We ended Part 1 last month by asking this question: How much protein does a deer need? Fawns and yearlings need as much as 24 percent, but generally do well with 16 to 17 percent. Once grown, bucks seem to need less protein than any other segments of the herd. I have observed bucks produce quality antlers with as little as 10 percent protein (15 to 17 percent is optimum).

Once they reach maturity, bucks seem to need less protein than does, fawns and younger bucks. Does, on the other hand, need a great deal more, especially during pregnancy and lactation.

Does, on the other hand, need a great deal more, especially during pregnancy and nursing (16 to 24 percent). There also are short-term critical times, such as right after weaning, when does attempt to recoup body mass. Bucks have two stress periods: 1) just after antler casting, and 2) during mineralization and velvet stripping.

So how is protein measured? The above values are percentages of total intake. If a deer eats about 10 pounds of forage per day, that means a 16 percent protein demand converts to 1.6 pounds of protein per day. When we send in forage samples to our research laboratory for analysis, two different protein levels are measured: 1) dry weight, and 2) "as fed." These are important differences.

The first is measured after the sample is thoroughly dried, while the second is calculated as what is present when the animal swallows it. We classify plants as either "nutrient dense" or "nutrient diffuse." In the former, a single mouthful contains a great deal of nutrition, while for the latter, the volume is the same but the amount of nutrition is lower.

ENERGY AND FAT IN DEER
More often than not, energy is the limiting factor for whitetails. Energy permits almost every body function. Digestible forages allow the rumen organisms to produce more volatile fatty acids, sugars, etc., to power the deer's body. However, foods can be too digestible, creating some very serious problems. For example, where legal, corn grain is commonly used as bait for deer. But too much corn can speed up production of the waste products of rumen organisms.

Understanding What Deer Need Don't miss Part 1 of this story, available here.

Normally, these waste products are useful, but too many can change the rumen environment. Remember, in Part 1 last month I noted that the rumen must remain at neutral pH (7). A buildup of acidity kills the rumen organisms, leaving the deer without a means of acquiring nutrients. It starves to death in the presence of plenty!

Deer are obligatory fat depositors, meaning they deposit fat at certain times of the year, no matter what the level of nutrition may be. This is why hunters frequently misinterpret a fat deer harvested during the hunting season as deer being in good shape the rest of the year. Biologists conduct "health checks" in many areas during late summer and late winter, the two worst times for deer.

Deer generally have a very different type of fat than cattle. White fat found in deer has a very low melting point, allowing deer to mobilize this stored energy quickly. The yellow fat common to cattle is much more difficult to metabolize. This is one of the many reasons why venison is so much better for you!

Deer do not have a gall bladder. This is important, since they only need about 3 percent fat in their diet. Bile serves to emulsify fat in the diet. Since deer do not seek out fatty foods, this process is not necessary. Deer are on a "reverse" Atkins diet. They seek out, rather than shun, high carbohydrate foods. Too often, managers try to provide fat supplements with disastrous results. At best, a deer given a high fat diet will excrete oil through its skin. If you rub your hand down the back of such an animal, your hand will become greasy!

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