Do you really know why the pig farm has a high return rate?

The normal estrus cycle of pigs is 18-24 days, and the phenomenon that breeding sows are not pregnant after mating is called return to estrus. The increase of the return rate of the pig farm will lead to the decrease of the mating delivery rate, thus affecting the economic benefits of the farm.

There are three main reasons for sow return: first, the quality of boar semen is unqualified; second, the mating time is not accurate; third, sow pathological and physiological return.

1. Rule retaliation

21 days or 42 days or so, indicating that the identification of estrus is accurate, but pregnancy failure occurs.

The reasons for this phenomenon may be: management stress factors within 30 days after insemination (excessive driving, vaccination, mixed group fighting, continuous high temperature in the house, etc.); excessive reflux during insemination and failure of insemination; unqualified semen; insemination time is not accurate, too early or too late.

two。 Irregular regurgitation

(1) the reasons for the return of estrus within 20 days (usually 18-19 days) may be: inaccurate identification of estrus; accurate identification of estrus, but the first pregnancy signal of sows (about 9-12 days after insemination, the fertilized egg reaches the uterus); diseases that lead to high fever (especially classical swine fever, influenza); it may also be caused by late mating.

(2) 24-39 days' return mainly refers to the embryo loss caused by problems in 3-4 weeks after mating, which is a non-management factor.

The possible reasons are: embryo absorption or pregnancy failure caused by disease; individual differences of sow genetic type; lactation period is too short, the uterus has not yet fully recovered.

(3) non-pregnancy return in the second trimester (45-105 days), if the exact abortion is not seen. It is caused by omissions in pregnancy identification; if obvious mid-term miscarriages are accurately observed, it may be caused by the most common pathogens of parvovirus, Japanese encephalitis virus and influenza virus, especially in the south and north in early summer.

(4) in addition to management factors, abortion / preterm delivery with more than 106 days should pay attention to whether there is blue ear virus infection.

II. Measures often taken to reduce returns

In order to reduce the return rate of sows, the following measures are often taken:

1. Provide qualified semen

Semen quality is one of the main factors affecting the conception rate. Without high-quality semen, it is unrealistic to improve the conception rate of sows. The physical properties of semen (semen volume, color, odor, sperm density, motility, deformity rate, etc.) were examined to ensure that the semen quality was qualified.

At the same time, the heat prevention and cooling equipment should be adjusted before the arrival of the high temperature season, and measures such as adding anti-stress drugs and nutritional drugs to drinking water should be taken to reduce the effect of heat stress on boar semen quality.

two。 Improve mating techniques

3. Do a good job in the environmental hygiene of the pig house

Clean the pig house every day to reduce the breeding environment of pathogenic microorganisms and disinfect it regularly to ensure the cleanliness and hygiene of the pig house environment.

In order to ensure a healthy condition of sows, we must do a good job of prevention and health care of sows. In particular, the vaccination of swine fever vaccine (3 times per year), porcine reproductive and respiratory syndrome, porcine pseudorabies and porcine parvovirus will directly or indirectly affect the pregnancy of sows.

Reduce the chance of bacterial infection, especially uterine inflammation caused by lax disinfection or rude action in the process of artificial midwifery, artificial insemination and postpartum care. The existence of uterine inflammation is prone to the occurrence of empathy, and even lead to repeated infertility. Once sow uterine inflammation is found, it should be treated in time.

Because zeomycin is easy to cause false estrus in sows, the feed quality of sows must be guaranteed to ensure that sows have a healthy and suitable body condition in order to facilitate estrus breeding. The mastery of feed nutrition level of sows before and after mating, especially after mating, is the key factor to ensure the conception and litter size of sows.

It is forbidden to feed high-energy feed within one month after general mating, because excessive nutritional intake will lead to the death of fertilized eggs and failure of implantation. Appropriate supplement of green feed, add electrolytic multi-dimensional, to supplement the lack of vitamins. Improve the nutritional level within 25 days of late pregnancy to ensure the healthy growth of the fetus.