Effect of Temperature on Food and Water Intake and Rumen Fermentation

Abstract

The purpose was to determine volatile fatty acid concentrations at normal (18 C) and high (35 C) ambient temperature, and to determine the effect of increasing the rumen temperature with an intraruminal heating coil in an 18 C ambient temperature. Four nonlactating, fistulated Holstein cows were placed in a climatically controlled chamber. Treatments were (18) ambient temperature 18.2 C; (35) ambient temperature 35 C; (18–43) ambient temperature 18.2 C, intraruminal coil temperature 43.4 C; and (18–51) ambient temperature 18.2 C, intraruminal coil temperature 51.0 C. Analysis of variance indicated that significant differences (P < 0.05) for acetic, propionic, and butyric acids, rumen temperature, rectal temperature, feed intake, and water intake were observed. Cows subjected to 18.2 C ambient temperature, but whose rumen temperatures were increased by intraruminal heating coils, consumed significantly less (P < 0.05) feed and water than cows subjected to the other treatments. The data indicate that lower ruminal volatile fatty acid concentrations which occur at high ambient temperatures cannot be explained by changes in ruminal temperature. © 1970, American Dairy Science Association. All rights reserved.