A deer’s antler size is governed by age, nutrition, and genetics. Age is the most important, since antler growth is not maximized until at least 6 years of age.
While supplemental food such as food plots can be beneficial, the best way of optimizing nutrition is by reducing forage competition by controlling the animal numbers and managing habitat. Good habitat practices include prescribed burning, brush management, and invasive species control (bermudagrass, bahiagrass, etc.). Yaupon and eastern red cedar can also present serious problems.
While genetics will dictate the size of all antler characteristics (mass, number of points, spread, and B&C score), genetics are not usually significant deficient in deer herds throughout the state. Many studies have been conducted to see if culling bucks, removing small-antlered deer, will improve future antler characteristics. Yearling spikes, however, may eventually catch up with fork-antlered yearlings later in life. Heritability is not usually very high.
Older mature deer do most of the breeding, except when there aren’t enough mature deer. Keeping only a few large-antlered deer, however, usually results in a depleted population as a buck, on average is only responsible for a few fawns. Studies have shown that body size and attitude have higher correlation with breeding success than antler size.
Culling according to antler size may result in lower density, an elevated sex ratio, delayed breeding, and a reduced age structure. Culling had to be suspended in a King Ranch study after 7 years because it was not sustainable.
Culling can be a valuable tool if you have sufficient information on the population. Remember, however, when you select for one trait such as antler size, you may be selecting against another trait such as resistance to parasites and disease, body size, or reproduction. Maintaining a healthy deer population means utilizing annual surveys to determine the density, sex ratio, fawn crop, and buck age structure. Over harvesting bucks, even if they are culls can result in a low density, wide sex ratio, and reduced age structure.
