What are the prevention and control measures for reproductive disorders in sows?
Reproductive disorders in sows have become an important factor threatening the development of the @#@227@#@ industry. Their main manifestations include failure to come into estrus, refusal to mate, abortion, premature birth, stillbirth, mummification, weak piglets, deformities, and small litter size, causing huge economic losses to pig production. In order to control reproductive disorders in sows, the author raises the following issues for reference by pig producers.
Sow anestrus
Causes: There are many reasons why sows do not come into estrus, mainly related to the pig's breed, age, season, feeding and management methods, and disease factors.
Prevention and control measures: strengthen feeding and management, maintain suitable body condition, and appropriately increase the amount of exercise.
Pen sows that are not in estrus together with a boar with strong libido in the same pen, and stimulate the sows to come into estrus through the boar's chasing and mounting. Sows not in estrus can also be penned together with sows that are already in estrus, using the sows in estrus to induce estrus. In production, gilts and empty sows can be kept together in groups of 3 to 4 per group.
For sows not in estrus, massage the udder for 5 to 10 minutes after daily feeding, which can promote estrus in sows.
Use hormones to induce estrus. Inject pregnant mare serum subcutaneously once a day for 3 consecutive days: 5 to 10 milliliters on the first day, 10 to 15 milliliters on the second day, and 15 to 20 milliliters on the third day. After estrus symptoms appear, increase the injection of 500 international units of human chorionic gonadotropin before mating.
Sows refusing to mate
Causes: Mainly caused by sows suffering from limb diseases, cervical inflammation, urethral inflammation, etc. At the same time, because the boar's body weight is too large for the sow to bear, mating cannot be completed.
Prevention and control measures: Carefully examine sick sows, determine the type of disease, and take measures for symptomatic treatment. When the weight difference between the boar and sow is too large, it is best to use artificial insemination or replace the breeding boar.
Sow abortion, stillbirth, and mummified fetuses
Causes: There are many causes of abortion in sows, including the effects of disease, poisoning, genetics, and drugs, as well as abortion caused by high temperatures or sudden climate changes, biting and fighting after grouping, too many sows in the group, crowded pens, and trauma.
Prevention and control measures: For abortion caused by disease, mainly strengthen epidemic disease prevention and control to prevent the occurrence of disease. According to the local epidemic situation, formulate a scientific and reasonable immunization program, focusing on preventing pseudorabies, parvovirus infection, porcine reproductive and respiratory syndrome, Japanese encephalitis, swine fever, brucellosis, chlamydiosis, and toxoplasmosis in pigs.
For abortion caused by non-disease reasons, corresponding measures should be taken according to the specific situation. When the ambient temperature is high and pigs mainly dissipate heat by panting and evaporating from the body surface, it is necessary to increase drinking water, strengthen ventilation, and wash the pig pens to promote body heat dissipation. At the same time, open windows and pig house doors to avoid excessive temperature inside the house. Mating of boars and sows should be carried out in the early morning and evening when temperatures are low. Strengthen inspection of feed ingredients to prevent toxic and harmful feed from being supplied to pregnant sows.
Avoid inbreeding; the inbreeding coefficient must not exceed 10 percent. Sows with hereditary or habitual abortion that cannot be cured should be culled as early as possible. Strengthen the management of pregnant sows to prevent mechanical abortion. Group reasonably and maintain suitable stocking density. Keep the pregnant sow house quiet and cool, and avoid feed spoilage, poisoning, and the effects of drugs and hormones.
Small litter size in sows
Causes: Mainly related to the pig's breed, parity, use of heterosis, age at first mating, mating method, boar's mating ability, utilization intensity, sow's lactation period, sow's nutrient supply, and epidemic diseases.
Prevention and control measures: Improve embryo survival rate. Embryonic death losses mainly occur during the first 3 weeks of gestation; 6 to 9 days and 13 to 25 days after mating are the main periods of embryonic loss. Therefore, in the production of pregnant sows, reducing sow infection with disease and maintaining a relatively stable feeding environment and reducing stress can improve embryo survival rate and litter size. Because energy is a major factor affecting embryo survival, pregnant sows must be restrictively fed during the first 3 weeks after mating to improve embryo survival rate.
Select breeds with high reproductive performance, make full use of reproductive traits and strong heterosis characteristics, and increase the litter size of sows.
Master the appropriate mating age for sows and increase the proportion of sows in parities 3 to 7 in the herd. According to the actual production situation of the pig farm, determine the appropriate lactation period, which should generally be controlled within 45 days, preferably weaning at 28 to 35 days, to increase the number of litters per sow.
Provide a complete-price diet. Nutrients closely related to sow reproductive performance must fully meet requirements, such as vitamin A, vitamin D, vitamin E, folic acid, selenium, zinc, and essential amino acids.