Article

Effects of stocking density and dietary vitamin C on performance, meat quality, intestinal permeability, and stress indicators in broiler chickens

Dong Gwon Yu1, Nyun Namgung1, Jong Hyuk Kim1, Seung Yeon Won1, Won Jun Choi1, Dong Yong Kil1,*
Author Information & Copyright
1Chung-Ang University , Anseong 17546, Korea.
*Corresponding Author: Dong Yong Kil, Chung-Ang University , Anseong 17546, Korea, Republic of. E-mail: dongyong@cau.ac.kr.

© Copyright 2021 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: Feb 23, 2021; Revised: May 16, 2021; Accepted: May 17, 2021

Published Online: Jul 26, 2021

Abstract

The objective of the current study was to investigate the effects of stocking density (SD) and dietary supplementation of vitamin C on growth performance, meat quality, intestinal permeability, and stress indicators in broiler chickens. The study was conducted using a completely randomized design with a 2 × 2 factorial arrangement consisting of 2 different SD and 2 supplemental levels of dietary vitamin C. A total of 1,368 Ross 308 broiler chickens of 21 days of age with similar body weights (BW) were randomly allotted to 1 of 4 treatments with 6 replicates each. Different numbers of birds per identical floor pen (2.0 m × 2.4 m) were used to create 2 different SD levels of low SD (9 birds/m<sup>2</sup>) and high SD (18 birds/m<sup>2</sup>). The basal diet was formulated with no supplemental vitamin C to meet or exceed nutrient recommendations of the Ross 308 manual. The other diet was prepared by supplementing 200 mg/kg vitamin C in the basal diet. The study lasted for 14 days. At the end of the study, 3 male birds per replicate were selected to analyze meat quality, intestinal permeability, and stress indicators such as blood heterophil:lymphocyte (H:L) and feather corticosterone (CORT) concentrations. Results indicated that there were no interactions between different SD and dietary supplementation of vitamin C for all measurements. For the main effects of SD, birds raised at high SD had less (<italic>p</italic> &lt; 0.01) BW, BW gain, and feed intake with increasing stress responses including greater blood H:L and feather CORT concentrations (<italic>p</italic> &lt;  0.01) than those raised at low SD. Transepithelial electrical resistance in the jejunal mucosa was decreased (<italic>p</italic> &lt; 0.05) at high SD, indicating an increase in intestinal permeability. However, the main effects of dietary supplementation of 200 mg/kg vitamin C were insignificant for all measurements. In conclusion, high SD of broiler chickens impairs growth performance and intestinal barrier function with increasing stress responses. However, dietary supplementation of vitamin C may have little beneficial effects on broiler chickens raised under the high SD condition used in the present study.

Keywords: Broiler chicken; Dietary vitamin C; Growth performance; Intestinal permeability; Stress indicator; Stocking density