Pigs, commonly called hogs in the farming industry, are raised for their meat, which is sold in the form of ham, bacon, tenderloins, spare ribs and various cuts of pork. Hog farmers may breed their own hogs from a boar and sow or purchase young pigs to finish preparing them for market. A hog is ready for slaughter when it has reached a target weight, usually set by the slaughtering houses. The hog's age will vary slightly depending upon its feed and genetics, but it typically reaches slaughter weight at around 24 to 29 weeks.
A healthy piglet weighs 3 to 3.5 pounds at birth. The heavier the piglet, the greater its chances of survival. Smaller piglets tend to get kicked, crushed or crowded out when the piglets nurse. They also lose body heat more rapidly than heavier piglets and suffer from more ailments. The heaviest piglets usually gain weight the fastest, reaching the target slaughtering weight at a younger age. All piglets, regardless of size, normally nurse for two to three weeks before progressing to the next stage.
After two to three weeks, the farmer weans the piglets and separates them from the sow in a hog confinement. They are given an unlimited food supply comprised of around 18 per cent protein for approximately six weeks, or until they are 9.07 to 27.2 Kilogram. A 40 pound pig is usually sought if it will be moved to an outdoor confinement for the next stage. The purpose of this phase is to grow the pigs to a healthy weight without fattening them rapidly like a finishing hog. Pigs usually reach the weight of a feeder pig at around eight to nine weeks old.
Pigs that are still in the growth stage and that weigh approximately 40 to 125 pounds are called feeder pigs. They remain in this stage for approximately seven to eight weeks, during which time the protein level of their feed is dropped to around 16 per cent. Due to the hog's favourable rate of feed conversion and the proportionally higher levels of carbohydrates, the feeder hog can gain a pound and a half per day or more. By the time they are 15 to 17 weeks old, they have reached the proper weight to enter the finishing stage.
The goal of the finishing stage is to quickly fatten the hogs to slaughter weight. This weight varies according to slaughterhouse in question, but usually averages 240 to 270 pounds. When the hog farmer brings in animals at weights above or below this range, he can incur an additional fee. During this stage, the hogs' rations are reduced to 14 per cent protein or less. The proportionally higher carbohydrate levels, combined with the unlimited availability of feed, brings the hogs to slaughter weight by the age of 24 to 29 weeks old.