Is Oat Bran just Oats? Sorry probably me being thick. I have fed oats to tiny baby pigs made up into porridge with goats milk. Some people I think just add water. They can be fed dry. I have fed them dry short term to guinea pigs that need short term building up, with other things of course. Depends really why you are feeding them. xx
I've fed bran to horses before, and it's like the outer husk of the seed, so it's quite fine. In winter I used to make a bran mash for my ponies just mixed with cool boiled water, I suppose a bit like ready brek for ponies.
It expands when waters added, so maybe it's a good idea to expand it for piggies before it hits their tummies, where if it's fed dry it will expand inside them.
I'm still confused about the oats / bran thing. But with regard to expansion, if you are wetting the oats? either with milk or water, and allowing them to expand before feeding then there should not be too much expansion in the tummies. Probably more careful with dry feeding. xx
I've tried bran with my pigs before (after hearing of other people here doing the same) but mine didn't like it. I gave 100% oat bran (Tescos own) but I think some people probably also use wheat bran. I tried it dry, mixed with water and also mixed with cranberry juice but they wouldn't touch any of it!
As slackalice said, bran comes from the husk of cereal crops, i.e. the rougher, outer layers of the cereal grain which are removed when processing the grain. Some people sprinkle bran on top of their breakfast cereal when they need extra roughage, usually wheat bran, as it's so high in fibre.
I've fed my pigs Wheat Bran from H&B for a couple of winters now and they've never had any problems with it! I just mix it with a bit of warm water (or boiled and left to cool a bit if I'm making a cup of tea for myself!), give it a good mix so it's all wet and give it to them - they love it!