I know I am thinking about hog hunting way to much.
As women who are in close quarters will cycle at the same time(not bicycle), would you think the packs of sows come into season at the same time? Maybe a hog farmer will know.

Inquiring minds needs to know. Lee

As far as I know it's a matter of opportunities.
If the "food season" is long enough you can find sows with small piglets, sows with big ones and others with the rut.
When the place they live at is not so friendly they sinchronize in order to have the piglets born in a season that gives it and they more chances to feed properly and survive.

Ale.

I grew up farming, pigs were a big part of it. That was back in the days of generalized farming. As I recall, sows breed year round and if I remember correctly, we were able to get them to breed about the same time, because we tried to hit the spring pig sale at the livestock market. It might have beem more related to when the boar was introduced, but it seems to me that pigs cycle regularly on a thirty or forty day cycle and they do time up when you keep sows together. I should be able to remember this, I got my first rifle with pig money, but we need a real hog farmer in this.

...here in EU (Russian wild boar) adult saws (2 years old +) come in heat in the beginning of winter - November and give birth in April next year, however young saws (- 1 year old) come in heat up to two months later and give birth in June ...

feral hogs with little influence from wild stock do not, and they come into heat repeatidly during the year. In California they could actually have several litters if the weather and food supply allow.