Note that the greatest part of total fat is seam fat located between the muscles. The actual total amount of fat on different animals varies greatly. Differences in fatness are due to plane of nutrition, genetic potential, age and sex. Obviously, among genetically similar cattle the more feed and the better the feed the fatter the cattle become. There are also great differences in total fatness on the same feed among cattle that are different genetically.
Age has a great effect and in general as cattle grow older they become fatter.
Variations in fat also occur due to sex and among cattle genetically similar, of the same age and treated alike, heifers are fatter than steers and steers fatter than bulls. Not only are there large differences in total fatness but also great variation in the percentage of total fat found in the four major depots. For example, dairy cattle generally deposit less subcutaneous fat and show a major increase in the internal messenteric and KPH fat while British breeds have a higher percentage of total fat as subcutaneous deposits. There is one more site for fat deposition. This site is within the muscles and is known as marbling.