In the animal kingdom, the general term gland falls into two major categories with further subtypes falling under each of these.
An Exocrine gland is distinguished by the fact that it excretes its essential product by way of a duct to some environment external to itself, be it either inside the body or on a surface of the body.
Secondary sex characteristics are features that appear during puberty, especially those that distinguish the two sexes of a species, but that are not directly part of the reproductive system. They are believed to be the product of sexual selection for traits which give an individual an advantage over its rivals in courtship and aggressive interactions.]citation needed[ They are distinguished from the primary sex characteristics — the sex organs — which are directly necessary for reproduction to occur.
Well-known secondary sex characteristics include manes of male lions and long feathers of male peacocks. Other dramatic examples include the tusks of male narwhals, enlarged proboscises in male elephant seals and proboscis monkeys, the bright facial and rump coloration of male mandrills, and horns in many goats and antelopes. Male birds and fish of many species have brighter coloration or other external ornaments. Differences in size between sexes are also considered secondary sexual characteristics.
The anatomy of the human breast was fundamentally revised in 2005, overturning assumptions held since 1840.
The standard model of the human breast is largely based on anatomical dissections carried out on cadavers by Astley Cooper and published in 1840 under the title “Anatomy of the Breast”.
Dairy farming is a class of agricultural, or an animal husbandry, enterprise, for long-term production of milk, usually from dairy cows but also from goats, sheep and camels, which may be either processed on-site or transported to a dairy factory for processing and eventual retail sale.
Most dairy farms sell the male calves born by their cows, usually for veal production, or breeding depending on quality of the bull calf, rather than raising non-milk-producing stock.]citation needed[ Many dairy farms also grow their own feed, typically including corn, and hay. This is fed directly to the cows, or is stored as silage for use during the winter season.