Use of probiotics in diets of wild-type chickens and its effects on performance

SUMMARY The objective of this study was to evaluate the performance of male colonial chickens fed diet supplemented with commercial probiotic (Calsporin ®). A total of 210 male chicks Label Rouge lineage were used and they were raised in experimental shed up to 30 days old. These birds had free access to the pickets of Tifton-85, from 31-90 days of age. The experimental design was completely randomized, two treatments, one containing feed supplemented with probiotic Bacillus subtillis (300 g t-1 Bacillus subtillis 1×109 UFCg-1) and another one without it, with ten replications per treatment, consisting of 21 chickens/replication. The mean of body weight (BW), weight gain (WG), feed intake (FI), feed conversion (FC), mortality and viability were evaluated. The data were submitted to variance analysis and the averages of the treatments were compared by the F-test at 5% of significance. The addition of probiotic (300 g t-1 Bacillus subtillis 1×109 UFCg-1) in the diet of Label Rouge broilers did not interfere in the MW, WG, and FC variables in the total period from 1 to 90 days (P>0.05); the MFI variable differed (P <0.05), with higher consumption in chickens receiving the diet with the probiotic. The inclusion of probiotic in the wild-type chicken ration did not improve the productive performance of poultries possibly due to a low challenge by pathogenic microorganisms in the environments in which they were raised.