Specifically on the subject of sow housing, NPPC supports the position of the American Veterinary Medical Association and the American Association of Swine Veterinarians, which is that both gestation stalls and group housing are appropriate for sows. There is no scientific consensus on the best way to house gestating sows because each type of housing has advantages and disadvantages.
AVMA and AASV also stress that the factor that most affects animal well-being is husbandry skills, or the care we give to each animal.