Skip to main content
ARS Home » Plains Area » Miles City, Montana » Livestock and Range Research Laboratory » Research » Publications at this Location » Publication #98451
Title: EFFECTS OF CROSS-INOCULATION FROM ELK AND FEEDING PINE NEEDLES ON THE PROTOZOAN FAUNA OF PREGNANT COWS: OCCURRENCE OF PARENTODINIUM AFRICANUM IN DOMESTIC U.S. CATTLE (BOS TAURUS)

Author
item DEHORITY, BURK - OHIO STATE UNIVERSITY
item Grings, Elaine
item Short, Robert

Submitted to: Journal of Eukaryotic Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/1/1999
Publication Date: N/A
Citation: N/A

Interpretive Summary: The primary types of organisms important to digestion and fermentation within the rumen are bacteria, protozoa, and fungi. There are numerous species of each of these classes of organisms within the ruminal environment and each has a specific niche or function. Protozoa are important in the nitrogen economy of the ruminant. Protozoa are retained in the rumen longer than bacteria and may breakdown and recycle bacterial nitrogen for reuse in the rumen. Understanding the types of organisms that exist within the rumen and identifying their characteristics is important to understanding the fermentation dynamics that occur within the rumen. This leads to understanding how to provide nutrients to improve efficiency of ruminal fermentation and digestion and optimize nutrient availability to the host animal. During the course of attempting to determine if ruminal microorganisms were involved in the production of a vasoactive compound involved in pine needle abortion, a species of protozoa were identified that had not previously been observed in either Bos taurus or in any ruminant host in the northern hemisphere. The organism, Parentodinium africanum had originally been identified in the hippopotamus in Africa and has been found in Bos indicus cattle in Brazil. The significance of this organism in the rumen has yet to be determined.

Technical Abstract: The cycloposthid ciliate Parentodinium africanum was observed in rumen contents from several domestic cattle (Bos taurus) in Montana. Concentrations ranged from 1.4 to 130.6 x 10**4 per ml of rumen contents, which comprised 4.6 to 80.3 percent of the total ciliate population. Mean dimensions of this species were: length, 33.4 micro m; width, 19.7 micro m; length/width ratio, 1.70, which were similar to those previously reported for this species from Bos indicus in Brazil. This is the first observation of P. africanum, originally observed and described in stomach contents of the hippopotamus, either in Bos taurus or in any host in the northern hemisphere.