Based on the results of the research, the use of yeast extract as a flavor and aroma protein additive in the feeding of broiler chickens and quails for meat production was theoretically justified for the first time. It has been proven that the most effective level of introducing yeast extract into compound feed for broiler chickens and meat quails is 0,5 %. It is shown that the use of compound feed with effective levels of yeast extract (Saccharomyces cerevisiae) increases the live weight and intensity of growth of poultry, and decreases feed costs per unit of production (1 kg increase in live weight of poultry). it was noted that the use of compound feed with yeast extract at the level of 0,3–0,7 % contributes to increasing the productivity of broiler chickens by 3,5–5,2 % (Р<0,001). According to the conducted studies, it was shown that the introduction of 0,5 % of yeast extract into compound feed for broiler chickens contributed to an increase in feed consumption by 1,2 % and water by 18,9 %, which led to an increase in pre-slaughter live weight by 4,6 % (P<0,001). Production profitability increased by 9,7 %, compared to poultry that did not consume yeast extract (Saccharomyces cerevisiae) as part of the compound feed. In addition, the introduction of 0,5 % yeast extract into the compound feed of broiler chickens contributed to an increase in profitability by 9,7 %. According to the results of the research, it was established that the use of compound feed for quails with yeast extract in the amount of 0,5 % contributed to an increase in the live weight of the bird by 3,6 %, a decrease in feed consumption per 1 kg of growth by 1,6 %, an increase in water consumption by 1,1 %, an increase in the yield of cartridge carcasses by 1,8 %, which contributed to an increase in profitability by 0,9 %. the introduction of yeast extract to compound feed at the level of 0,5 % made it possible to obtain young animals with an average live weight at the end of the experiment that was 4,6 % (р<0,01) higher than that of the counterparts of the control group. It is worth noting that the use of yeast extract at the level of 0,7 % also contributed to an increase in the live weight of animals, namely by 4,0 % (р<0,05). When studying the consumption
of compound feed by young broilers, it was determined that during the fifth week of the experiment in the 3-rd experimental group there was a tendency towards lower consumption of compound feed than in the control group (by 2,2 %). It should be noted that, in contrast to the 3-rd experimental group, the 2-nd and 4-th experimental groups consumed more feed than the control respectively by 4,8 and 3,6 %. During the entire growing period, the indicator of feed consumption per 1 kg of production increase was the lowest in the group where yeast extract was used at the level of 0,5 %, which is 0,051 kg or 3,4 % lower than the analogues of the control group. The largest mass of pectoral muscles was noted in the 3-rd experimental group, which is 2,74 % higher than the indicator of the control group. At the same time, the difference between the 2-nd experimental group and the control was – 1,54 %, the 4-th experimental group and the control – 2,1 %. It was established that when the yeast extract was added to the compound feed for young quails, an increase in live weight was observed at the level of 0,3–0,7 %, compared to the group where the yeast extract (Saccharomyces cerevisiae) was not used. Based on the conducted research, it was proven that the addition of the extract contributed to increase in the weight of the uncarcased carcass by 0,8–3,4, as well as the mass of semi-cartridge and cartridge carcass respectively by 1,3–3,1 % and 1,1–1,6 %. Considering the results obtained during the research, in order to increase the meat productivity of broiler chickens and young quails, to reduce feed costs per unit of production, to increase the profitability of production, it is recommended to add 0,5 % of yeast extract (Saccharomyces cerevisiae) to the composition of complete feed.
