Cow milk

cow_milk_ft

Cow milk

Milk is the only food of the young mammal during the first period of its life. The substances in milk provide both energy and the building materials necessary for growth. Milk also contains antibodies which protect the young mammal against infection. A calf needs about 1000 litres of milk for growth, and that is the quantity which the primitive cow produces for each calf. 

cow_milkThere has been an enormous change since man took the cow into his service. Selective breeding has resulted in dairy cows which yield an average of more than 6000 litres of milk per calf, i.e. six times as much as the primitive cow. Some cows can yield 14000 litres or more.

Before a cow can start to produce milk she must have calved first. Heifers reach sexual maturity at the age of seven or eight months but are not usually bred until they are 15 – 18 months old. The period of gestation is 265 – 300 days, varying according to the breed of cow, so a heifer produces her first calf at the age of about 2 – 2.5 years.