How many glasses of milk does a cow give during her lifetime?

The average California cow produces 19,825 pounds of milk each year, more milk per cow than any any other state in the nation. That's 2,305 gallons of milk a year or about 8 gallons of milk every day of her milking period. That’s enough for 128 people to have a glass of milk every day!

http://www.moomilk.com/faq/1-cow-faqs/5-how-much-milk-do-cows-produce

The average dairy cow produces 22.5 quarts (60lbs) or 90 glasses of milk a day, 1,500 gallons or 16,000 glasses of milk a year, and 18,750 gallons or 200,000 glasses of milk in a lifetime.

The average dairy cow is milked for 20 minutes from start to finish, and they are milked 2-3 times a day. This is actually a relief on the dairy cows, considering the avery dairy cows udder can hold 25-50 pounds of milk.

The dairy cow can not be milked until after it is a mother. Pregnancy is what causes the cow to produce milk. After carrying for 9 months (full term), the calf is born. Within one hour they can walk on their own, and are taken from their mothers to be bottle raised. 12 hours after giving birth a dairy cow is milked for the first time.

https://www.dairymoos.com/how-much-milk-do-cows-give/