Hot summer weather, high temperature, is a big obstacle for aquaculture to increase production efficiency. For sustained high temperatures, severe effects on growth and reproductive performance of swine, and even lead to death. Look at the high temperature in summer which have influence on the pig.
One, a decrease in feed intake
The summer temperature is high, the pig heat production is inhibited, thereby reducing the intake.
Two, feed conversion rate
The high temperature in summer, the heat increased energy consumption, so that the feed conversion rate decreased.
Three, weight reducing
The pig for optimum growth temperature was 18 ℃ ~ 25 ℃, temperature is higher than the upper critical temperature, every increase of 1 degrees Celsius, ADG reduces 30 grams.
Four, to reduce the rate of oestrus of sow
The temperature reached a certain degree of heat stress occurs, it may cause the decrease in sex hormone secretion, so that the oestrus rate, anestrus rate.
Five, embryonic death, abortion increased
High temperature causes the uterus to temperature increase, form, is not conducive to the implantation of the fertilized egg, embryo death caused by long-term under high temperature, leading to increase of abortion.
Six, the survival rate of piglets and pre weaning
Heat stress during lactation feed intake is low, will make the milk volume is insufficient, thus affecting the survival rate of piglets weaned before growth and.
Seven, the impact of live pig growth
Summer high temperature will make the pig feed intake generally decline, reduced the growth rate, slaughter time delay. At the same time, the increase in endogenous virus and pathogen infection, coupled with increased temperature will affect the surface heat consumption, and reduce the degree of digestion of feed.
Eight, fertilization rate
Testicular temperature directly in the pig, when the temperature rise caused by fine tube, genital epithelial degeneration, affect sperm formation and maturation, the semen quality decline, resulting in decreased sow conception rate. 20 ℃ is 85% ~ 90%, and at 33 ℃ after exposure for 72 hours for 50% ~ 60%. Studies have shown that, when the environmental temperature up to 33 ℃ for 72 hours, 15 ~ 20 days of boar sperm activity began to decline, dead sperm and sperm deformity increased, the sow conception rate decreased.
Nine, increase the risk of disease
Summer sow canal open for a long time, the number of artificial midwifery increase, greatly increasing the chance of bacterial infection in the birth canal, which easily occur after delivery sow endometritis mastitis - no milk syndrome.
Heat stress resulted in pregnant sows from pneumonia, gastric ulcer, gastric torsion sudden death increased.
Severe diarrhea in piglets and fattening pigs increased chronic ileitis.
Summer high temperature is easy to induce the swine high fever syndrome, multiple pathogens infection, the incidence of death in pigs.
Summer is easy to feed mildew metamorphic, causing immunosuppressive diseases.
Summer mosquito breeding pigs, directly cause restlessness and stress response, and infectious eperythrozoonosis, Haemophilus parasuis disease, toxoplasmosis, blue ear disease, encephalitis B virus disease incidence rate, enhance.