Pregnancy causes a marked decrease in persistency compared to open cows. Lactation curves of milk yield and milk fat and protein percentages of Holstein cows. D. Age and size of cow 1. Milk yield increases at a decreasing rate until about the eighth year of age. E. Estrous cycle and pregnancy 1.
Pregnancy reduces milk production during concurrent lactation.
For example, a cow bred at 90 days postpartum produces 750-800 lb. Hypothetical Relationships between Calving Interval, Number of Calves Born and Lifetime Milk Production for Cows Remaining in the Herd for 48 Months. Diagram of the lactation curve of a dairy cow. Cow A is not pregnant. Cow B is pregnant.