Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)


Agricultural Engineering


Predictions for the future indicate that beef cattle production will continue to increase. The U. S. Department of Agriculture has estimated that the demand for red meat would increase by over 60 per cent between 1958 and 1975. Beef consumption in the United States is 80 to 85 pounds per capita per year. However, some light meat, turkey and chicken will be substituted for red meat, but due to the continuing increase in human population, the production of beef will have to increase to meet the domestic need. Following the trend of the last few years, more beef cattle production is going to take place in feedlots. The feedlots will become larger and the production of beef on natural grassland will decrease partly due to the increased performance realized from using more concentrated rations as tests indicate that about 20 per cent less total feed ls needed to produce one pound of gain with a concentrate-roughage ratio of 5:1 (five times more concentrate than roughage), as compared to commonly used 6:4 rations. Better pollution control improved environmental conditions for livestock and farm laborers and optimization of labor will hasten the trend toward beef cattle produced in confinement buildings. With more beef cattle production taking place in confinement buildings, the optimum environmental conditions for maximum performance must be defined and design criteria established. Factors such as ambient temperature, relative humidity, wind velocity, precipitation, solar radiation, type of shelter, animal density and conditions of the environmental surfaces affect the thermal environment of the beef cattle. One of the most important factors to consider in trying to achieve maximum animal production in confinement buildings is proper ventilation. The ventilation system must supply adequate oxygen, remove toxic gases and water vapor and prevent condensation and frost accumulation ln the building. Several ways of ventilating open and semi-open beef barns are being employed, but there is limited information on systems which will operate efficiently and effectively under different climatic conditions. This study was undertaken to evaluate ventilation characteristics in open front beef confinement buildings. The objectives of this study were: 1. Evaluate the effects of ridge vent design on air flow characteristics in a model of an open front beef confinement building. 2. Determine the effect of ridge vent design on temperature in a model of an open front beef confinement building. l. Develop prediction equations for air flow using a model of an open front beef confinement building.

Library of Congress Subject Headings

Beef cattle.
Barns -- Heating and ventilation.



Number of Pages



South Dakota State University