Characteristics of cows include their large size, boxy body type and calm temperament. They have bulky, long bodies with relatively small heads. Cows can weigh more than 2,000 pounds, but height and weight can vary significantly between breeds.
Physical traits, including color and ear placement, also vary between cow breeds. They have good peripheral vision to detect the approach of predators, and they can hear sounds at a high pitch. The average natural lifespan of cows is 25 years, but many are killed by the age of 3 as part of modern farming practices.
Cows feed mostly on grass and stems. When they eat, they curve their tongue around a plant and slice it with their bottom teeth. They are ruminants and have stomachs with four chambers to digest fibrous plants. Bacteria break down the plant material in their stomach to create cud, which re-enters the throat so the cow can chew it again. Total digestion time for a cow can be as much as 100 hours.
Research at Northampton University in 2011 indicates that cows' emotions may be deeper than previously thought. Cows can form social relationships and are typically calm and peaceful. However, the research notes they can also be aggressive bullies. Mother cows are often extremely protective of their calves, and many cows are curious about new things but afraid at the same time.