The Makeup of Deer Blocks
Deer blocks are generally mineral based, and have especially high concentrations of trace minerals. Depending on the specific block, they may contain calcium and phosphorous, as well as vitamins A, D and E. The deer are attracted by the salty taste. Many blocks also contain molasses to make the block more palatable. Simple white salt blocks are also used to attract deer, although they do not offer as many nutritional benefits as mineral blocks.
Using Deer Blocks as Attractants
The principle use for deer food blocks is to attract deer to a specific location. Generally, hunters set them out within range of their tree stand, making sure they have a clear and manageable shot. The hunter does not necessarily have to put them on a deer trail, as the deer will naturally find the food block. It must be set up at least several weeks before the season, however. Generally, it is best to place a deer food block in a location at least several months before hunting, to ensure the deer are already used to traveling to it.
Using Deer Blocks for Herd Health
Some hunting enthusiasts use deer food blocks to supplement the local herd's natural diet and bolster their health. The nutrients found in food blocks can reduce the mortality rate of deer by providing pregnant does with minerals and vitamins to improve their metabolic condition, or can allow deer to maintain their weight or add extra fat to their bodies during the times of year they need it the most. There are also special blends that are marketed to increase antler size.
Alternatives to Food Blocks
There are other ways to attract deer to an area without the cost of commercial food blocks. Planting a small crop that is especially palatable to deer is a popular way to offer a food source for the local herd, such as alfalfa or corn. Some people pile acorns or make their own food blocks with molasses or bagged mineral salt. Before setting out a deer food block, it is important to check with the local ordinances, since it is illegal to bait deer in some states.