I have had chickens for almost a year. I’ve had 4 hens go broody and the first 3 was successful and not one baby died. This last hen hatched 5. There 2 weeks old now but one by one there getting pasty butt and two has died. I moved her to a more comfortable pen with her babies. I’ve gave them electrolytes. They eat purina chick starter grower. Why are the babies dying.