1, the ambient temperature. The viability of the boar semen is negatively correlated with the ambient temperature, and the higher the ambient temperature, the lower the vigor of the semen. In summer, the pighouse temperature is mostly 38-40°C, or even higher. Boar libido decreases, semen is thin, dead spermatozoa increase, and vitality decreases significantly. This is the most direct reason for the low fertility rate of sows in summer.
2, nutritional reasons. (1) In summer, the temperature is high, the sow's heat dissipation is difficult, the feed intake is reduced, the intake of nutrients required for sow breeding is insufficient, irregular estrus and ovulation occur, affecting breeding and conception, and stillbirth and weak birth. (2) The stability of vitamins in feed during high temperature season is poor, especially the fat-soluble vitamins A and E are more rapidly deactivated when the ambient temperature exceeds 30°C. Vitamins A and E are the most basic and most important vitamins for maintaining normal breeding activities. Due to the lack of vitamins in the feed, it is the basic cause of low conception rate and abnormal embryo development. (3) Lack or deficiency of green feed can cause constipation in male and female pigs, affecting feed intake and normal reproductive activities.
3, improper use of boars. In summer, the heat stress of boars is obvious. Some pig farms are mated during the day, causing more damage to the boars, which results in some boars not being used in the short term, thereby increasing the frequency of use of other boars. Boars are used too frequently. Semen quality will inevitably drop, and the conception rate will also be affected.
4, the cause of the disease. The epidemic that causes the decline in the viability of male boar semen is mainly Japanese encephalitis in summer. The disease is mainly transmitted by mosquitoes and flies, and occurs frequently in summer. The boar mainly manifests as orchitis, sexual dysfunction, and reduced semen quality. Sows are The performance of breeding difficulties, miscarriage, stillbirth and so on. Therefore, Japanese encephalitis also directly affects the conception rate of sows.
5, lack of exercise. Insufficient exercise can cause sow weakness in the sow, which directly affects the conception rate. Boar movement is too low and semen activity declines, directly affecting the conception rate.
Shenzhen Sunson Tech Co., Ltd , https://www.sunsonkiosk.com