Digestion and gas formation processes in sheep under the influence of a complex of phytogenics

The article presents the results of a study of the effect on digestion processes and methane emissions in sheep when fed phytogenic feed additives based on condensed tannins of Lárix dahúrica and their complex with dihydroquercetin. The experiment was conducted at the physiological yard of the L.K. Ernst Federal Research Center for Animal Husbandry and Animal Welfare on Romanov sheep with chronic rumen fistulas according to Basov. The experiment was conducted using the 2 × 3 Latin square method (n = 6). In the first period, the sheep received a hay-concentrate diet containing 40% concentrates by nutritional value. The dosage of tannins was 5 g/head per day, dihydroquercetin — 0.1 g/head per day. At the end of each balance experiment, rumen contents were sampled from all animals (n = 6) to determine rumen digestion indices. When feeding the studied additives, a tendency to increase amylolytic activity in the experimental groups is observed. In the control, this indicator was 17.403 U/ml, in the first experimental group — 18.128 U/ml, in the second — 18.423 U/ml. The amount of VFA significantly (p < 0.05) increased when consuming the complex additive (tannin + DHQ) — 9.137 mmol/ml versus 8.385 mmol/ml in the control. These data correlate with an increase in symbiotic microflora (both bacteria (p = 0.013) and ciliates) relative to the control in the third group (tannin + DHQ) and a decrease in the second. When feeding only tannin, the level of ciliate formation was lower and the concentration of VFA after feed intake was lower. This indicates the inhibition of microflora under the influence of tannin. At the same time, the synergistic effect of the action of Lárix dahúrica tannins and DQV on the intensification of rumen digestion processes is demonstrated. There is a decrease in methane release by 14.8% when consuming tannins, and by 26.8% when consuming a complex additive, which indicates the presence of synergy in the effect of the studied additives on methanogenesis in sheep in vivo .