Peachicks need to be kept in a brooder until they feather out or until the brooder temperature meets the outdoor temperature. Each week that a peachick is in the brooder you should lower the brooder temperature by 5 degrees. This will ease the peachick into lower temperatures with the least amount of stress possible.
Bergenia (Bergenia cordifolia) is another perennial you can plant under pine trees. This deer and rabbit resistant plant grows in USDA zones 2 through 9 in all soil pH levels, including acidic. It tolerates drought conditions, dense shade and dry soils. Pink lily-of-valley (Convallaria majalis var.
The easy answer is just don't grow grass there. Grass doesn't like to grow under pine trees, so why force it. The soil is acidic, it can be messy, there is little sunlight and competition for water is intense. Create a bed of mulch or pine straw preferably to the drip line of the tree.