A reduction in dietary crude protein with amino acid balance has no negative effects in pigs

Junyoung Mun1, Habeeb Tajudeen1, Hosseindoust Abdolreza1, Sanghun Ha1, Serin Park1, Jinsoo Kim1,*
Author Information & Copyright
1Department of Animal Industry Convergence, Kangwon National University, Chuncheon 24341, Korea.
*Corresponding Author: Jinsoo Kim, Department of Animal Industry Convergence, Kangwon National University, Chuncheon 24341, Korea, Republic of. Phone: +82-33-250-8614. E-mail:

© Copyright 2023 Korean Society of Animal Science and Technology. This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.


The aim of this experiment was to evaluate the effects of low crude protein (CP) level with essential amino acids (AA) addition on growth performance, nutrient digestibility, microbiota, and volatile fatty acid composition in growing pigs. A total of 160 growing pigs (LYD; average initial body weight 16.68 ± 0.12 kg) were randomly allotted to one of the four treatments on the basis of initial BW. A randomized complete block design was used to conduct this experiment in the Research Center of Animal Life Sciences at Kangwon National University. There were ten pigs/replicate with four replicates in each treatment. The treatments include; CON (Control, 17.2% dietary CP level), low protein (LP)-1.10 (15.7% dietary CP level + 1.10% lysine level), LP-1.15 (15.7% dietary CP level + 1.15% lysine level), LP1.2 (15.7% dietary CP level + 1.20% lysine level). The pigs fed CON and LP-1.2 diet showed greater final body weight than that of LP-1.1 diet (p<0.05). Although average daily gain, average daily feed intake, and feed efficiency did not show any difference in phase 2 and 3, average daily gain and feed efficiency was significantly greater in CON and LP-1.20 in phase 1. However, the average daily feed intake did not show any difference during the experimental period. Isobutyric acid and isovaleric acid composition of LP treatments were lower than CON treatment in phase 2. Total branched chain fatty acid composition was significantly lower in LP treatment in phases 1 and 2. However, there was no significant difference among treatments in phase 3. The results of this study underscore the importance of AA supplementation when implementing a low-protein diet during the early growth phase (16-50 kg) in pigs.

Keywords: Pig; Crude protein; Amino acid; Growth performance; Volatile fatty acid