Respiration Calorimetry Studies with Growing Pigs Fed Diets Containing from Three to Twelve Percent Crude Fiber

RESPIRATION calorimetry is necessary to delineate completely energy utilization by animals. Laboratories in Germany and Denmark have reported results of extensive research on heat production and energy balance of growing pigs (Oslage and Fliegel, 1965; Thorbek, 1969) and of adult pigs (Nehring, Hoffmann and Schiemann, 1963). There have been, however, no studies specifically designed to evaluate the influence of crude fiber (CF) levels on overall energy utilization and heat production by market pigs. It is well established that CF depresses the digestibility of a diet. The source of CF may also be a factor in energy utilization as CF from different sources had different digestibilities (Troelsen and Bell, 1963). Lloyd and Crampton (1955) determined that one unit of CF was inversely equivalent to one unit crude protein (CP).The present study using respiration calorimetry was designed to obtain data on energy utilization and nitrogen balance of castrate male growing pigs from approximately 25 to 74 kg live weight when they were fed diets calculated to contain 3, 6, 9 or 12% CF.