Feed behavior and milk productivity in cows of different fattening

Abstract

The results of feed behavior and milk productivity in the cows of Ukrainian black-speckled dairy breed of different fattening of the first and second lactations from the first month to the end of lactation are given. The analysis of the herd showed that the highest milk productivity in cows of the first lactation was found in the group of fattening from 3 to 4 points, which was by 9.2 % (P ≥ 0.99) higher, compared to the group of cows with fattening 4 points and more. The milk yield in cows of the second lactation with fattening from 3 to 4 points exceeded the milk yield of cows with fattening 4 points and more by 12.9 % (P ≥ 0.95). The content of fat and protein in milk was higher in the cows with higher fattening, compared to the cows with lower fattening. The highest average daily milk yield was found in cows of the first lactation with fattening from 3 to 4 points. Depending on the month, it was by 5.5–11.7 % (P ≥ 0.95 – P ≥ 0.999) higher, compared to the cows with fattening 4 points and more, while it was by 6.9–10.0 % (P ≥ 0.95 – P ≥ 0.999) higher in cows of the second lactation. The gestation period of cows has a significant effect on the reduction of milk yield. The milk yield of cows in connection with the term of their gestation are reduced by 0.1 kg per day during the second month after insemination, by 0.2 kg per day during the third month, by 0.3 kg per day during the fourth month, by 0.6 kg per day during the fifth month, by 1.0 kg per day during the sixth month, by 1.7 kg per day during the seventh month and by 2.8 kg per day during the eighth month. The analysis of the dynamics of monthly milk yield shows that lactation curves of cows increase from the first day of lactation to its peak, which occurs in the 2nd – 4th month after calving. The lactation curve in the cows with fattening from 3 to 4 points has a higher peak in the 2nd –3d month of lactation, compared to the cows with higher (more than 4 points) fattening. The animals of all groups, except for cows of the second lactation (with fattening 4 and more points) showed the maximum productivity in the 2nd –3d month of lactation; then the lactation curve decreased with different intensity. The index of constancy of lactation and the index of falling milk yield are the important indicators that characterize the stability of lactation curves. The constancy of lactation curves having been determined by I. Johansson-Hansson index was higher in the cows with fattening 4 and more points, compared to the indicator of the cows with fattening from 3 to 4 points. The studies of behavioral reactions have shown that the animals of the first lactation with an average (from 3 to 4 points) fattening consume feed during 208.5 minutes, which is by 17 minutes (P ≥ 0.999) longer than the animals with higher average fattening, and by 14.5 minutes (P ≥ 0.99) longer than the animals of the second lactation.