Guinea hogs are generally good mothers. I don't own a farrowing crate and I never plan to. All my sows give birth outside with plenty of free space to move around and the piglets are up and exploring within a day or two.
The needs of the mother sow are simple, but it is vitally important to make sure that she has appropriate accomodations. Without the right environment, no matter how good a mother she is, expect to find lots of dead piglets.
The sow needs a roof, walls on at least two sides (in the direction of the prevailing winds), ground with good drainage, lots of clean dry straw or hay for bedding, water, food, and solitude. The location can be in a real barn or it could be in a pasture with an A-frame or temporary shelter.
When I first started out with guinea hogs, I had two females from the same litter. They did everything together and were due on the same day, so I expected they would share their house happily with each other when they gave birth. Wrong!!! The first one gave birth in their shared house, did a great job, and was a wonderful mother to a litter of wiggling, happily nursing baby piglets. The second mother gave birth about 4 hours later and the first mother either wouldn't let her into the house or she just decided she wanted her own space and gave birth to her piglets outside on the wet ground on a chilly spring day. If I hadn't been watching out my window and hurried out right away, the piglets would not have survived. After I explained to the new mothers that they should share the house, they all lived happily together in the house, with both mothers nursing the two litters together. For their second litters, I assumed that now that they knew what they were doing, they would both happily share the house of their own accord Wrong again!!! Only this time the piglets were born in the night, I wasn't there to rescue them, one litter was born in the house and did well, but the other litter was born outside and they were all dead in the morning. I have finally learned my lesson. Now, on my farm, all pregnant sows get their own pen with their own roof, shelter, bedding, and space at least a week before they are due to give birth. After the piglets are several weeks old I put them all back together again in a big pasture, as long as the piglets are close enough to each other in age.