On the Mechanism of Non-Protein-Nitrogen Utilization by Ruminants

Johnson, B. Connor; Hamilton, T. S.; Robinson, W. B.; Garey, J. C.

doi:10.2527/jas1944.33287x

Cited by 69 publications

(27 citation statements)

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“…To this extent our results are merely a confirmation and extension of the findings of Lofgreen, Loosli, and Maynard (1947) and in regard to the effect of methionine supplements in increasing the value of urea, also those of Loosli and Harris (1945). They are, however, in contrast to those of Johnson et al (1942Johnson et al ( , 1944 and do not support the claim of these workers that with sheep "the biological value of the nitrogen of rations containing 10-12 per cent. crude protein (N X 6.25) generally varies only within a few per cent.…”

Section: Discussioncontrasting

confidence: 57%

“…A biological value of 80 was found for whole egg protein, 76 for linseed meal protein, 74 for urea plus methionine, and 71 for urea. It should be noted that all these values are appreciably higher than 60, the figure quoted by Johnson et al (1942Johnson et al ( , 1944, although the nitrogen intake in each case was equivalent to 10 per cent. crude protein (N X 6.25).…”

Section: Discussionmentioning

confidence: 42%

“…III 383 No data are available with which our figure for the biological value of subterranean clover seed protein can be compared but there are a number for casein. Thus Harris and Mitchell (1941) obtained for casein a figure of 59 and Johnson et al (1942and Johnson et al ( , 1944 a figure of 60 for the growth of lambs. In both these cases the casein comprised 50 per cent.…”

Section: (F) Counting Techniquesmentioning

confidence: 99%

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Ruminal Flora Studies in the Sheep III. The Influence of Different Sources of Nitrogen Upon Nitrogen Retention and Upon the Total Number of Free Microorganisms in the Rumen

Williams¹,

Moir²

1951

Aust. Jnl. Of Bio. Sci.

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SummaryThe data are presented from a replicated feeding trial designed to determine the influence of different sources of nitrogen, fed at a constant level, upon the nitrogen balances and numbers and types of ruminal microorganisms in growing Iambs. Six Merino Iambs were fed a basal ration of oaten chaff and wheaten grain supplemented with six sources of nitrogen: linseed meal, subterranean clover seed, whole powdered egg, casein, urea, and urea plus methionine. In each diet the test nitrogen contributed 40 per cent. of the total nitrogen and the crude protein (N X 6.25) content of the whole diet was very close to 10 per cent. All diets were very similar in crude fibre and gross energy content. Additional data for certain of these diets were obtained with seven mature Merino wethers.The mean biological values of the nitrogen of the different rations as fed to the Iambs were: linseed 79.7 ± 2.59; subterranean clover seed 83.0 ± 3.43; egg 86.7 ± 4.28; casein 82.0 ± 6.05; urea 68.6 ± 1.52; urea plus methionine 75.2 ± 1.48. The biological value of the nitrogen of the whole powdered egg ration was significantly greater (P < 0.01) than that of linseed, of linseed significantly greater (P < 0.01) than that of urea plus methionine, and this significantly greater (P < 0.01) than that of urea. The values for the casein and subterranean clover seed rations were significantly greater than that of the urea (P < 0.01) and urea plus methionine (P < 0.05) rations but were not significantly different from each other nor from the other protein nitrogen sources. The mean concentrations of ruminal bacteria on the different rations were found to be: linseed 23.9 ± 8.46; subterranean clover seed 25.2 ± 10.5; egg 41.2 ± 5.23; casein 42.8 ± 9.94; urea 17.7 ± 2.09; urea plus methionine 43.7 ± 9.12 million per cu. mm. The ruminal bacterial numbers were highly significantly greater (P < 0.01) for the. egg, casein, and urea plus methionine diets than for the linseed, subterranean clover seed, and urea diets. It is concluded that: (i) Different sources of nitrogen can vary markedly in their biological value, i.e. capacity to promote nitrogen retention in growing Iambs.(ii) Different sources of nitrogen can vary markedly in their capacity to promote bacterial growth in the rumen of both growing Iambs and mature sheep.(iii) The value of methionine, as a supplement to urea, in improving nitrogen retention in growing Iambs is due largely to its stimulating effect on bacterial growth in the rumen, thus increasing the amount of bacterial protein available to the host. The numbers of ruminal protozoa were found to be highly variable and to bear no obvious relationship to the diets fed.Some of the morphological characteristics of the rumina I bacteria on the various diets are presented and discussed.

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Section: Discussioncontrasting

confidence: 57%

Section: Discussionmentioning

confidence: 42%

Section: (F) Counting Techniquesmentioning

confidence: 99%

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Ruminal Flora Studies in the Sheep III. The Influence of Different Sources of Nitrogen Upon Nitrogen Retention and Upon the Total Number of Free Microorganisms in the Rumen

Williams¹,

Moir²

1951

Aust. Jnl. Of Bio. Sci.

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“…This is confirmed by the finding of similar patterns for a different sheep fed on diet R 9 (Warner, 1962b) and for grazing sheep where the grazing behaviour resembled the feeding behaviour of these pen-fed sheep (Warner, 1966 b). Also, Johnson et al (1944), Purser & Moir (1959) and Clarke (1965) found similar patterns for the ophryoscolecid protozoa, and Purser (1961) and Clarke (1965) found similar patterns for the holotrichs, with animals fed rather different diets. Total bacterial counts, where many very different species may be confounded, may be expected to be more affected by the nature of the diet, since the different diets would allow different species to dominate and these species might well have different growth behaviours.…”

mentioning

confidence: 69%

Diurnal Changes in the Concentrations of Micro-organisms in the Rumens of Sheep Fed Limited Diets Once Daily: WITH AN APPENDIX ON THE KINETICS OF RUMEN MICROBES AND FLOW

Warner¹

1966

Journal of General Microbiology

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SUMMARYThe pattern of change of concentration of different groups of microorganisms in the rumen was found to be characteristic of the group and little affected by the time of day, the nature of the diet, or the host animal. The dilution rate of rumen liquor and the rate of change of concentration of several groups of micro-organisms were measured a t intervals following feeding; this allowed calculation of the apparent specific growth rate. The changes in concentration of the ophryoscolecid ciliate protozoa, the selenomonads and the oval organism described by Eadie could be explained as the resultant of the changes in dilution rate due to the act of eating and in growth rate in response to incoming nutrients. Rates of change in concentration greater than could be accounted for on the basis of growth and dilution alone were found with the peptostreptococci, the polymastigate flagellate protozoa and the holotrich ciliate protozoa. It is suggested that the peptostreptococci underwent lysis or engulfment by other organisms and that the polymastigates became sequestered, .probably close to the rumen wall. The concentration changes of the holotrichs were more difficult t o understand, but it would appear that little division took place for some 18 hr after feeding, followed by several divisions in quick succession. The oscillospirae showed two peaks in concentration; no explanation can be offered for this.

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“…Furthermore, the AA composition of this material appears to be constant irrespective of dietary and animal conditions (Storm et al 1983). It has been difficult to obtain precise estimates of the nutritive value of microbial N for ruminants due to difficulties in isolating sufficient quantities of rumen micro-organisms (RMO) for experiments with large animals, though some evaluations of nutritive value have been undertaken using rats (Johnson et al 1944;McNaught et al 1954; Mason & Palmer, 1971).…”

mentioning

confidence: 99%