Submitted to: American Society of Agri Engineers Special Meetings and Conferences Papers
Publication Type: Other
Publication Acceptance Date: August 4, 1998
Publication Date: N/A
Interpretive Summary: Pigs of two genetic lines (average and high-lean) were tested for response to high air temperatures in temperature-controlled chambers. The temperatures were increased until the pigs ate 13 or 26% less feed than similar pigs kept in normal conditions. The most important measurements were eating behavior, how quickly the animals grew, and the amount of fat and lean tissue. The results were as expected as the high-lean animals grew faster and gained more lean tissue than the average animals. Temperature caused the amount of fat tissue to increase and lean tissue to decrease in both genetic lines as it got hotter. Pigs spent less time eating mostly by reducing the average size of their meals. These results showed an improvement in growth rate and efficiency of feed use compared to a previous study under similar conditions. The difference was in the use of a diet balanced in amino acids but reduced in crude protein. This balancing of nutrients caused less waste. However, direct comparisons could not be made between the studies.
Technical Abstract: Swine of two genetic composites (moderate-growth and high-lean-growth) were each subjected to three environmental temperatures: control treatment of thermoneutral (TN) (18C), and two elevated air temperature treatments to reduce ad libitum feed intake by 13 or 26%, based on intake forTN control animals of each composite. Each animal was penned individually, three anim mper chamber, and chamber temperatures were adjusted daily to obtain the desired feed intakes, based on treatment averages. Total feed intakes were similar among composite types for TN and 26% conditions but differed at the 13% condition and caused an interaction effect in total feed intake and fee conversion. Daily feed intake was greater for the high-lean-growth composi and followed treatment protocol (13 and 26% reductions) for temperature treatments.