Cows’ meat is well marbled, but why?

When I eat beef, I place the most importance on whether it is cow or not.

Compared to oxen meat, the mouthfeel of cow’s one is tenderer, and its meat looks more marbled. Moreover, the melting point of cow’s meat is lower than that of oxen’s one since cow’s meat contains more unsaturated fatty acid.

The taste and smell are remarkedly better than those of oxen meat.

However, the reason why cows’ meat is marbled is poorly known.
Cows have uterus. Storing fat in order to protect the uterus is the lows of nature.

women tend to put on fat more than men, don’t they?
Compared to muscular men, women’s body contains more subcutaneous fat and the same is true of beef.
In the first place, why In the first place, why do cows grow such larger and put on fat, although they are herbivores?

In stomachache, cows as well as horses have micro-organisms, which is essential to convert a bunch of plants and vegetables into muscles. 
Surprisingly, cows have four tripes. In the tripe that what they feed enters at first, micro-organisms are active, which ferment and digesting hay to absorb as a nutritient. 

This is how cows keep their large body active and alive. 
How amazing cows are and so is yummy!!!