The objective of this study was to evaluate the effect of growth promoters additives on performance, carcass yield (parts and abdominal fat), total intestinal bacteria counts in broilers from 1 at 42 days old fed with corn and soybean meal based diets, compared to antibiotics supplementation diets. In this study were urilized a 7 x 2 factorial design, with seven differents additives (antibiotic, basal, MOS, FOS, fumaric acid, mutshroom extract and probiotic) and two sex (males and females). A total of1680 sexed broilers chickens from Hybro line were distributed in 14 treatments, with 4 replicates and 30 chickens per experimental unit. Effects of growth promotant additives on feed intake , feed conversion and production efficiency factor were measured. Male chickens shown better performance results than females in all parameters evaluated, except for viability. Additives shown positive effects on carcars yield, parts yield, and abdominal fat. Male chickens were heavier at slaughter and shown higher leg yields than females. Additives also influenced total bacteria counts in duodenum and caecum altering the microbiota of the intestinal chickens. These changes in intestinal microbiota might have contributed for a higher stability and better survival of good microorganisms in the intestinal ecosystem, resulting in benefits for the host. The results of this study shown that the use the addictive as a growth promoters should be used in the feeding for broilers chickens, in substitution to the antibiotic, without affecting the performance and carcass yield , in the period from 1 to 42 days of age.
Antibiotic; broilers chickens; growth promoter; performance; carcass yield
