<abstract xmlns="http://www.w3.org/1999/xhtml"><p>In general, higher mammals need nine amino acids (AA) in their diets as building blocks to synthesize proteins while ruminants can produce some of them through the synthesis of microbial proteins. Diet is utilized by ruminal microorganisms to synthesize microbial protein (MCP) which is digested in the small intestine (SI). Although protein and amino acid requirements in ruminants are subject to microbial protein synthesis, it is not enough for optimal daily production. Therefore, there is a current trend towards supplementing amino acids in ruminant diets. In the rumen, free amino acids can be degraded by rumen bacteria, therefore, the AAs need to be supplemented in a protected form to be stable in the rumen and absorbable post-ruminal for metabolic purposes. The main site of amino acid absorption is the small intestine (SI), and there is a need to keep AA from ruminal degradation and direct them to absorption sites. Several approaches have been suggested by feed scientists to decrease this problem such as defaunation and debacterization of the rumen against amino acid-fermenting fungi and bacteria, inhibitors or antagonists of vitamin B<sub>6</sub> enzymes, diet composition and also protecting AA from rumen degradation. A number of studies have evaluated the roles of amino acids concerning their effects on milk yield, growth, digestibility, feed intake and efficiency of nitrogen utilization of ruminants. The focus of this review was on experimental and research studies about AAs in feedstuff, metabolism, supplementing amino acids for ruminants and the current trends of using rumen protected amino acids.</p></abstract>

In general, higher mammals need nine amino acids (AA) in their diets as building blocks to synthesize proteins while ruminants can produce some of them through the synthesis of microbial proteins. Diet is utilized by ruminal microorganisms to synthesize microbial protein (MCP) which is digested in the small intestine (SI). Although protein and amino acid requirements in ruminants are subject to microbial protein synthesis, it is not enough for optimal daily production. Therefore, there is a current trend towards supplementing amino acids in ruminant diets. In the rumen, free amino acids can be degraded by rumen bacteria, therefore, the AAs need to be supplemented in a protected form to be stable in the rumen and absorbable post-ruminal for metabolic purposes. The main site of amino acid absorption is the small intestine (SI), and there is a need to keep AA from ruminal degradation and direct them to absorption sites. Several approaches have been suggested by feed scientists to decrease this problem such as defaunation and debacterization of the rumen against amino acid-fermenting fungi and bacteria, inhibitors or antagonists of vitamin B6 enzymes, diet composition and also protecting AA from rumen degradation. A number of studies have evaluated the roles of amino acids concerning their effects on milk yield, growth, digestibility, feed intake and efficiency of nitrogen utilization of ruminants. The focus of this review was on experimental and research studies about AAs in feedstuff, metabolism, supplementing amino acids for ruminants and the current trends of using rumen protected amino acids.

Harnessing the Value of Rumen Protected Amino Acids to Enhance Animal Performance – A Review

Department of Animal, Veterinary and Food Sciences, Department of Agriculture

Department of Animal and Dairy Sciences, Faculty of Agriculture

Annals of Animal Science

This work is licensed under the Creative Commons Attribution 4.0 International License.

In general, higher mammals need nine amino acids (AA) in their diets as building blocks to synthesize proteins while ruminants can produce some of them through...

Harnessing the Value of Rumen Protected Amino Acids to Enhance Animal Performance – A Review

Published Online: Feb 04, 2022

Page range: 43 - 62

Received: Dec 17, 2020

Accepted: Mar 05, 2021

DOI: https://doi.org/10.2478/aoas-2021-0018

Keywords
essential amino acids, methionine, lysine, rumen protected amino acid, ruminants

© 2022 Mitra Mazinani et al., published by Sciendo

This work is licensed under the Creative Commons Attribution 4.0 International License.

Harnessing the Value of Rumen Protected Amino Acids to Enhance Animal Performance – A Review

Published Online: Feb 04, 2022

Page range: 43 - 62

Received: Dec 17, 2020

Accepted: Mar 05, 2021

DOI: https://doi.org/10.2478/aoas-2021-0018

Keywordsessential amino acids, methionine, lysine, rumen protected amino acid, ruminants

© 2022 Mitra Mazinani et al., published by Sciendo

This work is licensed under the Creative Commons Attribution 4.0 International License.

Keywords
essential amino acids, methionine, lysine, rumen protected amino acid, ruminants