Want bigger bucks now? This three-step plan from Auburn University research sheds light on the best ways to maximize food availability for deer on a year-round basis while maximizing nutrition and keeping costs down.
For many hunters today, the sport of pursuing white-tailed deer has become a 365-day-a-year endeavor that goes far beyond the relatively short deer season each year. For them, all of the hard work and preparation before and after each season is just as satisfying and rewarding as killing the buck of a life- time, filling the freezer with venison or spending time in the woods.
By Dr. Steve Ditchkoff
and Michael Glow
Each year, countless hours and billions of dollars are spent in preparation for the deer season. While there are numerous important aspects of this preparation, which might include scouting new areas, hanging treestands or upgrading to the newest hunting gear, hunters are increasingly realizing the importance of managing their deer herds. Many hunters are taking an active role in improving the quality of the deer they hunt, and as a result have become just as much a deer manager as a hunter.
Just like there are many ways to prepare for the upcoming deer season, deer management encom- passes a variety of different tactics to improve the quality of a deer herd. However, nutritional management for deer is a vital component that has become a primary focus for many deer managers today.
Deer are a product of their environment and, consequently, the nutritional quality of the habitats they utilize has a major impact on their productivity. Research has shown that high-quality diets promote greater body weight and antler size in male deer, and can reduce pregnancy length and increase fawning rates in female deer. Therefore, an understanding of how to improve deer nutrition is extremely important for managers who want to produce a healthy deer herd.
DON’T JUST FOCUS ON BUCKS
Frequently, actions designed to improve nutrition are focused on the buck segment of the herd because of the importance of antlers to most hunters and managers. However, nutrition is equally important to does and fawns, and efforts toward improving the nutritional plane of these deer will inherently impact antler quality and the condition of bucks as well.
Does with access to an abundance of high quality nutritional resources will give birth to larger, healthier fawns, and will also produce sufficient milk during lactation to maximize fawn growth and development. This ultimately results in improved fawn survival, and buck fawns have a legitimate head start toward quality antler production later in life. For these reasons, efforts designed to improve nutrition should be focused on the entire deer herd.
Ensuring that an adequate supply of nutritional resources is available for deer generally involves efforts to improve natural habitat quality, preparation and planting of food plots, and/or providing supplemental feed. However, the nutritional availability, quality and types of habitat vary across the whitetail’s range, suggesting that maximization of management efforts to enhance available nutrients for a deer herd might differ from one property and/or region to the next.
Extensive farmland and fertile soils across much of the Midwest provide deer with high-quality native and agricultural forages throughout most of the year, while poor soil fertility and hot climatic conditions can lead to nutritionally deficient habitats in much of the southeastern United States. Additionally, the quality and quantity of natural forages and food plot vegetation varies throughout the growing season.
Vegetation is typically most nutritious during spring and early summer as young plants are highly digestible and high in energy and protein content, but the nutritional quality tends to decline throughout the summer and into fall as plants mature and become less digestible. These natural fluctuations in forage quantity and quality throughout the year result in a dynamic system where nutrient availability is constantly changing, and the most appropriate management strategy for maximizing nutrition is also changing.
In addition to the ever changing forage base for deer, nutritional demands of deer fluctuate, creating certain periods when deer are nutritionally stressed. Although it is important to ensure adequate nutritional resources are provided on a year-round basis, it is increasingly important during periods of nutritional stress.
Three periods during which nutrient demands are greatest are antler growth for bucks and pregnancy and lactation for does. Antlers begin as growing cartilage and are one of the fastest growing tissues in the animal kingdom. Antlers require a surplus of nutrients to maximize growth, and bucks have a limited amount of time each year to grow these structures that might represent up to 20 percent of their skeletal structure.
For females, the nutritional demands of pregnancy are relatively low during the first two trimesters of pregnancy, but increase substantially during the last trimester, when energy and protein demands might be 45 percent greater for pregnant does compared to non-pregnant does.
In addition to giving birth, lactation represents the most nutritionally demanding process for deer, and crude protein requirements might be up to 2 1⁄2 times greater at this time compared to the rest of the year. The demands of milk production typically peak between 10 to 37 days after birth, and does need to produce an adequate supply of milk rich in both energy and protein so fawns can meet the requirements for body growth. In general, if nutrient availability is low during lactation, does will still produce high-quality milk, but the quantity of milk will be significantly reduced.
While peak antler growth is generally consistent across the whitetail’s range, the timing of pregnancy and subsequently lactation can vary from state to state, particularly in the Southeast. This is because fawns are typically born during early June across most of their range, but might be as early as April or as late as August in some parts of the Southeast. The timing of these periods will have implications for management and must be considered when determining deer management plans.
CREATE A PLAN
Habitat management, food plots and supplemental feed can all be utilized to provide high-quality nutritional resources on a year-round basis, especially during the nutritional stress periods discussed above. While each of these can be useful, employing any one of these options alone is rarely the best management strategy. Deer managers trying to decide how to increase nutrition for their deer herd need to have an understanding of the benefits and drawbacks to habitat management, food plots and supplemental feed, and how these nutritional inputs vary during different times of the year in order to make well informed, effective management decisions.
When properly managed, natural vegetation is a sustainable resource that can provide deer with a variety of high-quality resources. Habitat management techniques are commonly implemented to mitigate factors that lead to decreased forage productivity and enhance the abundance and quality of natural forage available for deer.
Deer commonly consume many types of vegetation, but often prefer herbaceous forbs when available because they tend to be more digestible and greater in nutritional value compared to many woody browse species. Because many high-quality forbs require an abundance of sunshine and might not compete as well with low-quality woody species, two general goals of habitat management are to increase sunlight avail- ability at the forest floor or ground level and reduce competition with woody species, thereby allowing nutritious, herbaceous forages to flourish.
Although natural vegetation might be present throughout the summer and fall, there is a limited time frame before the nutritional quality begins to decline and is too low to support higher diet qualities for deer. There- fore, natural vegetation alone is not capable of providing deer with significant quantities of high-quality resources throughout the entire year.
Food plots are a valuable resource that can enhance nutrition during times when high-quality natural forage is limited, and landowners of any size have the capability of increasing available nutrients for their deer herd by planting food plots. A variety of warm and cool season food plot forages may be planted to provide deer with high-quality forage throughout the year. Although food plots can produce a substantial amount of high-quality forage per acre of land, they also can be expensive, especially when considering initial establishment costs. In addition to being expensive, food plots have the potential for crop failure due to drought, disease or insects.
Conversely, supplemental feed can provide high-quality resources on a consistent basis regardless of environmental conditions and is not subject to crop failure. However, supplemental feed can also be expensive, especially when provided over long periods of time, and its use is controversial.
Despite the increased nutritional resources that food plot forages and supplemental feed can provide, research has shown that deer continue to consume native vegetation even when provided with these additional resources, indicating that the management of native forage is important even when nutrition is supplemented.
Additionally, food plots and supplemental feed are more costly than native habitat management from a nutritional perspective. These factors suggest that a comprehensive management approach where native habitat management combined with food plot provisioning and/or supplemental feed should provide a variety of nutritious food sources for deer. However, providing adequate nutritional resources through a combination of these options can quickly become expensive, so keeping costs to a minimum is also extremely important. Staying at or below budget while ensuring an adequate supply of resources is provided can be even more challenging when also considering that the relative nutritional value of native forage and food plots varies throughout the year, and nutritional needs of deer vary.
MANAGE FOR NUTRITION
So how do hunters or deer managers decide on the best combination of management options to provide for their deer herd? What is the best way to maximize food availability for deer on a year-round basis, especially during key nutritional stress periods, while also staying within a budget?
To try to help answer these questions, we conducted a study in east-central Alabama to determine the relative nutritional value of natural vegetation, food plots and supplemental feed. We then used that information to determine how to cost effectively maximize food production during the three nutritional stress periods for deer discussed earlier, which corresponded to the beginning of June, July and September at our study area. For our study, we used data from natural forage production in pine/hardwood stands treated with prescribed fire, Ladino clover production and a 20 percent crude protein commercial deer feed.
Our results indicated that during June and July a combination of habitat management with prescribed fire and food plots cost effectively provided an abundance of nutritional forage for deer without the addition of supplemental feed. Intuitively, management plans that included supplemental feed increased total food production, but it was considerably more expensive with a much lower return value.
In pine and mixed pine/hardwood forests in the Southeast, prescribed fire is a very cost effective habitat management tool that improves the quality and quantity of high-quality forages. On our study area, an abundance of high-quality natural forage was produced following prescribed fire due to the large area that could be burned at a low cost. In addition to natural forage, food plots, although more expensive, produced over 1,700 pounds/acre of forage exceeding 20 percent crude protein. Therefore, supplemental feed at this time provided an unnecessary additional resource at a costly price.
However, our results were different in September, when lactation and fawn growth can be extremely important. Native forage became much less important due to the natural decline in forage quality during late summer/ early fall, and supplemental feed became a potential viable option to compensate for the decline in natural forage quality.
Food plots remained an important input nutritionally. Our results in September highlight an important point to consider when managing a piece of property. While there was still an abundance of natural forage on the landscape during September, the vast majority was too low from a nutritional quality perspective to provide the nutrients needed to maximize lactation and fawn growth. It is important for managers to realize that even though there might be an abundance of forage available, it might be poor quality compared to just a few weeks earlier. Therefore, additional nutritional resources became increasingly important during this time period.
A key point to remember is that the relative importance of nutritional inputs (natural forage, food plots and supplemental feed) varies seasonally, which managers need to consider when determining how to maximize food production during nutritional stress periods. Just because certain habitat management options can increase natural forage quantity and quality at some points during the year doesn’t mean it is the most suitable method for nutritional management year-round. Likewise, supplemental feed might be a consistent, high-quality resource for deer, but it might not be necessary during certain times of the year when there is an abundance of other nutritional resources that can be produced at a much lower cost.
Additionally, while maximizing nutrient availability for a deer herd is very important, other considerations should also be made when determining optimal habitat management options. Suitable cover is an important resource for deer, especially to provide protection for fawns from predation. However, habitat management options designed to improve the nutrient quality of habitats such as prescribed fire are generally utilized to open the understory, and thus eliminate many species that provide adequate cover. Managers should consider designating certain areas where heavy cover is a priority. Hard and soft mast can also provide important food resources for deer, and management options that increase these resources should also be utilized. Retention and management of hard mast-producing trees can help provide high-energy food sources during the fall when natural forage quality has declined.
In regard to food plot management, monthly forage production, costs to establish and maintain food plots, and responses to varying rainfall, soil conditions and browsing pressure vary by species. Therefore, planting a variety of annual and perennial food plot species throughout the year will help ensure an abundance of high-quality forage is available.
Herd management is another important consideration and option to increase the availability of nutritional resources. Increasing the quantity of high-quality nutritional resources might have little effect if deer densities are greater than a property can support. Increased doe harvest might be necessary to reduce deer numbers to a sustainable level to prevent over browsing and allow more resources to be available for fewer deer.
It is also important to remember that the effectiveness of different management options will vary depending on individual regions or locations, but providing a sufficient quantity of nutritional resources should be an integral component of any management plan that aims to maximize deer condition and quality. Many different factors will affect management decisions when deciding the optimal management plan such as property layout, financial resources, management goals and deer density.
Therefore, each property will require a unique management plan, but an understanding of different management options will help managers make the best decisions on how to produce quality deer next season and for many seasons to come.
— Dr. Steve Ditchkoff is a professor at the School of Forestry and Wildlife Sciences at Auburn University. He manages the Deer Research Program at Auburn and has conducted research
on white-tailed deer for 25 years.
— Michael Glow recently completed his M.S. degree at Auburn. He currently works as a biological science technician at the National Wildlife Research Center in Fort Collins, Colorado, with the Management of Ungulate Disease and Damage group.