A bull is an intact (i.e., not castrated) adult male of the species Bos taurus (cattle). More muscular and aggressive than the females of the same species (i.e. cows proper), bulls have long been an important symbol in many religions, including for sacrifices. These animals play a significant role in beef ranching, dairy farming, and a variety of sporting and cultural activities, including bullfighting and bull riding.
Due to their temperament, handling of bulls requires precautions.
Nomenclature
The female counterpart to a bull is a cow, while a male of the species that has been castrated is a steer, ox, or bullock, although in North America, this last term refers to a young bull. Use of these terms varies considerably with area and dialect. Colloquially, people unfamiliar with cattle may also refer to steers and heifers as "cows", and bovines of aggressive or long-horned breeds as "bulls" regardless of sex.
A wild, young, unmarked bull is known as a micky in Australia. Improper or late castration on a bull results in him becoming a coarse steer, also known as a stag in Australia, Canada, and New Zealand. In some countries, an incompletely castrated male is known also as a rig or ridgling.
The word "bull" also denotes the males of other bovines, including bison and water buffalo, as well as many other species of large animals, including elephants, rhinos, seals and walruses, hippos, camels, giraffes, elk, moose, whales, dolphins, and antelopes.
Characteristics
Bulls are much more muscular than cows, with thicker bones, larger feet, a very muscular neck, and a large, bony head with protective ridges over the eyes. These features assist bulls in fighting for domination over a herd, giving the winner superior access to cows for reproduction. The hair is generally shorter on the body, but the neck and head often have a "mane" of curlier, wooly hair. Bulls are usually about the same height as cows or a little taller, but because of the additional muscle and bone mass, they often weigh far more. Most of the time, a bull has a hump on his shoulders.
In horned cattle, the horns of bulls tend to be thicker and somewhat shorter than those of cows, and in many breeds, they curve outwards in a flat arc rather than upwards in a lyre shape. It is not true, as is commonly believed, that bulls have horns and cows do not: the presence of horns depends on the breed, or in horned breeds on whether the horns have been disbudded. (It is true, however, that in many breeds of sheep only the males have horns.) Cattle that naturally do not have horns are referred to as polled, or muleys.
Castrated male cattle are physically similar to females in build and horn shape, although if allowed to reach maturity, they may be considerably taller than either bulls or cows, with heavily muscled shoulders and necks.
Reproductive anatomy
Bulls become fertile around seven months of age. Their fertility is closely related to the size of their testicles, and one simple test of fertility is to measure the circumference of the scrotum; a young bull is likely to be fertile once this reaches ; that of a fully adult bull may be over . Bulls have a fibroelastic penis. Given the small amount of erectile tissue, little enlargement occurs after erection. The penis is quite rigid when not erect, and becomes even more rigid during erection. Protrusion is not affected much by erection, but more by relaxation of the retractor penis muscle and straightening of the sigmoid flexure. Bulls are occasionally affected by a condition known as "corkscrew penis". The penis of a mature bull is about 3–4 cm in diameter, and 80–100 cm in length. The bull's glans penis has a rounded and elongated shape.
Misconceptions
A common misconception widely repeated in depictions of bull behavior is that the color red angers bulls, inciting them to charge. In fact, like most mammals, cattle are red–green color blind. In bullfighting, the movement of the matador's cape, and not the color, provokes a reaction in the bull.
Management
Beef production
Other than the few bulls needed for breeding, the vast majority of male cattle are castrated and slaughtered for meat before the age of three years, except where they are needed (castrated) as work oxen for haulage. Most of these beef animals are castrated as calves to reduce aggressive behavior and prevent unwanted mating, although some are reared as uncastrated bull beef. A bull is typically ready for slaughter one or two months sooner than a castrated male or a female, and produces proportionately more and leaner muscle.