Diet is More Important than Genes for Big Bucks

Biologists at MSU have been researching whitetail deer for many years and their latest study comparing genetics and nutrition is yielding some surprising results. Eric Michel, a graduate student, and researcher on the project led by Dr. Steve Demaris and others says they’ve found what deer eat has the most to do with what antlers they grow.

The program, which uses the university’s whitetail captivity facilities, is an 8-year study that has been tracking sets of deer brought in from the coast, from the middle of the state, and from the Delta and comparing the development of their body mass and antler size over time. The three sets of deer are kept separate from one another but are otherwise fed identical diets and offered the same access to water and shelter.

Michel says results from the study underway since 2005 seem to show, at least within the span of deer found inside the confines of the state of Mississippi, nutritional improvements can lead herds of traditionally smaller-bodied and smaller-antlered deer to completely catch up to their larger cousins, though it takes more than one generation to do so.

The first generation of bucks in the study exhibited the size differences you’d expect to see – Delta deer grew antlers on average 24 total inches larger than coastal deer, with mid-state deer falling in between. Body sizes of Delta deer far outstripped the other two. Two generations later the antler measurements were effectively identical and the gap in body mass had been greatly reduced as well.
What the study shows, other than the direct relation of body and antler mass to nutrition is that nutritional improvement can’t be expected to be a quick fix. While growing better food for deer leads to larger animals and bigger racks in the long run, you can’t plant a new food plot this summer and expect to see bigger antlers this fall.

“We’re finding the nutritional state of the mothers can permanently affect their fawns,” Michel said. A doe that has had fewer nutritional advantages will give birth to fawns that cannot grow up to be as large as those birthed by does in better nutritional circumstances. Those fawns, however, can mature and give birth to others with more potential of their own. Michel discounts the harvest of “cull bucks” as a method of herd improvement, noting that while it has some advantages, the improvement of genetics is not one of them.
“Because 50 percent of any buck’s genes come from its mother,” Michel said, “and since there’s no way to know the pedigree of the does in any wild herd sample, managing for genetics is an impossibility.” Nutrition and management of herd size are the most productive paths to follow, he said. “On average, a whitetail will eat 6 pounds of food per day,” Michel said. “The more you limit the number of deer you have eating the available food, the less stressed the herd will be from a nutritional standpoint.”

What hunters will harvest this season begins, in many cases, with what they sow today and in the coming weeks. Maintaining a healthy herd of whitetail deer so that its members can reach their maximum potential requires careful planning and management of the land they call home. Most noticeably, maybe most significantly, it requires the planting of food plots or green fields to supply or supplement nourishment and minerals otherwise lacking in their diet. Green fields supplement and attract deer in the fall, but they do their most critical work in the summer when does are raising fawns and bucks are growing antlers.