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:

© 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 ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.


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