| Popis: |
An important problem in organizing full-fledged feeding of cows is to establish the optimal level of energy nutrition, taking into account productivity, age and lactation period. The studies were carried out in the conditions of the foothill zone of the North Caucasus. 45 first-calf cows of the Schwyz breed were selected, from which three groups (15 heads in each) were formed according to the principle of pairs of analogues, taking into account age, live weight and body condition. The animals of the first group were control animals, and they received a diet that corresponds to the detailed norms (2003) of the All-Russia Institute of Animal Husbandry (ВИЖ). The rations for first-calf cows consisted of leguminous-cereal hay, corn silage, herb haylage, and compound feed. The basic feeds of the diet were given in equal amounts to cows of all groups. The second and third experimental groups during the period of milking received rations in which the level of energy supply was increased by 10 and 20%, respectively. Corn fodder meal was used as additional feeding. In terms of nutritional value, this was 0.92 and 1.84 EFU (0.7 and 1.4 kg), respectively. It was found that the introduction of an additional dose of energy feed (10 and 20% of corn flour) into the feeding ration of experienced first-calf cows contributed to an increase in milk yield in the first 100 days of lactation by 11.5 and 14%, respectively, as well as to some improvement in the quality indicators of milk. For example, in terms of milk fat content, cows from the experimental groups exceeded the control group by 0.06–0.08%, and in terms of milk fat yield, the difference between the groups was 10.9–16.6 kg. The protein content is 0.04–0.08%. The difference in the yield of milk protein is 9.1–14.9 kg. The duration of the interbody period was 6–8 days shorter than in the control group. The introduction of an additional dose of energy feed into the diet reduced the service period by 10–12 days, the frequency of inseminations by 0.3–0.5, and an increase in calf yield by 2–3%. |
