IMMUNE AND HORMONAL STATUS OF SOWS DURING GESTATION AND LACTATION

Abstract

The study was focused on the immune and hormonal status of sows during
gestation and lactation. The study involved 20 sows (a cross between Large White and Landrace) in their second to fifth farrowing, weighing 180-230 kg. They were selected from the pig
farm ZAO “Yudanovskie Prostory” in the Bobrovsky District of the Voronezh Region in
2022. Blood samples for laboratory analysis of immunological and hormonal parameters were
collected at three key physiological stages: on days 110-112 of gestation, 3-4 days after farrowing, and on day 28 of lactation. During gestation, the leukocyte count in the sows' blood
was 13,57±0,51∙109
/L. With the onset of lactation, their number decreased, and before weaning the piglets, was lower by 11,9% compared to the gestation period. The number of Tlymphocytes increased in the periods of the studies by 10,8% and 42,1%, respectively.
Changes in the content of B-lymphocytes were characterized by an increase in their concentration in the first days after farrowing by 15,6% and a decrease by weaning by 19,5%.
Changes were observed in the concentration of total immunoglobulins, bactericidal and lysozyme activity of the blood serum, aimed at enhancing the immune defense of sows, the deficiency of which was caused by gestation. Blood levels of progesterone and estradiol-17β in
sows and their ratio during gestation were 87,05±3,62 nM/L, while estradiol-17β was
5741,9±362,7 nM/L, respectively. Their ratio was 15,2:1. By days 4-5 of the postpartum period, these levels significantly decreased, contributing to the strengthening of the cellular and
humoral components of nonspecific immunity. By the end of the lactation period, blood levels
of progesterone and estradiol in sows increased, which was aimed at developing sexual dominance for the new reproductive cycle. Cortisol levels underwent minor changes during gestation and lactation.