Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)


Agricultural Engineering


Many of the technological advances in the swine industry have resulted in increased capital requirements for buildings and equipment. This has made multiple farrowing, including summer farrowing, a near necessity. Hog farmers recognize the problem of sow mortality due to severe heat stress during periods of high ambient temperatures, and hog producers utilizing the free stall farrowing system recognize yet another problem, that of poor stall occupancy. Sows in this type of system tend to seek relief by leaving their stalls and lying in moist or breezy areas. This decreased stall occupancy has resulted in pigs being severely neglected, reduced weight gains and starvation in extreme cases. A need to modify the thermal environment in the free stalls to provide sows with thermal relief is desired. Preliminary work has indicated that cooling the entire environment is very expensive. Therefore, an alternate system of partial modification of the environment using a stream of cooled air directed on sows was investigated.

The objectives of this research were the following:

1. Determine the effects of cooled air directed toward the sow on swine performance as indicated by pig weight gain, mortality and weight change of the sow.

2. Evaluate sow response in terms of respiration rate and pen occupancy.

3. Describe the environmental conditions of temperature and relative humidity within the farrowing building.

4. Determine the electric energy use of the environmental control equipment.

Library of Congress Subject Headings

Swine -- Housing



Number of Pages



South Dakota State University