Runt, an unusually small and weak piglet, often one in a litter Boar or hog, male pig of breeding age Barrow, male pig castrated before puberty Stag, male pig castrated later in life (an older boar after castration) Gilt, young female not yet mated, or not yet farrowed, or after only one litter (depending on local usage). Sow, breeding female, or female after first or second litter Pigs for slaughter Suckling pig, a piglet slaughtered for its tender meat Feeder pig, a weaned gilt or barrow weighing between and at 6 to 8 weeks of age that is sold to be finished for slaughter Porker, market pig between and about dressed weight Baconer, a market pig between and dressed weight. The maximum weight can vary between processors. Grower, a pig between weaning and sale or transfer to the breeding herd, sold for slaughter or killed for rations. Finisher, a grower pig over liveweight Butcher hog, a pig of approximately , ready for the market. In some markets (Italy) the final weight of butcher pig is in the range. They tend to have hind legs suitable to produce cured ham Backfatter, cull breeding pig sold for meat; usually refers specifically to a cull sow, but is sometimes used in reference to boars Groups Herd, a group of pigs, or all the pigs on a farm or in a region Sounder, a small group of pigs (or wild boar) foraging in woodland Pig parts Trotters, the hooves of pigs (they have four hoofed toes on each foot, walking mainly on the larger central two) Biology In pig, pregnant Farrowing, giving birth Hogging, a sow when on heat (during estrus) Housing Sty, a small pig-house, usually with an outdoor run or a pig confinement Pig-shed, a larger pig-house Ark, a low semi circular field-shelter for pigs Curtain-barn, a long, open building with curtains on the long sides of the barn. This increases ventilation on hot, humid summer days Environmental and health impacts Feces and waste often spread to surrounding neighborhoods, polluting air and water with toxic waste particles. Waste from swine on these farms carry a host of pathogens and bacteria as well as heavy metals. These toxins can leach down through the soil into groundwater, polluting local drinking water supplies. Pathogens can also become airborne, polluting the air and harming individuals when ingested. Contents from waste have been shown to cause detrimental