Investigating the effects of dietary probiotic feeding regimens on broiler chicken production and Campylobacter jejuni presence.

An experiment was conducted to investigate the effect of restricted feeding of a commercially available probiotic diet on production/processing performance, Campylobacter jejuni prevalence, and organ weights in broiler chickens. Five hundred forty 1-d-old broiler chicks were randomly assigned to a control or a direct-fed microbial (PrimaLac, DFM) diet and subjected to ad libitum full-fed (A), restricted 8-h (R), or skip-a-day (S) feeding regimens. Each of the 6 treatments was replicated 3 times with 15 male and 15 female chicks per pen for 49 d. Significant (P<0.05) differences between BW in the control and DFM groups with regard to feed type were found at d 7 (A), female d 21 (R) male and females, and d 49 (A and S) male and females. Body weights of males in the control group were significantly higher than the DFM (A) and differed by regimens (A>R>S) at d 49, whereas weights of females did not differ in regimens A and S. Body weight in the control females of regimen R was significantly higher than those in regimens A and S. Carcass yield was significantly higher for males in the control regimen A, 78.1 vs. 74.6% for the DFM regimen A; however, females did not differ significantly in this regimen, but did so in regimen S with 72.6 vs. 69.0%. The gizzard weights were significantly higher for broilers exposed to S and R regimens when compared with the A regimen. The prevalence of C. jejuni in the DFM-treated broilers regimen R was lower (33 vs. 60% positive) for the control group at 21 d. The weekly BW throughout the study reflected many variations, but broiler chickens receiving the control feed on regimen A performed better than those receiving the DFM feed. From the present results, it was concluded that supplementation of DFM reduced the presence of C. jejuni but had no significant effect on the growth performance of broilers; however, there were some significant trends regarding sex, feed, and feeding methods on the performance results.