Page 34 of articles about sow
Effect of parity and number of suckling piglets on milk production of sows
U.S. pork industry moving toward open sow housing as an alternative to gestation crates
Effects of folic acid on the performance of suckling piglets and sows during lactation

Anoestrus upon weaning
Short weaning to service interval isn’t always a synonym for good management, since we have to take into consideration not only average number of days, but also the effect on the percentage of distribution after returns.