Indicators of protein exchange in high-productive lactating cows of different age

Abstract

In the question of age variability of physiological parameters of the organism, a great interest is a methodological approach to understanding biological age. It is the biological age that determines the pace of individual development, growth, maturation, and ageing of the organism. Obviously, the individual characteristics that determine the biological age or the period of ontogenesis can be most pronounced during pregnancy, when during a relatively short period of time there are significant morphofunctional alterations in the body. Most of them are directly or indirectly related to the level of protein metabolism, changes in some biochemical and immunological parameters.

The purpose of our work was to study the parameters of protein exchange in high-productive lactating cows of all ages.

The research was carried out at the Scientific-Production Association of the Agro-Firms "Naukova" of the Dnipropetrovsk region. For research, cows of black-and-white Holstein breed with a milk yield of 5-6 thousand kg per lactation for 8-9 months of calving were used. We conducted a biochemical study of blood plasma according to commonly accepted methods.

Analyzing our results of protein metabolism research (one month before calving), we did not notice the likely changes in the total protein content of blood in cows associated with age, except for decreasing this indicator compared with previous pregnancies to 76.08 ± 2.47 g / l in animals that had the fourth temperament. In cows of the fifth pregnancy, there was a significant increase in the total protein in 1.11 times (p < 0,05) due to the fraction of the globulins, with the protein coefficient to be lower than that of the younger cows (0.65 vs. 0.8- 0.85). In cows of the 4th and 6th pregnancies, the protein the level was the lowest relative to other groups of animals and was 76.08 ± 2.47 and 76.43 ± 2.97 g / l, respectively. Reductions in total protein content were due to both albumin and globulins.

In the study of the activity of aminotransferases in the blood of cows in different periods of infertility, a significantly lower activity of ALT in the 4th and 6th pregnancy was observed in comparison with other groups of animals, which coincided with the level of protein.

During analyzing the fractional spectrum of globulins in blood plasma, it was noted that their percentage content tended to decrease in cows from the second to the fourth cohesiveness. In the cows of the fifth pregnancy, the changes had a different direction: the α-, β-, and γ-globulins were significantly higher (p <0.05), in 1,33 times, in 1.34 times, in 1,25 times respectively.

Since the literature did not find data regarding the age-related dependence of the protein exchange of Holstein breed cows, we compared our data with the results of local breeds (black-and-bark and Shvytsky breeds).

Comparing our data with the results obtained by other researchers in the deep-breeding Shark breed cows, we observed a similar tendency of changes in the content of total protein and γ-globulins – their decrease in cows of the third-fourth volume and rise on the fifth density. Note that Yu.R. Kravtsov considered the age-old dynamics in the even older age groups of the black-and-white breed, and, as we noted, the decline in these indicators with an average of 4.8% and 6.3% respectively.