The premise behind spike culling is that yearling bucks with spike antlers are genetically inferior and will never attain quality antlers typical of yearlings that grow forked antlers. Can selection against spike bucks be effective in changing the genetic character of the herd?

Not so says Harry Jacobson. To the contrary, he observed that spike antlered yearlings in his Mississippi research pens frequently grew exceptionally large antlers at maturity.

Jacobson and Texas A&M animal geneticist Steven Lukefahr teamed up, using a special computer program, to determine the genetic and environmental factors responsible for antler traits of 220 yearling bucks Jacobson had raised at his research facility.

In a nutshell, this research revealed that genetics accounted for only 5 percent of spike antler traits recorded among yearlings. Instead, the doe's nurturing ability and care of her offspring was more important, accounting for 29 percent to 34 percent of the variation in the yearling's antler points, spread, weight and beam length.

Jacobson and Lukefahr concluded the following: "Our results do not support the use of yearling antler records as criteria for selective breeding management or harvest schemes to alter the genetic quality of a white-tailed deer population."

More recently, Mitchell Lockwood and his cohorts from the Texas Parks and Wildlife Department completed an 8-year study to determine how genetic and environmental factors interact to influence yearling buck antler quality — and produced results different from those of Jacobson and Lukefahr.

In the Texas experiments, buck fawns were nutritionally stressed by being fed a restricted (half-ration) diet consisting of only 8 percent protein. Each year they then selected the best antlered yearling bucks as sires, to determine if such selective breeding would yield yearling bucks with superior antlers in subsequent years.

From 1993 to 1999, such selection produced improvements in all recorded antler measurements. For example, average Boone and Crockett yearling buck antler scores increased by 36.4 inches.

According to Lockwood and his group, "Our findings clearly indicate that under constant suboptimal environmental conditions, phenotypic change in antler quality can be realized with intensive selective harvest of yearling males."

These same researchers, and others, also contest the idea of protecting only small antlered deer from harvest, because it allows the harvest of yearlings with superior antlers but protects even older bucks with poor antlers. This (high-grading) tends to degrade antler quality in subsequent years.

Instead, they favor the so-called "slot-limit" approach, which protects medium-sized bucks. Such a harvest strategy allows for harvesting mature bucks with antlers larger than some pre-determined spread, and encourages the harvest of the poorest quality young bucks with unbranched antlers. At the same time this protects the best quality young bucks and minimizes the adverse effects of high-grading.

Conclusions

Clearly, many factors can interact to determine the quality of yearling buck antlers. Although inheritance of antler traits may be important, genetic effects are often masked by a multitude of environmental influences.

In my view, variations in climate, nutrition, social behavior, birth date and nurturing, as well as other factors that impact the young male's rate of sexual maturity, are more important than genetics in determining the quality of a buck's first set of antlers.

Ironically, after more than three decades of study, there still seems to be little agreement among researchers as to the relationship between the quality of a buck's antlers at yearling age versus those grown at maturity — probably because the animal's response varies regionally.