The use of lactose, glucose and white sugar in suckling pig feed

Ask the expert: what is the biochemical reaction of lactose in suckling pigs? Can glucose replace the energy part of lactose? Is there any difference in the stage of use of glucose, white sugar and lactose? What is their optimal usage? What are their respective maximum limits? I'm not sure. I'm passing by to study. Lactose can easily turn into lactic acid in the intestines-it can't be replaced, it's not clear.