Influence of phytobiotics dose on feed conversion in broiler chickens

The inclusion of Chaga decoction in the compound feed for broiler chickens in the amount of 20 mg, 40 and 60 mg/kg of live weight of the broilers during the entire period of its rearing had a different influence on the digestibility and use of nutrients in the diet. The results of the physiological experiment at the age of 3 weeks of broilers showed that a small dosage of the phytobiotic compared with the control group stimulated an increase in the digestibility of crude protein in the feed by 4.05 abs.%, crude fat by 1.92 abs.%, crude fiber by 1.21 abs.%. With the increase in the dosage of the phytobiotic in the broiler compound feed, the increase in the digestibility of crude fi ber by 2.01–2.12 abs.% was noted. Nitrogen digestibility in poultry with a low rate of Chaga decoction introduction exceeded the control group by 0.16 g, and other experimental groups by 0.13–0.14 g. As a result, the average daily nitrogen deposition in the body of broiler chickens in the group with a low rate of phytobiotic introduction was 2.53 g or 16.1 % higher than in broilers in the control group and 2.3–3.2 % higher than in other experimental groups. At the fi nal stage of broiler chicken rearing, the digestibility of crude protein in the diet of broiler chickens of the 1st experimental group with a low dosage of phytobiotic was higher than in the control group by 3.17 abs.%, crude fat by 4.15 abs.%, crude fi ber by 2.60 abs.%, and nitrogen-free extractive substances by 0.17 abs.%. In broilers of other experimental groups this diff erence was less expressed. A decrease in nitrogen losses with undigested substances in the droppings of broilers of the 1st experimental group increased its deposition by 5.7 %, in other experimental groups only by 0.9–2.1 %. Analysis of the dynamics of live weight of broiler chickens during the rearing period showed that the 1st experimental group with the low dosage of Chaga decoction in the diet increased the absolute gain in live weight in comparison with the control group by 5.0 %, with the 2nd experimental group by 3.4 % and with the 3rd experimental group by 1.4 %, and feed costs accordingly by groups decreased by 4.7 %, 3.2 and 1.5 %.