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Title: Effect of dietary protein level on nitrogen utilization and ruminal influx of endogenous urea nitrogen in growing animals

Abstract

Three experiments were conducted to evaluate the impact of ruminal influx of blood urea nitrogen (BUN) on intestinal protein supply and nitrogen (N) metabolism in growing animals at both excess and growth-limiting protein intake. In Experiment 1, wether lambs were given diets, either high or low in protein, containing 25% cottonseed hulls and 75% corn-soybean meal hourly in 24 equal portions. Single injections of /sup 14/C- and /sup 15/N-urea, and /sup 15/N-ammonium sulfate (AS) were made into the BUN and ruminal ammonia N (RAN) pools, respectively, to measure rate of flux through, and transfer of N between these and the bacterial N pool. In Experiment 2, beef calves were given HP and LP diets containing 30% cottonseed hulls and 70% corn-soybean meal every 4 h in 6 equal portions. Single injections of /sup 15/N-urea and /sup 15/N-AS were made into the BUN and RAN pools, respectively, to measure rate of flux through, and transfer of N between these and the bacterial N pool. Abomasal N flow was 24% greater than intake in LP and 29% less than intake in HP. An inverse relationship may exist between level of N intake and rate of influx of BUN into the rumen. Inmore » Experiment 3 ruminal fluid samples were obtained. With HP, BUN-derived /sup 15/N-ammonia appeared to rapidly equilibrate with RAN in the primary digesta mass. In contrast, with LP, there appeared to be an enrichment gradient for both RAN and bacterial N, declining from the rumen wall toward the center of the digesta mass, suggesting that bacteria at or near the rumen wall may preferentially utilized some BUN-derived ammonia N entering through the rumen wall.« less

Authors:
Publication Date:
Research Org.:
Kentucky Univ., Lexington (USA)
OSTI Identifier:
5989977
Resource Type:
Thesis/Dissertation
Resource Relation:
Other Information: Thesis (Ph. D.)
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; NITROGEN COMPOUNDS; METABOLISM; PROTEINS; BIOLOGICAL EFFECTS; RUMINANTS; ANIMAL GROWTH; CARBON 14 COMPOUNDS; DIET; NITROGEN 15; TRACER TECHNIQUES; UREA; AMIDES; ANIMALS; CARBONIC ACID DERIVATIVES; GROWTH; ISOTOPE APPLICATIONS; ISOTOPES; LABELLED COMPOUNDS; LIGHT NUCLEI; MAMMALS; NITROGEN ISOTOPES; NUCLEI; ODD-EVEN NUCLEI; ORGANIC COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; STABLE ISOTOPES; VERTEBRATES; 550501* - Metabolism- Tracer Techniques

Citation Formats

Bunting, L D. Effect of dietary protein level on nitrogen utilization and ruminal influx of endogenous urea nitrogen in growing animals. United States: N. p., 1987. Web.
Bunting, L D. Effect of dietary protein level on nitrogen utilization and ruminal influx of endogenous urea nitrogen in growing animals. United States.
Bunting, L D. Thu . "Effect of dietary protein level on nitrogen utilization and ruminal influx of endogenous urea nitrogen in growing animals". United States.
@article{osti_5989977,
title = {Effect of dietary protein level on nitrogen utilization and ruminal influx of endogenous urea nitrogen in growing animals},
author = {Bunting, L D},
abstractNote = {Three experiments were conducted to evaluate the impact of ruminal influx of blood urea nitrogen (BUN) on intestinal protein supply and nitrogen (N) metabolism in growing animals at both excess and growth-limiting protein intake. In Experiment 1, wether lambs were given diets, either high or low in protein, containing 25% cottonseed hulls and 75% corn-soybean meal hourly in 24 equal portions. Single injections of /sup 14/C- and /sup 15/N-urea, and /sup 15/N-ammonium sulfate (AS) were made into the BUN and ruminal ammonia N (RAN) pools, respectively, to measure rate of flux through, and transfer of N between these and the bacterial N pool. In Experiment 2, beef calves were given HP and LP diets containing 30% cottonseed hulls and 70% corn-soybean meal every 4 h in 6 equal portions. Single injections of /sup 15/N-urea and /sup 15/N-AS were made into the BUN and RAN pools, respectively, to measure rate of flux through, and transfer of N between these and the bacterial N pool. Abomasal N flow was 24% greater than intake in LP and 29% less than intake in HP. An inverse relationship may exist between level of N intake and rate of influx of BUN into the rumen. In Experiment 3 ruminal fluid samples were obtained. With HP, BUN-derived /sup 15/N-ammonia appeared to rapidly equilibrate with RAN in the primary digesta mass. In contrast, with LP, there appeared to be an enrichment gradient for both RAN and bacterial N, declining from the rumen wall toward the center of the digesta mass, suggesting that bacteria at or near the rumen wall may preferentially utilized some BUN-derived ammonia N entering through the rumen wall.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1987},
month = {1}
}

Thesis/Dissertation:
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