One or four commonly used methods for estimating the expected date of sows
1. "333" push algorithm
This method is now a commonly used extrapolation method, from the number of months and days of mating and conception of sows plus "3 months, 3 weeks and 3 days", that is, 3 months is 90 days, 3 weeks is 21 days, plus 3 days, exactly 114 days. For example, if the mating period is December 20, the sow will give birth on April 14.
2. "Month plus 4, daily minus 8" push algorithm
That is, from the sow mating and conception month plus 4, mating conception date minus 8. The resulting number is the approximate expected date of the sow. In this way, the month plus 4 is calculated, regardless of the large month, the small month and the peaceful month, but the daily minus 8 is calculated according to the large month, the small month and the peaceful month. This push algorithm is simpler than the "333" push algorithm and can be used to estimate the approximate expected date of the sow.
For example, the mating date is December 20, December plus 4 is April, and 20 days minus 8 is 12, that is, the sow's delivery date is roughly April 12. When using the above deduction algorithm, if the month is not enough to reduce, you can borrow 1 year (that is, 12 months), and if the day is not enough, you can borrow 1 month (calculated by 30 days); if it exceeds 30 days, you can enter 1 month, and if you exceed 12 months, you can enter 1 year.
3. "Month plus 3, daily plus 20" push algorithm
That is, from the month after the sow mating and conception plus 3, mating conception date plus 20. For example, mating on February 1, delivering on May 21, mating on March 20, giving birth on July 10.
4. "Month minus 8, daily minus 7" inference algorithm
That is, from the sow mating and conception month minus 8, mating and conception date minus 7, regardless of the large month, small month, flat month, the average month is calculated according to 30 days, the answer number is the approximate delivery date of the sow pregnancy. It is also easier to remember than to use this method. For example, the mating period is December 20, December is reduced by 8 months to April, and the mating date is reduced by 7 to 13 days on the 20th, so the sow delivery date is about April 13.