In the first phase of the pregnancy (day 1 to 35 or 40), the embryos are very sensitive to any lack of nutrients. So the quality of the food is very important at this time. On the other hand, the bitch does not need an increased energy supply until day 35 or 40 as the egg cells are simply settling down and the foetuses’ organ systems are being created. A “normal” high quality food is sufficient at this time.
As the second phase of pregnancy commences (after day 35 – 40), the embryos start to grow rapidly, the skeleton is mineralised and the organs mature. The bitch now needs food with a higher energy content and appropriate mineral and vitamins. She should now be offered a high quality puppy food.