No. Dairy cows, such as Jersey, Holstein and Swiss brown, are capable of giving milk for more than two years after the calf is born. “The exact time will depend on the genetic characteristics of each animal”, says veterinarian Alexandre Vaz Pires, from Esalq. In beef cows, milk production decreases from the third month after the birth of the calf. By the seventh month, they produce very little liquid.
But why, then, is the answer “no”? Because the period of milk production can be prolonged thanks to the physical stimulus that the cow receives when being milked.
So let’s go, step by step. When the calf is born, the mother cow starts producing milk. After 60 days, on average, the puppy is weaned. This is where the function of frequent milking comes in: when the breast is pressed, a message is sent to the cow’s brain, stimulating the pituitary gland, which releases a hormone called oxytocin. This substance reaches the breast through the bloodstream, contracting the muscle fibers and leading to the release of more milk. To slow down and stop milk production, just stop milking the animal.
That is, during this period, she does not need to be pregnant, just well fed, healthy and raised in good environmental conditions, explains Sandra Gesteira Coelho, veterinary doctor and professor of the Dairy Cattle discipline at the UFMG Veterinary School.
A final reminder: cows that produce milk spend a lot of their lives pregnant, yes. On dairy farms, animals are re-inseminated an average of 60 days after each calving, and they tend to give birth an average of once a year. In this scheme, of the 12 months of the year, a cow produces milk for ten (during suckling and then stimulated by milking), stays still for 2 months and becomes pregnant with a new calf. Then the cycle starts again.