White-tailed Deer
White-tailed Deer are a kind of deer that weigh between 45 and 70 kilograms and are primarily indigenous to America, particularly Bolivia and Peru. They get their name from the local whitetail deer. Their horns, which have unusually branching antlers that can be used for food (gelatin), medicine, ornament, and trophies, are another distinguishing trait. In this approach, growing and properly breeding these deer to attain excellent antlers is very significant due to the necessity to fulfill these utilities.
Genetic Modification
The term "genetic engineering" or "genetic modification" refers to the alteration of all or a portion of a gene in an organism to produce desired characteristics (Bruce, 2014). The process involves elimination of unwanted organic characteristics through various ways such as genetic silencing and/or genetic insertion. Genetic silencing consists of the turning of not so useful traits in organisms based on desired need while genetic addition is the introduction of foreign traits into an organism to alter its characteristics into desirable ones (Wiedenheft, Sternberg & Doudna, 2012). The need to silence undesired whitetail antler traits and introduce desired ones prompts the modification of whitetail deer genetics concerning these antlers. Mainly, smaller and malnourished antlers are not desirable and the fact that the traits of antlers are inherited means that they can be genetically manipulated. Farmers desire bigger and healthier antler growth, which is geared towards enhancing the supply of antlers. Thus, the aim of this research paper is to establish; genetic characteristics of white tail deer antlers, various factors that contribute to greater antler growth, how antler development in deer can be genetically steered and the genetic procedures were undertaken to ensure the maximum potential growth of antlers for harvesting.
Genetic Characteristics of White-tailed Deer
Heritability of Antlers
Whitetail deer antlers are hereditary, meaning that based on the dominance of antler features in the parents, offspring may take up the same traits. For instance, if the parents had weak and undesired antlers, there is an absolute possibility that the offspring will have the same. The case is similar to the yearlings, whose parents had well-formed antlers. In light of this, it becomes essential to note that antlers in whitetail deer have a significant genetic variance of 0.22-0.56 antler points (Webb et al., 2012). Precisely, the size and weight of antlers is proven to be genetically passed down from parents to offspring.
Gender-Based Genetics
Whitetail Deer have variance in genes to offspring, usually predominantly predetermined by the male deer, a clear implication that to genetically modify the antler growth into desirable weight and sizes, the males have to undergo gene deletion or insertion to boost the outcome in the herds.
Subjectivity to Environment
Antler traits may be affected by the environment and season within which offspring are delivered. Yearlings born through summer periods tend to have heavier and bigger antlers unlike those born in winter or other seasons. Also, the yearlings born in the earlier times of viability of a female and/or male tend to exhibit better growth of antlers due to stronger genetic connectivity to the parents. The case is different for yearlings born of way older deer, which are sexually selected features, in that deer born in later seasons tend to be phenotypically stunted (Swaim, 2015).
Factors that Contribute to Greater Antler Growth
The key to desired white deer antler growth is based on the measures of performance on various weightings. These include the weight of the antler, its shape (spiked or forked), length and base circumference. The main factors that affect antler growth are age, genetics, and nutrition.
Age
In ordinary perspectives, the antlers grow bigger the deer gets older. Approximately, deer that are over three years tend to have bigger and more massive antlers with larger circumference and length. The younger ones have room for growth of antlers but are not so big. The gender aspect can also be used to quantify antler growth. Male yearlings are found to have more significant and more massive antlers as compared to female ones of their exact age. Precisely, the male's growth is more concentrated and exponential as compared to the females.
Genetics
The hereditary aspect has been quite unquantifiable over time, but with the identification of genetic features, there has been the improved use of modifications to suit given needs in antler growth. The gene in the siring deer is comprised of its offspring, and as such, many white-tailed deer offspring are a reflection of the genes in their parents. The growth of antlers, therefore, for weak siring deer will have weak antler growth in offspring and the reverse holds too.
Nutrition
In any animal growth, nutrition is critical. After genetically identifying and modifying deer to have better antler growth, farmers focus on nutrition to scale growth upwards. Most individuals and even game management entities base on protein intake for whitetail deer to improve their growth. However, it has to be noted that only +14 % or -14% crude protein is needed by these deer to fully grow antlers at a maximum potential (Spurlock, 2015).
Genetic Modification of Whitetail Deer Antlers
Biologically, it is intriguing to have regeneration of given appendages such as antlers that in normal circumstances cannot grow again once cut or degenerated. Therefore, it is a unique occurrence that white deer can recurrently regenerate antlers to enable the harvesting of antlers based on the knowledge that the same can grow again (Li et al., 2014). Antlers have unique tissue types called velvets that capsulate other tissues at the base and within the antlers. Their growth and degeneration is usually in tandem with seasons and based on the rise and fall of testosterone- high levels of testosterone results in the degeneration of the velvet and antler base, which is shed off and harvested. Antlers regenerate when the testosterone is low.Naturally, the modification process can be enhanced through population increase or reduction of the desired males in a herd. Males with spiked antlers are not so desirable and as such, are removed from the population. The remaining forked antler deer will then breed and have more offspring being forked. The same happens with forked deer that do not have strong and massive antlers.In a lab setting, the genes from deer with desired traits are harvested through cell RNA and various tissue. The same is studied and cultured to grow. The sensitive tissue and cells are then purified by introducing or deleting unwanted genetic strands to remain with exceptional genetic formulations, which are then used in breeding. The outcome is that over time, the white deer existing in farms tend to be of given qualities regarding weight, disease resistance, and antler feature growth among many other aspects that can be manipulated.
Conclusion
White-tailed deer are unique to the fact that their antlers can regenerate with changes in season. These antlers have various uses, and for this purpose, farmers and game communities have sought the best way to enhance the deer growth from the purpose of improved antler development, thus, increase the supply of antlers needed to meet its demand. Genetic manipulation is incurred by artificially selecting desired traits that include more massive antlers, long antlers, and broader base circumference of antlers among other vital traits, achieved through deletion or insertion in a farm or lab setting. The result is that over the years, some undesired traits in these deer are eliminated or faced out gradually through the elimination of animals that exhibit these unwanted traits such as lightweight and spiked antlers. Evidently, desired traits in whitetail deer have forced farmers to genetically manipulate these mammals for the improvement of antler qualities, essential for given uses.
References
Bruce, D. (2014). Engineering Genesis: ethics of genetic engineering in non-human species. Routledge.
Li, C., Zhao, H., Liu, Z., & McMahon, C. (2014). Deer antler-a novel model for studying organ regeneration in mammals. The international journal of biochemistry & cell biology, 56, 111-122.
Spurlock. S., 2015. The Key to Antler Growth. Age, Genetics, Nutrition. Retrieved from: https://www.gohunt.com/read/life/the-key-to-antler-growth-age-genetics-nutrition#gs.8s6LPKU
Swaim, A. (2015). Documentation of Missouri white-tailed deer chronoclines: Implications for archaeology, paleoecology, and conservation biology (Doctoral dissertation, University of Missouri-Columbia).
Webb, S. L., Demarais, S., Strickland, B. K., Deyoung, R. W., Kinghorn, B. P., & Gee, K. L. (2012). Effects of selective harvest on antler size in white‐tailed deer: A modeling approach. The Journal of Wildlife Management, 76(1), 48-56.
Wiedenheft, B., Sternberg, S. H., & Doudna, J. A. (2012). RNA-guided genetic silencing systems in bacteria and archaea. Nature, 482(7385), 331-338.
