Mimeo AS-289 August, 1960
Purdue University Agricultural Experiment Station Lafayette, Indiana
THE EFFECTIVENESS OF A MIST-TYPE SPRAY FOR COOLING SWINE WITH AND WITHOUT SUPPLEMENTAL THIAMINE
C. J. Heidenreich, J. H. Conrad, F. N. Andrews Department of Animal Science
Environmental temperatures exceeding 80°F 1/ have been shown to reduce growth rate in swine. Research conducted during the past four summers at Purdue has attempted to determine effective methods of alleviating the detrimental effects of high temperatures on swine production.
Initial studies were mainly concerned with physical methods of reducing the stress imposed by high environmental temperatures. ’Such research led to the development and recommendation of a mist-type spray system, which has proven both effective and economical.
An alternate approach to the problem of thermal stress in swine involves investigations concerned with internal heat production and appetite regulation of the animal. Studies were initiated in 1958 to determine possible dietary modifications (10 percent added fat) which would reduce the heat increment of a ration per unit of caloric intake, thus reducing the thermal burden on the animal. Further dietary modifications were studied during the summer of 1959 when thiamine, on high energy rations (10 percent added fat), was studied in relation to appetite, subsequent growth rate and feed conversion. Suggestive evidence was presented which showed that thiamine increased daily feed intake with a resultant increase in daily gain.
The research reported herein was designed to study (l) the effectiveness of spray cooling during the summer months in Indiana and (2) the role of thiamine when added to a conventional (essentially carbohydrate) ration during periods of appetite depression, which accompanies elevated ambient temperatures.
Experimental Procedure
Cn June 10, i960 44 pigs averaging 85 pounds each were assigned to four concrete lots on the basis of weight, litter and sex. Each lot was equipped with a 12 foot x 15 foot shade of frame construction, having a white, 1/2-inch exterior plywood roof. Lots 1 and 2 contained a mist-type spray system, and lots 3 and 4 had none.
Each spray system was made up of a 1/2-inch steel pipe, six feet long, hung approximately four feet above the concrete floor. To this was attached three mist-type nozzles, each producing one gallon of mist per hour at 40 pounds pressure. The system was operated automatically by a thermostat and solenoid valve. The spray operated whenever the air temperature was 72°F or above.
All four lots received a complete mixed ration consisting of ground shelled corn and Purdue Supplement 2. This ration contained 14 percent crude protein. In addition, lot 2 (sprayed) and lot 4 (nonsprayed) received supplemental thiamine added at the rate of three milligrams per pound of total ration. The composition of the highly fortified Purdue Supplement 2 is given in table 1.
1/ Heitman, H. Jr., C. F. Kelly and T. E. Bond. J. An. Sci. 17:62. 1958.