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

Riboflavin and Bacillus subtilis effects on growth performance and woody-breast of Ross 708 broilers with or without Eimeria spp. challenge

Sabin Poudel, George Tabler, Jun Lin, Wei Zhai, Li Zhang
1Mississippi State University, Mississippi State 39762, United States.
2University of Tennessee, Knoxville 37996, United States.
*Corresponding Author: Li Zhang, E-mail:

© Copyright 2022 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.

Received: Feb 05, 2022; Revised: Apr 02, 2022; Accepted: Apr 07, 2022

Published Online: May 10, 2022


This study was conducted to assess the effects of the dietary supplementation of  riboflavin (as a bile salt hydrolase (<strong>BSH</strong>) inhibitor) and <italic>Bacillus subtilis </italic>on  growth performance and woody breast of male broilers challenged with <italic>Eimeria </italic>spp. Intestinal bacteria, including supplemented probiotics, can produce BSH enzymes that deconjugate conjugated bile salts and reduce fat digestion. A 3 × 2 × 2 (riboflavin ×<italic>Bacillus subtilis </italic>× <italic>Eimeria </italic>spp. challenge) factorial arrangement of treatments in randomized complete block design was used. On d 14, birds were gavaged with 20× doses of commercial cocci vaccine (Coccivac<sup>R</sup>-B52, Merck Animal Health, Omaha, NE). Dietary treatment of riboflavin and <italic>B. subtilis</italic> did not affect body weight (<strong>BW</strong>), body weight gain (<strong>BWG</strong>), and feed conversion (<strong>FCR</strong>) d 0 to 14 and overall d 0 to 41. <italic>Eimeria</italic> spp challenge reduced BWG, FI, and increased FCR between d 14 to 28, but increased BWG and lowered FCR between d 28 to 35. There were no effects of the <italic>Eimeria </italic>spp<italic>.</italic> challenge on the overall d 0 to 41 FCR and FI, but BWG was reduced. <italic>Eimeria spp.</italic> challenge increased the abdominal fat pad weight and slight woody breast incidences on processed birds on d 42. Dietary inclusion of <italic>B. subtilis</italic> and riboflavin at tested levels did not help birds to mitigate the negative impact of <italic>Eimeria</italic> spp. challenge to enhance the growth performance.

Keywords: Riboflavin; Bacillus subtilis; Coccidiosis; growth performance