Gestating sows are pregnant pigs. Gestation stalls are prohibited under the HFAC standards under all circumstances.
HFAC’s Animal Care Standards require that sows be given a minimum total floor space of 37.6 ft2 each for mature adults and 28.9 ft2 /sow for first and second parity animals. Lying area should be at least equal to the square of the length of the pig, which roughly equates to a minimum of 16 ft2 for each adult sow. The pig must be free to turn around without difficulty at all times. Individual stalls that prevent pigs from turning around (except for hospital pens) and tethers for pigs are prohibited.
The following are photos of types of housing for gestating sows allowed and not allowed on the Certified Humane® program: