We raise our LBH’s on certified organic grain which is very expensive. The breeders were getting too high on the body condition scale for our taste, so we just kept reducing the grain and monitoring body condition scores. We ended up at 2lbs/day for a maintenance ration, where normally we would be at 4 lbs./day. For our market hogs that we raised over the winter, they did not seem to have the same appetite for the 2nd cutting hay that our breeding hogs did, so we have kept them at about 3% of body weight for grain and free choice hay. That seems to work for us.
Really the bottom line is what is their body condition score and how fast are they gaining. You don’t want a breeding pig to be too fat or too skinny. For butcher hogs, it depends a lot on what kind of meat you are looking to produce. A steady, reasonably fast rate of gain is important to tenderness of the meat, but too much and the fat percentage goes up quite a bit.
This is what works for us at Cross Island Farms on Wellesley Island NY. I would be interested to hear what other hog farmers have to say on the subject.