Cargando…

Ureases in the gastrointestinal tracts of ruminant and monogastric animals and their implication in urea-N/ammonia metabolism: A review

Urea in diets of ruminants has been investigated to substitute expensive animal and vegetable protein sources for more than a century, and has been widely incorporated in diets of ruminants for many years. Urea is also recycled to the fermentative parts of the gastrointestinal (GI) tracts through sa...

Descripción completa

Detalles Bibliográficos
Autores principales: Patra, Amlan Kumar, Aschenbach, Jörg Rudolf
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Elsevier 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6077136/
https://www.ncbi.nlm.nih.gov/pubmed/30094081
http://dx.doi.org/10.1016/j.jare.2018.02.005
_version_ 1783344844105580544
author Patra, Amlan Kumar
Aschenbach, Jörg Rudolf
author_facet Patra, Amlan Kumar
Aschenbach, Jörg Rudolf
author_sort Patra, Amlan Kumar
collection PubMed
description Urea in diets of ruminants has been investigated to substitute expensive animal and vegetable protein sources for more than a century, and has been widely incorporated in diets of ruminants for many years. Urea is also recycled to the fermentative parts of the gastrointestinal (GI) tracts through saliva or direct secretory flux from blood depending upon the dietary situations. Within the GI tracts, urea is hydrolyzed to ammonia by urease enzymes produced by GI microorganisms and subsequent ammonia utilization serves the synthesis of microbial protein. In ruminants, excessive urease activity in the rumen may lead to urea/ammonia toxicity when high amounts of urea are fed to animals; and in non-ruminants, ammonia concentrations in the GI content and milieu may cause damage to the GI mucosa, resulting in impaired nutrient absorption, futile energy and protein spillage and decreased growth performance. Relatively little attention has been directed to this area by researchers. Therefore, the present review intends to discuss current knowledge in ureolytic bacterial populations, urease activities and factors affecting them, urea metabolism by microorganisms, and the application of inhibitors of urease activity in livestock animals. The information related to the ureolytic bacteria and urease activity could be useful for improving protein utilization efficiency in ruminants and for the reduction of the ammonia concentration in GI tracts of monogastric animals. Application of recent molecular methods can be expected to provide rationales for improved strategies to modulate urease and urea dynamics in the GI tract. This would lead to improved GI health, production performance and environmental compatibility of livestock production.
format Online
Article
Text
id pubmed-6077136
institution National Center for Biotechnology Information
language English
publishDate 2018
publisher Elsevier
record_format MEDLINE/PubMed
spelling pubmed-60771362018-08-09 Ureases in the gastrointestinal tracts of ruminant and monogastric animals and their implication in urea-N/ammonia metabolism: A review Patra, Amlan Kumar Aschenbach, Jörg Rudolf J Adv Res Article Urea in diets of ruminants has been investigated to substitute expensive animal and vegetable protein sources for more than a century, and has been widely incorporated in diets of ruminants for many years. Urea is also recycled to the fermentative parts of the gastrointestinal (GI) tracts through saliva or direct secretory flux from blood depending upon the dietary situations. Within the GI tracts, urea is hydrolyzed to ammonia by urease enzymes produced by GI microorganisms and subsequent ammonia utilization serves the synthesis of microbial protein. In ruminants, excessive urease activity in the rumen may lead to urea/ammonia toxicity when high amounts of urea are fed to animals; and in non-ruminants, ammonia concentrations in the GI content and milieu may cause damage to the GI mucosa, resulting in impaired nutrient absorption, futile energy and protein spillage and decreased growth performance. Relatively little attention has been directed to this area by researchers. Therefore, the present review intends to discuss current knowledge in ureolytic bacterial populations, urease activities and factors affecting them, urea metabolism by microorganisms, and the application of inhibitors of urease activity in livestock animals. The information related to the ureolytic bacteria and urease activity could be useful for improving protein utilization efficiency in ruminants and for the reduction of the ammonia concentration in GI tracts of monogastric animals. Application of recent molecular methods can be expected to provide rationales for improved strategies to modulate urease and urea dynamics in the GI tract. This would lead to improved GI health, production performance and environmental compatibility of livestock production. Elsevier 2018-02-26 /pmc/articles/PMC6077136/ /pubmed/30094081 http://dx.doi.org/10.1016/j.jare.2018.02.005 Text en © 2018 Production and hosting by Elsevier B.V. on behalf of Cairo University. http://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
spellingShingle Article
Patra, Amlan Kumar
Aschenbach, Jörg Rudolf
Ureases in the gastrointestinal tracts of ruminant and monogastric animals and their implication in urea-N/ammonia metabolism: A review
title Ureases in the gastrointestinal tracts of ruminant and monogastric animals and their implication in urea-N/ammonia metabolism: A review
title_full Ureases in the gastrointestinal tracts of ruminant and monogastric animals and their implication in urea-N/ammonia metabolism: A review
title_fullStr Ureases in the gastrointestinal tracts of ruminant and monogastric animals and their implication in urea-N/ammonia metabolism: A review
title_full_unstemmed Ureases in the gastrointestinal tracts of ruminant and monogastric animals and their implication in urea-N/ammonia metabolism: A review
title_short Ureases in the gastrointestinal tracts of ruminant and monogastric animals and their implication in urea-N/ammonia metabolism: A review
title_sort ureases in the gastrointestinal tracts of ruminant and monogastric animals and their implication in urea-n/ammonia metabolism: a review
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6077136/
https://www.ncbi.nlm.nih.gov/pubmed/30094081
http://dx.doi.org/10.1016/j.jare.2018.02.005
work_keys_str_mv AT patraamlankumar ureasesinthegastrointestinaltractsofruminantandmonogastricanimalsandtheirimplicationinureanammoniametabolismareview
AT aschenbachjorgrudolf ureasesinthegastrointestinaltractsofruminantandmonogastricanimalsandtheirimplicationinureanammoniametabolismareview