Influence of the hormonal background on the morphological replacement piglets

Abstract

The puberty period in pigs depends on the functional activity of the endocrine system, which has an effect on the blood through the connective tissue. It has been established that steroid and thyroid hormones regulate the processes of metabolism and proliferation, differentiation and apoptosis of cells. The aim of the research was to establish the peculiarities of formation of the morphological composition of blood under the influence of steroid and thyroid hormones in the process of puberty in different directions of productivity in the pigs. Experiments were performed on two groups of clinically healthy pigs of Pietrain breed and Large White breed. To assess the hormonal and morphological blood was taken from pigs from the anterior hollow vein in the 4-, 5-.6-, 7-month-old age (when their live weight reaches 100 kg). The predominance of hemoglobin content and the amount of erythrocytes in the blood of piglets of Pietrain breed over a Large White breed on the 120–150th day of development (P < 0.05) was observed, against the background of the general decrease in leukocytes in pigs of both breeds at the age of 5 months with the next gradual increase. The age-related changes in the leukocyte formula were directly related to the direction of animal productivity. In the Large White breed, from the beginning of the experiment, there was an increase in the number of rodenuclear neutrophils to 210-day-olds, followed by a sharp decreasing on 36.4%. In Pietrain breed, the level of the rodenuclear neutrophils decreased on 28.6% (P < 0.01) at the age of 5 months, followed by a sharp increasing over the coming months. From the 5th to the 7th months of the development of animals, the concentration of estradiol decreased in the first genotype 2 times (P < 0.05); in the second genotype – 1.9 times (P < 0.01). The content of thyroxine and triiodothyronine increased in the blood serum in Pietrain breed pigs (P < 0.01) and Large White breed (P < 0.001) in the period from 120th to 180th day of development. It was found that the amount of progesterone in Large White breed was higher relatively to Pietrain breed in all investigated periods. The content of estradiol in pigs of both breeds from the 120th and the 150th day of development tended to decrease – by 2.8 times (P < 0.001) in Large White breed, 1.4 times (P < 0.05) in Pietrain breed, and testosterone increases, respectively, 2.1 (P < 0.05) and 1.9 (P < 0.05) times. The significant influence of progesterone on the number of lymphocytes and common leukocytes in Pietrain breed pigs was established. The level of estradiol significantly influenced the number of granulocytes in Pietrain breed pigs at the age of 5 months (r = 0.92 ... 0.99), and in animals of Large White breed the maximum correlation level was observed at the achievement of the 150th (r = 0.61) and 180 days of development (r = 0.94).