Artificial insemination can be extremely effective with as little as one dose in the 24-hour period prior to ovulation. The problem occurs in determining when ovulation is going to occur. This optimal 24-hour period ensures maximum fertilization potential of the sperm and the egg. Extender, age, dosage, freezing, and backflow during AI all affect the fertilization potential. Increasing semen quality, deep uterine insemination, uterine white blood cell reduction, and certain sow characteristics are all being investigated to improve the fertilization of sows.

Predicting ovulation timing is difficult due to the variability between sows. Work is being done to identify the application of varying stimulus intensities to identify different stages of estrus. For example, it is possible that the shade of vulva redness can be used to identify what stage of estrus the sow is showing. A red inner vulva would mean to put off the insemination until the redness disappears.

When it comes to insemination frequency, studies show that 24 hour intervals between inseminations has the same reproductive results as 12 hour intervals. In fact, insemination of sows as often as possible may not just be a waste of semen, labor and money, but may also have negative effects. This is due to uterine infections interfering with maximal fertilization. The optimal timing of insemination during estrus varies between farms. Sows with a short (3-4 days) wean to estrus average have a long estrus, associated with an advanced ovulation time. To get farm-specific data, farmers should establish the duration of estrus and also take into account the effect of weaning to estrus interval on the duration of estrus. This also enables checking of the appropriateness of insemination timings of individual sows.

Sperm transport within the sow is essential. External boar stimulus increases the hormone oxytocin, which initiates uterine contractions. Boar presence during insemination is a must-have, as it positively influences uterine contraction activity especially when the contraction pattern of a sow is low.