Linear growth of dairy calves under the condition of additional introduction into the diet of lysine and methionine

Abstract

need for research is related to the search for optimal content of critical amino acids in feed for calves in the milk period. The purpose of the study is to investigate the effects of synthetic L-lysine and DL-methionine supplements on the milk replacer and starting compound feed on the linear growth rates of calves in the milking period. The objectives of the study were to study the linear measurements and body building index calves. The study was conducted on six groups of calves (20 heads in each) in two experiments. In the first experiment, the content of lysine and methionine in the composition of MR was changed: in the 1st group, the content of these amino acids was 1.95 and 0.49 % respectively, the second one was 2.24 and 0.49; ІІІ-th - 2.44 and 0.49; IV-th - 1.95 and 0.56; V-th - 1.95 and 0.61; VІ-th - 2.34 and 0.59 %. In the second experiment, the content of these amino acids in the granulated feed varied. Accordingly, calves of the 1st group received it containing lysine and methionine - 0.66 and 0.32 %, the second - 0.76 and 0.32; III-th - 0,83 and 0,32; IV - 0.66 and 0.37; V-th - 0.66 and 0.40; VІ-th - 0,79 and 0,38 %. The age of calves in the first experiment was 22-62 days, the second - 2-62 days. Experimental calves were kept in individual cages. The obtained results indicate that in the beginning of experiments, according to linear measurements and indices, between the groups, in both experiments, there was no significant difference. At the end of the I Experiment, the probable difference (P≤0.05) was observed at the height in the forearm in the III and IV groups, and was noted the statistical significance for broad-spectrum in groups II and V (P≤0.05). There was an increase (P≤0.05) of the depth of breast in animals of the IV group at 0.95 cm and the chest sheathing of breast in animals of the group VI at 0.88 cm in relation to the control calves. The skeletal length of the trunk in all groups was approximately the same and there was no reliable difference. The longitudinal index for calves II and V groups was lower than control animals at 0.97 and 1.18% (p ≤ 0.05), while the breast index was the best in group II by 3.45% and in V - by 3.39% than in the control. Indices of loss and mass in calves of group IV were significantly lower than control: loss index - by 1.11% (P≤0.05), mass index - by 1.60% (P≤0.005). The mass index of calves of the III group was below the control by 2.07%, which indicates a lower development of the body of animals. At the end of the II experience in the 62-day-old calves of group II, the results for height at the withers and the width of the chest were statistically significant (p ≤ 0.05). There was an increase (p ≤ 0,05) of the depth of the breast in the V group at 0.67 cm in relation to the control. According to indicators such as the slanting length of the trunk and the circumference of the breast behind the shoulder blades, none of the research groups had a significant difference with regard to control. It was established that according to the longevity index calves of the III group had more developed limbs, unlike control animals, by 0.94% (P≤0.05). At the same time, the development of breasts in animals of this group was probably lower by 2.55% (R≤0.05). The longevity index for calves of the IV group was lower by 0.78% (P≤0.05). In group V, there is a worse development of the breast, and the index of mass in calves of this group is 1.57% lower than control. Dairy calves of the II and V groups did not differ significantly from controls on the calculated indices.

Keywords: calves, milk replacer, granulated feed, lysine, methionine, linear measurements, body structure indices