Effect of a Feed Supplemented Yeast Extract and Soluble Vitamins with Aminoacids on the Performance and Microbiology Count in Broiler Chickens

The aim of this study was to evaluate the effect of a yeast extract supplemented in feed and a vitamins-aminoacids compound in the drinking water on the performance and microbiology count of broiler chickens. A 42- day experiment was carried out and replicated twice in time at Universidad ISA. In each experiment, 240 straight run day-old chicks were randomly distributed in 4 treatments of a Completely Randomized Design with a factorial arrangement. The 4 treatments were from the combination of two levels of the factor yeast (0 and 1.65 g/kg of feed) with 2 levels of the factor vitamins-aminoacids (0 and 0.5 ml/liter of water). Each treatment was replicated six times for a total of 24 experimental units of 10 chicks each one. The evaluated variables were: body weight (BW), Feed intake (FI), body weight gain (BWG), Feed Efficiency (FE), carcass yield (CY), carcass yield percentage (CYP), gut weight (GW), gut length (GL), gizzard weight (GW), gizzard length (GL), gizzard width (GW), mortality rate (MT), enterobacterias count (CFUE), E. coli (CFUEC) and Salmonella count (CFUS). There were no consistent significant differences (P> 0.05) for any of the evaluated variables; except, when the CFUEC was significantly (P≤0.05) reduced from 607,667 cfu/g in the treatment without yeast to 390,083 cfu/g in the yeast supplemented treatment. The results of this research suggest that supplementing yeast with soluble vitamins and aminoacids does not have a consistent effect on the performance, but it reduces the E. coli count in the broiler chickens gastrointestinal tract.

Key words: yeast, vitamins, aminoacids, microbiology count.