Rationing of diets of dairy cows for non-degradable protein with protein supplements of plant origin

Methods . This scientific and economic experiment was conducted under the conditions of the Moscow Region on 3 groups of Holstein breed cows showing milk yield of 8000 kg to study the efficiency of rationing of the content of non-degradable protein in feed rations for highly productive cows upon the use of various sources of protected plant-based protein. Results . It was found that the increase in content of non-degradable protein from 35% in the control group to 40% in experimental groups I and II for the period from day 21 until day 100 of lactation by feeding corn gluten (0.85 kg) and extruded soy protein concentrate (1.0 kg) accordingly instead of sunflower meal (1.2 kg) in the control group, with the similar concentration of raw protein of 17.2% in dry matter of the feed, contributed to the increase in milk yield with 4% fat content over 100 days of lactation by 6.3% and 8.5% (p ≤ 0.05) and the increase in feed costs (ME) by 5.3–6.7%. In physiological studies, an increase in the digestibility of crude protein by 2.0% and 3.2% abs (p ≤ 0.05), in groups of cows receiving protected protein supplements, as well as a tendency for more intensive digestion of crude fat by 1.2% and 2.2% abs. (p ≤ 0.1). Economic calculations showed that the use of the studied protein supplements in the diets of animals of experimental groups I and II made it possible to reduce the cost of 1 c of milk with basic fat content by 41.8 and 56.0 rubles, while receiving additional profit in the amount of 2845.1 and 3861.3 rubles compared to control.