Numerous factors can affect your herd's farrowing rate, and of course the higher the rate the happier you'll be. To obtain a 90 percent farrowing rate, you need to eliminate or adequately control all reproductive challenges, according to Don Levis, Extension swine specialist at the University of Nebraska.

Here are his top 10 rules for achieving a 90 percent farrowing rate:

1. Use highly skilled, knowledgeable and motivated workers for estrus detection, artificial insemination procedures, supervising natural matings and managing boar semen doses.

2. Monitor your sows to detect estrus at least once a day, preferably during the early morning hours. This way you can better implement the correct frequency and timing of insemination.

3. Use high-quality boar semen for artificial insemination and highly fertile boars when mating sows naturally.

4. Properly manage boar semen doses by correctly evaluating samples for motility, storing it correctly and using all semen within 72 hours of collection.

5. Do an excellent job of feeding sows during lactation, especially during the first 7 to 10 days of lactation; thus, reducing the weaning-to-service interval.

6. Identify and cull problem breeders to maintain a high farrowing rate.

7. Try to prevent all types of stress during the first 28 days of gestation, such as heat stress and social stress to help reduce the partial or total loss of embryos.

8. Properly grow, develop and manage replacement gilts so they are in excellent body condition when mated between 200 to 250 days of age.

9. When boar fertility is unknown, use heterospermic semen or mate sows to two different boars during the same estrus. Unless a large difference exists in farrowing rate and litter size, it is very difficult to identify a true difference in farrowing rate between boars.

10. Implement a herd-health program designed to prevent reproductive diseases.