Energy utilization, nitrogen balance and microbial protein supply in cattle fedPennisetum purpureumand condensed tannins

In ruminants, daily urinary excretion of purine derivatives (PD) reflects the absorption of microbial purines and can be used as an index of microbial protein supply (Chen, Ørskov and Hovell, 1991). The application could be extended to farm conditions if measurements based on spot urine samples or plasma could serve as an alternative index. The objective of this study was to examine whether PD concentrations in spot urine or plasma samples vary diurnally during a given feeding regime and if they reflect differences in daily PD excretion induced by varying feed intake.

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Rumen microbial protein supply to sheep given diets containing either urea or casein as the main N source

Proceedings of the British Society of Animal Production (1972) ◽

10.1017/s0308229600023242 ◽

1992 ◽

Vol 1992 ◽

pp. 215-215

Author(s):

X. B. Chen ◽

C. X. Gu ◽

W. X. Zhang ◽

E. R. Ørskov

Keyword(s):

Live Weight ◽

Basal Diet ◽

Microbial Protein ◽

Host Animal ◽

Rumen Microbes ◽

Feed Formulation ◽

N Source ◽

Ruminant Diets ◽

Protein Supply ◽

N Requirement

The ability of rumen microbes to synthesize protein from ammonia-N enables the use of non-protein-N as a N source in ruminant diets. The strategy for feed formulation therefore would be to meet the microbial N requirement with a cheap N source (such as urea) and to increase the proportion of dietary protein for use directly by the host animal. There has been some indication that the efficiency of rumen microbial protein synthesis could be higher if protein N is provided (Stock, Klopfenstein, Brink, Britton and Harmon, 1986). The objective of this experiment was to compare the use of urea and casein as a source of rumen degradable nitrogen (RDN) for the production of microbial protein in sheep.Five male Blackface x Suffolk lambs (33-42 kg live weight) fitted with rumen cannula were used. The animals were fed a restricted amount (721 g DM/day) of a low-N basal diet with or without supplementation with either urea or casein.

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Coffee hull in the diet of dairy heifers: nitrogen balance and microbial protein synthesis

Revista Brasileira de Zootecnia ◽

10.1590/s1516-35982010000500027 ◽

2010 ◽

Vol 39 (5) ◽

pp. 1141-1145 ◽

Cited By ~ 2

Author(s):

Alexandre Lima de Souza ◽

Rasmo Garcia ◽

Luciano da Silva Cabral ◽

Mara Lúcia Albuquerque Pereira ◽

Rilene Ferreira Diniz Valadares

Keyword(s):

Protein Synthesis ◽

Nitrogen Balance ◽

Dry Matter ◽

Block Design ◽

Nitrogen Excretion ◽

Microbial Protein ◽

Purine Derivative ◽

Microbial Protein Synthesis ◽

Random Block ◽

Random Block Design

It was evaluated nitrogen compounds and microbial protein synthesis in heifers fed diets containing coffee hulls (0.0; 8.75; 17.25; and 26.25% of dry matter) replacing ground corn concentrate at the following levels of coffee hulls in the total diet dry matter: 0.0, 3.5, 7.0 or 10.5%. It was used 24 crossbreed heifers (7/8, 15/16 and 31/32 Holstein-Zebu), which were distributed in a random block design made up accordingly to the weight of the animals. Spot samples of urine were colleted aproximatelly four hours after morning feeding and were used to estimate microbial protein synthesis by using urine purine derivatives. It was not observed effect of coffee hull levels in the diet on total nitrogen intake (160 g/day) and nitrogen excretion in the urine (87.4 g/day). The inclusion of coffee hull in the diet linearly increased nitrogen excretion in feces, as well as nitrogen balance. There was linear reduction in urinary excretion of allantoin, in total purine derivative and absorbed purine, which reduced 0.715, 0.873, and 0.954 mmol/day to each coffee hull unity added to the concentrate, respectively. Coffee hull altered microbial protein synthesis, which reduced in 0.687 g/day to each coffee hull unity added to the concentrate. Reduction in microbial protein synthesis can reduce weight gain in heifers fed coffee hulls.

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