Growing-Finishing Swine in Outdoor Lots

Housing, feeding and health of pigs kept outside are discussed by William G. Luce (extension swine specialist), Joseph E. Williams (Professor of Agricultural Economics) and Raymond L. Huhnke (extension agricultural engineer) at Oklahoma State University. The publication was published by Oklahoma Cooperative Extension Service in July 2007.
calendar icon 1 January 2009
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Feeding growing-finishing pigs in a low investment system is usually done in outdoor lots with little or no permanent vegetation. Growing-finishing swine, unlike breeding stock, make poor use of pasture; thus pasture is seldom provided. With proper management, pigs can usually gain as rapidly in outdoor lots as in confinement systems but may require slightly more feed per pound of gain.

The main advantage of the outdoor lot system of finishing hogs is its low initial investment. Disadvantages of feeding hogs in outdoor lots include high labor requirements and less climatic control. It is also difficult to control internal parasites and excessive dust or mud that may complicate any existing disease problems.


In outdoor lot systems of swine production, hogs should reach market weight (240 lb) in 180 days or less. Feed efficiency should not exceed 3.5 pounds of feed for each pound of gain from 40 to 240 pounds. In addition, hogs should be produced that yield lean, meaty carcasses. Carcasses should average 30.0 inches or more in length, less than 1.2 inches of backfat at the last rib, 5.0 square inches or more of loin eye and be at least 54 per cent lean meat. Eighty per cent or more of the hogs produced should grade USDA No. 1 or 2 when marketed.


Ideal locations for outdoor lot finishing include sandy soils, shade, good quality water and natural protection. The site should have a slope between 2 and 5 per cent to maintain adequate drainage without causing excess runoff and erosion. The space allotted per pig in outdoor lot systems varies depending on soil type, drainage, amount of rainfall, etc. Usually 100 square feet of lot space is sufficient. While a lot capacity of 50 head is desirable to reduce social stresses, as many as 100 head may be fed in one lot provided they are uniform in size.

Permanent or portable shelters that provide 4 square feet of roof area per head for pigs up to 100 lb and 6 square feet for pigs over 100 lb are recommended. Ideally, these shelters will be open during the summer and closed on all but the south side during the winter. It is often advantageous to use straw for bedding in the winter and imperative that the shelter area be kept dry.

Sprinklers that emit large droplets of water and are located over sand are recommended to keep pigs cool in the summer. Misters or foggers are not recommended. One feeder space should be provided for each four or five pigs. One watering space will serve up to 15 head with a minimum of two waterers per pen.


Feed represents the major cost of producing pork. Thus, diets that supply proper nutrition at least cost will help increase profits considerably. A commercial protein, mineral and vitamin supplement is often mixed with ground grain. This practice is sound if the available commercial supplements are properly formulated and priced competitively. Tables 1 and 2 present examples of rations using this method. Another possibility is to purchase a base mix which contains all the necessary minerals and vitamins and mix it with grain and soybean meal. It is important to note that the least cost ration may not be the most profitable. Quality of the ration is important.

Many pork producers purchase individual ingredients and formulate their own diets. A pork producer will need to consider cost of ingredients, equipment and labor in determining the feasibility of this practice. Suggested diets for pork producers who mix their own diets are shown in Tables 3 and 4. The relative price and availability of feed ingredients often dictates which is selected. Antibiotics or other feed additives should usually be added to these diets to improve feed efficiency and increase growth rate.

The diets in Tables 3 and 4 are formulated for average quality hogs. For fast growing, extremely lean hogs it may be feasible to substitute 40 lb of 44 per cent soybean for 40 lb grain in the growing diets in Table 3 and 20 lb of soybean meal for 20 lb grain in the finishing diets (Table 4). For additional information on the protein needs of extremely lean gain pigs see OSU Extension Facts ANSI-3509 “Protein Needs of High Lean Gain Pigs.”

Feed additives often used in swine diets include apramycin, bambermycin, carbadox, chlortetracycline, lincomycin, neomycin, oxytetracycline, tiamulin, tylosin, virginiamycin and arsenic compounds such as arsanilic acid. Copper sulphate, when added at levels of 125 to 250 ppm in swine diets, also has a growth promoting effect.

Some antibiotics or chemotherapeutics and all arsenic and sulpha compounds are required by Federal Law to be withdrawn from finishing diets within a specified time prior to slaughter. Always read the label and comply with the withdrawal time. It is the livestock producer’s responsibility to comply with withdrawal periods.

Disease Control

Prevention of disease in outdoor lots is similar to controlling diseases in confinement. However dirt and dust can complicate and make the control of disease such as pneumonia more critical. Therefore, proper sanitation and good management are very important. Some items to consider when setting up a proper disease control system include:

  1. Control visitor traffic and other carriers of disease.
  2. Do not allow outside vehicles such as feed, rendering and fertilizer trucks in area of swine production.
  3. Provide footwear (overshoes) to visitors that you allow in the production facilities.
  4. Change clothing and shoes after visiting neighboring farms, auctions, shows, fairs etc. where hog disease may be present. A 24-48 hour waiting period before returning to your own hog farm would even be a better safeguard to minimize the transfer of disease.
  5. Discourage dogs and wild animals from coming into the production unit.
  6. Vaccination for erysipelas may be advisable if the disease is prevalent in your area. Consult your local veterinarian to determine disease incidence.

Your veterinarian should be called immediately if unusual problems or losses occur. Watch closely for any signs of illness such as laboured breathing, coughing or scours. Early treatment is the cheapest and most effective way of preventing death losses.

Control of Internal Parasites

To help control internal parasites (worms), it is recommended to disk outdoor lots and leave them idle for six weeks if possible between pig crops. Therapeutic control will usually be necessary too, in an outdoor lot system. If possible, have your local veterinarian examine faecal samples to determine the type of internal parasites infecting your herd.

Table 6 lists several anthelmintics (dewormers) and the parasites they are effective against. Piperazine and Tramisol (levamisole hydrochloride) can be administered in feed or water. Atgard (dichlorovos), Banminth (pyrantel tartrate), Safegard (fenbendazole) and Hygromix are administered in feed only. Hygromix needs to be fed in a continuous program. Ivermectin is an injectable anthelmintic that is also effective against lice and mange. Banminth can be used as a single therapeutic treatment (purge wormer) or fed in a continuous program. When Piperazine, Atgard, Tramisol, Safegard or Banminth (fed as a purge wormer) are used, it is usually recommended that pigs be de-wormed at 9 to 10 weeks of age and again 30 days later. Read the product label carefully on anthelmintics before using and observe all restrictions and precautions.

Control of External Parasites

External parasites (lice and mange) can be controlled in farrow-to-finish herds by purchasing initial breeding stock and replacement boars that are free of these parasites. In operations in which feeder pigs are purchased to feed out, it may be very difficult to consistently buy feeder pigs that are free of lice and mange.

External parasites can also be controlled by the use of insecticides. Spraying animals with insecticides is the most common method used but dusting or dipping is also used. Injectable ivermectin can also be used to control lice and mange. To effectively control lice or mange, it is necessary to spray sleeping quarters as well as treating the individual animals.

Table 7 lists some of the insecticides that can be used to control lice or mange. Read the product label on any insecticide before using and observe all restrictions and precautions. Some insecticides should not be used on pigs under three months of age. Be sure to follow waiting periods before selling hogs for slaughter.

January 2009

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