DYNAMICS OF LIPID EXCHANGE IN BLOOD DONOR COWS FOR THE USE OF A BIOLOGICALLY ACTIVE PREPARATION
Authors: Vergeles O. P. , Sheremeta V. I. , Dzhus P. P. 
Published: December 2019

Introduction. The stimulation of superovulation in embryonic donor cows is a complex process that depends on the hormonal regulation of metabolism and biological functions of cells, as well as the influence of genetic, physiological, biotechnological and environmental factors. Crucially, the generative function of the ovaries depends on the functioning in the body of the female hypothalamic-pituitary system. Activation of its functioning causes maturation in the body of females of cattle of more follicles and ovulation of mature eggs. However, stimulation of the poliovulatory response of the gonadotropin foal mare serum (GSHK) causes impaired ordering of the metabolic processes and hormonal status of the animal body, which, in turn, is one of the reasons for the large number of non-ovulated follicles, which adversely affects the output. The long-term biological half-life of HCGC causes its residual concentration, which causes the growth of a new wave of follicles and an increase in the concentration of estrogens in the blood of the donor [2]

Currently, it is important to conduct research on the search and development of new biologically active drugs that could reduce the number of unvoluted follicles and increase the yield of bio embryos suitable for transplant recipients [3].

To improve the results of superovulation in donor cows based on the use of metabolically correcting adaptogenic and complexing properties of environmentally safe succinic and glutamic acids, we have developed a biologically active drug of neurotropic-metabolic action "Stimulin-Vet" [4]. To substantiate the modifying effect of the components of the drug preparation of the neurotropic-metabolic action "Stimulin-Vet" and to evaluate the degree of its impact on the processes of tissue metabolism, we conducted a biochemical study of the lipid profile of donor blood.

Materials and methods of research. The researches were carried out at the NULES of Ukraine «Velikosnitsynsky NDG named after. OV Muzychenko» on animals-analogues of Ukrainian black-and-white milk breed. Eight cows with a live weight of 500–615 kg and with a milk yield of higher lactation of 4600–5300 kg, which were kept under the same conditions, were selected.

To induce superovulation to the donor cows of the control and experimental groups on the 10 th day of steppe hunting, HCG Folligon was administered at a dose of 3 thousand IU. Donor cows of the experimental group on the 10 th and 11 th days of the sexual cycle was injected subcutaneously with 20 ml of the drug "Stimulin-Vet". 48 and 72 hours after the injection of gonadotropin, donor cows were injected with an intramuscular analogue of prostaglandin F2α-Estrofan at a dose of 2 ml/goal. Donors were inseminated by the rectocervical method three times at intervals of 12 hours of frozen-thawed semen of one boogie. In each dose of semen there were at least 30 million sperm with rectilinear movement.

Before washing the embryos, a rectal donor study was performed to evaluate the efficiency of hormonal treatment, counting the number of yellow bodies and non-ovulated follicles. The embryos were washed on the 7 th day of the sexual cycle by a non-surgical method using phosphate-buffered saline Dulbecco (Sigma, Germany) with the addition of 1% fetal calf serum and antibiotics. The number and quality of embryos were evaluated by microscopic method, taking into account their stage of development.

Blood sampling for biochemical studies from donors was performed prior to treatment with hormones, after administration of gonadotropin and Stimulin-Vet preparation, and before embryo leaching.

The activity of enzymes in serum was investigated: aspartate aminotransferase (AsAT,), alanine aminotransferase (AlAT), alkaline phosphatase (LF) by enzymatic-kinetic method using the semi-automatic biochemical analyzer Stat Fax 1904 (Awareness Technology, USA). Indicators of lipid profile of donor blood serum were also determined by the following methods: total cholesterol – cholesterol oxidase method; triacylglycerol – enzymatic, lipase hydrolysis; high density lipoprotein cholesterol (HDLC) – precipitation of lipoproteins with phosphotangic acid and magnesium chloride. The low cholesterol lipoprotein cholesterol (LDLC) cholesterol and very low density lipoprotein (VLDLC) cholesterol were determined using the calculations.

Research results. The results of the studies showed that the activity of aminotransaminases in the donor cows of both groups on the 8 th day of the sexual cycle differed little.

Injection of Stimulin-Vet on the 10 th and 11 th day of the sexual cycle to the donor cows of the experimental group resulted in a 4.7% and 22.6% increase in the activity of AsAT and AlAT on the 12 th day compared to 8 – the day of the cycle. The  AsAT,  and AlAT parameters in the animals of the experimental group were statistically significant (p ≤ 0.05) and 8.3% and 14.6%, respectively, compared to the animals in the control group.

At 8 days after the second administration of the drug (on day 7 of the sexual cycle), the activity of AsAT and AlAT in the experimental animals decreased by 2.4% and 6.7% compared with the 12 th day of the sexual cycle, but was higher than in the control respectively by 3.7% and 10.6%.

It should be emphasized that the increase in the activity of the enzymes AlAT and AsAT in some cases is interpreted as diagnostic factors for the physiological state of the organism and the development of some pathologies. In cows of the control group, the activity of the three enzymes during the study days of the sexual cycle during stimulation of superovulation by gonadotropin FFA varied within the error, ie it was stable.

At the beginning of the experiment, the difference in LF activity between the test and control donors was within 3.4%. Following the administration of Stimulin-Vet to donors, enzyme activity increased by 10% (p ≤ 0.05) on day 12 of the sexual cycle, and 7.5% compared with day 8 and LF in control animals. In the control group, no differences in LF activity were observed between day 12 and day 7 of the sexual cycle. A similar pattern is typical of the experimental group. But the donor activity of the enzyme at day 7 of the sexual cycle was probably 9.1% higher than at the beginning of the experiment.

To establish the physiological norm or pathological state of the animal body by changing the activity of aminotransferases, use the de ritis factor, which, according to some authors, in the state of physiological norm should be equal to 2 with fluctuations in the direction of growth of this indicator [5]. The results of the studies showed that the increase in the activity of both aminotransferases on the 12 th and 7 th day of the sexual cycle in the experimental donors caused a decrease in the de Ritis factor by 7.4% and 8.2% compared to the control. The data obtained should not be interpreted as a negative factor, since the difference in the mean values of the coefficients was within the margin of error. In addition, the ratio of these enzymes was not lower than 2.

The analysis of the results shows that the donor cows biologically active drug "Stimulin-Vet" causes an increase in the activity of aminotransaminases (AsAT and AlAT) and LF, thus causing a prolonged effect in changing their activity.

Analysis of lipidogram indices in the donor cows of the control and experimental groups showed that the injection of the experimental donor cows of the gonadotropic drug FFA “Folligon®” and the biologically active drug “Stimulin-Vet” resulted in reduction of total cholesterol on day 12 and 7.6% and 16%, and in control by 8.9% and 7.2% compared to baseline.

It is worth noting that the reduction of cholesterol in the studied groups of donor cows did not occur uniformly with respect to transport lipoprotein fractions of blood, which may be due to the use in the study group of the drug "Stimulin-Vet".

As a percentage of the control group on the 12 th day of the sexual cycle, the dynamics of reduction of total cholesterol is due mainly to the LDLC fraction (16.8%) and to a small extent HDLC (5.3%), in contrast to the experimental group, where the concentration of probable concentrations was mostly observed HDLC (25.8%) relative to baseline) and control (p ≤ 0.05).

At day 7 of the sexual cycle, the control group noted a slight increase in cholesterol concentration, which was accompanied by a change in the metabolism of lipoprotein fractions and led to an increase in LDLC (by 6.13%) and a decrease in high density lipoprotein cholesterol (by 4%) in the eyesight. A somewhat different situation in the redistribution of lipoprotein fractions was observed in similar days of the cycle in experimental donors, which led to a further decrease in total cholesterol (by 5%) in the blood plasma due to low density lipoprotein cholesterol (by 14.3%). 1.3 times HDLC.

The results of studies show that the forced change of hormonal status in the organism of donors in the stimulation of multiple ovulation influenced the cholesterol metabolism and the spectrum of lipoproteins. It is known that the intensity of cholesterol biosynthesis and its transport is subject to multifaceted regulation, both on the part of intracellular metabolites and hormones, including sexual [6].

In turn, the use of the biologically active drug "Stimulin-Vet" in the induction of gonadotropin FFA of superovulation in donor cows, to some extent adjusted the biochemical processes of cholesterol metabolism and the distribution of lipoprotein fractions during polyphysicolysis, 9%) and an increase in the number of embryos transplantable (by 27.6%) and reduced the number of unvoluted follicles by 2.7 times [7].

Conclusions. In the blood of donor cows during the growth of follicles induced by the introduction of exogenous gonadotropin FFA shows a decrease in the concentration of cholesterol, HDLC, LDLC  and an increase in VLDLC content. The neurotropic-metabolic drug Stimulin-Vet, administered to the donors together with the gonadotropin FFA, intensifies the growth of AsAT, AlAT and LF activity on the 12 th day of the sexual cycle and causes a prolonged effect of increasing their activity until the 7 th day of the sexual cycle. within the physiological norm.