They said Mama Pig has 6 piggies to the litter, 3 litters in 14 months, and a pig can breed from age 6 months.
The pig experts always say that because sows under the best conditions can have 3 litters in 14 months. Conditions in the wild are far from ideal, especially in a year when there is little mast.
One litter per year is the norm in the wild hog population here. The litters here are usually 6-10 pigs. Some pigs are lost to coyotes and bobcats. By the time the pigs weigh about 30 pounds the sow is usually running with 4 or 5. The big mean old sows often raise all their pigs to weaning time. Even at this rate the wild hog population quadruples in one year.
Strange things sometimes happen with those sows. I have killed five 2-4 year old sows in the past year that have never had a litter. Two of them were pregnant with their first litter.