Efficiency of bacterial protein synthesis in the rumen of sheep receiving a diet of sugar beet pulp and barley

Grass and Forage Science

Wait

1982

The main object of the experiment was to assess the effect of the relative proportion of nonprotein nitrogen (NPN) to total nitrogen in silage on digestion in the sheep. Four unwilted perennial ryegrass silages were made with the addition of formic acid at 0, 2-3, 4-6 and 5-9 litres t"' to provide foods with NPN proportions reducing from 0-56 to 0 40 of the total N, The digestion of the silages was studied in a 4 x 4 Latin Square experiment with sheep cannulated in the rumen, proximal duodenum and terminal ileum.Results for organic matter (OM), cellulose and N showed no major difference between silages in their digestion in the rumen, small intestine and caecum and colon, though small differences (/'<0 05) in rumen fermentation pattern and in the proportion of digestible OM disappearing in the small intestine were observed. Concentrations of ammonia N in the rumen and rates of rumen bacterial protein synthesis did not differ significantly between silages and there were no treatment effects on the passage of individual amino acids to the small intestine. The results indicate that the proportions of NPN to total N in the silages examined had little influence on the efliciency of silage N utilization in the rumen or on the passage of undegraded dietary protein to the small intestine.

Section: Methodsmentioning

confidence: 99%

The rate of addition of formic acid to grass at ensilage and the subsequent digestion of the silage in the rumen and intestines of sheep

Grass and Forage Science

Wait

1982

“…Samples were prepared and stored as described previously (Chamberlain et al, 1976). Faeces samples for nitrogen analysis were preserved with 0 5 M H2SO4 and stored at 4°C.…”

Section: Preparation and Storage Of Samplesmentioning

confidence: 99%

“…Methods of chemical analysis were as described by Chamberlain et al (1976) and Kelly and Thomas (1978). Samples for amino acid analysis were hydrolysed by refluxing with 6 M HCI for 24 h under a nitrogen atmosphere.…”

Section: Chemical Analysismentioning

confidence: 99%

Utilization of silage nitrogen in sheep and cows: amino acid composition of duodenal digesta and rumen microbes

Grass and Forage Science

Quig

1986

Two experiments are reported. In the first experiment the amino acid compositions of rumen bacteria and protozoa isolated from sheep given a diet of grass silage were compared with those taken from sheep given a diet of hay and barley; four sheep were assigned to each diet. There were no significant differences (P<0·05) between diets in the amino acid compositions of the microbial fractions and bacterial contents of α‐ɛ‐diaminopimelic acid were also similar for both diets. In the second experiment the digestion of a grass silage and barley diet (65:35; 135 g CP (kg DM)‐1) was studied using four non‐lactating Ayrshire cows fitted with cannulae in the rumen and in the proximal duodenum. The mean N intake was 154 g d‐1 and the corresponding duodenal flow was 126 ± 10 g d‐1 indicating that 0·21±0·07 of the N intake was absorbed between the mouth and the duodenum. The mean rumen NH3‐N concentration was high, 297 g litre‐1, and the mean rate of microbial protein synthesis in the rumen was low, 17 g microbial N (kg OM apparently digested in the rumen)‐1. There was a low content of bacterial N in the non‐ammonia N at the duodenum (mean proportion 0·52±005) and low concentrations of methionine and lysine in the duodenal digesta protein. The results are discussed in relation to previously published data on the digestion of silage diets in sheep and to the utilization of silage diets for milk production in the cow. It is concluded that with silage diets the supply of methionine and lysine to the duodenum is likely to be low because of the low rates of microbial protein synthesis in the rumen and that in cows those two amino acids may be limiting for milk production.

“…The bacterial crude protein synthesised in the rumen was estimated from the amount of a-c-diaminopimelic (DAPA) acid passing to the duodenum and the DAPA content of bacterial nitrogen in the bacteria obtained from the rumen of animals receiving each diet.l. 2 The results were analysed using a one way analysis of variance.…”

Section: Calculations and Statistical Analysismentioning

confidence: 99%

Ruminal nitrogen metabolism and the passage of amino acids to the duodenum in sheep receiving diets containing hay and concentrates in various proportions

1979

J Sci Food Agric

Self Cite

Three sheep fitted with rumen cannulas and three sheep fitted with duodenal re-entrant cannulas in addition to rumen cannulas were given, in successive periods, 700 g d-1 of five diets consisting of chopped hay and a concentrate mixture of rolled barley and flaked maize (50: 50) in the ratios of 1 : 0, 5 : 2, 3 : 4, 1 : 6, and 0: 1. For bacteria isolated from the rumen of sheep fitted with rumen cannulas only, there were no significant differences in either the content of nitrogen in their dry matter or in the amino acid composition, but the content of a-r-diaminopimelic acid varied significantly ( P < 0.05) between diets, mean values ranging from 39 to 50 kg-l nitrogen. As the proportion of concentrate in the diet increased, the intake of nitrogen was progressively reduced from 11.9 to 9.8 g d-1 and this was accompanied by an increase in the amount of organic matter apparently digested in the rumen, from 296 to 402 g d-l. But there were no significant differences between diets in either the ruminal concentration of ammonianitrogen (mean values varied from 78 to 96 mg litre-l) or in the duodenal passage of total nitrogen, which ranged from 12.1 to 14.7 g d-l with a peak value for the 5:2 diet. Rates of synthesis of bacterial protein in the rumen were 186, 228, 124 and 94 g crude protein per kg organic matter apparently digested in the rumen for the 1 : 0,5 : 2, 3 :4, 1 : 6 and 0: 1 diets respectively, the rates for the 1 : 6 and 0: 1 diets being significantly (P< 0.05) lower than those for the other diets. The 0: 1 diet was associated with a low proportion, 0.5, of bacterial protein in the duodenal crude protein and it is suggested that with this diet, protozoal protein made an appreciable contribution to the crude protein passing from the rumen.