Boar Rearing Precautions and Key Points of Feeding Management

1. Irregularly check the semen quality of boars

The low conception rate in many pig farms is related to the semen quality of boars. Boar semen quality is not constant; stress, disease, high temperature, insufficient nutrition, and overly frequent or overly infrequent use can all affect sperm motility. Therefore, semen quality should be checked regularly, and for boars whose quality is poor or unstable, the cause should be analyzed and measures taken early. In recent years, after the adoption of artificial insemination technology, it has been found that many boars either have a low semen volume, poor sperm motility, or thin semen. If quality is not tested, they are often used as good boars, and these problems are difficult to detect, resulting in a low conception rate and a small number of piglets born. Such boars should be culled early.

2. Ignoring the impact of high temperature on breeding results

Sperm has very high temperature requirements during storage. The testes that store sperm are outside the body, and the temperature must be 2°C to 3°C lower than body temperature. When the boar's body temperature is 38.5°C, the temperature of the testes is only 35°C to 36°C. If sperm is in a relatively high-temperature environment, metabolism strengthens and it quickly loses its fertilization ability. This is also the reason why cryptorchid boars have no breeding ability.

In production, there are several situations that put sperm in a high-temperature environment: first, when sick and feverish; second, when stress occurs, such as fighting or vaccine injection; third, when the external temperature is too high. The third situation has the greatest impact on pigs, and this is the reason for the low conception rate in breeding in many pig farms in July and August. In July and August, the air temperature is above 30°C, and in some areas it can reach 40°C during the day. Both the outside and the inside of the body are in a high-temperature state, the heat of the testes cannot dissipate, and sperm is therefore kept in a high-temperature environment, accelerating death. At breeding time, the semen ejaculated by the boar contains very few effective sperm, the breeding rate is low, and the number of piglets born is small.

There are two ways to solve the problem of high environmental temperature. One is to lower the ambient air temperature, such as with cooling pads or air conditioning. The other is to lower the local temperature by reducing the temperature near the boar through water evaporation. Both methods have a good effect. Some people try to solve it by simply increasing ventilation, but this can only cause greater adverse effects, because increasing ventilation can only increase the feeling of comfort, and when the outside temperature is close to body temperature, it has no cooling effect.

3. Unplanned use of boars

This is most obvious in natural mating. Some boars have strong libido and are easy to use, so the keeper uses them more, while other boars that are not easy to use are not used or are used less. Boars used too frequently have thin semen and a low sperm count, while boars not used for a long time have a high rate of sperm abnormalities. Both cause the problems of a low conception rate and a small number of piglets born. Therefore, boars should be used according to a plan, and supervision should be strengthened to eliminate the phenomenon of overly frequent or overly infrequent use.

4. Ignoring the impact of disease and vaccines

When pigs are sick and when they are injected with foot-and-mouth disease vaccine, their body temperature rises, which accelerates sperm death and lowers semen quality. Therefore, monitoring of boars should be strengthened in production. For boars that have been sick or injected with foot-and-mouth vaccine, semen quality should be checked, and they can be used only after passing the check.

5. Lack of exercise in boars

Exercise is necessary for the health and normal use of boars. Boars lacking exercise show premature aging and have a reduced service life. Small-scale pig farms can consider driving them to exercise, and pig farms with many boars can consider building a boar exercise yard, where boars can move freely without supervision.