A finishing pig is a hog in its final growth stage before slaughter, typically weighing between about 50–60 pounds at entry and reaching a market weight of around 280 pounds. This phase lasts 115 to 120 days (roughly 16 to 17 weeks) and represents the bulk of a pig’s life on a commercial farm. By the time a pig reaches market age of about six months, the finishing phase alone accounts for more than half of that timeline.
Where Finishing Fits in the Pig’s Life Cycle
A market pig’s life spans about 25 to 28 weeks. After birth, piglets spend their first few weeks nursing before being weaned. They then move into a nursery, where they grow to 50 or 60 pounds. Once they hit that weight, they’re transferred to a finishing barn, a larger facility designed to accommodate rapid growth. The entire goal of the finishing phase is simple: convert feed into lean muscle as efficiently as possible until the pig reaches the weight packers want.
The current national average live weight for market hogs in the U.S. is about 289 to 291 pounds, based on USDA weekly reports. That number has crept upward over the decades as genetics and nutrition have improved.
How Fast Finishing Pigs Grow
During finishing, pigs gain roughly 1.9 to 2.0 pounds per day. That rate stays fairly consistent across the phase but does slow slightly as pigs get heavier. A pig in the 240–250 pound range gains about 1.97 pounds daily, while one approaching 280 pounds gains closer to 1.92 pounds.
What changes more noticeably is feed efficiency. A 245-pound pig converts feed to body weight at a ratio of about 3.5 pounds of feed per pound of gain. By 275 pounds, that ratio climbs to roughly 4.1, an 18% drop in efficiency. This is why producers watch market timing closely. Every extra week in the barn costs more feed per pound of pork produced, and at some point the economics tip against keeping the pig any longer.
What Finishing Pigs Eat
Finishing diets are corn-and-soybean-meal based in most of the U.S., formulated to deliver the right balance of energy and protein for each sub-phase of growth. Producers typically split finishing into early and late stages, adjusting the diet as the pig matures.
Early finishing rations contain around 14 to 15% crude protein, while late finishing diets drop to roughly 12 to 13%. The amino acid lysine, which drives lean muscle growth, is the nutrient producers pay closest attention to. Early finishing diets include about 0.82% total lysine, dropping to around 0.60% in late finishing as the pig’s rate of muscle deposition naturally slows and fat deposition increases. Energy levels stay relatively stable throughout, keeping pigs eating consistently without excessive fat gain.
Water Needs
Finishing pigs drink 4 to 10 liters of water per day (roughly 1 to 2.5 gallons), with intake increasing as the pig grows and as barn temperatures rise. Adequate water flow is essential because even mild dehydration reduces feed intake, which slows growth. Most finishing barns use nipple-style drinkers mounted at shoulder height, with producers checking flow rates regularly to make sure larger pigs can drink enough.
Temperature and Housing
Pigs can’t sweat, so barn temperature has a direct effect on growth performance. Finishing pigs are comfortable in a range of about 50°F to 75°F. Below 50°F, they burn extra calories generating body heat. Above 75°F, they eat less to avoid overheating, and growth slows. Larger finishing pigs are more cold-tolerant than younger pigs (which need 61°F to 81°F) because their greater body mass generates more metabolic heat.
Finishing barns are typically long, enclosed buildings with mechanical ventilation systems that adjust airflow based on temperature. Producers manage curtains, fans, and heaters to keep pigs within that comfort zone year-round. In summer, cooling systems like sprinklers or cool cells become critical, especially in southern climates.
All-In, All-Out Management
The standard approach in modern finishing is called all-in, all-out (AIAO). Instead of continuously adding new pigs to a barn, producers fill an entire building with one group of similar-aged pigs. That group stays together until every pig ships to market. Then the barn is emptied, cleaned, and sanitized before the next group arrives.
This system exists primarily to break disease cycles. When pigs of different ages share a building, older animals can harbor infections that spread to younger, more vulnerable ones. Keeping groups separated, ideally in distinct air spaces with no nose-to-nose contact between pens, eliminates that transmission route. AIAO systems have consistently been shown to improve daily gain and feed efficiency by 5 to 10% compared to continuous-flow barns, which means the health benefits translate directly into economic ones.
Common Health Problems
Finishing pigs face two main categories of disease: respiratory and digestive. Respiratory issues are the bigger concern because pigs are housed in enclosed barns where airborne pathogens spread easily.
The most routine respiratory problems include infections caused by Mycoplasma (a bacterial lung infection that causes chronic coughing), circovirus-associated disease, and several bacterial pneumonias. Swine influenza and PRRS (porcine reproductive and respiratory syndrome) are also common. These diseases often layer on top of each other. A pig might pick up a mild viral infection first, which weakens its lungs enough for bacteria to move in and cause a more serious pneumonia.
On the digestive side, swine dysentery is the most frequent issue, causing bloody diarrhea and significant weight loss. Ileitis (an inflammation of the lower intestine), salmonella infections, and gastric ulcers also occur regularly. Ulcers in particular can develop quickly in finishing pigs fed finely ground diets or pigs under stress from overcrowding or temperature swings.
Vaccination programs, ventilation management, and the AIAO system described above are the primary tools for keeping these diseases in check. When respiratory disease does break out in a finishing barn, the economic impact comes less from death loss and more from reduced feed efficiency and slower growth, meaning pigs take longer and cost more to reach market weight.
Why the Finishing Phase Matters Most Economically
Feed accounts for roughly 60 to 70% of the total cost of raising a market pig, and the vast majority of that feed is consumed during finishing. A pig eats relatively little during its first few weeks of life, but by the end of finishing it may be consuming 7 to 8 pounds of feed per day. Small improvements in feed efficiency during this stage, whether from better genetics, precise nutrition, or disease prevention, have an outsized impact on profitability.
This is also why the finishing phase gets the most attention from producers and nutritionists. The decisions made here, when to adjust the diet, how to manage barn temperature, when to ship, determine whether a pig operation makes money or loses it.