Laboratory study to determine the effect of a probiotic mixture on chicken-broiler

The experiment was performed in two groups of broiler chickens. The birds from the experimental group were treated with the combination of 3% lactic bacteria. 1% baker's yeasts and 0.7% citric acid, added to food. It was found out that the treatment resulted in shifting the microbial balance in avian gastrointestinal tract in favour of Gram-positive bacteria (77-80%) while in control birds Gram negative organisms prevailed (90%). Both the volume and the weight of viscera of experimental chickens, obtained following slaughtering was by 20-60% higher compared to controls. Furthermore, 75% of treated birds reached a slaughtering weight (1800 g) for 42 days with an average daily weight gain of 57 g and expenditure of 2.3 kg fodder per 1 kg weight gain, whereas the body weight of control birds was by 26.5% lower than the standard one, the fodder expenditure was 3.1 kg per 1 kg weight gain and the average daily gain was 42 g. The mortality in controls was 13% while in treated birds there were no lethal cases. The price of one kilogramme body weight in experimental birds was by 0.15 $ lower compared to controls.