In a nutshell
Even the short answer is a bit complicated: oxen and cows are both cattle, but not all cattle are cows and oxen. The umbrella term for the animal is “cattle” (or cattle), while cows and oxen play a specific role under this umbrella. Oxen are work animals, while cows are females kept solely for their milk or meat production and their breeding potential.
The whole bushel
Cattle is the term that includes all cattle, regardless of age, sex and purpose. Interestingly, recent DNA studies have shown that the roughly 1.5 billion cattle populating the world as of 2013 come not only from the same area – today’s Iran – but also from the same small herd of around 80 animals. These animals were a creature (now extinct) called aurochs, a type of wild bovine that is much larger than most cattle today. While they once stretched across Europe, Asia, and North Africa, they were also hunted frequently, and the numbers suffered greatly from forced competition with pets. They were slowly being threatened with extinction, and the last specimens died in Poland in 1
While herds were once countless, it is believed that due to the simple idea of mobility, only the only Iranian herd was ever domesticated. Most early humans lived a more nomadic lifestyle than ranching would allow; Peoples in the Middle East who settled in permanent territories were able to selectively breed the aurochs, creating the basis for the breeds we know today. At the time of the spread of the cattle there was already a clear difference between the wild aurochs and the domesticated cattle.
Oxen exist under the umbrella of cattle and are animals that have been trained to either work in the fields or to pull things by yoke and collar. Any breed of cattle can be trained as an ox, but larger, stronger animals are generally selected. Oxen are usually male animals as they rely on their size and strength in their work. Large horns also play a role in the ox’s ability. When the animal withdraws, the large, sturdy horns prevent the yoke from loosening over their heads.
While any cattle can be an ox, some breeds or individuals are better suited to the task. In addition to size and strength, those who want to train oxen also look for the animal’s intelligence, willingness to learn, and personality.
Oxen are some of the largest cattle in general, but that’s not because of the breed. Most male cattle that have not been selected for training (or breeding) are killed for their meat before they reach full size. Continued training of ox also helps in building muscle mass and overall size. Horns will continue to grow throughout the ox’s life. One team of oxen believed to be some of the largest ever bred were Granger and Mt. Katahdin; These 1930s Maine oxen weighed a total of 4,450 kilograms when fully grown.
Cows are female cattle that have had calves or are older than 2.5 years. (Younger female cattle that have not yet given birth are called heifers.) In many agricultural areas, cows have historically and often been trained as oxen. In this way, the family has a single animal that can not only plow their fields, but also multiply and provide milk. In addition, cows can continue to be bred while they are used as oxen. This allows the farmer to choose substitute labor born from his own animals, rather than buying new males (used only for training) to replace the current labor team when they have ages beyond their useful years. Cows that serve more than one purpose generally stay smaller than oxen, but can ultimately be more efficient for smallholders.
Show me the proof
Aurochs –Bos primigenius
PBS Nature: Holy Cow
Wired: cattle DNA traces back to a single herd of wild oxen
The Prairie Ox Drovers: Ox Issues