Swine Barn Layout and Pen Design

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-08-14

Key Takeaways

• Space allowance is paramount for optimal growth and welfare: Grow-finish pigs require 8-10 square feet per head, with final weight dictating the minimum. Insufficient space (crowding) directly reduces average daily gain and increases the incidence of tail biting, a significant welfare and economic concern.
• Pen dimensions and shape influence pig behavior and flow: A length-to-width ratio near 2:1 promotes better pig movement and reduces dead corners, while rectangular pens are generally preferred over square ones to mitigate social stress and resource competition.
• "All-in, all-out" management is the gold standard for disease control: Designing barns with distinct rooms or zones that can be completely emptied, cleaned, and disinfected between groups is critical for breaking disease cycles and improving herd health and performance.
• Flooring choice impacts pig health, labor, and manure management: Fully slatted concrete floors are common for deep pit manure systems, facilitating waste removal but requiring careful slat gap management (approx. 1 inch for grow-finish) to prevent foot injuries. Partially slatted floors can reduce costs but necessitate more labor for cleaning solid areas.
• Adequate feeding and watering infrastructure is essential: A minimum of one feeder space per 3-4 pigs for dry feeders, or one wet-dry feeder per 8-10 pigs, is recommended. At least two waterers per pen, positioned away from lying areas and over slatted floors, are crucial to ensure consistent access to clean water.
• Ventilation must be integrated with barn layout for effective environmental control: Inadequate ventilation, regardless of pen design, leads to poor air quality (high ammonia, CO2, moisture), increasing respiratory disease prevalence and negatively impacting growth rates.

Planning a new swine barn or remodeling an existing one is one of the most consequential decisions you will make as a pork producer. The layout you choose affects pig health, labor efficiency, manure management, ventilation performance, and your bottom line for the next 20 years or more. This guide covers the key decisions in swine barn layout and pig pen design, including space allowances, flooring options, feeding systems, ventilation considerations, and common planning mistakes. It is written for independent farmers, herd managers, and anyone planning a new grow finish facility or renovating an older barn.

At a Glance

• Space allowance is the single most important design decision. Most grow finish pigs need 8 to 10 square feet per pig depending on final weight. Crowding reduces gain and increases tail biting.
• Pen shape matters. Rectangular pens with a length to width ratio near 2 to 1 allow better pig flow and reduce dead corners.
• All in all out is the gold standard. Design the barn so you can completely empty and clean each room or barn before restocking.
• Flooring choice affects health and labor. Fully slatted floors are the most common for grow finish barns in the United States. Partially slatted floors reduce cost but require more daily labor.
• Feeding space is critical. Provide at least one feeder space per 4 pigs for dry feeders. Wet dry feeders handle more pigs per space.
• Water is often overlooked. Provide at least two drinkers per pen and position them away from the lying area.
• Ventilation must match the layout. A good pen layout fails if the ventilation system cannot deliver fresh air to every pig.
• Plan for pig flow. Design alleys wide enough for your equipment and for moving pigs without stress.
• Write everything down. Keep a barn plan, equipment list, and maintenance log from day one.

Understanding Swine Barn Layout Fundamentals

A swine barn layout is the complete arrangement of pens, alleys, feeding systems, ventilation equipment, and manure handling components within a building. The layout determines how pigs move through the facility, how you care for them, and how the environment stays healthy. A good layout accounts for the pig's behavioral needs, the worker's daily tasks, and the long term durability of the building.

Why Layout Matters

The layout is not just about fitting the maximum number of pigs into a building. It is about matching the building to the pig's stage of life and to your management style. A layout that is difficult to clean will lead to disease buildup. A layout that crowds pigs will reduce average daily gain. A layout that places feeders in the wrong spot will cause feed waste and aggression. Every square foot of a swine barn should have a purpose.

Who This Guide Serves

This guide serves farmers who are building new, remodeling existing, or simply evaluating their current setup. The principles apply to grow finish barns, wean to finish barns, and breeding gestation facilities, though the focus here is on grow finish and wean to finish pig pen design. If you are a beginning farmer, use this guide to ask better questions of your builder and your extension agent. If you are an experienced producer, use it to check your assumptions and find small improvements that reduce labor.

Key Design Decisions Before You Pour Concrete

Before you draw a single pen, you need to make several high level decisions. These decisions interact with each other, so think through them as a system rather than in isolation.

Facility Type and Pig Flow

The first decision is what kind of facility you are building. A farrow to finish operation keeps sows and pigs through all stages. A wean to finish barn takes pigs at weaning, around 3 weeks of age, and keeps them until market weight. A dedicated grow finish barn takes feeder pigs at 40 to 60 pounds and grows them to 280 to 300 pounds.

Each facility type has different space needs. Wean to finish barns need to accommodate small pigs initially but must be designed for the final market weight. This means the space allowance is set by the final weight, not the starting weight. Grow finish barns have more flexibility because pigs arrive at a more uniform size.

The pig flow model you choose also determines how many rooms you need. All in all out management requires that a room or an entire barn be emptied at one time. This breaks disease cycles and improves growth. If you cannot fully empty a barn, you are not truly all in all out.

Building Dimensions and Pen Layout

The building footprint sets the boundaries for your pen layout. Common barn widths for grow finish facilities are 30 to 60 feet. Wider barns allow more pens per square foot of building but require more sophisticated ventilation. Narrower barns are simpler to ventilate but use land less efficiently.

A typical grow finish barn is 40 to 50 feet wide with pens on either side of a central alley. This design places the alley in the middle, with pens along both exterior walls. The central alley gives you access to every pen and shortens the distance you walk each day.

Another common layout is the "drive through" barn where the alley runs along one side and pens are all on the other side. This layout is simpler to build but requires longer reach into pens and longer travel distances for feed delivery.

Manure System Choice

The manure system is one of the first decisions because it affects the floor design and the building foundation. The three main options are deep pit, shallow pit with pull plug, and flush systems.

Deep pit storage under slatted floors is the most common in the Upper Midwest. The pit stores manure for 6 to 12 months. This reduces daily labor but requires careful management of pit gas levels and agitation at pump out time.

Shallow pits with pull plug systems store manure for a shorter period, often 30 to 60 days. The pit is drained frequently to an outside storage structure. This system allows more flexible manure application timing.

Flush systems use water to move manure from shallow gutters to an outside lagoon. They are more common in warmer climates because they add humidity to the barn air.

Your manure system choice affects the floor construction. Fully slatted floors are required for deep pit systems. Partially slatted floors work with shallow pits and flush systems. The percentage of slatted floor affects pig comfort and labor.

Space Allowance and Pen Size for Pigs

Space allowance is the most researched and most important number in pig pen design. It directly affects growth rate, feed efficiency, and behavior. The National Pork Board and university extension services have published extensive data on this topic.

How Much Space Does a Pig Need

The general rule for grow finish pigs is to provide enough floor space so that the pigs can lie down comfortably at market weight. The most commonly cited formula comes from the work of animal scientists who found that space allowance should be based on the expected final weight of the heaviest pig in the pen.

A common recommendation is 0.033 to 0.036 square meters per kilogram of body weight, which converts to roughly 8 to 10 square feet per pig at 280 pounds. For pigs marketed at 300 pounds, plan on 9.5 to 10.5 square feet per pig. For pigs marketed at 250 pounds, 8 to 8.5 square feet is adequate.

These numbers assume fully slatted floors. If you use partially slatted floors, add 5 to 10 percent more space per pig because the solid area becomes soiled more quickly.

Calculating Pen Dimensions

Once you know the space per pig, you can calculate pen dimensions. A pen for 25 pigs at 9 square feet per pig needs 225 square feet. A pen that is 9 feet wide and 25 feet long provides exactly that. A pen that is 10 feet wide and 22.5 feet long also works.

The length to width ratio matters for pig behavior. Pens that are too long and narrow create a "runway" effect where pigs at one end cannot access resources at the other end without pushing through the group. Pens that are too square create dead corners where pigs bunch up. A ratio of about 2 to 1 is a good starting point.

Group Size Considerations

Group size affects social dynamics and labor. Smaller groups of 20 to 30 pigs are easier to manage and observe. Larger groups of 50 to 100 pigs reduce building cost per pig but increase the risk of aggressive behavior and make it harder to spot sick pigs.

If you are a new producer, start with smaller groups. You can always combine pens later if you find the management is too labor intensive. Splitting a large group into smaller pens after mixing is very difficult.

Adjusting Space for Weight

As pigs grow, their space needs increase. A pig at 50 pounds needs only 4 to 5 square feet. The same pig at 280 pounds needs 9 to 10 square feet. This is why all in all out management is so important. In a continuous flow barn, you must design for the heaviest pigs at all times, which means smaller pigs have excess space early in the grow out period.

In a wean to finish barn, you have a choice. You can either provide the final space allowance from day one, which means small pigs have lots of extra room, or you can use internal gates to reduce pen size early and expand pens as pigs grow. The second approach is more efficient but requires daily labor to move gates.

Grow Finish Pen Layout

The grow finish period, from about 60 pounds to market weight, is where most commercial pork is produced. The pen layout for this stage must balance pig comfort, labor efficiency, and building cost.

The Standard Grow Finish Layout

The most common grow finish layout in the United States is a barn with a central alley and pens on both sides. Each pen is 8 to 12 feet wide and 20 to 30 feet deep, holding 20 to 40 pigs. The alley is typically 8 to 12 feet wide to allow feed delivery equipment and pig moving panels to pass.

Pens along the exterior walls have one solid wall (the exterior wall) and one or two interior walls. This arrangement gives pigs a sense of security because they have a solid wall to lie against. It also reduces drafts because the exterior wall is the source of incoming fresh air in most ventilation systems.

Feeder Placement

Feeder placement within the pen is a critical decision. The feeder should be placed along a pen partition so that pigs from two adjacent pens can share the same feeder. This reduces equipment cost and makes the feeder easier to adjust and clean.

Place the feeder so that pigs can approach it from the lying area without having to walk through the dunging area. In a fully slatted floor system, this is less critical because the entire floor is a dunging area. In a partially slatted system, place the feeder over the slatted area near the alley so that feed wastage falls into the pit rather than onto solid flooring.

Waterer Placement

Waterers should be placed away from the feeder and the lying area. Pigs tend to defecate near waterers, so placing them over the slatted floor keeps the solid area cleaner. Provide at least two drinkers per pen, spaced far enough apart that a dominant pig cannot block access to both.

Nipple drinkers should be adjusted to shoulder height of the smallest pig in the pen. Cup drinkers are easier for pigs to use but require more maintenance. The water flow rate should be at least 1 to 2 cups per minute for grow finish pigs.

Lying and Dunging Areas

Pigs have a natural tendency to separate their lying area from their dunging area. In a fully slatted floor, this distinction is less important because all waste falls through the slats. In a partially slatted floor, you need to encourage pigs to dung on the slatted area.

The key is to make the solid area comfortable for lying. Provide a solid floor that is dry and draft free. Place a heat source if the barn is cold. Pigs will quickly learn that the solid area is for resting and the slatted area is for dunging.

Pen Partitions and Gates

Pen partitions can be solid or open. Solid partitions reduce drafts and aggression between pens but limit airflow. Open partitions, such as vertical bars, allow better ventilation and social contact but can increase fighting.

Gates should be at least 3 feet wide for grow finish pigs. Larger gates make it easier to move pigs and equipment in and out. Consider a self locking gate that can be opened from the alley without entering the pen. This reduces stress on both pigs and workers.

Wean to Finish Pen Design

Wean to finish barns present a unique design challenge because the pigs arrive at 12 to 15 pounds and leave at 280 to 300 pounds. The pen must work for both the tiny pig and the market hog.

Design for the Final Weight

The most important rule in wean to finish design is to size pens for the final weight. A pen that works well for 15 pound pigs but is too small at 280 pounds will hurt performance at the end of the grow out period. This is a common mistake among new producers who try to maximize pig numbers in the early stages.

Internal Gates for Early Space Reduction

To avoid giving small pigs too much space, use internal gates that can be moved as pigs grow. When pigs arrive, use a temporary gate to block off one third of the pen. As pigs grow, move the gate back until the full pen is available.

This approach requires more labor but improves feed efficiency and reduces heating costs in the early stages. Small pigs need a warm, draft free environment. A smaller pen is easier to keep warm.

Flooring for Wean to Finish

Wean to finish barns can use either fully slatted or partially slatted floors. Fully slatted floors are simpler to manage and keep clean. However, small pigs can get their feet caught in wide slat openings. Use slats with openings no wider than 3/8 inch for the nursery phase.

Some producers use a plastic coated expanded metal floor for the nursery area and concrete slats for the grow finish area. This adds cost but reduces foot problems in small pigs.

Heating and Ventilation

Wean to finish barns need supplemental heat for the first few weeks after weaning. The room temperature should be 85 to 90 degrees Fahrenheit for newly weaned pigs, dropping gradually to 70 degrees by 8 weeks of age. This requires a heating system that can maintain even temperatures across the room.

The ventilation system must be able to provide minimum ventilation in cold weather without creating drafts at pig level. Inlet placement is critical. Air should enter above the pigs and mix with warm room air before falling to pig level.

Swine Barn Floor Plan Options

The floor plan of a swine barn determines how you move pigs, feed, and people through the building. Several common floor plans work well for grow finish production.

Central Alley Design

The central alley design has pens along both exterior walls and an alley down the middle. This is the most common design in the Midwest. It allows efficient use of floor space and short travel distances. The alley is typically 8 to 12 feet wide.

This design works well with tunnel ventilation because the air enters through the side walls and exhausts at the end of the building. The central alley can be used for feed delivery, pig movement, and daily observation.

Single Alley Design

The single alley design has all pens on one side of the building with an alley along the opposite side. This is simpler to build and allows direct access to every pen from the alley. However, it wastes space because the alley occupies a larger percentage of the building footprint.

This design is sometimes used in remodeled buildings where the existing structure limits the layout. It can work well for small herds but is less efficient for large scale production.

Double Row with Center Feed Alley

Some barns use a design with feed storage and delivery in a center alley and pens on both sides. The feed alley is wider to accommodate a feed cart or conveyor. This design reduces feed delivery time but requires more building width.

Room Divisions for All In All Out

Regardless of the floor plan, you should design the barn so it can be divided into rooms that can be completely emptied and cleaned. This is the foundation of all in all out management. Each room should have its own entrance, its own ventilation controls, and its own manure handling.

Rooms should be sized so that a room can be filled with pigs from a single source. If you buy feeder pigs, each room should hold pigs from one source. Mixing pigs from different sources in the same room increases disease risk.

Flooring Systems and Pit Design

The floor is the foundation of the pig pen. It must be durable, comfortable for pigs, and compatible with your manure handling system.

Fully Slatted Floors

Fully slatted floors are the most common choice for commercial grow finish barns. All waste falls through the slats into a pit below. This keeps the pen surface clean and reduces labor.

Concrete slats are the standard. They are durable and relatively inexpensive. Slat width is typically 5 to 6 inches with a 1 inch gap between slats. The gap should be sized to prevent pig feet from getting caught. For grow finish pigs, a 1 inch gap works well. For nursery pigs, use a 3/8 inch gap.

Plastic slats are lighter and warmer than concrete. They are easier on pig feet but more expensive. They are commonly used in nursery and wean to finish facilities.

Partially Slatted Floors

Partially slatted floors have a solid concrete area for lying and a slatted area for dunging. The slatted area is typically 30 to 40 percent of the pen floor. This reduces the cost of slats and pit construction.

The challenge with partially slatted floors is keeping the solid area clean. Pigs need to be trained early to dung on the slatted area. This is easier if the slatted area is near the alley and the feeder, because pigs tend to dung where they eat and drink.

Pit Depth and Management

The pit below a fully slatted floor should be at least 6 to 8 feet deep for long term storage. Deep pits can store 6 to 12 months of manure, reducing the frequency of pump out. However, deep pits require careful management of gas levels. Hydrogen sulfide and methane can accumulate and pose serious safety risks.

Shallow pits are 2 to 4 feet deep and are drained frequently. They are easier to keep clean but require more labor and more frequent manure application.

Flush Systems

Flush systems use water to move manure from shallow gutters to an outside lagoon. The gutters are flushed periodically, often with recycled lagoon water. This system is common in warmer climates where water is plentiful.

Flush systems require less pit storage but use significant amounts of water. They also add humidity to the barn, which can be a problem in cold weather.

Ventilation and Environmental Control

A well designed pen layout fails if the ventilation system cannot deliver fresh air to every pig. Ventilation is the most important environmental factor in a swine barn after the pigs themselves.

Minimum Ventilation

In cold weather, the ventilation system must remove moisture and gases while retaining heat. Minimum ventilation rates for grow finish pigs are about 20 to 30 cubic feet per minute per pig in cold weather. This rate increases as pigs grow and as the weather warms.

The ventilation system should run continuously, even in the coldest weather. A common mistake is to turn off the ventilation to save heat. This leads to high humidity, ammonia buildup, and respiratory disease.

Tunnel Ventilation

Tunnel ventilation is the standard for grow finish barns in warm weather. Air enters through inlets at one end of the barn and exhausts through fans at the other end. This creates a wind chill effect that keeps pigs cool.

Tunnel ventilation works best in barns that are at least 40 feet wide and 100 to 200 feet long. The air speed at pig level should be 400 to 700 feet per minute in hot weather.

Inlet Placement and Pen Layout

The placement of air inlets affects the pen layout. In a tunnel ventilated barn, the air enters at one end and travels the length of the building. Pens near the inlet end will be cooler than pens near the exhaust end. This is acceptable in warm weather but can be a problem in cold weather.

In a cross ventilated barn, air enters through side wall inlets and exhausts through the center of the barn. This design requires pens to be arranged so that air can flow freely across the pen. Solid partitions can block airflow, so use open partitions in cross ventilated barns.

Monitoring Temperature and Air Quality

Every barn should have temperature sensors at pig level, not just at human height. Place sensors in several locations to detect hot or cold spots. Monitor carbon dioxide and ammonia levels. Ammonia should be below 10 parts per million at pig level.

Feeding Systems and Feed Delivery

The feeding system must match the pen layout and the number of pigs per pen. The two main options are dry feeders and wet dry feeders.

Dry Feeders

Dry feeders deliver feed in a dry form. They come in two basic types: self feeders and drop feeders. Self feeders hold a supply of feed in a hopper and dispense it as pigs eat. Drop feeders are filled from a central auger system and dispense feed on a schedule.

Self feeders are the most common in grow finish barns. The feeder space should be sized so that all pigs can eat at the same time. Provide one feeder space per 3 to 4 pigs. A feeder space is typically 12 to 15 inches wide.

Wet Dry Feeders

Wet dry feeders combine feed and water in one unit. Pigs can mix feed with water at the feeder, which reduces feed dust and improves feed intake. Wet dry feeders can handle more pigs per space than dry feeders. One wet dry feeder space can serve 8 to 10 pigs.

Wet dry feeders require more maintenance because the water system can clog and the feeder can become wet and moldy. They are a good choice for producers who are willing to check feeders daily.

Feed Delivery Systems

Feed can be delivered by auger, chain conveyor, or flexible auger. The delivery system must match the barn layout. A central auger with drop tubes to each feeder is the most common system. The auger should be sized to deliver feed at the rate needed to fill all feeders.

Consider the location of the feed bin relative to the barn. The bin should be close to the barn to minimize the length of the auger. The auger should be accessible for maintenance and repair.

Water Systems

Water is the most important nutrient, yet it is often overlooked in pen design. Pigs need constant access to clean, fresh water.

Water Flow Rate

Grow finish pigs need 2 to 4 gallons of water per day depending on temperature and feed intake. The water flow rate at the drinker should be at least 1 to 2 cups per minute. If the flow rate is too low, pigs will not drink enough and feed intake will drop.

Drinker Types

Nipple drinkers are the most common. They are simple, reliable, and inexpensive. The nipple should be positioned at shoulder height of the smallest pig in the pen. As pigs grow, the nipple height should be adjusted.

Cup drinkers are easier for pigs to use and waste less water. They are a good choice for nursery and wean to finish facilities. Cup drinkers require more maintenance because they can become clogged with feed.

Drinker Placement

Place drinkers over the slatted floor and away from the lying area. Provide at least two drinkers per pen, spaced at least 10 feet apart. This prevents a dominant pig from blocking access to water.

In a partially slatted floor, place the drinkers over the slatted area. This encourages pigs to dung near the drinkers and keeps the solid area clean.

Lighting and Worker Comfort

The barn layout should be designed for the people who work there as well as the pigs. A barn that is difficult to work in will not be managed well.

Lighting

Provide adequate lighting for daily observation and for working in the pens. A minimum of 20 to 30 foot candles at pig level is recommended for daily work. Brighter lighting is needed for detailed inspection and for veterinary procedures.

Consider natural lighting from windows or skylights. Natural light reduces electricity costs and improves worker morale. However, windows can create drafts and increase heat loss in cold weather.

Alley Width and Worker Access

Alleys should be wide enough for the equipment you use. A central alley should be at least 8 feet wide to allow a feed cart or a small skid steer to pass. If you use a full size skid steer, the alley should be 12 feet wide.

Consider the height of the alley as well. If you need to use a loader to remove manure or move pigs, the ceiling should be high enough to accommodate the equipment.

Handling Facilities

Every barn should have a handling area for sorting, weighing, and loading pigs. This area should be located near the loading dock. The handling area should have a scale, a sorting panel, and a chute to the loading dock.

The handling area should be designed to minimize stress on pigs. Use solid walls to prevent pigs from seeing distractions. Use curved chutes rather than sharp corners. Provide non slip flooring.

Common Mistakes in Swine Barn Layout

Many producers make the same mistakes when designing their barns. Learning from these mistakes can save you thousands of dollars and years of frustration.

Overcrowding Pens

The most common mistake is putting too many pigs in a pen. Producers often calculate space based on the average weight of the group rather than the heaviest pigs. By the end of the grow out period, the heaviest pigs are overcrowded.

Overcrowding reduces average daily gain, increases tail biting, and increases the risk of disease. The cost of overcrowding usually exceeds the revenue from the extra pigs.

Inadequate Feeder Space

Another common mistake is providing too little feeder space. When pigs cannot eat at the same time, the dominant pigs eat first and the subordinate pigs get less feed. This leads to uneven growth and increased aggression.

Provide at least one feeder space per 4 pigs for dry feeders. If you see pigs waiting to eat, you need more feeder space.

Poor Waterer Placement

Waterers placed in the wrong location can cause problems. If waterers are placed in the lying area, pigs will dung near the waterers and the lying area will become dirty. If waterers are placed too close to the feeder, pigs will waste feed while drinking.

Place waterers over the slatted floor and at least 10 feet from the feeder. Check water flow rates regularly.

Ignoring Ventilation Needs

Many producers focus on pen layout and ignore ventilation. A barn with a good layout but poor ventilation will have respiratory problems, poor growth, and high mortality.

Work with a ventilation specialist to design the system. The ventilation system should be tested and adjusted after the barn is stocked.

Not Planning for All In All Out

Producers who design for continuous flow often regret it. Continuous flow makes it impossible to clean and disinfect the barn between groups. Disease builds up over time and performance declines.

Design the barn so you can completely empty and clean each room. This may require more rooms and more space, but the improvement in health and growth is worth it.

Decision Thresholds for Pen Size and Group Size

How do you know if your pen size is right? Here are some practical thresholds to guide your decisions.

When to Increase Space per Pig

Increase space per pig if you see any of these signs:

• Pigs are lying on top of each other in the lying area
• Tail biting is increasing
• Growth rate is below your target for the last 4 weeks of the grow out period
• Pigs are fighting at the feeder

If you see these signs, reduce the number of pigs per pen or increase the pen size. Even a 10 percent increase in space can improve growth by 3 to 5 percent.

When to Reduce Group Size

Reduce group size if you see these signs:

• Aggression is high and fighting is frequent
• You cannot identify sick pigs quickly
• Mortality is above 3 percent for the grow finish period
• You are spending too much time sorting and moving pigs

Group sizes of 20 to 30 pigs are easier to manage than groups of 50 or more. The labor savings from smaller groups often offset the higher building cost.

When to Redesign the Barn

Consider a major redesign if you see these signs:

• You cannot achieve all in all out management
• Ventilation is inadequate and cannot be fixed with adjustments
• The floor is deteriorating and causing foot problems
• The alley is too narrow for your equipment
• You are spending more than 30 minutes per day per 100 pigs on routine chores

A major redesign is expensive, but it can be cheaper than continuing to operate an inefficient barn for another 10 years.

Monitoring and Recordkeeping

Good barn design is the foundation, but daily monitoring and recordkeeping are what make a barn work well over time.

Daily Checks

Walk every pen in the barn at least once a day. Look for:

• Pigs that are lying separately from the group, which may indicate illness
• Pigs that are not eating or drinking
• Feeder adjustment and feed wastage
• Waterer function and flow rate
• Floor condition and slat damage
• Ventilation system operation and air quality

A daily walk through should take 15 to 30 minutes for a 1000 head barn. Use a checklist so you do not miss anything.

Weekly Checks

Once a week, do a more thorough check. Look at:

• Manure pit level and pump out schedule
• Ventilation fan operation and belt tension
• Inlet adjustment and air distribution
• Feed delivery system operation
• Pest control and biosecurity

Recordkeeping

Keep records of:

• Pig inventory and mortality
• Feed delivery and feed consumption
• Water consumption
• Medication and treatment
• Temperature and ventilation settings
• Manure removal dates
• Equipment maintenance

These records help you spot problems early and make better decisions. Review your records monthly and compare performance across groups.

Using Records to Improve

Compare the performance of different groups of pigs. If one group has better growth or lower mortality, look for what was different. Was the space allowance different? Was the ventilation set differently? Were the pigs from a different source?

Use your records to test changes. If you increase space per pig, track growth and feed efficiency before and after the change. If you change the feeder type, track feed wastage and growth.

When to Call a Veterinarian or Extension Agent

Most barn management decisions are yours to make. But some situations call for professional help.

Call Your Veterinarian When

Call your veterinarian if you see:

• A sudden increase in mortality, especially if it is more than 1 percent in a week
• Signs of a contagious disease such as severe diarrhea, coughing, or lameness
• Pigs that are not eating for more than 24 hours
• A disease that does not respond to your standard treatment
• Any suspected foreign animal disease

Your veterinarian can help you diagnose the problem and develop a treatment plan. They can also help you review your biosecurity and vaccination protocols.

Call Your Extension Agent When

Call your extension agent when you are planning a new barn or major remodel. Extension agents can provide:

• Current research on space allowances and pen design
• Ventilation design recommendations
• Manure management guidance
• Financial analysis of different design options
• Help interpreting your production records

Extension agents are a free or low cost resource. They have access to research and expertise that can save you money and prevent costly mistakes.

Questions to Ask Your Veterinarian or Extension Agent

Before you call, write down your questions. Include:

• The current situation and what you have observed
• The history of the barn and the current group of pigs
• What you have tried and what happened
• What you are thinking of doing next

The more information you provide, the better advice you will receive.

Frequently Asked Questions

How many square feet does a grow finish pig need?

A grow finish pig needs 8 to 10 square feet of floor space depending on its final market weight. For pigs marketed at 280 pounds, provide 9 to 9.5 square feet per pig. For pigs marketed at 300 pounds, provide 10 to 10.5 square feet. These recommendations assume fully slatted floors. If you use partially slatted floors, add 5 to 10 percent more space per pig.

What is the best pen size for 25 pigs?

For 25 pigs at market weight, a pen of 225 to 250 square feet works well. A pen that is 9 feet wide and 25 feet long provides 225 square feet. A pen that is 10 feet wide and 25 feet long provides 250 square feet. This gives each pig 9 to 10 square feet at final weight. The length to width ratio near 2.5 to 1 allows good pig flow and efficient use of floor space.

Should I use fully slatted or partially slatted floors?

Fully slatted floors are the most common for commercial grow finish barns. They require less daily labor because all waste falls through the slats. Partially slatted floors cost less to build but require more management to keep the solid lying area clean. If you are a new producer, fully slatted floors are easier to manage. If you are experienced and want to reduce building cost, partially slatted floors can work well.

How many pigs can use one feeder space?

For dry feeders, provide one feeder space per 3 to 4 pigs. A feeder space is typically 12 to 15 inches wide. For wet dry feeders, one feeder space can serve 8 to 10 pigs because pigs eat faster and there is less competition. If you see pigs waiting to eat or fighting at the feeder, you need more feeder space.

How many waterers should I put in each pen?

Provide at least two drinkers per pen, regardless of the number of pigs. Place the drinkers at least 10 feet apart so a dominant pig cannot block access to both. The water flow rate should be at least 1 to 2 cups per minute. Check waterers daily and clean or replace them as needed.

What is the best barn width for grow finish pigs?

A barn width of 40 to 50 feet works well for most grow finish operations. This allows a central alley of 8 to 12 feet with pens 14 to 20 feet deep on each side. Wider barns of 50 to 60 feet can be used but require more sophisticated ventilation. Narrower barns of 30 to 36 feet are simpler to ventilate but use land less efficiently.

How do I design a barn for all in all out management?

Design the barn so it can be divided into rooms that can be completely emptied and cleaned. Each room should have its own entrance, its own ventilation controls, and its own manure handling. Rooms should be sized so that a room can be filled with pigs from a single source. After a group is marketed, the room should be cleaned, disinfected, and rested before restocking.

What ventilation rate do grow finish pigs need?

Minimum ventilation for grow finish pigs is about 20 to 30 cubic feet per minute per pig in cold weather. This rate increases as pigs grow and as the weather warms. In hot weather, tunnel ventilation should provide 400 to 700 feet per minute of air speed at pig level. The ventilation system should run continuously, even in cold weather, to remove moisture and gases.

Related Farming Guides

This section will be populated with links to related farming guides on swine production, barn management, and pig health. Check back for updated content on nursery management, grow finish nutrition, and biosecurity planning.

Related Clinical & Scientific Guides

• Pig Enrichment Programs and Behavior Monitoring
• Swine Handling Facility Design for Safe Pig Movement
• Swine Feeding Management for Grow-Finish Pigs

References

• National Pork Board: https://www.pork.org/
• USDA APHIS Swine Health: https://www.aphis.usda.gov/livestock-poultry-disease/swine
• FAO Pig Production: https://www.fao.org/pig-production-and-products/en/
• FAO Animal Production and Health: https://www.fao.org/animal-production/en/
• WOAH (World Organisation for Animal Health): https://www.woah.org/en/home/

This article is educational and is not a substitute for veterinary diagnosis, treatment, public-health guidance, or regulatory reporting.