AGE OF BUCKS VERSUS THE SIZE OF ANTLERS: 



The size of a deer'^ antlers is reflective of its age, nutrition, social position, health of the 

 herd, and genetics. 



Nutrition is a major determinant in antler growth. In penned and enclosed simations it has 

 been shown that altering the feeding mixture to increase protein will change antler size in all 

 age classes and especially yearling bucks. In Montana, this is most apparent during drought 

 periods in the eastern prairie. During years of extreme drought, a higher percentage of the 

 older aged bucks have smaller antlers. 



Age is another important factor influencing antler growth. Measurements of main beam 

 antler length at checking stations in southwestern Montana show the length continues to 

 increase up through 6.5 years, although the percent change in length decreases markedly as 

 deer get older. (Table 1). The Havre check station main beam antler length information 

 shows that deer gain the majority of their antler growth by 4 years of age. The difference in 

 length between the 4 and > 5 year classes was only 0.9 inches. 



Studies have shown that bucks bom later in the year typically have smaller antlers as 

 yearlings, and often are spikes. A whitetail study by Dr. Harry Jacobson, Mississippi State 

 University, refuted the conventional wisdom that these smaller yearlings are inferior. In that 

 study, antler growth of those smaller bucks caught up to that of the larger yearlings in later 

 years and at times surpassed them to become large trophy class bucks. 



Genetics is becoming a more popular theory for why some bucks grow larger antlers than 

 others. Although there is much to be learned about genetic influences, the findings of Dr. 

 Jacobson indicate that bucks with typically small antlers throughout life can sire offspring 

 with larger antlers. Large antler bucks did not predictably sire large antler bucks in those 

 studies. 



Additionally, an important factor in antler size was the genetic contribution of the female. 



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