dc.contributor.author |
Batista, E. D. |
|
dc.contributor.author |
Detmann, E. |
|
dc.contributor.author |
Titgemeyer, Evan C. |
|
dc.contributor.author |
Valadares, S. C. |
|
dc.contributor.author |
Valadares, R. F. D. |
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dc.contributor.author |
Prates, L. L. |
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dc.contributor.author |
Renno, L. N. |
|
dc.contributor.author |
Paulino, M. F. |
|
dc.date.accessioned |
2016-09-20T17:40:42Z |
|
dc.date.available |
2016-09-20T17:40:42Z |
|
dc.identifier.uri |
http://hdl.handle.net/2097/34107 |
|
dc.description |
Citation: Batista, E. D., Detmann, E., Titgemeyer, E. C., Valadares, S. C., Valadares, R. F. D., Prates, L. L., . . . Paulino, M. F. (2016). Effects of varying ruminally undegradable protein supplementation on forage digestion, nitrogen metabolism, and urea kinetics in Nellore cattle fed low-quality tropical forage. Journal of Animal Science, 94(1), 201-216. doi:10.2527/jas2015-9493 |
|
dc.description.abstract |
Effects of supplemental RDP and RUP on nutrient digestion, N metabolism, urea kinetics, and muscle protein degradation were evaluated in Nellore heifers (Bos indicus) consuming low-quality signal grass hay (5% CP and 80% NDF, DM basis). Five ruminally and abomasally cannulated Nellore heifers (248 +/- 9 kg) were used in a 5 x 5 Latin square. Treatments were the control (no supplement) and RDP supplementation to meet 100% of the RDP requirement plus RUP provision to supply 0, 50, 100, or 150% of the RUP requirement. Supplemental RDP (casein plus NPN) was ruminally dosed twice daily, and RUP supply (casein) was continuously infused abomasally. Jugular infusion of [(NN)-N-15-N-15]-urea with measurement of enrichment in urine was used to evaluate urea kinetics. The ratio of urinary 3-methylhistidine to creatinine was used to estimate skeletal muscle protein degradation. Forage NDF intake (2.48 kg/d) was not affected (P >= 0.37) by supplementation, but supplementation did increase ruminal NDF digestion (P < 0.01). Total N intake (by design) and N retention increased (P < 0.001) with supplementation and also linearly increased with RUP provision. Urea entry rate and gastrointestinal entry rate of urea were increased by supplementation (P < 0.001). Supplementation with RUP linearly increased (P = 0.02) urea entry rate and tended (P = 0.07) to linearly increase gastrointestinal entry rate of urea. Urea use for anabolic purposes tended (P = 0.07) to be increased by supplementation, and RUP provision also tended (P = 0.08) to linearly increase the amount of urea used for anabolism. The fraction of recycled urea N incorporated into microbial N was greater (P < 0.001) for control (22%) than for supplemented (9%) heifers. Urinary 3-methylhistidine: creatinine of control heifers was more than double that of supplemented heifers (P < 0.001). Control heifers reabsorbed a greater (P < 0.001) fraction of urea from the renal tubule than did supplemented heifers. Overall, unsupplemented heifers had greater mobilization of AA from myofibrillar protein, which provided N for urea synthesis and subsequent recycling. Supplemental RUP, when RDP was supplied, not only increased N retention but also supported increased urea N recycling and increased ruminal microbial protein synthesis. |
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dc.relation.uri |
https://doi.org/10.2527/jas2015-9493 |
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dc.rights |
Copyright © 2016. American Society of Animal Science. |
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dc.rights.uri |
http://www.sherpa.ac.uk/romeo/issn/0021-8812/ |
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dc.subject |
Bos Indicus |
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dc.subject |
Cattle |
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dc.subject |
Muscle Degradation |
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dc.subject |
Protein Supplementation |
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dc.subject |
Tropical Forage |
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dc.subject |
Urea Recycling |
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dc.title |
Effects of varying ruminally undegradable protein supplementation on forage digestion, nitrogen metabolism, and urea kinetics in Nellore cattle fed low-quality tropical forage |
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dc.type |
Article |
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dc.date.published |
2016 |
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dc.citation.doi |
10.2527/jas2015-9493 |
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dc.citation.epage |
216 |
|
dc.citation.issn |
0021-8812 |
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dc.citation.issue |
1 |
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dc.citation.jtitle |
Journal of Animal Science |
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dc.citation.spage |
201 |
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dc.citation.volume |
94 |
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dc.description.embargo |
2017-01 |
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dc.contributor.authoreid |
etitgeme |
|