HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Rumsey, T. S. Articles by Samuelson, G. Search for Related Content PubMed PubMed Citation Articles by Rumsey, T. S. Articles by Samuelson, G.

Effect of Ruminal and Esophageal Fistulation on Ruminal Parameters, Saliva Flow, EKG Patterns and Respiratory Rate of Beef Steers

U.S. Department of Agriculture,¹ Beltsville, Maryland 20705

Abstract

TWO experiments were conducted to study the effects of ruminal and esophageal fistulation on steers fed high and low forage diets. In experiment 1, ruminal parameters and saliva flow were studied using four intact steers, four ruminally fistulated steers and two groups of four bifistulated steers. The fistulas had been established at least 1 year prior to the experiment. Twelve different steers were used in the second experiment to study ruminal parameters, saliva flow, respiratory rate and EKG patterns. These steers were initially intact, eight were then ruminally fistulated and 22 days later, four of the ruminally fistulated steers were esophageally fistulated. Periodic samples were collected before and after fistulation. Significant temporary changes were noted during the 20-day period following ruminal fistulation for ruminal NH₃, pH, total VFA, acetate, isovalerate, and valerate, respiratory and heart rates, the Q-T interval and the R wave amplitude. Beyond the 20-day period, propionate was lower in ruminal-fistulated steers, particularly when low forage diets were fed. Significant temporary changes were noted during a 20-day period following esophageal fistulation for ruminal NH₃, heart rate, the Q-T interval and the P amplitude. Significant animal differences were found for ruminal acetate and butyrate. The collection of saliva at the esophageal fistula 1 day prior to sampling ruminal ingesta from bifistulated steers affected ruminal VFA patterns. Over a 2-hr, collection period, average saliva flow rates were similar for cardial and esophageal collections; however, flow rates determined via the esophageal fistula at 30-min. intervals were more uniform over a 2-hr. collection period when compared with the cardial determinations. This study demonstrated that post-operative recovery, sampling schedule and saliva collection techniques are important considerations when conducting studies with fistulated animals.

¹ Nutrition Institute, Ruminant Nutrition Laboratory, A.R.S.