Effect of TGF and VEGF proteins on prenatal diseases of calves: Correlation analysis under complicated pregnancy conditions in cows

Background. The study of the role of transforming growth factor (TGF) and vascular endothelial growth factor (VEGF) in the development of prenatal pathologies in calves, especially in the context of complicated pregnancy in cows, is relevant due to the high incidence of morbidity and mortality in newborn young animals, which significantly reduces the economic efficiency of the livestock industry. The study is based on analyzing placental tissue collected immediately after calving to identify relationships between the levels of these proteins and the incidence of pathologies in newborn calves. Changes in TGF and VEGF concentrations can serve as predictors of feto- and uteroplacental insufficiency, which in turn negatively affects the health of calves. Correlation analysis revealed statistically significant relationships between TGF and VEGF levels and clinical disease manifestations, highlighting their role in prenatal disorder pathogenesis. These studies underscore the importance of monitoring TGF and VEGF levels in veterinary practice, potentially enabling early risk identification and the development of effective disease prevention strategies in young animals.

Purpose. The objective of the present study is to develop new methods for predicting prenatal diseases in calves based on the correlation analysis of TGF and VEGF protein levels.

Materials and methods. At the SPC “Plemzavod Vtoraya Pyatiletka”, in the period from 2023 to 2024, a correlation analysis of the proteins TGF and VEGF in the context of complicated pregnancy was carried out.

For the experiment, 200 dry first-calf heifers aged 24 to 48 months were randomly selected. The animals were divided into two groups: Group A included 100 cows with a physiological pregnancy and uncomplicated births, and Group B consisted of 100 animals with complicated pregnancy, accompanied by feto- and uteroplacental insufficiency.

The distribution of livestock into groups was carried out on the basis of anamnesis data and clinical examination results.

Placental tissue collected immediately after calving in compliance with the temperature (cold) regime was used as research material.

The study analyzed the protein level of transforming growth factor (TGF), which regulates various cellular functions such as growth, development, immune responses, and tissue remodeling. The protein level of vascular endothelial growth factor (VEGF), which is involved in angiogenesis, was also assessed using enzyme immunoassay kits from the biotechnological company Cutimmune systems, located in the United States.

The licensed program “Primer of Biostatistics 4.03. For Windows” was used to process the data in the study.

The homogeneity of variances was assessed using the Fisher criterion, which allows determining the uniformity of variances in a group.

To test the statistical significance of differences between the compared groups, two criteria were used: the Student criterion and the nonparametric Mann-Whitney criterion. The Student criterion is a parametric method and is designed to compare the average values of two groups. The nonparametric Mann-Whitney criterion, in turn, is designed to compare two independent and unrelated small samples by a quantitative feature of two groups. Differences were considered reliable at p<0.05.

To conduct a correlation analysis, the Spearman method was used, which allows determining the strength and direction of the relationship between two features.

Results. During the study, it was found that prenatal disorders in calves born from cows with feto- and uteroplacental insufficiency have a direct correlation with the level of protein transforming growth factor (TGF) and protein vascular endothelial growth factor (VEGF).

Conclusion. The results of the studies revealed significant differences in the levels of VEGF and TGF proteins in cows with complicated pregnancy. Data analysis showed that the level of VEGF in animals from group B was 24% higher compared to the indicators of group A (p<0.05). At the same time, a significant decrease in the concentration of TGF in the placentas of cows with complicated pregnancy was observed - 2.4 times lower than in animals with a physiological course of pregnancy (p<0.01). These changes may indicate a compensatory mechanism in which an increase in VEGF production is aimed at leveling out the consequences of a sharp decrease in the level of TGF.

Also, special attention was paid to the ratio of VEGF and TGF in the placenta. In group A, this coefficient was 1.1%, which indicates a balance of the processes regulated by these growth factors. At the same time, a significant increase in the VEGF/TFR ratio was observed in Group B – approximately 3.2 times compared to Group A. This indicates a pronounced imbalance in the regulation of angiogenesis and metabolic processes in cows with complicated pregnancy.

The obtained VEGF/TFR ratio can become a valuable tool for predicting physiological disorders in calves during postembryonic ontogenesis. Its use will optimize veterinary strategies and, possibly, prevent the development of diseases in the long term. This is important not only for ensuring animal welfare, but also for increasing the economic efficiency of animal husbandry by reducing losses associated with morbidity and mortality of young animals.