Prediction of duodenal flow of non-ammonia nitrogen and amino acid nitrogen in dairy cows

Röhr, Klaus; Lebzien, Peter; Schafft, Helmut; Schulz, Edgar

doi:10.1016/0301-6226(86)90094-1

Cited by 42 publications

(6 citation statements)

References 22 publications

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“…The total amino acid profile absorbed at maximal gain (Table 7) then was compared to 1974). This calculation is supported by the total duodenal CP flow data in the summary by Rohr et al (1986). The resulting equation was: the requirements estimated by Burroughs et al (1974).…”

Section: 5mentioning

confidence: 53%

Hydrolyzed feather meal as a protein source for growing calves.

Goedeken

Klopfenstein

Stock

et al. 1990

Journal of Animal Science

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Growth, digestion and in situ studies were conducted to determine the protein value of hydrolyzed feather meal (Fth) for growing ruminants. Dacron bags containing blood meal (BM), Fth, corn gluten meal (CGM) and soybean meal (SBM) were suspended in the rumen of two steers for 12 h to estimate escape protein. The escape protein value for Fth, 69.1%, was less than that for BM (82.8%) and CGM (80.4%; P less than .05) but greater than that for SBM (26.6%; P less than .05). Apparent protein digestion by lambs was similar (P greater than .10) for isonitrogenous diets containing urea (U), BM, Fth, CGM and SBM. Amino acid contents of the protein sources before vs after a 12-h ruminal in situ digestion were similar (P greater than .10). In a growth study, a basal diet of 80% ensiled corncobs and 20% alfalfa was fed to 60 individually fed crossbred steers (215 kg BW). Steers were supplemented with U, BM, Fth, 1/2 BM:1/2 Fth, 1/2 BM:1/2 CGM and 1/3 BM:1/3 Fth:1/3 CGM (protein basis). Protein sources were fed at 30, 45 and 60% of the supplemental N with urea supplying the remainder. Protein efficiency was calculated using the slope ratio technique. Protein efficiency was similar (P greater than .10) for BM- and Fth-supplemented calves. Protein efficiencies were similar (P greater than .10) for BM:CGM, BM:Fth and BM:Fth:CGM combinations. These data indicate the Fth is a digestible high escape protein source that is useful in diets for growing ruminants.

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Section: 5mentioning

confidence: 53%

Hydrolyzed feather meal as a protein source for growing calves.

Goedeken

Klopfenstein

Stock

et al. 1990

Journal of Animal Science

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“…This value was the mean derived from experiments with dairy cows fed on a total of 10 mixed rations in earlier studies (Schröder et al., 1989, 1997; Südekum et al., 1992, 1994). This value is only slightly lower than the factor 0.64 reported by Rohr et al. (1986) and was chosen because general conditions under which the cows were kept in the earlier studies were similar to those used for the steers in the present study.…”

Section: Methodsmentioning

confidence: 81%

Effects of amount of intake and stage of forage maturity on urinary allantoin excretion and estimated microbial crude protein synthesis in the rumen of steers

Südekum

Brüsemeister

Schröder

et al. 2005

Animal Physiology Nutrition

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Using ruminally cannulated steers, we investigated how urinary allantoin excretion was related to variations in feed intake and stage of forage maturity. Further, different approaches were compared for predicting ruminal microbial crude protein (MCP) synthesis and its efficiency. Experimental diets were arranged in a replicated 3 x 3 Latin square design (experiment 1) and a 4 x 4 Latin square design (experiment 2). In experiment 1, a mixed diet [forage to concentrate, 68:32 on a dry matter (DM) basis] was fed at three intake levels corresponding to 1, 1.5 and 2 times maintenance energy requirements. In experiment 2, four silage-based diets were fed based on perennial ryegrass (Lolium perenneL.), which was harvested at four maturity stages. Both experiments demonstrated the influence of diet on microbial growth rate and by this on efficiency of MCP synthesis, although the magnitude of the effects differed between approaches used for estimating MCP. Linear functions satisfactorily characterised the relationship between urinary allantoin excretion (y) and digestible organic matter (OM) intake (x, kg/day; experiment 1: y = 7.94 + 17.34 x; R(2) = 0.785) or intake of OM effectively degraded in the rumen (x, kg/day; experiment 2; y = 22.32 + 5.93 x; R(2) = 0.695). Urinary excretion of allantoin permitted a semi-quantitative prediction of MCP synthesis: ranking of diets and magnitude of changes in MCP synthesis were reflected.

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“…However, the calculated average microbial yield, 106.7 g of microbial true protein per kilogram of TDN, from the NRC (1985) data set ( n = 1181, is similar to that of Burroughs et al (1974). Rohr et al (1986) summarized 22 experiments in which the f0rage:concentrate ratio varied between 1OO:O to 49:51 for the purpose of determining microbial protein production. Their prediction of microbial production is similar to that of Burroughs et al ( 1974) when expressed on the same protein and energy basis: 106.4 vs 104.4 g of microbial true protein per lulogram of TDN intake, respectively.…”

Section: Discussionmentioning

confidence: 99%

“…Sixteen of the 22 experiments evaluated by Rohr et al (1986) included I5N as the microbial marker. They further concluded that diaminopimelic acid underestimated microbial protein production by 14% compared with estimates based on I5N.…”

Section: Discussionmentioning

confidence: 99%

Metabolizable protein and amino acid requirements of growing cattle

Wilkerson

Klopfenstein

Britton

et al. 1993

Journal of Animal Science

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Metabolizable protein and amino acid requirements for growing cattle were estimated using data from 11 research trials. A total of 543 steers were individually fed a high-roughage diet supplemented with protein at several levels above a urea supplement control. The mean weight for all animals was 253 kg, with a range in mean initial to final weights of 200 to 316 kg, respectively. Daily gain ranged from -.04 to .89 kg. Metabolizable protein for each treatment group was calculated at the point at which the protein requirement was met. The sum of dietary escape protein (basal and supplemental) and calculated microbial protein represented metabolizable protein supplied per test protein source analyzed in each trial. Daily gain was regressed against calculated metabolizable protein flow using weighted regression analysis (r2 = .69, n = 45) to determine the metabolizable protein requirements for maintenance (3.8 x BW.75 g/d, where BW is expressed in kilograms) and growth (305 g/kg of live weight gain). Calculated metabolizable amino acid requirements as a percentage of metabolizable protein for a 253-kg animal gaining .49 kg/d were as follows: methionine, 3.0%; total sulfur amino acids, 5.8%; lysine, 8.0%; tryptophan, 1.0%; threonine, 5.2%; valine, 5.7%; isoleucine, 5.6%; leucine, 6.9%; phenylalanine, 3.9%; and histidine, 1.6%. The proposed requirements were based on live animal gain and intake of metabolizable protein and should represent the needs of the growing beef animal.

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Prediction of duodenal flow of non-ammonia nitrogen and amino acid nitrogen in dairy cows

Cited by 42 publications

References 22 publications

Hydrolyzed feather meal as a protein source for growing calves.

Hydrolyzed feather meal as a protein source for growing calves.

Effects of amount of intake and stage of forage maturity on urinary allantoin excretion and estimated microbial crude protein synthesis in the rumen of steers

Metabolizable protein and amino acid requirements of growing cattle

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