Sow breeding technique: how many days is it in estrus? What are the symptoms? What if you don't go into estrus?

Sow estrus is the premise of breeding and giving birth, and it is very important to find sow estrus at the first time, so both novice and professional pig farmers need to make an accurate judgment on sow estrus and mating time. What are the symptoms? What if you don't go into estrus?

How many days is the sow in estrus?

When does the sow begin to go into estrus?

In the early stage of sexual development and maturity, the time of oestrus in sows is irregular, and it will become regular only after three times of estrus. In general, sows are in estrus every 18 to 23 days, with an average of 21 days. However, due to different breeds, the time of oestrus is different. For example, hybrid sows are in estrus every 19 to 20 days on average. The local breed sows are in estrus once every 18-19 days. Foreign sows are in estrus every 20-23 days.

2. How many days does a sow usually go into estrus?

When sows are in estrus, they usually last for 2-5 days, with an average of 2.5 days of estrus. When in estrus, certain changes will take place according to the season and variety. For example, in spring, sows have shorter days of estrus. The number of days of estrus lasts longer in autumn or winter. The sows produced in China are in estrus for a long time, while those imported from abroad are relatively short.

3. How many days does the sow begin to have second estrus?

After giving birth, sows will have a second estrus when they are weaned or litter divided. Generally speaking, it is normal from 2 to 12 days after weaning, but about 7 days after weaning is the best time for mating. If it is more than 20 days, treatment should be taken to assist its estrus mating.

Second, what are the symptoms of sow estrus?

1, vulva changes: when the sow is in estrus, the vulva will gradually change from white pink to pink, until it becomes purplish red, and gradually swells.

2. Vaginal fluid: when sows are in estrus, there will be some sticky fluid in the vulva, which looks like a runny nose.

3. Appearance: when sows are in estrus, they will lie uneasy and often walk or stand while other pigs are sleeping. Once people are close, they will approach people.

4, appetite: when the sow is in estrus, the appetite will drop, and often send out a unique purr.

5. Reaction to boars: when sows are in estrus, they are more sensitive to boars. Once boars approach, they will tremble, glaze in their eyes and prick up big ears. If the estrus is high, it will directly step over other pigs and make other pigs scream.

However, due to different breeds of pigs, there will be some differences in the symptoms of estrus, but generally share the same symptoms of estrus, so it is easy to identify.

Third, what if the sow is not in estrus?

1. What's wrong with sows not going into estrus?

The main results are as follows: (1) the non-estrus of sows may be due to stress response: during the growth period, if the immunity of sows is low or the temperature is too high, it will lead to stress response and non-estrus of sows.

(2) the non-estrus of sows may be caused by diseases such as endometritis, respiratory syndrome and so on.

(3) the non-estrus of sows may be due to nutritional imbalance: during the growth period, if the feed is malnourished, the sows will not be in estrus.

(4) the non-estrus of sows may be due to improper feeding by the administrator: during the breeding period, if the amount of exercise is low, the sows will not be in estrus, so during the feeding period, large columns should be used as far as possible.

2. The solution for sows not to be in estrus:

(1) changing the pigsty to make the sow in estrus: when the sow is in estrus, it should be moved to another pigsty as far as possible to facilitate its activities. At the same time, the sows of similar size can be put together, and the parturient sows can climb across the reserve sow after oestrus to promote its estrus.

(2) increase exercise to make sows in estrus: drive sows to the mountains or wide no man's land to exercise, in order to promote sows in estrus.

(3) Boar stimulation makes sows in estrus: let boars approach 180-day-old sows to induce estrus. Generally, it can be contacted once every two days, and a boar can be replaced every three days for seduction.

(4) injection of hormone to make sows in estrus: when sows are not in estrus, appropriate amount of human chorionic gonadotropin or pregnant horse serum hormone can be injected to promote sow estrus. However, if you use it many times, the effect is still not obvious, so you don't need to use it anymore.