Without the shelter of evergreens that characterize their winter habitats, they will suffer from severe winter weather. In Maine, predation, not starvation, is the major cause of winter mortality among deer. Deer concentrated around a feeding station often bed near the food and have a very limited network of escape trails, increasing mortality due to predation. When a feeding station is near homes, free-roaming dogs, family pets, run and kill deer, aided in the chase by deep and crusted snow. Deer are ruminants, so bacteria, protozoa and yeasts in the four chambers of the stomach break down food.
Deer take weeks or months to adapt to new food types.
If they are not accustomed to the food, they won't be able to digest it and, very likely, will starve. The feeding program should start early in winter, while the deer are still healthy and their stomachs can adjust to the foods. The program, once started, should continue until spring when greenery is available to the deer. Any kind of hay, kitchen scraps, cabbage and lettuce are not a good diet for deer. Feeding these foods can lead to starvation.