Ruminal Volatile Fatty Acid Concentrations and Performance of Steers Fed Different Levels and Forms of Hay and Grain

Publisher Website
Google Scholar
Abstract
Forty-eight Angus steers averaging 340 kg. were self-fed for III days on rations consisting of no hay, long hay, or ground hay with flaked or ground corn. Half of the steers on each ration were given a sustained release antibiotic bolus. Feed-lot gains, feed efficiency, carcass data, ruminal pH, and VFA concentration were measured. Steers receiving no hay gained less and had lower feed consumption per day than steers receiving hay in their ration. There were no significant differences in feed efficiency. Steers receiving no hay had lower dressing percent, less cooler shrink and lower carcass grades than steers receiving long hay. Those receiving no hay had a lower ruminal pH than those receiving ground hay, and both were lower than steers fed long hay. Steers fed long hay had more acetate and less propionate with a wider acetate-propionate ratio. Steers fed no hay had more n-valerate than steers fed hay; however, those fed long hay had less total VFA. Steers receiving flaked corn had molar percents of VFA similar to those receiving ground corn but less total VFA than did the steers fed ground corn. There were no differences in VFA concentration due to the administration of antibiotics. Copyright © 1965. American Society of Animal Science . Copyright 1965 by American Society of Animal Science