through caecotrophy was 119 (SE 4·0) mg/d, compared with 406 (SE 1·8) mg/d available from the diet. This study confirms the importance of caecotrophy in rabbit nutrition (15% of total protein intake).
És part deBritish Journal of Nutrition, 2005, vol. 94, p. 763-770
Projectes de recerca europeus
Mostrant elements relacionats per títol, autor i matèria.
Abecia, Leticia; Balcells Terés, Joaquim; Fondevila, Manuel; Belenguer, Álvaro; Holtrop, G.; Lobley, Gerald E. (Cambridge University Press, 2008)The contribution of microbial amino acids through caecotrophy to tissue protein metabolism was investigated in lactating does. Attempts were made to vary microbial supply through a dietary antibiotic, Zn bacitracin, and ...
Balcells Terés, Joaquim; Belenguer, Álvaro; Abecia, Leticia; Belanche, Alejandro; Milne, Eric (Elsevier, 2012)In rabbits, caecal fermentation relies to a large extent on the type of substrate available for bacteria. Therefore, in order to study the dietary effect of the source of carbohydrate on microbial nitrogen (N) absorption, ...
Study of the effect of presence or absence of protozoa on rumen fermentation and microbial protein contribution to the chyme Belanche, A.; Abecia, Leticia; Holtrop, G.; Guada, J. A.; Castrillo, C.; de la Fuente Oliver, Gabriel; Balcells Terés, Joaquim (American Society of Animal Science, 2011-06-29)The aim of this study was to investigate the effect of presence or absence of protozoa on rumen fermentation and efficiency of microbial protein synthesis under different diets. Of 20 twin paired lambs, 1 lamb of each pair ...