Routine semen collection of boars at three- to four-day intervals initially at 6.5 to 7.0 months of age seems to have no effect on the development of the testes, accessory sex glands, or subsequent semen characteristics. By 10 months of age, the volume of ejaculate is reduced when daily collections are compared to three-day collections. Although there is a reduced sperm concentration in the daily ejaculations, total weekly numbers of sperm are only slightly increased from daily vs. three-day collections. Increased boar usage generally does not result in increased sperm production.
The impact of different feeding strategies on sperm numbers and viability has not been fully investigated. Nutrients that may be required in greater amounts with higher producing animals and those under heat stress are vitamin E, vitamin C, zinc, selenium, manganese, and copper.