Matters needing attention in boar breeding

1. Irregularly check the semen quality of boars.

The low pregnancy rate in many pig farms is related to the semen quality of boars. Boar semen quality is not immutable, stress, disease, high temperature, lack of nutrition, use too frequently or too little will affect its sperm motility. Therefore, semen quality should be checked regularly, and measures should be taken as soon as possible to analyze the causes of boars with poor or unstable quality. Because in recent years, after the implementation of artificial insemination technology, it has been found that many pigs have little ejaculation, or poor sperm motility, or thin semen. If the unmeasured quality is often used as a good boar, it is difficult to find these problems, resulting in low conception rate, low litter size and so on. Such boars should be eliminated as soon as possible.

2. Ignore the effect of high temperature on mating effect.

The temperature requirement of sperm during storage is very high. The testes that store sperm are in vitro, the temperature is 2 ℃ ~ 3 ℃ lower than the body temperature. When the body temperature of boars is 38.5 ℃, the temperature of testis is only 35 ℃ ~ 36 ℃. If the sperm is at a higher temperature, the metabolism is strengthened, and the fertilization ability will soon be lost, which is the reason why cryptorchidism boars have no breeding ability.

In production, there are several conditions that will make the sperm in a hot environment, first, when sick and feverish, second, when there is stress, such as fighting, vaccination, etc., and third, when the external temperature is too high. The third condition has the greatest impact on pigs, which is the reason for the low conception rate in July and August in many pig farms. In July and August, the air temperature is more than 30 ℃, and in some areas it can reach 40 ℃ during the daytime. The outside and the body are in a state of high temperature, and the heat of the testis cannot be dissipated. As a result, the sperm has been kept in a high temperature environment, and the rate of death is accelerated. During mating, the number of effective sperm in the semen of the boar is very small, the mating rate is low, and the number of offspring is small.

There are two ways to solve the high ambient temperature, one is to reduce the ambient air temperature, such as using wet curtains, air conditioners and so on. The second is to reduce the local temperature and reduce the temperature near the boar through water evaporation. Both of the previous two methods have worked well. Some people think that simply increasing ventilation can only cause greater adverse effects, because increasing ventilation can only increase comfort, but it has no cooling effect when the external temperature is close to body temperature.

3. Boar use is not planned.

This is most obvious at the time of this transaction. Some boars have strong sexual desire and easy to use, so the breeders use more, while other boars that are not easy to use do not use or use less. The semen of boars that are used too frequently is thin, the number of sperm is small, and the rate of sperm deformity is high in boars that are not used for a long time. Both will cause low pregnancy rate and low litter size. Therefore, boars should be used in a planned way, and supervision should be strengthened to put an end to the phenomenon of using too frequently or too little.

4. Ignore the effects of diseases and vaccines

When pigs are sick and injected with foot-and-mouth disease vaccine, their body temperature will increase, resulting in faster sperm death and a decline in semen quality. Therefore, the monitoring of boars should be strengthened in production. Boars sick or injected with foot-and-mouth disease vaccine should be examined for semen quality before they can be used.

5. Boars lack of exercise

Exercise is necessary for boars' health and normal use. Boars without exercise will appear premature senility and reduce their useful life. Small pig farms can consider catching up movement, and pig farms with more boars can consider building a boar sports ground so that boars can move freely without supervision.