Although not an industry that many people think about on a daily basis (or even an annual basis for that matter), reproduction truly is the basis for all our food production, as well as for genetic improvement that allows our current food needs to be met.
Consider, 604 pounds of dairy products are consumed by each person in the U.S. every year. All the required milk is produced by cows.
Cows must be pregnant every year to give milk! There are about 9 mm cows in the U.S. This number has remained relatively constant for the past 10 years. This means that every cow produces more milk per year, an increase due to improved genetics.