Measures for preventing and controlling reproductive obstacles of sows

The reproductive barrier of sows has become an important factor threatening the development of the industry. Its main manifestations are non-estrus, refusal of mating, abortion, premature delivery, stillbirth, mummies, weak babies, deformities, small litter size and so on, resulting in huge economic losses in pig production. In order to control the reproductive obstacles of sows, the author puts forward the following questions for pig producers' reference.

Sow lack of estrus

There are many reasons for non-estrus in sows, which are mainly related to pig breeds, age, season, feeding and management methods and disease factors.

Prevention and control measures to strengthen feeding and management, maintain a suitable physical condition, appropriately increase the amount of exercise.

The non-estrus sow and the libido boar are enclosed in the same house, and the sow is chased by the boar to stimulate the sow to be in estrus. Non-estrus sows can also be cooped up with oestrus sows to induce oestrus through oestrus sows. In production, reserve sows and empty sows can be raised in groups of 3 to 4 sows per group.

For non-estrus sows, breast massage for 5-10 minutes after daily feeding can promote oestrus.

Use hormones to get into the mood. Pregnant horse serum was subcutaneously injected once a day for 3 days, 5: 10 ml on the first day, 10: 15 ml on the second day, and 15: 20 ml on the third day. After the onset of estrus symptoms, 500 IU of human chorionic gonadotropin was injected before mating.

Sows refuse to breed

The reason is mainly due to sows suffering from limb diseases, cervical inflammation, urethral inflammation and so on. At the same time, due to the boar weight is too large, sows can not bear, also can not complete breeding.

Prevention and control measures carefully check the sick sows, determine the types of diseases, and take measures for symptomatic treatment. When the weight difference between boars and sows is too large, it is best to use artificial insemination or replacement of boars.

Miscarriage, stillbirth and mummified fetus in sows

There are many causes of sow abortion, including disease, poisoning, heredity, drug influence, high temperature or abrupt climate change, bite after herding or too many sows in the herd, crowded enclosure, trauma and so on.

Prevention and control measures for abortion caused by disease, mainly by strengthening the prevention and control of epidemic disease to prevent the occurrence of disease. According to the epidemic situation of the local epidemic, formulate scientific and reasonable immunization procedures, focus on the prevention of pseudorabies, parvovirus infection, porcine reproductive disorders and respiratory syndrome, Japanese encephalitis, classical swine fever, brucellosis, chlamydia and toxoplasmosis.

For miscarriages caused by non-disease causes, corresponding measures should be taken according to specific conditions. When the ambient temperature is high, pigs need to increase drinking water, strengthen ventilation, wash pig pens and promote pig heat dissipation when gasping for breath and body surface evaporation. At the same time, open the window and the door of the pigsty to avoid excessive temperature in the house. Mating between boars and sows should be carried out when the temperature is low in the morning and evening. Strengthen the inspection of feed raw materials to prevent the supply of toxic and harmful feed to pregnant sows.

To avoid inbreeding, the inbreeding coefficient must not exceed 10%. When hereditary and habitual miscarriage sows cannot be cured, they should be eliminated as soon as possible. Strengthen the management of pregnant sows to prevent the occurrence of mechanical abortion. Reasonable grouping and suitable feeding density. Keep the pregnant sow house quiet and cool to avoid feed deterioration, poisoning and the effects of drugs and hormones.

Small litter size in sow litter

The reasons are mainly related to pig breeds, parity, utilization of heterosis, first mating age, mating methods, breeding ability of boars, utilization intensity, lactation period of sows, nutritional supply of sows and epidemic diseases.

Prevention and control measures can improve the survival rate of embryos. The loss of embryo death mainly occurred in the first 3 weeks of pregnancy, and the main period of embryo loss was 6-9 days and 13-25 days after mating. Therefore, in the production of pregnant sows, we should reduce the infection of sows and maintain a relatively stable feeding environment, and reducing stress can improve embryo survival and litter size. As energy is a major factor affecting embryo survival, pregnant sows in the first three weeks after mating must be restricted to improve the embryo survival rate.

Select the breeds with high reproductive performance and make full use of the characteristics of reproductive traits and strong heterosis to improve the litter size of sows.

It is appropriate to master the mating age of sows and increase the proportion of 3-7 sows in the pig herd. According to the actual production situation of the pig farm, the suitable lactation period should be controlled within 45 days, preferably within 28-35 days, in order to increase the litter size of sows.

Provide full-price diets. Nutrients closely related to sow reproductive performance should fully meet the needs, such as vitamin A, vitamin D, vitamin E, folic acid, selenium, zinc, and essential amino acids.