HOUSING
PIH-55
pork industry handbook
PURDUE UNIVERSITY • COOPERATIVE EXTENSION SERVICE • WEST LAFAYETTE, INDIANA
Space Requirements for Swine
Authors:
R.D. Fritschen, University of Nebraska
Arthur J. Muehling, University of Illinois
Reviewers:
Al H. Jensen, University of of Illinois
Ray Stevermer, Easton, Minnesota
The amount of space needed per pig for optimal performance is an important planning-management consideration for modern production systems. Failure to plan for adequate space causes problems with overcrowding, scheduling, and a host of animal interactions. Research has led to general recommendations but many variables exist between individual farms. Thus recommendations based upon research must be tempered with good judgment and common sense. Most recommendations are based upon animal performance criteria. However, overall well-being of the pig is also important.

General Space Management
Too few pigs per pen increases initial building and equipment investment. However, care must be taken to prevent overcrowding. The results of overcrowding may include tail biting or cannibalism, reduced gain, increased feed required/unit gain, gastric ulcers, and/or additive stress factors. Various levels of these, plus others, may cause increased susceptibility to disease or other adverse effects on performance or reproduction.

It is generally impractical to provide the optimal area per pig at all stages of the life cycle because the pig is continuously increasing in size, and space requirements change at a similar rate. Movement of pigs from one building to another to provide optimal space has, in at least one study, caused setback in pig performance and health. Moving pigs to larger pens to adjust for increased size may be best accomplished when the move is within a building rather than between buildings, especially for young pigs. For most producers, providing optimal space must be a manageable compromise between adjusting the pen size and/or the number of pigs per pen. Optimizing pen occupancy is perhaps best achieved by utilizing pens of increasing size. Mixing groups of pigs is a risky method of obtaining optimum occupancy.

Tables 1-3 give space recommendations based upon current research and field observations that take into
account most factors. Space recommendations may vary slightly between sources.
Space requirements for flat-decks and battery cages have not been well established. However, these types of weaning facilities are generally stocked at a rate of at least 2.0 sq. ft. per pig to a terminal weight of 40 lb. Apparently, the higher stocking density is functional because of the smaller size group characteristic of this system, as compared to a conventional nursery and the greater cleanliness and sanitation of the wire floors. See PIH-77, Decking for Nursery Pigs.
Table 1. Space recommendations for nursery-growingfinishing pigs using partial or total slats.
Pig weight or class	Space for partial or total slats
lb.	sq. ft.
15-30	1.7-2.5
30-60	3-4
60-100	5
100-150	6
150-market	8*
* Adjusting pig numbers per pen seasonally may result in improved performance. For example, increasing the number per pen by 1 or 2 pigs during winter or decreasing the number in summer may be desirable.
Table 2. Space requirement recommendations for each animal using building with outside apron.
Class	                   Sq. ft. needed	
	Inside	Outside
Growing-finishing	6	6
Sows	11-12	11-12
Boars	40	40