Abstract
One performance trial was conducted to determine the effects of supplementing feed or drinking water with a Lactobacillus-based probiotic or feed antibiotic on growth parameters. gut health and control pathogen colonization of broilers under Clostridium perfringens challenge as compared to unchallenged, unsupplemented diet. One hundred and fifty, 0-d-old male Ross 308 broilers were allocated in 5 experimental treatments for 30 d. The experimental treatments received acorn-soybean basal diet and were as follows: positive control (+CONT) with no additions; negative control (-CONT): antibiotic (ENRA) with addition of Enramycin; Primalac in feed (PF) and Primalac in water (PW). Chicks in treatments 2 to 5 were challenged with C. perfringens. Five birds were sampled at 16 and 30 d of age for gross and histologic examination of the duodenum, jejunum and ileum. Overall, feed conversion ratio (FCR) in treatment PF was significantly better (P < 0.05) than the +CONT and -CONT treatments, whereas treatments PRIM and PW were intermediate and not different from PF. Feed intake (FL) and body weight gain (BWG) were not influenced by treatment. Birds which had received PF had longer and wider duodenal and jejunal villi than did +CONT, -CONT or ENRA. The changes in C. perfringens count appear in parallel to observed changes in villi height and width in the small intestine. The performance of the birds which had consumed PF was better than the birds which consumed the antibiotic treatment (ENRA). The results from this study indicated that Primalac not only helped in the maintenance of beneficial bacteria but also could act as a replacement for antimicrobial growth promoters in broilers.