Food for thought,
I have three dogs, eight pigs (they're addictive, I take any that people don't want anymore and occasionally the local rescue calls me when they have a pig they failed to find a mate for or has been there a while and I take them in no problems. 15 is the max I've had so far at one time. I dream of a bigger property and a herd of like 80 piggies

Back to the dogs and pigs..
My 13 and a half year old great Dane X, Dexter, is a prey dog, i adopted him at 12 months of age with a few issues but resolved them pretty quickly. He loved chasing wild rabbits on the rare occasion he had the opportunity in his youth. Due to his size and inability to change direction at speed, he never caught one. It took me 12 months (So he was 2 at that stage) to be able to get his drive under my control, i.e recall him from prey chase (kangaroos were the hardest, and they're dangerous to dog and can easily kill them for those non aussie folks)
2 years after gotcha day makes him three years young, two years of INTENSE bonding, training loads of exercise. The bonding part was easy, he was a mummas boy instantly, he just needed some love after his rough start. We got 12 chickens, and he wanted to eat them the day they arrived. I told him to LEAVE (pre trained command) once. One week later they chickens were free-range and pecking him to get him off his bed so they could steal it (or maybe just on it coz they were now boss of this 55kg dog.)
We also had a damn with resident ducks. My now ex partner allowed him to chase them around the damn, as they would fly or swim to one side, he hated water and would run all the way around this large 50 metre damn. They would fly back and he would go around again. Was his way of lazily exercising the dogs. I thought this would encourage him to chase the chickens if it was allowed to continue. What do men do? Not what they're asked typically! Anyway, he never hurt a chicken, never chased or scared them, even bought one back to the herd that got lost one day. But a wild duck at the damn wasn't part of the family tribe so they were fair game. He never caught one either. Basically he would try to chase almost anything he got the chance to, but if I told him to leave it. He did, wouldn't bat an eyelid and would allow them to come to him if they wanted to be friends and they always did, he is a gentle giant that listens. But that switch could flick, all animals are unpredictable, even humans. But.. he has the front garden and front end of the house when we go out so the two younger dogs don't hassle the senior too much. The pigs in the front garden obviously were scared of him at first. But after a few senior dog naps on the grass, the pigs were able to approach him and check him out for a sniff. Wasn't long until they would curiously follow him around the garden, but act like they weren't if he turns around

.
It's been 12 months since we've been in this house with this kind of set up, if Dexters asleep, the pigs nibble the grass around him and hang out and rest near his stomach and legs, they even popcorn and zoom around his legs, he just stands there and looks at them like what are they doing?
He grooms them, checks where they are when they're hiding. I'm yet to catch a nose kiss between them on camera, it's almost like they know his doing a head count and they're letting him know they're there. I do trust him 100% and if he did flick, he doubt he could catch one and it would be 100% my fault. Not his. My only worry is he will accidentally stand on one. He has heavy feet, and his super stompy now his so old
Staffy one: people pleaser, wants to be a terrier but isn't 100% sure how. He corned a rabbit and looked around like... now what do I do? And didn't even notice this rabbit use the opportunity to dart between his legs. His muzzle trained so I put a muzzle on for safety and lead him around a few times a day and let him watch them. I have great confidence he could be a guardian dog to the pigs, his showing great potential. But I don't think I'll even risk leaving him unattended with them. His self control isn't as good, his 7 and we rescued him 2 years and he come with MAJOR issues, still a work in progress but he is so much better and happier now!
Staffy two: my beautiful conniving, loving, too smart for her own good almost 4 years old. She's a sweet.. smart.. calculated little b!tch, in both forms. I love her to death... but I will NEVER trust her with the pigs. She knows she not allowed where they are, she's not allowed in their shed and she's not allowed in the study where I bring them in for cuddles, training etc. I can leave the door open and she won't go in. But the moment we leave the house.. she checks EVERYTHING! we watch her on the cameras check if all gates and doors are shut, twice. She knows she wants to kill and she knows she can't do it while we're around. So when I'm cleaning pens and bring them in and out etc, she goes in her crate with a long chew treat (she's crate trained and loves it, she's not unhappy in there, and she would be doing the same thing anyway, just sitting around

) so I play it extra safe and lock her away
So depends on the dog and how much effort and time you're willing to put into the dog. Crate training them before piggie intros is a great way to start introducing and getting a feel of how the dog might be around them.
Each dogs different!