Validation of purine bases as a microbial marker in lambs Validation of use of purine bases as a microbial marker by 15 N labelling in growing lambs given high-concentrate diets: effects of grain processing, animal age and digesta sampling site (original) (raw)
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Animal Science, 2005
The origin of post-ruminal purine bases ( PB) was studied in 24 growing lambs that were given a pelleted concentrate plus barley straw (C) or whole barley grain plus protein supplement ( WB). Six lambs from each treatment were slaughtered at 10 and 30 days post weaning after 15 N labelling of microbial nitrogen (N) and PB. Microbial contribution to digesta nonammonia N (NAN) and PB was lower ( P < 0·01) when estimated from duodenal rather than abomasal samples (0·36 v. 0·52 (s.e.d. 0·021) for NAN and 0·47 v. 0·77 (s.e.d. 0·029) for PB) as a result of endogenous contamination. In comparison with 15 N, total PB/N led to higher estimates ( P < 0·01) of microbial contribution to abomasal NAN in WB treatment (0·62 v. 0·46 s.e.d. 0·049). The difference was removed after correcting for microbial PB, while this effect was not observed with < the C diet, resulting in a marker by diet interaction ( P < 0·05). Abomasal PB flow increased ( P < 0·1) from 10 to 30 days after weaning mainly due to the higher proportion of microbial PB (0·70 v. 0·81 (s.e.d. 0·047)). Rumen apparent PB degradation did not differ between diets in older lambs, but it was proportionally 0·39 lower for WB treatment ( P < 0·05) in younger lambs. When the microbial PB flow was estimated indirectly from labelled microbial N and the PB/N ratio of bacterial extracts the estimates were in agreement with those derived from PB-15 N in the WB treatment but resulted in unrealistic values in lambs on diet C. Results suggest that significant proportions of dietary PB can escape rumen degradation which may lead to overestimation of microbial contribution to abomasal NAN when the PB/N ratio is used as marker. The extent of the overestimation is affected by the lamb age and grain processing.
British Journal of Nutrition, 1996
The present study compares estimates of rumen microbial-N production derived from duodenal flow measurements (15N and purine bases) with those from measurements of the urinary excretion of purine derivatives. Four Rasa Aragonesa ewes fitted with simple cannulas in the rumen and proximal duodenum were used. Four diets consisting of 550 g lucerne (Medicago sativa) hay/d as sole feed or supplemented with 220, 400 and 550 g rolled barley grain/d were given in a 4 x 4 random factorial arrangement. Duodenal digesta flows were determined by the dual-phase marker technique during continuous intraruminal infusions of Co-EDTA and Yb-acetate. Microbial contribution to the non-NH3N (NAN)flow was estimated from 15N enrichment and purines: N ratio in duodenal digesta and bacterial fractions isolated from the rumen content. Whole tract organic matter (OM) digestibility and duodenal flow of OM and NAN increased (P<0·001) with the level of barley supplementation. Digestible OM intake ranged from ...
Journal of Animal Physiology and Animal Nutrition, 2010
This study examined the reticulo-rumen characteristics of the microbial community and its fermentative characteristics in milk-fed, at weaning and finished lambs in a conventional fattening system. Five lambs were assigned to each of three groups: milk-fed lambs slaughtered at 30 days (T30), weaned lambs slaughtered at 45 days (T45) and 'finished lambs' slaughtered at 90 days (T90). At slaughter, rumen size, fermentation parameters (pH, volatile fatty acids and microbial enzyme activity) and protozoal counts were recorded. Quantitative PCR was used to quantify the genes encoding 16S and 18S ribosomal DNA of the rumen bacterial and protozoal populations, respectively, and the sequential colonization of the rumen by cellulolytic (Ruminococcus albus, Ruminococcus flavefaciens) and amylolytic (Prevotella ruminicola, Streptococcus bovis) bacteria, and protozoa (Entodinium sp.). Denaturing gradient gel electrophoresis was used to study the development of rumen microbiota biodiversity. Intake of solid food before weaning caused a significant increase in rumen weight (p < 0.0001) and bacterial DNA (p < 0.05) and volatile fatty acid analysis concentration (p < 0.01), whereas pH declined. In milk-fed lambs, cellulolytic bacteria were evident after 30 days. Thereafter, in the 45-day and 90-day groups, the proportions of R. flavefaciens decreased and R. albus increased. Amylolytic bacteria were present in milk-fed lambs; the proportion of P. ruminicola increased in fattening lambs and S. bovis was the least abundant species. Protozoal concentrations were irregular; milk-fed lambs had a significant number of protozoa species from Entodinium and subfamily Isotrichiidae, but they disappeared at weaning. Lamb rumen were refaunated in some individuals at 90 days (Entodinium and subfamily Diplodiniinae spp.), although individual concentrations were variable.
Journal of animal science, 1991
Five sheep (average BW 62 kg) were fed 65% roughage: 35% concentrate diets (CP = 15%) in a 5 x 5 Latin square design to study the effects of combinations of defaunation and N supplements (soybean meal [SBM], corn gluten meal [CGM], blood meal [BM], urea, and casein) differing in ruminal degradation on ruminal microbial numbers and activity. Diets were fed twice daily (DM intake 1,759 g/d). Defaunation was accomplished with doses of 30 ml of alkanate 3SL3.sheep-1.d-1 for 3 d with 2 d of fasting. Treatment 1 (control) involved feeding faunated sheep a diet in which the supplemental N was 67% SBM N and 33% urea N. Treatment 2 involved feeding defaunated sheep the same diet as the control. Treatments 3, 4, and 5 involved feeding defaunated sheep diets in which the supplemental N source was either 67% CGM-BM N (CGM and BM combined on a 1:1 N ratio): 33% urea N, or 33% CGM-BM N:67% urea N or 33% CGM-BM N:33% urea N:33% casein N, respectively. Compared with the faunated control, defaunatio...
Advances in Biological Sciences Research
This experiment aimed to compare the rumen microbial nitrogen supply in male and female Garut Sheep. Six male and female Garut sheep were put in the metabolism cages, fed ad libitum with Pennisetum purpureum and bran pollard with a ratio 60 : 40. This study begins with an adaptation period of 14 days. Urine collection was carried out for seven days. Urine samples be measured for purine derivatives (PD), consisting of allantoin, uric acid ,and xanthine-hypoxanthine. During the collection period, samples of feed, uneaten feed, and feces were taken out for dry matter and organic matter analysis. The total urinary PD excretions data were used to estimate microbial nitrogen supply (EMNS) based on the equation postulated with modification in endogenous PD excretion for male and female Garut sheeps. Data obtained were analyzed using the Independent Student T-Test design. The results showed that urinary PD excretion in male Garut sheep was higher than in females (0.160 vs 0.127 mmol/W 0.75 /day). EMNS in male Garut sheep also tended to be higher than in females (1.14 vs 0.74 g N/day). In conclusion, the excretion of PD and EMNS in male Garut sheep tended to be higher than in females.
Scientific Reports
The objective of this study was to determine the influence of a total-mixed ration including unsalable carrots at 45% DM on the rumen microbiome; and the plasma, rumen and liver metabolomes. Carrots discarded at processing were investigated as an energy-dense substitute for barley grain in a conventional feedlot diet, and improved feed conversion efficiency by 25%. Here, rumen fluid was collected from 34 Merino lambs at slaughter (n = 16 control; n = 18 carrot) after a feeding period of 11-weeks. The V4 region of the 16S rRNA gene was sequenced to profile archaeal and bacterial microbe communities. Further, a comprehensive, targeted profile of known metabolites was constructed for blood plasma, rumen fluid and biopsied liver metabolites using a gas chromatography mass spectrometry (GC–MS) metabolomics approach. An in vitro batch culture was used to characterise ruminal fermentation including gas and methane (CH4) production. In vivo rumen microbial community structure of carrot fed ...
Frontiers in microbiology, 2018
Modulating the assembly of the ruminal microbiota might have practical implications in production. We tested how an early-life dietary intervention in lambs influences the diversity and function of the ruminal microbiota during and after the intervention. Microbiota resilience during a repeated dietary intervention was also tested. The treatment, aiming to mitigate enteric methane emissions, combined garlic essential oil and linseed oil. Fifty-six lambs and their dams were allocated to two groups and treatment (T1) or placebo (C1) was drenched from birth until 10 weeks of life. Lambs were weaned at 8 weeks. From 16 to 20 weeks, lambs in each group were divided in two subgroups that received (T1-T2 and C1-T2) or not (T1-C2 and C1-C2) the same treatment. Measurements were done at 8, 14, and 20 weeks. Average daily gain was similar between groups. Methane production was reduced by treatment at 8 and 20 weeks but at 14 weeks it was similar between C1 and T1. Interestingly, early-life tr...
Frontiers in Microbiology, 2021
Using two successive types of diets (100% concentrate and 67% forage), this study explores the relationship between the ruminal microbiota of 78 Romane lambs and their feed efficiency (residual feed intake trait) or feeding behavior (feeding rate trait). Analysis was carried out phenotypically by correlating feed efficiency or feeding behavior traits with the relative abundance of bacteria at the phylum, family, and genus levels, and then genetically by comparing the microbiota of lambs selected for extreme breeding values for residual feed intake or feeding rate. Our results confirmed the major effect of diet on the ruminal microbiota composition. The microbiota of lambs consuming a forage-based diet was distinguished by higher microbial diversity and also by higher relative abundance of Firmicutes, whereas Bacteriodetes and Actinobacteria were relatively more abundant in the microbiota of lambs consuming a concentrate-based diet. Moreover, the comparison of lambs divergent for res...
The effect of feed processing on ruminal parameters in intensively fattened lambs
2014
The aim of the study was to assess the influence of three processing ways of the concentrate feed on ruminal dry matter degradability, ruminal pH and ruminal protozoa population. Pelleted concentrate feed was mechanically processed to a particle size of ø 5 mm (variant A), ground at ø 2 mm (variant B) or by replacing the 50% of ground corn grain with expanded corn with ø 2 mm particle size as in B (variant C). The trial was carried out alternately on three lambs during their 90-132 days of life fitted with ruminal fistula. Feed bags and ruminal fluid was collected through the ruminal cannula at 3, 6, 9, 12, and 24 hours of incubation. After 24 hours of incubation the intra-ruminal feed concentrate dry matter degradation was significantly higher in expanded concentrate compared to pelleted concentrate (80.81% vs. 70.48%, P0.049). The same parameter had an intermediary value of 77.85% for ground feed concentrate. Reducing pH value of the ruminal fluid from values of over 5.7 to an av...