Amino acid utilization by dairy cows. I. Methods of varying amino acid supply

Oldham, J. D.; Tamminga, S.

doi:10.1016/0301-6226(80)90082-2

Cited by 27 publications

(9 citation statements)

References 25 publications

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“…Bacterial protein, rather than feed protein escaping ruminal degradation, accounted for most of the differences between diets, since bacterial protein was 55% greater (P<.01); nonbacterial protein reaching the duodenum was only 20% greater (P<.05) for the grain than for the forage diet. This indicates that more bacterial protein was synthesized in the rumen of the grain-fed steers, which might be attributed to a higher intake of ruminal available energy (Oldham and Tamminga, 1980). The marked net gain (from diet to duodenum) for total protein on the grain diet, shown in table 1, has been reported previously by Wanderley and Theurer (1983).…”

Section: Resultssupporting

confidence: 74%

“…Mathison and Milligan (1971) found microbial growth resulting in the assimilation of 4.1 and 4.3 g N/Mcal energy fermented in the rumen of sheep receiving barley and high-protein hay diets, respectively. Oldham and Tamminga (1980) state that the "limiting value" of duodenal supply of nonammonia N appears to be close to 2.5 to 3.0 g/MJ ME intake (or 10.5 to 12.6 g/Mcal) for both forage or concentrate diets. Their values agree with estimates from the equation of Journet and Verite (1979).…”

Section: Resultsmentioning

confidence: 96%

“…The higher intake of nonstructural carbohydrate in the grain diet apparently increased ruminal microbial synthesis as well as microbial protein reaching the small intestine, and may be proportional to the estimated increases in ME intake. However, response to various grains may differ (Oldham and Tamminga, 1980). Using the data of Spicer et al (1986), grams of duodenal N/Mcal ME intake were 9.2, 7.4 and 9.0 respectively, for sorghum-, corn-and barley-based diets.…”

Section: Resultsmentioning

confidence: 99%

“…; forage or grain processing methods (Tamminga, 1975;Prigge et al, 1978) and forage-to-concentrate ratios (Cole et al, 1976;Tamminga, 1979;Oldham and Tamminga, 1980;Wanderley and Theurer, 1983;Zinn and Owens, 1983b). However, accurrate in vivo measurement of bacterial and feed protein reaching the small intestine is difficult and, according to Theurer (1979Theurer ( , 1982, part of the difficulty is caused by the methods used to quantitate bacterial and feed protein in digesta samples, as well as digesta flow rates throughout the gastrointestinal tract.…”

Section: )mentioning

confidence: 99%

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Duodenal Bacterial and Nonbacterial Protein Supply in Steers Fed Forage and Grain Diets

Wanderley

Theurer

Poore

1987

Journal of Animal Science

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Four beef steers (avg wt 300 kg) fitted with duodenal re-entrant cannulae were used to study the effect of dietary concentrate to forage ratio on bacterial and nonbacterial N flow in the duodenum. According to a change-over design, the steers were designated to receive an all forage (83% alfalfa hay and 17% wheat straw) and an 80% sorghum grain diet. Lignin (ADL) and chromium oxide (Cr2O3) ratio techniques were compared with automated total collection (ATC) of digesta for quantitating duodenal protein flow and efficiency of bacterial N yield in the rumen. Estimates of bacterial protein synthesis and ruminal escape of feed protein based on Cr2O3 and lignin tended to be higher by 8 to 16% than those obtained by ATC. Efficiency of ruminal bacterial protein yield estimated by these two markers tended to be greater than that based on ATC (16 vs 12 g of bacterial protein/100 g ruminal true digestion of dry matter corrected for bacterial cell synthesis). Efficiency values did not differ between diets. Crude protein flow into the duodenum was about 33% greater (P less than .01) for the grain than the forage diet, although protein intake was about 10% less on the grain diet. Duodenal bacterial protein, rather than feed protein escaping ruminal degradation, accounted for most of this difference. Average duodenal flow of N, expressed as g/Mcal metabolizable energy (ME) intake, was 11.9 for the forage diet and 10.3 for the grain diet.(ABSTRACT TRUNCATED AT 250 WORDS)

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Section: Resultssupporting

confidence: 74%

Section: Resultsmentioning

confidence: 96%

Section: Resultsmentioning

confidence: 99%

Section: )mentioning

confidence: 99%

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Duodenal Bacterial and Nonbacterial Protein Supply in Steers Fed Forage and Grain Diets

Wanderley

Theurer

Poore

1987

Journal of Animal Science

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“…The fractional degradation rate of SC can be as low as 0.01/h , which is likely to be lower than the lowest particle passage rate observed and survival of the SC degrading bacteria is only possible by attachment to newly ingested particles with a low probability of passage. Equally, the highest degradation rate (3.5 /h) of NSC is obviously much higher than the maximum fractional growth rate rumen microbes can realize (Russell and Baldwin, 1978) (Oldham and Tamminga, 1980 (Sutton, 1985).…”

Section: Introductionmentioning

confidence: 98%