Kosher meat must comply with certain rules.
Kosher Species of Animals:
According to the laws of the Torah, the only types of meat that may be eaten are cattle and game that have “cloven hooves” and “chew the cud.” If an animal species fulfills only one of these conditions (for example the pig, which has split hooves but does not chew the cud, or the camel, which chews the cud, but does not have split hooves), then its meat may not be eaten.
Examples of kosher animals in this category are bulls, cows, sheep, lambs, goats, veal, and springbok.
According to the laws of the Torah, to be eaten, a kosher species must be slaughtered by a "Schochet," a ritual slaughterer.
Since Jewish Law prohibits causing any pain to animals, the slaughtering has to be effected in such a way that unconsciousness is instantaneous and death occurs almost instantaneously.
There are also other processes and restrictions after death.
http://www.koshercertification.org.uk/whatdoe.html