Nutritional value of feed mixtures and milk productivity in ayrshire breed cows by lactation periods

The article analyzes the composition and nutritional value of feed mixtures for first-calf cows of the Ayrshire breed, used during three periods of lactation. It was established that in the first period of lactation the ration had an excess content of dry matter. Throughout lactation an increased content of degradable protein and an insufficient level of non-degradable protein were noted. The sugar content in the feed mixture in the first two periods of lactation is less than the norm, by 30.1% and 27.3%, respectively. The daily milk yield of first-calf cows during the first period of lactation was 29.3±3.3 kg; for the second period - 24.5±3.3 kg; for the third period - 21.9±4.1 kg. Over 305 days of lactation, 7666±900 kg of milk was obtained from the cows of the experimental group. The mass fraction of fat in cows’ milk increased over lactation periods from 3.86 to 4.11%; the mass fraction of protein varied within 3.45-3.39%. The consumption of energy feed units per 1 kg of milk averaged 0.74 over 305 days of lactation; the consumption of digestible protein per 1 kg of milk was 75.4 g.