By Scout Nelson
A dairy cow begins producing milk shortly after giving birth, continuing for about 300 days before resting. This period, called the lactation cycle, is divided into four important phases, each playing a key role in milk yield and cow health.
Early lactation begins around two weeks after calving and lasts up to 100 days. Milk production rises quickly and reaches its peak between 40 to 70 days. Younger cows often peak later, between 70 and 100 days, and their milk curve is more persistent compared to mature cows. However, cows face negative energy balance during this stage since milk output is higher than their dry matter intake.
To meet energy demand, cows may lose weight. Body condition scoring (BCS) helps monitor this loss, where one score equals about 120 pounds. Ideally, cows should not lose more than 0.5 BCS, or around 60 pounds. Peak milk is a key indicator of total yield, and the “200 rule” suggests multiplying peak milk by 200 to estimate lactation output.
Mid lactation, from 100 to 200 days, is when cows maintain milk production while slowly increasing feed intake. Nutrition plays a vital role here, as rapid declines in milk yield may indicate inadequate diets. Cows regain some weight during this stage.
Late lactation, between 200 and 305 days, sees a gradual decline in milk production and feed intake. At this point, cows build body reserves and support the growth of the developing fetus. They should not gain more than 0.5 BCS during this phase.
Finally, the dry period follows after about 305 days. This resting stage lasts 45 to 60 days, allowing the cow, especially the mammary gland, to recover. It also supports fetal growth and prepares the cow for the next calving and lactation cycle.
Photo Credit: gettyimages-digitalvision
Categories: Minnesota, Livestock, Dairy Cattle