Effect Of Low Temperature Environment On Min Pig Immune Response

Cold stress is one of the most common stress factors of livestock and poultry in cold condition ofnorthern area. It is of important practical significance to discuss the influences of low temperatureenvironment on the pig immune response, and the research of low temperature and low temperatureresistance measures in northern area. The effect of low temperature environment on the immuneresponse of the pig can be analyzed by the change of endocrine hormones, antibodies, cytokines and soon.In this study, twenty48-day old Min pigs and Large White pigs were selected and randomlydivided into low temperature Min pig group (ML), low temperature Large White pig group (YL),optimal temperature Min pig group (MH), optimal temperature Large White pig group (YH). Usingswine plague vaccine as means of immune response, we collected blood and separated serum in thepreimmune before (0), immune after7days and14days. By the ELISA method, endocrine and immuneindexes were determined. The main results were as follows:The results of endocrine indexes showed:7days of immunization, insulin concentrations of YL group reduced by13.81%and12.34%thanMH group and YH group respectively (P<0.05), Insulin concentrations of each treatment group aresimilar in14days of immunization (P>0.05). Before immune, Cortisol concentrations of YL groupincreased34.29%and46.06%than MH group respectively (P<0.05). Cortisol concentration of YLgroup significantly increased than the other three groups in7days and14days of immunization (P <0.05).7days of immunization, T4concentrations of YL group was significantly different than MHgroup and YH group (P<0.05). T4concentrations of ML group was similar with the other two groups(P>0.05).14days of immunization, T4concentrations of YL group reduced by20.56%than YH groupand19.81%,22.01%than ML group and MH group respectively (P<0.05). Before immune, T3concentrations of ML group increased10.85%than MH group (P<0.05), T3concentration of YL groupincreased16.44%than YH group (P<0.05).14days of immunization, T3concentrations of YL groupreduced by16.26%than YH group and14.98%,17.75%than ML group and MH group in14days ofimmunization respectively (P<0.05).The results of immune indexes showed:14days of immunization, Interferon‐αconcentrations of YL group reduced by23.79%than YH group (P<0.05), YL group increased14.02%and11.12%than ML group and MH group respectively (P>0.05). Before immune, interleukin-6concentrations of YL group was similar with ML group(P>0.05). There was no significantly different between interleukin-6concentrations of YL group andYH group (P>0.05). Interleukin-6concentrations of ML group increased27.14%than MH group (P<0.05), interleukin-6concentrations of YL group increased26.56%than YH group (P<0.05). Interleukin-6concentrations of YL group significantly decreased than the other three groups in7days and14days of immunization (P<0.05).Antibody concentrations of YL group reduced by17.69%than YH group (P<0.05), YL group reduced by12.93%and19.03%respectively in14days of immunization (P<0.05). Antibody of other treatment groups were no significantly different (P>0.05).The conclusions of this study were as follows: under the condition of immunization, the blood insulin, T3and T4concentration of Large White pig significantly decreased in low temperature, cortisol concentration in the blood and the level of interleukin-6and interferon‐αincreased, and then, reduced the swine fever antibody levels. Min pig has good resistance to low temperature environment than Large White pig.