The influence of age and live weight at conception on the consumption of metabolizable energy and crude protein during 6 months of pregnancy, processes of their growth and development was studied. The gain of live weight of springer heifers during the first three months of pregnancy was determined to be 67,0±3,66 kg in group I, 65,0±5,26 kg in group II and 49,0±4,40 kg in group III. Studying the growing power of the animals during 0-3 months (92 days) of pregnancy, the springer heifers of groups I and II were found to be superior to the herdmates of the group III by 196g and 174g or 26,9 and 24,4% (p<0,01) in terms of the average daily gain. Comparing the characteristics of the live weight gain at 4-6 months (92 days) of pregnancy, the springer heifers of groups I and II were found to be significantly superior to their analogues in group III by 29.0 and 28.0 kg. The springer heifers of groups I and II outweighed their herdmates of group III by 316 and 305 g or 43,4% and 47,5% (p<0,001) in terms of the average daily gain. It is necessary to underline that animals of groups I and II had higher gain of live weight during the whole experimental period by 47,0 and 43,0 kg or 58 and 53% as compared to the analogues of group III. According to the results of multicriteria analysis, for group I the objective function was determined to be lower and was 0.0359 on the examined criteria, while the objective functions of groups II and III were worse at 1.4 and 12.1 respectively. At the same time, the animals in group II were 8.6 times superior to their analogues in group III. It indicates the superiority of animals in groups I and II with a productive mating age of 14.8-15.3 months and a live weight of 373-414 kg. They had a more intensive gain of live weight during pregnancy and spent less energy and crude protein feed per kilo of gain. The linear, partial quadratic and partial quadratic regressions were developed to describe the correlation between the increase of live weight of heifers and their age and live weight at the time of conceiving and the consumed metabolizable energy and crude protein for 6 months of pregnancy. The season of the year was determined to have no significant impact on the heifers' development during the pregnancy period in the herd and their further milk productivity.

The article presents the results of research on the influence of duration of kneading of udder of springer heifers on further development of mammary gland and future productivity of cows. An important chain of effective dairy farming is the accurate organisation of herd reproduction, preparation of springer heifers for calving and lactation and milking of first calves. It has been determined that during the formation of productivity of dairy animals the first pregnancy has a decisive importance. The specific feature of this physiological state is that complex morphological and functional changes in the reproductive organs happen for the first time in the body, and pregnancy, calving and lactation proceed in the further formation of the animal organism. One of the most significant stressors on the first calving heifer's body is the first birth in combination with machine milking. The inability to overcome the influence of the first milking stress factor is the reason why some first calves are already being eliminated at this phase of the technological chain in commercial milk production. One of the techniques that can reduce the impact of the above mentioned stress factors is udder massage of springer heifers. To study effectiveness of manual massage of udder of springer heifers its duration (from 1 to 4 min.) was tested. There was also studied the effect of different durations of manual massage on the performance of heifers and their morphological traits. The experiment was carried out in SE "Ukrainka Slobodskaya" by IAS NAAS on animals of Ukrainian black-motley dairy breed. For that, five groups were formed with different duration of manual massage (I - 1min, II - 2min, III - 3min, IV - 4min, V - without massage). Massage was started in the 6th month of pregnancy. It was found that kneading of udder of springer heifers compared to no massage increased udder of first calving heifers according to the following measurements: udder girth by 17,4 - 18,7 % (P≤0,05), width 17,9 - 23,7 (P≤0,05), length 15,9 - 20,7 (P≤0,05), depth 16,1 - 20,8 (P≤0,05). It should be noted that using different time of hand massage (groups I-IV) positively shortens the time of litter secretion and increases milk production by 11.7 - 12.3%.

No abstract

The article examines the problem of forming groups of heifers in the dairy period in order to obtain cows with high milk productivity, as increasing milk production is an important and complex problem of agricultural science and practice. The results of a study on improving the breeding of heifers of the Ukrainian black-and-white dairy breed in the conditions of the State Enterprise "Kutuzivka" of Kharkiv region are presented.Scientific and economic research was focused on substantiating the effectiveness of the influence of different numbers of heifers in the technological group on their growth and development in the milk period of ontogenesis. It was found that the actual difference in feed consumption in each series of experiments between animals in each group of 5-10-15-20 heads and a den area of 1.8 m2-2.2 m2 on deep straw litter was not. And when comparing technological groups of 5-20, 10-20, 15-20 heads, differences were revealed. In the production conditions of the dairy complex of SE Kutuzivka of Kharkiv region, the experiment was conducted in the spring-summer period. The experimental groups were formed as follows: for research, four technological groups of heifers with a population of 5, 10, 15 and 20 heads in each were selected, which were kept on a deep straw litter with a den area of one head 1.8–2.0 – 2.2 m2. It is experimentally proven that the use of growing heifers from 10 days of age to 6 months. loose on a deep straw litter in group sections of 5, 10 and 15 heads compared to the counterparts of 20 heads, contributed to an increase in live weight gain on average during the experiment by 20.5-22.5 % (P <0.05) . It is established that the technology of cultivation in the spring-summer period in the premises of light type contributes to the increase of the average daily increase from 27.2% to 30.3 % (P <0.05). Under these conditions of growing heifers in the technological groups of 5, 10 and 15 heads in comparison with the analogues of the group of 20 heads there was a reduction in feed consumption per 1 kg of live weight gain by 20.4 –26.5 %. Analysis of the results on the formation of technological groups of heifers in the production conditions of the dairy complex showed that the maintenance of heifers in the technological group of 15 heads and an area of 1.8 m2 per head is the best. Since the results of the comparative analysis of the complex efficiency of each of the options N(Ck)compared to the idealized, showed a significant advantage of this option, for which the target function according to the considered criteria was lower and was 0.0894. Other options were 1.0381 – 3.5839 times worse.