Thesis - Open Access
Master of Science (MS)
Hog production is a 100 million dollar per year agricultural industry in South Dakota. accounting for 15 per cent of the total farm income, ranking it second only to beef cattle in cash farm income. During the past 10 years the United States pig crop -has averaged 90.5 million head annually, remaining quite stable over that period, while in South Dakota the annual production over the same period has averaged 2.9 million head. with production increasing during the period, Aanderud 1. This represents 3.2 per cent of the United States production, ranking South Dakota ninth in annual production. Technological advances adopted by many swine producers have increased capital requirements. Therefore, buildings and facilities must continuously operate at full capacity to return maximum profit on the investment, to obtain uniform yearly production and to eliminate seasonal market variations. Uniform reproductive performance, especially essential to farmers using multiple farrowing systems, is not always obtainable as reduced conception rates and smaller litter sizes are often noted for sows bred and farrowed during summer months. It is the responsibility of the agricultural engineer to fully evaluate seasonal and environmental effects on swine reproduction and to develop swine housing and environmental control systems that will allow more profitable swine enterprises. The need for this information is particularly evident in South Dakota, since farmers currently raise more feed than is used in the state, summer climatic conditions are often extreme and adequate land for increased swine production is available. Therefore, an investigation with the following objectives was initiated: 1. To compare the effects of a naturally varying environment with those of a controlled environment on swine conception rate and litter size. 2. To evaluate temperature and relative humidity conditions in the two environments. 3. To correlate environmental conditions with existing climatic conditions. 4. To determine energy consumption and costs of air conditioning the controlled environment.
Library of Congress Subject Headings
Swine -- Breeding
Number of Pages
South Dakota State University
Disrud, Ronald O., "Environmental Conditions and Effects on Litter Size and Conception Rate of Swine" (1972). Electronic Theses and Dissertations. 4652.