This a great question, and I believe that the answer lies in the difference in the lives of the animals in consideration.
While it is true that bovines are larger animals than elk, and can weigh 2 -2 1/2 times as much our largest elk, our domesticated cattle (of which the bones used in the aforementioned tests) do not live as tough a lifecycle as our elk do, or have to cover the amount of ground or terrain types as an elk does to travel from bedding areas to water and feeding areas. Nor do they have to be able to outrun predators on a daily basis, in the variety of terrain that an elk does. Our domesticated cattle do not travel more than a quarter mile to water or food if at all possible, in order to gain as much meat on their bones as possible prior to being shipped to the meat packers before they reach two years old. Even older cattle, while their bones grow larger, do not really live tougher lives for the most part. Cattle, also do not have the constitution of an elk (read will to live, vigor and tenacity of life).
A mature bull elk (most hunters primary target on license) is usually between 4-8 years old and has had to work hard every day of its life to survive. He lives in harsh environments 365 days a year, and can cover 15 miles between bedding and water/feeding areas each morning and evening. He works hard to traverse the often steep terrain that they life in, and has to be able to survive predator attacks, hunters and climatic conditions. This is going to result in an animal that is hardier, and tougher. And hard work builds heavier bone. Evolution and survival of the fittest have taken care of the rest.
As a comparison, think about the ancient and medieval soldiers and archers. Archeologists are able to determine which skeletons belonged to which army personnel just by the density of bone in the archers' drawing shoulder and arms. These archers practiced with their bows every day of their lives to build up their strength and skill. This extra work resulted in heavier bone in their drawing side compared to their bow hand side.
Hope this helps. There may be better or more scientific answers to your question, but this has been my conclusion to this same question after reading that article on the elk bone penetration experiment some 15 odd years ago.
While it is true that bovines are larger animals than elk, and can weigh 2 -2 1/2 times as much our largest elk, our domesticated cattle (of which the bones used in the aforementioned tests) do not live as tough a lifecycle as our elk do, or have to cover the amount of ground or terrain types as an elk does to travel from bedding areas to water and feeding areas. Nor do they have to be able to outrun predators on a daily basis, in the variety of terrain that an elk does. Our domesticated cattle do not travel more than a quarter mile to water or food if at all possible, in order to gain as much meat on their bones as possible prior to being shipped to the meat packers before they reach two years old. Even older cattle, while their bones grow larger, do not really live tougher lives for the most part. Cattle, also do not have the constitution of an elk (read will to live, vigor and tenacity of life).
A mature bull elk (most hunters primary target on license) is usually between 4-8 years old and has had to work hard every day of its life to survive. He lives in harsh environments 365 days a year, and can cover 15 miles between bedding and water/feeding areas each morning and evening. He works hard to traverse the often steep terrain that they life in, and has to be able to survive predator attacks, hunters and climatic conditions. This is going to result in an animal that is hardier, and tougher. And hard work builds heavier bone. Evolution and survival of the fittest have taken care of the rest.
As a comparison, think about the ancient and medieval soldiers and archers. Archeologists are able to determine which skeletons belonged to which army personnel just by the density of bone in the archers' drawing shoulder and arms. These archers practiced with their bows every day of their lives to build up their strength and skill. This extra work resulted in heavier bone in their drawing side compared to their bow hand side.
Hope this helps. There may be better or more scientific answers to your question, but this has been my conclusion to this same question after reading that article on the elk bone penetration experiment some 15 odd years ago.
