Only female cattle, known as cows, produce milk. The common use of “cow” to refer to any cattle can lead to misconceptions. Precise terminology clarifies the roles of different animals within a herd.
The Biological Imperative of Lactation
Lactation is a biological function in female mammals, including cattle, designed to provide nourishment for their young. It is linked to pregnancy and calving. Mammary glands, commonly referred to as the udder in cows, develop and mature during pregnancy. They contain millions of tiny structures called alveoli, which are responsible for synthesizing and secreting milk.
After a cow gives birth, hormonal changes occur that trigger and sustain milk production. Hormones like prolactin, released by the pituitary gland, stimulate the alveolar cells to produce milk. Oxytocin, another hormone, is released in response to suckling by a calf or mechanical milking, causing the muscle cells around the alveoli to contract and eject milk into the ducts, a process known as milk let-down. The continuous removal of milk helps maintain consistent production.
Understanding Cattle Terminology
Specific terminology for cattle clarifies their roles and characteristics. A “cow” refers to an adult female bovine that has given birth to at least one calf. Before she has her first calf, a young female is called a “heifer.”
In contrast, an intact adult male bovine is known as a “bull,” primarily kept for breeding purposes. A male bovine that has been castrated, meaning his testicles have been removed, is called a “steer.” Steers are raised for beef production. Young cattle of either sex are referred to as “calves.”
The Place of Male Calves in Dairy Operations
Male calves born on dairy farms do not produce milk and therefore have different roles within the agricultural industry. These calves are considered surplus to the dairy operation’s primary goal of milk production. Their common fates include being raised for beef, utilized for veal production, or, in some cases, a small percentage may be kept as breeding bulls.
Male dairy calves intended for beef are separated from their mothers shortly after birth and transported to other farms for rearing, where they are fed to gain weight for slaughter. Others may be raised for veal, a process that involves specialized feeding and housing to produce tender meat. While their role is distinct from milk production, male calves are an integrated part of the broader cattle industry, contributing to meat markets.