Colostral immunity of piglets to the Aujeszky disease virus in case of active immunization sows

Abstract

The current question of today is the formation of effective immune protection in young pigs against infectious diseases, achieved by piglets vaccination in the first weeks of their life. It is known that one of the factors influencing the quality of vaccination is colostral antibodies, which are able to deactivate the vaccine antigen. Considering this, it is important to determine the duration of colostral immunity of piglets to antigens of the Aujeszky’s disease virus during active sows immunization. For this, was formed a group of sows of 2nd-3rd gestation periods with 25 animals in each. Sows were immunized parenterally against Aujeszky’s disease with the «Adivak» vaccine at a dose of 2 ml, by mass vaccination, three times per year. The level of specific antibodies to glycoproteins E (gE) and B (gB) was determined in the blood serum of piglets before sucking colostrum and every 7 days of life until 77 days from birth by enzyme-linked immunosorbent assay (ELISA). It was revealed that before consuming colostrum, piglets did not have specific antibodies to the antigens of the Aujeszky disease virus. From 7th till 70th days of life, all piglets had specific IgG to the antigens gB and gE of the Aujeszky disease virus, and by the seventy-seventh day, 29% of the animals were seronegative. Thus, newborn piglets before colostrum suckling do not have specific immune protection against the Aujeszky disease virus against the background of sow immunization. Consumption of colostrum by piglets promotes their formation of colostral immunity, specific to the antigens of the Aujeszky disease virus. The duration of colostral antibodies’ circulation specific to the antigens of the Aujeszky disease virus in the piglets peripheral blood is 70 days. On the seventy-seventh day from birth, the level of colostral immunoglobulins decreased sharply, which contributed to the appearance of seronegative animals and an increase in their sensitivity to the action of an epizootic strain of the virus.

Features of the functioning of the natural defense mechanisms of piglets under the influence of immunotropic substances

“…The immune components activity in piglets during the first weeks of life has a downward trend. At the end of the suckling period, immunity changes to an upward trend due to the activation and intensification of their own immune system components (Martins Soto et al, 2008;Holda et al, 2020).…”