Journal of Animal Science and Technology
Korean Society of Animal Science and Technology
Article

Growth performance of male broiler chickens in different growth phases in response to amino acid concentrations in the pre-starter diet

Su Hyun An1, Changsu Kong1,2,3,*
1Research Institute for Innovative Animal Science, Kyungpook National University, Sangju 37224, Korea.
2Department of Animal Science, Kyungpook National University, Sangju 37224, Korea.
3Department of Animal Science and Biotechnology, Kyungpook National University, Sangju 37224, Korea.
*Corresponding Author: Changsu Kong, Research Institute for Innovative Animal Science, Kyungpook National University, Sangju 37224, Korea, Republic of. Department of Animal Science, Kyungpook National University, Sangju 37224, Korea, Republic of. Department of Animal Science and Biotechnology, Kyungpook National University, Sangju 37224, Korea, Republic of. E-mail: changsukong@gmail.com.

© Copyright 2024 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 (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Received: Apr 08, 2024; Revised: Apr 28, 2024; Accepted: May 20, 2024

Published Online: May 22, 2024

Abstract

An experiment involving 720 one-day-old male broilers (Ross 308) was conducted to investigate the effects of graded levels of crude protein and standardized ileal digestible (SID) amino acids (AA) on growth performance during the pre-starter period (0 to 7 d), and to compare the subsequent growth performance of birds fed a commercial diet in the later phase (8 to 28 d). On d 1, all birds were individually weighed and allocated to six groups with eight replicate pens (15 birds/pen). Broilers were fed diets containing six different dietary SID AA levels relative to the 90 to 115% requirement for 7 d. From d 8 to 28, birds were fed a commercial diet containing nutrient levels meeting their dietary requirements. The body weight gain (BWG; <italic>p</italic> = 0.044) and gain-to-feed ratio (G:F; p = 0.005) of birds increased quadratically, and feed intake of birds linearly increased with increasing dietary AA concentration during d 0 to 7. Growth performance exhibited linear increases in later phases (<italic>p</italic> &lt; 0.05) until 28 d, except for G:F at 28 d. BWG (p = 0.001) and feed intake (<italic>p</italic> = 0.008) linearly increased compared to the 90% SID AA treatment, whereas G:F was not affected (<italic>p</italic> = 0.088) by dietary treatment. Additionally, feed intake of birds linearly increased (<italic>p</italic> &lt; 0.01) as dietary SID AA concentration increased. Following the transition to a commercial diet, body weight at 14, 21, and 28 d, BWG, feed intake, and G:F linearly increased (<italic>p</italic> &lt; 0.05). Overall, BWG and the growth rate of broilers aged 8 to 28 d also exhibited linear increments (<italic>p</italic> &lt; 0.01) by the dietary AA concentrations in diets during the first week. The study findings confirm the influence of dietary AA concentrations on the growth performance of broilers in the first week after hatch, demonstrating that this impact persists in the later growth stage. Therefore, ensuring sufficient dietary AA intake during the first week of life can enhance performance in later stages of development in broiler chickens.

Keywords: amino acid content; standardized ileal digestible; ideal amino acid ratio; growth performance; broiler