ebruary 2 is Groundhog Day, when folks anxiously wait to hear if Punxsutawney Phil predicts another six weeks of winter. But news from the Pennsylvania prognosticator is of far greater importance to deer than it is to people.
Proper nutrition is important to deer survival throughout the year, but is most critical at winter’s end. Food is at its least abundant and least nutritious stage. Fall fat reserves are nearly depleted. The whitetail’s nutritional gas tank is on “E” and the next service station – spring green-up – lays several miles down the road. Supplemental feeding can be extremely helpful in getting them through this nutritional bottleneck, if done correctly. The effectiveness of supplemental feed is directly related to how well it meets the specific nutritional needs of deer at this critical time of year. To learn more about those needs, and how to fulfill them I spoke with Les Ray of Heartland Wildlife Institute.

Through winter deer subsist largely on a diet high in coarse fiber (predominantly woody browse). That’s often not enough to meet all their nutritional requirements; so they also live off fat they stored going into winter. By late winter, the quality of food may be so poor that deer use more energy feeding than they take in. But they must continue to feed on coarse browse and sometimes even bark merely to keep their rumen functioning.
The rumen – the first part of a deer’s complex four-chambered stomach – is what breaks down food into usable components. That’s why proper rumen function is so important. “You mess around with the deer’s rumen and you’ve mess around with the whole deer,” says Ray.
What deer need most during this transition from coarse fiber to greens is protein. You can enhance both nutritional intake and rumen function without shocking the system by providing a protein block. “You’re also trying to get them to eat vitamins and minerals they need,” says Ray, “and if you package them (blocks) with higher protein, deer will pick up on it.” He recommends Heartland’s Rack Maker Deer Block, which is 23 percent protein but also contains mineral supplements. This will get the rumen back to functioning at a higher level of efficiency while also providing important minerals for antler growth in bucks and fetal growth in pregnant does.
Once green-up occurs, deer switch rapidly over to the new growth and according to Ray, “…you’re gonna have a hard time getting supplemental vitamins and minerals into them.” That’s why he recommends adding a mineral block with calcium and phosphorous to your feed station toward the latter part of the transition period. He suggests Heartland’s Whitetail Antler Magic, which is 15 percent calcium and 9 percent phosphorous. It also contains salt, which provides no nutrition but will attract deer and get them to consume more valuable minerals.
Once you help deer over this hump, the next enhancement is having a high protein crop already in the ground ready to sprout when green-up comes, a subject we’ll cover in an upcoming installment.