Effect of defaunation on protein and fibre digestion in sheep fed on ammonia-treated straw-based diets with or without maize

Ushida, Kazunari; Kayouli, C.; Smet, Sarah De; Jouany, J. P.

doi:10.1079/bjn19900078

Cited by 44 publications

(24 citation statements)

References 38 publications

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“…Indeed, in our study, defaunation decreased in sacco DM degradation, but similar results have been observed by other authors [18,36]. The decrease of the in sacco DM degradation could be explained on the one hand, by the decrease in enzymatic activities and on the other hand, by the modification of the structure of the microbial population, after defaunation.…”

Section: Discussionsupporting

confidence: 74%

Effects of defaunation on microbial activities in the rumen of rams consuming a mixed diet (fresh Digitaria decumbens grass and concentrate)

et al. 2004

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-The effects of defaunation on microbial activities in the rumen of sheep given mixed diets (fresh Digitaria decumbens and concentrate) were studied. Eight faunated rams and eight defaunated rams, with ruminal cannula were used. Each animal was fed with 4 different mixed diets, Digitaria decumbens grass supplemented with 4 mixtures of Soya meal and ground maize. The protein digestible in the intestine (French feeding system, PDI) to energy (French feeding system, forage unit UFL) levels (P/E) in the diets were 80 (D1), 100 (D2), 120 (D3) and 140 (D4). The major cellulolytic bacteria were enumerated by specific 16S rRNA targeted hybridisation probes, some microbial activities of the rumen were estimated by enzymatic assays and by the in sacco degradation technique. The diet (P/E ratio) and defaunation had no effect on the percentage of the cellulolytic bacteria, represented by three species: Ruminococcus albus, Ruminococcus flavefasciens and Fibrobacter succinogenes. The diet had a significant effect (P < 0.05) on the total activity of the fibrolytic enzymes (Carboxymethyl cellulase, xylanase) and glycosidases (β-D glucosidase, β-D xylosidase). Defaunation decreased (P < 0.05) the total activity of fibrolytic polysaccharidase (Carboxymethyl cellulase, xylanase) and glycosidase (β-D glucosidase, β-D xylosidase) enzymes. Neither defaunation nor the diet had any effect on α-amylase activities. Defaunation decreased (P < 0.05) total α-D glucosidase activity. The decrease of the total activity of carboxymethyl cellulase after defaunation was more marked (P < 0.05) with the D3 diet. The diet had a significant effect (P < 0.01) on the in sacco DM degradation (96 h). Defaunation decreased the in sacco DM degradation (96 h, P < 0.05) and this decrease was negatively correlated with the P/E ratio. Defaunation significantly decreased the total volatile fatty acid concentration (P < 0.05) and the molar proportion of butyrate (P < 0.01). From these results, despite reduced fibrolytic and amylolytic activities, a lower proteolysis and a more advantageous ruminal VFA profile occurred in defaunated animals. As a consequence, a better use of nutrients (protein, energy) can be expected by defaunated animals. Résumé -Les effets de la défaunation sur les activités microbiennes du rumen de moutons ingérant des rations mixtes (Digitaria decumbens en vert complétée avec du concentré). Huit béliers faunés et 8 béliers défaunés munis de canules ruminales ont été utilisés. Chaque animal était alimenté par 4 rations mixtes différentes composées d'herbe de Digitaria decumbens complémentée avec 4 mélanges de tourteau de soja et de maïs broyé. Le niveau de protéine (PDIN) / énergie (UFL) de la ration (P/E) était de 80 (D1), 100 (D2), 120 (D3) et 140 (D4). Les principales populations de bactéries cellulolytiques ont été dénombrées à l'aide de sondes d'hybridation spécifiques ciblant l'ARNr 16S, certaines activités microbiennes du rumen ont été estimées par des dosages d'activités enzymatiques, et par la technique de dégradabilité in ...

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Section: Discussionsupporting

confidence: 74%

Effects of defaunation on microbial activities in the rumen of rams consuming a mixed diet (fresh Digitaria decumbens grass and concentrate)

et al. 2004

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“…In such conditions, defaunation decreases bacterial N recycling and OM digestibility (Eugène et al, 2004b) while increasing the efficiency of microbial protein synthesis (EMPS; Ushida et al, 1990). In such conditions, defaunation decreases bacterial N recycling and OM digestibility (Eugène et al, 2004b) while increasing the efficiency of microbial protein synthesis (EMPS; Ushida et al, 1990).…”

Section: Introductionmentioning

confidence: 99%

Study of the effect of presence or absence of protozoa on rumen fermentation and microbial protein contribution to the chyme1

Belanche

Abecia²,

Holtrop

et al. 2011

Journal of Animal Science

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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 was isolated from the ewe within 24 h after birth and reared in a protozoa-free environment (n = 10), whereas their respective twin-siblings remained with the ewe (faunated, n = 10). When lambs reached 6 mo of age, 5 animals of each group were randomly allocated to 1 of 2 experimental diets consisting of either alfalfa hay as the sole diet, or 50:50 mixed with ground barley grain according to a 2 × 2 factorial arrangement of treatments. After 15 d of adaptation to the diet, the animals were euthanized and total rumen and abomasal contents were sampled to estimate rumen microbial synthesis using C(31) alkane as flow marker. Different ((15)N and purine bases) and a novel (recombinant DNA sequences) microbial markers, combined with several microbial reference extracts (rumen protozoa, liquid and solid associated bacteria) were evaluated. Absence of rumen protozoa modified the rumen fermentation pattern and decreased total tract OM and NDF digestibility in 2.0 and 5.1 percentage points, respectively. The effect of defaunation on microbial N flow was weak, however, and was dependent on the microbial marker and microbial reference extract considered. Faunated lambs fed with mixed diet showed the greatest rumen protozoal concentration and the least efficient microbial protein synthesis (29% less than the other treatments), whereas protozoa-free lambs fed with mixed diet presented the smallest ammonia concentration and 34% greater efficiency of N utilization than the other treatments. Although (15)N gave the most precise estimates of microbial synthesis, the use of recombinant DNA sequences represents an alternative that allows separate quantification of the bacteria and protozoa contributions. This marker showed that presence of protozoa decrease the bacterial-N flow through the abomasum by 33%, whereas the protozoa-N contribution to the microbial N flow increased from 1.9 to 14.1% when barley grain was added to the alfalfa hay. Absolute data related to intestinal flow must be treated with caution because the limitations of the sampling and maker system employed.

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“…While the bacteria are the most numerous cellulolytic organisms in the rumen, some protozoal species are also believed to produce plant cell wall hydrolases and their larger individual size means that they could account for a significant proportion of rumen fibre digestion [4]. Defaunation, the removal of protozoa from the rumen, results in depressed plant fibre breakdown under conditions where nitrogen is not limiting, again suggesting a significant role for the protozoa in ruminal fibre digestion [5].…”

Section: Introductionmentioning

confidence: 99%

A xylanase produced by the rumen anaerobic protozoanPolyplastron multivesiculatumshows close sequence similarity to family 11 xylanases from Gram-positive bacteria

Devillard¹,

Newbold²,

Scott³

et al. 1999

FEMS Microbiology Letters

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We report for the first time the cloning and characterisation of a protozoal enzyme involved in plant cell wall polysaccharide degradation. A cDNA library was constructed from the ruminal protozoan Polyplastron multivesiculatum and a stable clone expressing xylanase activity was isolated. The encoded enzyme belongs to the glycoside hydrolase family 11, and phylogenetic analysis indicates a closer relationship with catalytic domains from Gram-positive bacteria than the other fibrolytic eukaryotes from the rumen, the anaerobic fungi.

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Effect of defaunation on protein and fibre digestion in sheep fed on ammonia-treated straw-based diets with or without maize

Cited by 44 publications

References 38 publications

Effects of defaunation on microbial activities in the rumen of rams consuming a mixed diet (fresh Digitaria decumbens grass and concentrate)

Effects of defaunation on microbial activities in the rumen of rams consuming a mixed diet (fresh Digitaria decumbens grass and concentrate)

Study of the effect of presence or absence of protozoa on rumen fermentation and microbial protein contribution to the chyme1

A xylanase produced by the rumen anaerobic protozoanPolyplastron multivesiculatumshows close sequence similarity to family 11 xylanases from Gram-positive bacteria

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