6 DEPARTMENT BULLETIN 1360, U. S. DEPT. OF AGRICULTURE 
A Slaughter animal is one that is intended for immediate slaughter 
or that is more suitable for slaughter than for any other purpose. 
A Feeder animal is one that is intended for intensive feeding in 
preparation for slaughter or one that is more suitable for that pur- 
pose than for any other ; also one that is on feed. 
A Stocker animal is one that is intended for further growth by pas- 
turing and rough feeding or one that is more suitable for that pur- 
pose than for any other. 
A Milker is a cow that is giving milk and usually is one that has 
calved recently. 
A Springer is a pregnant cow or heifer that is due to calve within 
a short time. 
Breeders are those animals that are suitable and are intended 
primarily for reproduction purposes. The term is commonly as- 
sociated with market ewes that are intended for reproduction pur- 
poses. 
Shearers are sheep or lambs that have a good growth of wool and 
that are purchased primarily for shearing before they are used for 
slaughter or other purposes. 
CLASSES 
The market class for any kind of livestock is determined by its sex 
or sex condition. The classes for Cattle are: Steer. Heifer, Cow, 
Bull, and Stag; for Sheep: Ewe. Wether, and Ram; and for Swine; 
Barrow, Gilt, Sow, Boar, and Stag. 
AGES 
Market animals generally are sorted or grouped according to 
approximate ages because many of the essential characteristics that 
affect values are associated with the different general ranges in ages, 
such as Vealers, Calves, Yearlings, and 2- Year-Olds in Cattle; as 
Spring Lambs, Lambs, Yearlings, and Mature Sheep in Sheep; or as 
Pigs and Hogs in Swine. The age groups indicate approximate ages 
only, since exactness in this respect is not feasible or material. 
WEIGHTS 
Market animals generally are grouped according to relatively 
narrow weight ranges because market values often vary materially 
with variations in weights. The principal object of grouping market 
animals within relatively narrow weight ranges is to offer the approx- 
imate weights usually desired by the prospective purchasers and thus 
materially facilitate trading. (See various classification schedules 
for usual weight ranges.) 
GRADES 
Grade is the final subdivision in a classification for marketing any 
kind of livestock and indicates the relative degree of excellence of an 
animal or group of animals. The standard grade prescribes a rela- 
tively narrow but fixed band or segment of the full range of excellence 
from the very best to the very poorest. The number of grades vary 
with the different kinds, classes, ages, and weights of livestock and 
