How do you determine the best breeding time for sows? A detailed guide to the key points

The best time for breeding is determined by the time of ovulation and how long sperm survive after entering the sow's body.

Ovulation time of sows: 26-46 hours after the start of standing estrus, with 95% of eggs released at the same time;

Survival time of eggs after release: no more than 6 hours;

Survival time of boar sperm after release: 18-24 hours; sperm capacitation takes 6-8 hours; after sperm enter the uterus, motility lasts 12 hours.

Check sows for estrus twice a day: 9 a.m. and 5 p.m. If estrus is detected in the morning and breeding takes place in the afternoon, 6-7 hours have already passed, and with sperm survival time of 18 hours, that is about 25 hours. Breed once more after 12 hours. 6/7+12+18=36/37, which basically covers the ovulation process.

Best time for breeding relative to ovulation in sows: if checking once a day, breed as soon as estrus is detected; if checking twice a day, delay breeding by half a day; if checking four times a day, breed after 24 hours.

Two breedings: for replacement gilts, the interval is 12 hours; for parous sows, the interval is 24 hours.

Folk sayings vividly summarize the timing of estrus and breeding in sows:

When the vulva is smeared with grass, insemination is just right;

When the expression is dazed, insemination leads to conception;

When she stands still, it is exactly the right time to breed;

When the mucus becomes thick, that is precisely the right moment.

1. If a sow returns to estrus within 20 days after breeding (18-19), it means breeding was too late.

2. If a sow returns to estrus after 22 days post-breeding (23-24), then breeding was too early.

3. If she returns to estrus within 21, 22, or 23 days after breeding, it means breeding failed, and semen quality needs to be checked.

4. If she returns to estrus within 39-45 days after breeding, it means the previous estrous cycle was missed, and the method used to detect return to estrus needs to be checked.

5. If she returns to estrus within 25-38 days after breeding, this is outside the normal range. The sow is pregnant but cannot carry the pregnancy, possibly due to: 1) stress. 2) moldy feed. 3) too few viable eggs. 4) uterine infection. (Source: Pig Industry Encyclopedia)