Interrelationships between protozoa and bacteria in rumen fermentation

Abstract

69 LITERATURE CITED 73 ACKNOWLEDGMENTS 82 APPENDIX --83 Procedures 83 Analysis of Variance Tables 93 (1964) and Abou Akkada and El-Shazly (1964). The presence of ciliate protozoa increased total volatile fatty acid production, especially during the first four to six hours after feeding. These same workers also observed a significant increase in concentration of ruminai ammonia during this period. These findings suggest a faster rate of fermentation in the faunated reticulo-rumen. Abou Akkada and El-Shazly (1965) measured the effect of ciliate protozoa upon several blood components and nitrogen retention in lambs. Blood samples taken three hours after feeding were analyzed for blood reducing sugars, hemoglobin, protein nitrogen, non-protein nitrogen, ammonia nitrogen and urea nitrogen. They found faunated lambs had higher levels of blood hemoglobin and blood protein nitrogen, but lower levels of reducing sugars, ammonia nitrogen and urea nitrogen than those of defaunated lambs. Faunated lambs retained 51.2 percent nitrogen compared with 400 percent nitrogen retention for defaunated lambs.Becker ^ (1929b) concluded from their studies that ciliate protozoa neither helped nor harmed the host animal and assigned the ciliate protozoal fraction a status of mere commensals. Research work reported since then has only par tially supported Becker's conclusions; therefore, the exact influence that ciliate protozoa exert on either the host animal or the ruminai bacteria is not clearly defined at the present. 6 The Relationship between Bacteria and Protozoa in the Reticulo-Rumen Appleby et (1956) attempted to demonstrate the presence of bacteria within ciliate protozoa and observed that Isotricha prostoma, Isotricha intestinalis and Dasytricha ruminatium which were fully motile prior to being fixed and stained did not harbor bacteria, however, Entodinium contained large numbers of Streptococcus bovis. It was concluded that intact viable bacteria did not appear to be vital for the life processes of rumen holotrich protozoa. By starving Dasytricha ruminatium from 48 to 72 hours, which decreased the quantity of stored amylopectin, Gutierrez and Hungate(1957) observed by use of phase contrast microscopy that Dasytricha ingested cocci from 0.5 to 0.8 microns in diameter. The ingested bacteria were then isolated, cultured and later fed to a bac terial free preparation of Dasytricha ruminatium. In an in vitro system the protozoa with bacteria divided frequently and remained alive for two weeks as compared to controls free of bacteria which died within 96 hours. It appeared that the holotrich rumen ciliates derive at least part of their nitro genous requirements from the ingestion of bacteria. Two years later Gutierrez and Davis (1959) reported that Entodinium and Diplodinium which had been starved from 48-72 hours ingested ruminai bacteria in large numbers. The amylolytic cocci en gulfed by Entodinium were identified as Streptococcus bovis. LITERATURE CITED Abou Akkada, A. R., J. M. Eadie and B. H. Howard. 1963. The biochemistry of r...