Ruminal and post-ruminal protein digestion in sheep fed on subterranean clover harvested at four stages of maturity

1975 ◽  
Vol 26 (1) ◽  
pp. 199 ◽  
Author(s):  
ID Hume ◽  
DB Purser
Keyword(s):  
Nitrogen Retention ◽  
Subterranean Clover ◽  
Causal Factor ◽  
Protein Digestion ◽  
Microbial Protein ◽  
Dietary Nitrogen ◽  
Microbial Nitrogen ◽  
Digestible Organic Matter ◽  
Faecal Nitrogen ◽  
Ruminal Digestion

Digestion of the protein of subterranean clover harvested at four stages of maturity was studied in Merino wethers fitted with re-entrant duodenal cannulae. The relative proportions of dietary and microbial nitrogen flowing into the duodenum were estimated from the incorporation into microbial protein of sulphur-35 from ruminal infusions of Na235SO4. Sheep given immature clover consumed more digestible organic matter (DOM) and retained more nitrogen per 100 g DOM intake than sheep given wilted and mature clovers. More protein of the immature clover was degraded in the rumen (73%) than of the mature clover (43–53%); post-ruminal digestibility of dietary protein escaping ruminal proteolysis was also higher for the immature clover (67–70% versus 51–53%). The quantities of clover protein (per 100 g DOM intake) digested post-ruminally were therefore similar at all stages of maturity. The yield of microbial protein (mean 19.9 g per 100 g OM digested in the rumen) was also similar on all treatments. However, ruminal digestion of the DOM of the immature clover was more complete (84%) than that of the mature clover (60–71%); consequently, microbial protein production per 100 g DOM intake was greater on the immature clover. Greater nitrogen retention by animals consuming immature clover was associated with a greater DOM intake. Whether the causal factor was the greater supply of microbial protein per 100 g DOM, or whether the causal factor was a greater DOM intake controlled by factors associated with ruminal digestion, is unresolved. It is also apparent that the greater faecal nitrogen losses per 100 g DOM intake on the mature clover compared with the immature clover were attributable entirely to differences in the amounts of dietary nitrogen excreted at different stages of maturity of the clover.

Rumen microbial protein synthesis and proportions of microbial and non-microbial nitrogen flowing to the intestines of sheep

1975 ◽  
Vol 26 (4) ◽  
pp. 699 ◽  
Author(s):  
DJ Walker ◽  
AR Egan ◽  
CJ Nader ◽  
MJ Ulyatt ◽  
GB Storer
Keyword(s):  
Protein Synthesis ◽  
Subterranean Clover ◽  
Ammonia Nitrogen ◽  
Microbial Protein ◽  
Total Flow ◽  
Mean Values ◽  
Microbial Protein Synthesis ◽  
Microbial Nitrogen ◽  
Flow Through ◽  
Sulphur Amino Acids

Microbial protein synthesis in the rumen of mature sheep was measured by a technique dependent upon the incorporation of 35S from radioactive sulphate into microbial sulphur amino acids. In two separate experiments, sheep were fed on four dried forages and three fresh forages. Mean values and standard deviations for microbial protein synthesis per mole of volatile fatty acid produced in the rumen were 16.1 ? 3.4 g and 20.4? 2.3 g for dried and fresh forages respectively. Corresponding values for microbial protein synthesized per 100 g of organic matter digested in the rumen were 15.1 ? 3.6 g and 24.6 ? 4.9 g. Turnover constants for microbial protein were 1.06 ? 0.12 day-1 and 1.42 ? 0.10 day-1 when dried and fresh forages respectively were eaten, and it is suggested that efficiency of microbial protein synthesis was dependent on the rate of digesta flow through the rumen. Of the non-ammonia nitrogen (NAN) reaching the duodenum up to 41, 53 and 68% was non-microbial in origin when perennial ryegrass, Tama ryegrass and white clover respectively were eaten fresh-cut. When either subterranean clover hay, lucerne hay, wheaten hay or a mixture of wheaten hay plus wheat straw was eaten, up to 67, 57, 52 and 57% respectively of NAN at the duodenum was non-microbial in origin. In the latter two cases, the total flow of NAN was relatively low but the apparent digestibility of the non-microbial fraction in the intestines was still appreciable.

The metabolic excretion and true digestibilities of nitrogen and fat by cattle and sheep with particular reference to forage-faeces relationships

1972 ◽  
Vol 23 (5) ◽  
pp. 879 ◽  
Author(s):  
KW Moir ◽  
AJ Swain
Keyword(s):  
Organic Matter ◽  
Nitrogen Excretion ◽  
Multiple Regression Equation ◽  
Detergent Solution ◽  
Dietary Nitrogen ◽  
True Digestibility ◽  
Digestible Organic Matter ◽  
Faecal Nitrogen ◽  
Digestible Protein ◽  
Cattle And Sheep

The non-dietary nitrogen excretion in faeces and the true digestibility of nitrogen determined in 23 digestibility experiments with grasses were respectively 0.60 ± 0.063 g N per 100 g forage organic matter and 84.9 ± 2.29%, when estimated from the regression of digestible nitrogen on percentage dietary nitrogen, and 0.60 ± 0.026 g N and 82.9 ± 2.33%, when estimated from data obtained by separating dietary and nondietary faecal nitrogen with detergent solution. The true digestibility of nitrogen, estimated similarly in four digestibility experiments with legumes, was higher than that in grasses. Among grasses and legumes but not within grasses, digestible organic matter was more closely correlated with non-dietary faecal nitrogen than with total faecal nitrogen. Among and within grasses and legumes the apparently digestible protein was more closely correlated with faecal nitrogen when undigested dietary nitrogen as a proportion of total faecal nitrogen was included as a variate in a multiple regression equation. The endogenous excretion of saponifiable fat was negligible and its average true digestibility estimated from regression analysis was 52. .6 ± 5.55 %.

scholarly journals Synthesis of microbial protein from ammonia in the sheep's rumen and the proportion of dietary nitrogen converted into microbial nitrogen

1970 ◽  
Vol 24 (2) ◽  
pp. 589-598 ◽  
Author(s):  
A. F. Pilgrim ◽  
F. V. Gray ◽  
R. A. Weller ◽  
C. B. Belling
Keyword(s):  
Steady States ◽  
Total Production ◽  
Microbial Protein ◽  
Entry And Exit ◽  
Nitrogenous Compounds ◽  
Dietary Nitrogen ◽  
N Concentration ◽  
Microbial Nitrogen ◽  
Starting Point ◽  
Microbial N

1. The extent to which ammonia-N (NH3-N) serves as a starting point for synthesis of microbial nitrogenous compounds was assessed when 15N as (15NH4)2SO4 was continuously infused into the rumen of a sheep for periods of 78–98 h. Steady states were reached in the composition of the rumen contents because the animal was fed equal parts of its ration at hourly intervals. Concentrations of 15N in bacterial-N, protozoal-N and rumen NH3-N were compared.2. In two trials with a low-N diet consisting largely of wheaten hay the 15N concentration in bacterial N was 76 and 78% of that in the NH3-N. For protozoa the values were more variable —64 and 43%.In two trials with a higher-N diet (lucerne hay), the corresponding values were lower—bacterial-N 62 and 64%, protozoal-N 41 and 35%.It was concluded that synthesis of microbial protein was more dependent on ammonia as a starting point with the low-N diet than with the higher-N diet.3. Entry and exit rates for ammonia into and out of the rumen system were determined, and the results, in combination with those obtained for bacterial-N in the first part of the work, allowed calculations to be made of the production of microbial-N/d formed from NH3-N, and this in turn allowed calculation of minimal values for conversion of plant-N to microbial-N in the lumen. Minimal extent of conversion was 68% for the low-N diet and 53–55% for the higher-N diet.4. Total production of microbial-N in relation to the amount of N given was also calculated by using previously reported values for the relative proportions of protozoal-N and bacterial-N in sheep given diets similar to those used here. These values for extent of conversion were 73% for the low-N diet and 58–59% for the higher-N diet.

The effect of antibiotics on ammonia accumulation and protein digestion in the rumen

1969 ◽  
Vol 20 (2) ◽  
pp. 339 ◽  
Author(s):  
JP Hogan ◽  
RH Weston
Keyword(s):  
Organic Matter ◽  
Food Intake ◽  
Dietary Protein ◽  
Alimentary Tract ◽  
Protein Digestion ◽  
Microbial Protein ◽  
Ammonia Accumulation ◽  
Digestible Organic Matter

A study was made of the feasibility of using antibiotics to reduce ruminal deamination of protein that comprised 27% of the organic matter in a diet of lucerne hay and casein. Six sheep were each dosed with a different antibiotic. At the levels given, penicillin and erythromycin reduced rumen ammonia levels by about 35%, but also reduced food intake. Chloramphenicol reduced rumen ammonia by about 50% but neomycin, oxytetracyclene, and streptomycin had little effect.When all six sheep were subsequently dosed with chloramphenicol at 1 g/day the levels of rumen ammonia were reduced only to 85% of the control. The antibiotic had little effect on the extent of digestion of protein, organic matter, and cellulose, both in the stomach and in the whole alimentary tract, and on parameters associated with the movement of digesta through the stomach The quantity of nitrogen passing from the stomach in forms other than ammonia was 52–54% of intake during both the control and treatment periods. Much of this nitrogen probably passed from the stomach in the form of microbial protein, which indicated that the dietary protein was extensively digested. In consequence of the loss of nitrogen from the stomach, the protein apparently digested in the intestines was equivalent to only about 14.5 g/100 g digestible organic matter.

Botanical and chemical components of the diet and liveweight change in cattle on semi-desert rangeland in central Australia.

1983 ◽  
Vol 5 (1) ◽  
pp. 28 ◽  
Author(s):  
VR Squires ◽  
BD Siebert
Keyword(s):  
Arid Zone ◽  
Experimental Period ◽  
Chemical Components ◽  
Dietary Nitrogen ◽  
Grazing Cattle ◽  
Digestible Organic Matter ◽  
Faecal Nitrogen ◽  
Central Australia ◽  
Semi Arid

A study was made of cattle grazing three plant communities in a 40 ha area of semi-arid rangeland in central Australia after the opening summer rains. The botanical and chemical composition of the diet selected was examined in relation to the site of grazing and the growth of the animals. Site af grazing and liveweight change in 12 Shorthorn yearling steers were recorded at two-week intervals for 24 weeks. Simultaneously diet samples were collected from a group of four similar cattle which had established oeso- phageal fistulas. The highest liveweight gains (1.2 kg per head per day) were recorded at times when green grass and forb species made up most of the diet. At such times there were peak levels of nitrogen and digestible organic matter in the diet and minimum levels of cell wall constituents. Faecal nitrogen showed a similar pattern to dietary nitrogen. Mean rate of liveweight gain shown by the cattle on these native rangelands over 126 days of growth was 0.79 kg per head per day and over the entire experimental period 0.6 kg per head per day. These gains are quite high and are discussed in terms of the digestible energy available to grazing cattle. Comparisons are made between this arid zone situation and that of native and improved pastures in humid tropical and temperate areas. The relationships between nutrients in the diet, or faecal nitrogen, and the liveweight change of cattle provided a means of determining the quality of the forage available and/or the degree of liveweight change of range land cattle.

7.1 Protein Digestion in Grazing Sheep

1982 ◽  
Vol 6 ◽  
pp. 141-143
Author(s):  
J. L. Corbett ◽  
E. P. Furnival ◽  
M. W. Inskip ◽  
F. S. Pickering
Keyword(s):  
Organic Matter ◽  
Protein Production ◽  
Protein Digestion ◽  
Microbial Protein ◽  
Adult Sheep ◽  
Digestible Organic Matter ◽  
Grazing Sheep ◽  
Native Pastures

In 23 experiments, measurements were made over 4 or 5 day periods of the digestion of herbage by lambs (Expts 1-10 and 14-18, Table 7.1.1) and adult sheep (Expts 11-13 and 19-23) grazing phalaris (P. aquatica), lucerne and unfertilized native pastures. All 38 animals used (Corriedales) had rumen and simple abomasal cannulae; seven adult sheep also had a simple ileal cannula. Corbett, Furnival, Inskip, Perez and Pickering (1976) and Corbett (1981) have described the techniques used for estimating intakes of organic and digestible organic matter and nitrogen (OMI, DOMI, NI) and the fractional outflow rates (FOR/h) of liquid from the rumen, the rate and composition of digesta flows and microbial protein production by reference to intra-ruminally infused 103Ru-phenanthroline, 51CrEDTA and Na235S04.

The estimation of the intake of grazing sheep II. Application of faecal nitrogen regressions to a group of grazing sheep

1962 ◽  
Vol 59 (3) ◽  
pp. 349-353 ◽  
Author(s):  
G. R. Pearce ◽  
J. E. Vercoe ◽  
D. E. Tribe
Keyword(s):  
Organic Matter ◽  
Feed Intake ◽  
General Pattern ◽  
Live Weight ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Lolium Rigidum ◽  
Digestible Organic Matter ◽  
Faecal Nitrogen ◽  
Grazing Sheep

1. Recordings of faecal organic matter (O.M.), faecal N% (O.M. basis) and live weight, were made over 52 consecutive weekly periods on ten Corriedale wethers grazing a pasture consisting mainly of Wimmera rye-grass (Lolium rigidum Gaud.) with some subterranean clover (Trifolium subterraneum) in a Mediterranean-type environment. The amount of available O.M. and its N% were also recorded.2. By applying regressions of (i) the ratio of O.M. feed intake to O.M. faecal output on faecal N% and (ii) the N% in the O.M. intake on faecal N%, to the above observations it was possible to estimate the following quantities: O.M. and digestible organic matter (D.O.M.) intake, N and digestible N intake and O.M. digestibility percentage.3. The patterns of O.M. and D.O.M. intake, and N and digestible N intake are described. Similar patterns exist for each of these quantities. Two maxima, a large one in the spring and a smaller one in the autumn, and two minima, one in the summer and one in the winter, are exhibited. The values for these various maxima and minima are presented in the text.4. Attention is drawn to variations from the general pattern for these quantities and factors which could influence these patterns are mentioned.

Effects of synchronising dietary nitrogen and energy supply in diets with a similar carbohydrate composition on rumen fermentation and microbial protein synthesis in sheep

1993 ◽  
Vol 1993 ◽  
pp. 111-111
Author(s):  
L. A. Sinclair ◽  
P. C. Garnsworthy ◽  
J. R. Newbold ◽  
P. J. Buttery
Keyword(s):  
Protein Synthesis ◽  
Rumen Fermentation ◽  
Carbohydrate Composition ◽  
Microbial Protein ◽  
Rumen Microbes ◽  
Microbial Protein Synthesis ◽  
Dietary Nitrogen ◽  
Microbial Nitrogen ◽  
Metabolisable Energy ◽  
Micro Organisms

The recently introduced metabolisable protein system for ruminants (Webster 1992) relates microbial nitrogen production to daily supply of fermentable metabolisable energy and effective rumen degradable protein but does not consider the effect of the pattern of supply of nutrients to rumen microbes on their efficiency and growth. However, synchronising the hourly supply of nitrogen and energy yielding substrates to rumen micro-organisms has been shown to increase the efficiency of microbial protein synthesis (Sinclair et al. 1993). The objective of the current experiment was to examine the effects of synchronising the hourly supply of energy and nitrogen in diets with a similar carbohydrate composition but differing in the rate of protein degradation, on rumen fermentation and microbial protein synthesis in sheep.

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