Effects of ambient temperatures on clinical and immune responses of pigs infected with transmissible gastro-enteritis virus

Abstract

Shimizu, M. and Shimizu, Y., 1979. Effects of ambient temperatures on clinical and immune responses of pigs infected with transmissible gastroenteritis virus. Vet. Microbiol., 4: 109--116.Two-to three-months-old pigs infected with transmissible gastroenteritis (TGE) virus showed no clinical response when housed at 30°C, but comparable infected pigs exposed to temperature changes from 30°C to 4°C following infection showed typical signs of TGE. Development of TGE-specific immune responses, as measured by blastogenic response of tissue lymphocytes, occurred at 3 days post-inoculation (DPI) in pigs held at 30°C, but not until 7 DPI in infected pigs held under the adverse conditions. Immunosuppression with corticosteroids resulted in a fall in circulatory T cells, lowering of non-specific blastogenic response of circulatory lymphocytes, and clinical signs of disease when immunosuppressed pigs were infected with TGE virus and held at 30°C. It is suggested that clinical responses to TGE virus infection may be affected by the influence of ambient temperatures on the immune responses of pigs.

Isolation of porcine epidemic diarrhea virus in porcine cell cultures and experimental infection of pigs of different ages

“…The majority of herd outbreaks of PED occur during the colder months, especially between January and April (Tsuda, 1997). In TGE virus infection, (Shimizu et al, 1978;Shimizu and Shimizu, 1979) showed that a high ambient temperature resulted in increased disease resistance, while a low ambient temperature or temperature changes caused a dramatic enhancement in clinical signs. In the present study, 2±12-week old pigs were kept at 23± 248C throughout the study.…”

The influence of the thermal environment on the productivity of pigs

“…Cold per se lowers the new-born piglets resistance to micro-organisms resulting in increased incidence of infectious diseases such as transmissible gastro-enteritis (Shimizu, Shimizu and Kodama, 1978) and Escherichia coli enterotoxaemia (Armstrong and Cline, 1977). Cold per se lowers the new-born piglets resistance to micro-organisms resulting in increased incidence of infectious diseases such as transmissible gastro-enteritis (Shimizu, Shimizu and Kodama, 1978) and Escherichia coli enterotoxaemia (Armstrong and Cline, 1977).…”

Hematological and biochemical changes following an acute stress in control and somatostatin-immunized pigs

“…Analyzing blood for hormonal or immune status is useful for estimating states of metabolic disorders (Basset 1978) and infectious diseases (Shimizu and Shimizu 1979). However, the major prerequisite of using such methods is that the procedure itself must not be stressful to the animal.…”