In Vitro Observations upon the Nature of Protein Influences upon Urea Utilization by Rumen Microorganisms

Burroughs, Wise; Arias, Carlos; DePaul, Peter; Gerlaugh, Paul; Bethke, R. M.

doi:10.2527/jas1951.103672x

Cited by 28 publications

(10 citation statements)

References 6 publications

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“…The ability of NPN to improve forage digestion is due to the supply of ruminal ammonia, the main source of N used by most cellulolytic bacterial strains (Petersen, 1987;Owens et al, 1991, Russell et al, 1992. In contrast, the depression in digestion observed at the high level of urea may have resulted from reduced availability of amino acids or peptides per se (Burroughs et al, 1951;Maeng and Baldwin, 1976) or other microbial growth factors (Petersen, 1987;Owens et al, 1991). For example, Hoover (1986) noted that branched-chain volatile fatty acids ( BCVFA) derived from the deamination of specific amino acids are required by cellulolytic microorganisms.…”

Section: Discussionmentioning

confidence: 99%

Effect of increasing proportion of supplemental nitrogen from urea on intake and utilization of low-quality, tallgrass-prairie forage by beef steers.

Koster

Cochran

Titgemeyer

et al. 1997

Journal of Animal Science

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Five Angus x Hereford steers with ruminal and duodenal fistulas were used in a 5 x 5 Latin square to determine effects of increasing the proportion of urea in supplemental degradable intake protein (DIP) on intake, fermentation, and digestion. Steers had ad libitum access to low-quality, tallgrass-prairie forage (2.4% CP, 76% NDF). Supplemental DIP (380 g/d) was from sodium caseinate and(or) urea and was balanced with cornstarch to provide a final supplement (approximately 939 g DM/d) that contained 40% CP. The percentages of supplemental DIP from urea were 0, 25, 50, 75, and 100%. Intake of forage OM was not affected (P > or = .30) by urea level. Ruminal and total tract digestibilities of OM and NDF generally responded in a quadratic manner (P < or = .09) to increasing urea, with the lowest values observed at the highest urea level. As a result, digestible OM intake (DOMI) declined (linear, P = .03) with increasing proportions of urea and tended (quadratic, P = .14) to exhibit the largest proportional decline at the highest urea level. The effects of increasing urea on duodenal N flow, microbial efficiency, ruminal contents, and fluid dilution rate were minimal. Ruminal ammonia N and molar percent acetate increased linearly (P < or = .02), whereas most other VFA (except propionate) decreased (P < or = .05) with increasing urea. In conclusion, although forage OM intake was not altered, OM digestion, NDF digestion, and DOMI were lowest when all supplemental DIP was supplied as urea. Changes in fermentation characteristics reflected the change in source of available nitrogen.

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Section: Discussionmentioning

confidence: 99%

Effect of increasing proportion of supplemental nitrogen from urea on intake and utilization of low-quality, tallgrass-prairie forage by beef steers.

Koster

Cochran

Titgemeyer

et al. 1997

Journal of Animal Science

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“…When molasses supplementation was decreased to 5% of total DM1 (similar to the present study) in dairy heifers, no differences in nutrient digestibility were detected (Davis et al, 1955). Arias et al (1951) found that supplementing molasses at 20 to 30% of total DM fed improved cellulose digestion in artificial rumens better than higher levels (50% of total DM fed) of molasses supplementation. The authors suggested that the energy in molasses was used to unlock the protein in the fiber component.…”

Section: Nutrient Digestibilitymentioning

confidence: 92%

“…Molasses may also supply essential minerals that are needed in cellulose digestion. Additional (>30% of total DM) molasses may not have been beneficial because these mineral requirements were met at the lower supplementation levels (Arias et al, 1951;Burroughs et al, 1951). There may be an important interaction between forage quality and digestion response to molasses supplementation, with molasses having a greater impact on digestibility of low-quality forages compared with higher quality forages (Broderick and Radloff, 2004;Titgemeyer et al, 2004).…”

Section: Nutrient Digestibilitymentioning

confidence: 99%

Effect of Molasses, Corn Meal, or a Combination of Molasses plus Corn Meal on Ruminal Fermentation of Orchardgrass Pasture During Continuous Culture Fermentation

Soder

Hoffman

Brito

2010

The Professional Animal Scientist

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Although molasses is being used by dairy farmers, particularly certified organic dairies, as a lower cost energy alternative to corn, little research currently exists evaluating the effects of molasses as the sole supplement on the ruminal fermentation of grazing dairy cows. This study evaluated the effects of pasture supplementation with molasses, corn meal, or a combination of molasses and corn meal, on ruminal nutrient digestibility and bacterial N synthesis in continuous culture fermenters. Experimental treatments were 1) orchardgrass (Dactylis glomerata L.) pasture only (control; 70 g DM/d); 2) molasses plus orchardgrass pasture (MOL; 3.5 g DM/d of molasses plus 66.5 g DM/d of pasture); 3) corn meal plus orchardgrass pasture

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“…Using their continuous transfer technique Burroughs and his colleagues have studied the use of urea by rumen micro-organisms incubated in mfro (226,227,228). In the first paper (226) they showed that more cellulose was digested in the presence of casein or gelatine than in their absence.…”

Section: Movements Of Food In the Alimentary Tractmentioning

confidence: 99%

Section A. Physiology of dairy cattle: Part II. Physiology and Biochemistry of Rumination

Owen

1954

Journal of Dairy Research

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Since the time of the previous review in this series by the present author it has been increasingly realized that the ruminant's adaptation to its herbivorous diet is very far-reaching. The biochemical consequences of its need for coarse roughage are still being worked out and have necessitated a reassessment of the causes of bovine ketosis, of the function of lower fatty acids in its blood and of the reasons for its large requirement of cobalt. Recent work on all these three aspects of ruminant metabolism is discussed in this review. The cow's chief function is to convert into milk vegetable materials, many of which are unsuitable for human consumption. Ac-, cordingly, some of the nutritional aspects of this conversion process have been discussed in the review. The literature on the subject has been reasonably well listed, but the author cannot claim that he has not perhaps inadvertently omitted certain pertinent new work. GENERAL Sherwood & Jones(l) found that alfalfa hay plus a mixture of wheat, barley and oats gave 20% more milk than the hay alone. Milk yield was also enhanced by adding the succulents squash and Jerusalem artichoke to the hay diet. Groups of cows receiving the concentrates needed 5-6 lb. more total digestible nutrients to produce 100 lb. milk, and the authors conclude that feeding of succulents is profitable only if they produce nutrients as cheaply as does hay. Watson, Davidson, Kennedy & Sylvestre(2) compared the digestibility of rations of hay plus increasing amounts of oats. As oats increased the digestibility decreased. This effect was most marked with barley, not so marked with oats and was only slight with linseed oil meal. Feeding standards are still the subject of informed criticism in Europe(3,4,5). Nehring(3) concludes that Kellner's starch equivalents cannot be used for pigs without prior respiration calorimetry. Blaxter(4) finds large discrepancies between different methods of computing rations for livestock, and Nicholls(5) enters a plea for food recording as a complement to milk recording. The trouble with all attempts to define standards for grazing animals is the extreme variability from year to year, from field to field, from treatment to treatment and from animal to animal of the nutrients provided by grass and hay or silage. Much current research all over the world is designed to measure more accurately the nutrient intake of cattle and sheep from pasture, with a view to striking a better balance between protein and fibre in the diet, always remembering that the content of fibre biologically best for maximal production per cow may not necessarily give the maximal production per acre. This may come from more cows per acre at somewhat more fibre per cow than would give maximal production per cow. In this connexion the observations of Hancock (6) are pertinent. He points out that the maximum production per animal does not necessarily yield the greatest net returns. In practice this can be achieved by a number of cows per acre too high for maximum productivity per cow or fo...

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In Vitro Observations upon the Nature of Protein Influences upon Urea Utilization by Rumen Microorganisms

Cited by 28 publications

References 6 publications

Effect of increasing proportion of supplemental nitrogen from urea on intake and utilization of low-quality, tallgrass-prairie forage by beef steers.

Effect of increasing proportion of supplemental nitrogen from urea on intake and utilization of low-quality, tallgrass-prairie forage by beef steers.

Effect of Molasses, Corn Meal, or a Combination of Molasses plus Corn Meal on Ruminal Fermentation of Orchardgrass Pasture During Continuous Culture Fermentation

Section A. Physiology of dairy cattle: Part II. Physiology and Biochemistry of Rumination

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