rockbilly, we feed year round. However, the best time to benefit whitetail with high protein is during the winter, and early spring. Bucks will need to replenish their bodies after the rut, when they eat little in order to find receptive does, and in the spring it benefits best does who are dropping their fawns. Never hurts, but the best time for high protein has already passed. Then again, with rising corn prices, protein is becoming a cheaper food source.
With the drought, this year it might be a good idea to include the protein, but I personally would introduce it at a lower rate, until they become accustomed to it. Some proteins suddenly introduced to hungry deer can cause some digestive issues for them. You might reverse that ratio to 25% protein and 75% corn for several weeks. Once you see them eating and doing well, increase the protein % a bit incrementally. However, once again the best time to benefit them with protein will be during winter, and early spring.
Glad to read about the nice bucks caught on camera. I hope you are blessed with a nice buck this coming season.