A COMPARISON OF RUMEN FLUID SAMPLED BY ORO-RUMINAL PROBE VERSUS RUMENFISTULA

Ten adult (height 63-85 cm) rumen-fistulated sheep were used to test t he usefulness of an oro-ruminal probe and a suction pump for the acqui sition of ruminal fluid, Use of these instruments in 50 samplings rend ered 200 mi of ruminal fluid each time. Introduction of the probe to a length of 91.3 +/- 3.5 cm took 18 +/- 6.5 s. Collection of 200 mi of ruminal fluid took 7.4 +/- 2.2 s, Sampling location was the ventral ru minal sack. Comparing fluid taken by the oro-ruminal probe with sample s taken via ruminal fistula by a tube-like probe, no significant diffe rences in pH, total acidity, reduction potential, ammonia, acetate, L- lactate, sodium and chloride concentrations were found. However, signi ficant differences between oro-ruminal probe samples and fistula sampl es were observed with regard to the concentrations of total volatile f atty acids, propionate, n-butyrate, i-butyrate, n-valerate, i-valerate , calcium, phosphate, magnesium and potassium. The differences were in dependent of the sampling order (oro-ruminal probe prior to fistula an d vice versa). These results indicate that samples taken by the oro-ru minal probe do not contain sampling-dependent saliva residues. Those s amples collected via the fistula had consistently higher concentration s of total volatile fatty acids, propionate, n-butyrate, i-butyrate, n -valerate, and i-valerate, as well as higher concentrations of calcium , phosphate, magnesium and potassium than samples taken with the oro-r uminal probe. These results indicate that samples taken via fistula or iginated from more dorsal regions than the samples taken by oro-rumina l probe from the ventral ruminal sack. The oro-ruminal probe and the s uction pump used proved to be useful for the collection of ruminal flu id from the ventral ruminal sack in adult sheep.