Physiological mechanisms of adaptation of intestinal digestion of sheep to soybean products

The article considers the issue of physiological mechanisms of adaptation of intestinal digestion in polygastric animals. Dynamic and absolute indices of enzymatic activity of duodenal chyme in sheep are presented when various soy products are given into the diet. The experiment was conducted on Kuybyshev sheep using a fistula of the duodenum for analysis of duodenal chyme. The activity of trypsin, lipase and amylase was studied in samples taken on an empty stomach, 1 and 5 hours after feeding. The results showed that long-term adaptation of intestinal digestion to soy products in sheep occurs on the 4th day after the change in diet. The most pronounced changes in proteolytic activity were observed with the introduction of soybean meal, where a sharp increase in trypsin activity (by 56%) was noted on the 2nd day, which may be associated with compensatory enzyme synthesis under the influence of rumen metabolites. Trypsin activity in the complex reflex phase indicated a higher taste attractiveness of thermally processed products (cake and meal) compared to native soybeans and forage. Lipolytic activity reached its peak values with the introduction of soybeans and amounted to 3587.6 ± 340.26 unit/l, which is explained by a high fat content in them, while amylolytic activity remained relatively stable and was within 14246.4 ± 254.39 - 16256.1 ± 552.23 unit/l, with the exception of a low level (9033.4 ± 338.92 unit/ l) when using soybean forage. For the first time, along with generally accepted soy products, the dynamics of enzymatic activity when using soybean forage was studied. The results reveal the influence of sensory and nutritional properties of feed on adaptation processes, which allows us to expand our understanding of the mechanisms of long-term adaptation of intestinal digestion in ruminants to newly introduced diet components and compensate for the load on the digestive glands during the adaptation period by correcting enzymes.