Ріст телят - молочників за додаткового введення метіоніну і лізину у замінник незбираного молока

Abstract

The relevance of the study is due to the need to optimize the content of lysine and methionine in milk replacer (MR) for calves. The aim of the work is to study the effect of additives of synthetic L-lysine and DL-methionine on the growth of calf calves. The objectives of the study were to study the growth rates of calves by live weight, average daily and relative gain. The study was conducted on six groups of calves (20 heads each) according to the scheme: Group I – control, which received a MR with a content of 1.95 % lysine and 0.49 % methionine; In groups II and III the lysine content was 2.24 and 2.44 %, respectively, the methionine content in these groups did not change and was 0.49 %; In MR for calves of group IV-V, 0.56 and 0.61 % of methionine were contained, respectively, and the lysine content did not change from the actual (1.95 %); The VI group received lysine and methionine supplements, the content of these amino acids in the MR was 2.34 and 0.59 %, respectively. The calves' age is 22-62 days in the experiment. The experimental calves were kept in individual cages, the microclimate parameters of the premises where the animals were kept corresponded to the accepted zoohygienic and veterinary-sanitary standards. Calves were fed three times a day using a MR, starting granulated feed and hay. At the beginning of the experiment, the difference in the BW between the groups did not exceed 5 % (39.4-41.2 kg). On the 10th day of the experiment, in all groups except II, results were obtained above the control group. The calves of group II had a BW of 2.11 kg less than the control group calves, while the animals of group VI, on the contrary, exceeded the control group by 1.75 kg (P> 0.1). The tendency to increase BW of calves, relative to control, remained for the calves of the VI group and for 42 days. They had an BW greater than the control animals, an average of 2.89 kg. In all other groups, this indicator was less by 2.8-9.4 %. On days 52 and 62, in all the test groups of calves, in contrast to the control, a decrease in the BW was observed. At the end of the experiment, the animals of the V and VI groups had close indicators to the control group (67.85, 69.76 and 70.38 kg, respectively). Analysis of the results of the study showed that the additional introduction of synthetic amino acids (lysine and methionine) into the composition of the MR for calves aged 22-62 days from 1.95 and 0.49 % to levels of 2.24- 2.44 and 0.56-0.61 % respectively, noticeably affects the growth rates. According to the BW, ADG, RG of calves enrichment of the MR with synthetic lysine and methionine does not give positive changes in the growth of calves during the dairy period under study. Changes in the growth of calves for 22-42 days indicate an increased need for lysine and methionine (content in the MR, respectively, 2.34 and 0.59 %), the provision of which contributes to the growth of BW by 5.3 % (P < 0.01). There was a slight increase in the calves' need for methionine during the growing period of 42-62 days. The increase in methionine content during this period from 0.49 to 0.61 % in the MR contributed to an increase in the relative growth of body weight by 1.4 %. Prospects for further research are to study the changes in the rates of linear growth in calves, the effectiveness of nutrient use in the diet, and the study of the impact on the milk productivity of first-calf cows. Keywords: calves, milk period, lysine, methionine, milk replacer, growth, body weight, gains