各种牛
母牛 Cow: a mature female bovine that has given birth to at least one or two
calves. Colloquially, the term "cow" is also in reference to the Bos
primegenius species of domestic cattle, regardless of age, gender, breed or
type. However for most people who work with or raise cattle, this term is
not used in the same reference as previously noted.
Bull: a mature, intact (testicles present and not removed) male bovine used
for breeding purposes.
幼年入宫阉公牛（肉用) Steer: a male bovine (or bull) that has been castrated
before reaching sexual maturity and is primarily used for beef.
青年入宫阉公牛(肉用) Stag: a male bovine (or bull) that has been castrated
after or upon reaching sexual maturity and is primarily used for beef, but
can and is also often used as a "gomer bull" for detecting cows and heifers
in heat.
少女牛 Heifer: a female bovine (often immature, but beyond the
"calf" stage) less than 1 to 2 years of age that has never calved. Such
females, if they've never calved beyond two years of age may also be called
heiferettes.
头胎孕妇牛 Bred Heifer: a female bovine that is pregnant with her first
calf.
独生子女家长母牛 First-calf Heifer or First-calver: a female bovine that has
given birth to her first calf, and is often around 24 to 36 months of age,
depending on the breed and when she was first bred.
苦力牛（以男牛为主） Ox (plural: Oxen): a bovine that is trained for draft
work (pulling carts, wagons, plows, etc.)This is a term that primarily
refers to a male bovine that has been castrated after maturity. However, an
ox can also be female bovine (cow or heifer) or even a bull that has been
trained for the same purpose. In the Biblical times, an ox was a general
term used, just like with the term "cows," to a domesticated bovine
regardless of age, gender, breed, type, or draft purposes.
婴儿牛（吃奶牛） Calf (plural: Calves): an immature bovine (male and
female) that is reliant on milk from its dam or from a bottle in order to
survive and grow. A calf is known as such from birth to around 10 months of
age.
Bull calf: an immature intact male bovine (since all males are born with
testes) that is reliant on milk from his dam or a bottle for growth and
survival.
太监婴儿牛 Steer calf: an immature male bovine that has been castrated a few
days to a couple months after birth, and is reliant on milk from his dam or
a bottle for growth and survival.
少女婴儿牛Heifer calf: an immature female bovine that is reliant on milk
from her dam or a bottle for growth and survival.
（龙凤胎）不孕少女牛 Freemartin: an infertile or sterile heifer or heifer
calf. Such infertility is a result of being maternally twinned with a bull
calf which placental tissues were shared in the womb. During the first
trimester, reproductive organs start to form and sexual hormones begin to be
produced in the fetus. When male and female fetal calves are twinned
together, the testosterone produced by the male inhibits estrogen production
in the female. This results in abnormal, underdeveloped or hermaphroditic
reproductive organs in the female fetus. This is not so for the male.
Freemartins are sometimes referred as "hermaphrodites" if they are born with
reproductive organs of both genders. As a result, these type of freemartins
tend to develop secondary male sexual characteristics (muscular crest over
neck, wide forehead, etc.) upon reaching puberty.
牛 （复数） Cattle: general plural term for more than one bovine
牛 （单数） Cattlebeast/bovine/animal: a singular term for a bovine whose
gender cannot be determined, particularly when viewed at a distance. Most
people like to call a bovine of unknown (or "unknown") gender as a "cow,"
simply because it is a much more well-known and popular term to use than "
bovine" or "cattle beast." This, however, is often not the case around
experienced cattlemen and cattle women or "ranchers" (as some like to call
them) who never use the term "cow" when referring to a bovine that is
anything but a cow. "Animal," "critter," "creature," or any other term,
coarse or not, are most often used over the colloquial word "cow."
