How do cows continue to produce milk?

Answer 1

Think of it like this as long as you keep on using the human breasts for milk it will keep on producing the milk same thing for a cow as long as you keep on using its nipples for milk it will keep on producing the milk just like a human can.

However, this in itself is not completely fool-proof. Most cows will start to decrease in milk production after the first few months of giving birth to a calf. To maximize the amount of milk that a cow produces, a dairy producer considers it pertinent to rebreed that cow so that she calves 11 to 12 months later. Thus, the other answer to this question is not only are cows able to keep producing milk by being milked regularly (not constantly), but also by being able to give birth to a calf once a year.

Answer 2

They continue to produce as long as the demand is there, whether it's from the suckling calf, the milking machine or the person hand-milking the cow. Every time the udder is stripped of milk, the alveoli of the udder are told by the body of the cow to keep producing more. The alveoli don't stop when the udder's full either, they'll keep collecting nutrients from the bloodstream to produce milk and secrete regardless whether the cow's udder is painfully full or not. However, if a cow's udder is continuously full there's a time where the alveoli do slow in production, and continue to slow if the udder is not emptied at all.

To understand how cows produce milk, see the related question below.