I understand your question is about why dogs need to heat their milk after giving birth. Dogs need to be fed warm milk after giving birth. This is because warm milk helps stimulate the dog's digestive system and immune system, and can increase the body temperature of newborn puppies. Cold milk can cause digestive problems and discomfort, so warm milk is a better choice.
In addition, feeding warm milk can help newborn puppies absorb nutrients better, because warm milk can Helps open their digestive tract so nutrients can be absorbed more easily. Therefore, when feeding your dog after giving birth, you should ensure that the milk temperature is appropriate. The temperature should be at the temperature of hot water, but not too hot to avoid scalding the dog or puppy.