1Rumen protozoa observed from impala (Aepyceros melampus). http://ojvr.org/index.php/ojvr/article/downloadSuppFile/327/249
Four earlier reports on protozoa in the impala are also included in Table 1 for comparison. To date, 13 species of protozoa have been observed in the impala rumen. In South Africa, 11 of these were reported by Kleynhans in 1977, nine in the present study and three by Van der Wath and Myburgh in 1941. Dogiel reported a total of five species from impala in Kenya (1925) and Uganda (1932). Table 2 reflects the occurrence and concentration of D. ruminantium and the larger ophryoscolecids (five species) as grouped by the collection site. Ostracodinium gracile was present in all 32 animals, E. maggii was present in 31 animals, whilst Eudiplodinium impalae and Epidinium caudatum were found in 30. In contrast, Epidinium ecaudatum was present in only 16 animals and Dasytricha species were found in nine. Thus, the majority of the larger ophryoscolecids were represented by four species, namely O. gracile, E. maggii, E. impalae and Ep. caudatum. The total concentration of all six species averaged about 1.6 x 104 per mL in the 24 animals from Ditholo, 0.32 x 104 per mL in the five from Loskop, 1.38 x 104 per mL in the two impala from Rietvlei and 0.28 x 104 per mL in the single animal from Karoobult.
2Occurrence and concentration of Dasytricha ruminantium and larger ophryoscolecid protozoa in rumen contents of the impala. http://ojvr.org/index.php/ojvr/article/downloadSuppFile/327/250
The caecum and colon contents were mixed, washed as described above, and examined microscopically for protozoa. The results in Table 3 show that only very low concentrations were present in the ingesta from these organs. Presumably, the protozoa would be digested as they move through the abomasum and small intestine; however, some cells are obviously able to pass through unharmed. It is possible that they are embedded in larger food particles and are not exposed to the acidic and enzymatic conditions in those organs. These concentrations are considerably higher than what one author (B.A.D.) has previously observed in domestic ruminants (unpublished).
3 Occurrence and concentration of Dasytricha ruminantium and larger ophryoscolecid protozoa in the caecum or colon contents of impala. http://ojvr.org/index.php/ojvr/article/downloadSuppFile/327/251
A possible relationship between the time (i.e. the month when the animal was harvested) and the concentration of the larger protozoa was investigated, taking all 32 animals into consideration. A correlation coefficient (r) of 0.65 was obtained (r2 = 0.42). However, when only the 24 animals from a single location (Ditholo) were used, the correlation coefficient was 0.865 (r2 = 0.75). Figure 1 shows the regression of protozoa concentration for all 32 animals, according to time of harvesting. The first sample was obtained in December and labeled as 0, followed by January as 1, February as 2, etc. This was based on the assumption that the start of the summer growing season would begin in December, when pasture and browse were low, and that feed would become increasingly available during the following months. It is also of interest that only two genera of the subfamily Diplodiniinae, Eudiplodinium and Ostracodinium, have been found in the impala. Species of Diplodinium, Metadinium, Enoploplastron, Elytroplastron and Polyplastron occur in many of the other wild ruminants in Africa (Dehority & Odenyo 2003; Dogiel 1925, 1932; Kleynhans & Van Hoven 1975; Van Hoven 1975, 1978, 1983). Physiological parameters Table 4 presents information on the collection site, age, sex, organ pH, weight of the organ contents, percentage dry matter, density and gas production from organ contents, incubated in vitro (gas production was not measured with small intestine ingesta). Except for the animal from Karoobult and the two from Rietvlei, rumen pH values averaged below 6.0. This value would be expected in grazing ruminants, as demonstrated in the study by Dehority and Tirabasso (2001), where sheep were fed 1, 6, or 24 times per day. Rumen dry matter values fell within the normal reported range of 10% – 13% (Dehority 2003).
4Physiological parameters of the impala digestive tract and gas production by rumen, caecum and colon contents. http://ojvr.org/index.php/ojvr/article/downloadSuppFile/327/252
The aim of measuring gas production was to evaluate whether this parameter was associated with protozoal concentrations. When gas production was correlated with numbers of larger protozoa, the correlation coefficient was 0.31, indicating little or no association. This is not entirely unexpected, because a number of factors would be involved. Probably the most critical would be the amount of available substrate in the rumen contents, regardless of the concentration of protozoa and bacteria. Gas production from rumen, caecum and colon contents was greater in the animals on the game farm, suggesting that more substrate was available in the ingesta from these animals than from those living in the bushveld. In future studies it would be desirable to measure fermentation capacity as described by El-Shazley and Hungate (1965), where additional substrate is added. Temperature of organ contents ranged from 30 ºC to 41 ºC for the rumen, between 11 ºC and 28 ºC for the small intestine, between 17 ºC and 31 ºC for the caecum and between 13 ºC and 30 ºC for the colon. Length of the organs ranged from 281 mm to 570 mm for the rumen, 6218 mm to 13 852 mm for the small intestine, 162 mm to 652 mm for the caecum, and 190 mm to 1411 mm for the colon (data not shown). ConclusionThe number of genera and species of protozoa occurring in the impala is limited compared to other African wild ruminants and domesticated cattle and sheep (Booyse & Dehority in press; Dehority & Odenyo 2003; Dogiel 1932; Kleynhans & Van Hoven 1976; Van Hoven 1975, 1978, 1983). Only four species of Entodinium, two genera of Diplodiniinae and two species of Epidinium have been observed. Acknowledgements Authors’ contributions D.G.B. collected the samples, was responsible for all the measurements and conducted the microscopic studies. B.A.D. assisted with identification of the species, compilation of the data and writing the manuscript. 1.BooyseD.GDehorityB.ARumen protozoa in South African sheep with a summary of the worldwide distribution of sheep protozoa26285632.BooyseD.GBoomkerE.ADehorityB.A2010Protozoa in the digestive tract of wild herbivores in South Africa. I: Warthogs (Phacochoerus aethiopicus)249263683.DehorityB.A1984Evaluation of sub-sampling and fixation procedures used for counting rumen protozoa4818218564768282403604.DehorityB.A2003Rumen Microbiology5.DehorityB.AOdenyoA.A2003Influence of diet on the rumen protozoal fauna of indigenous African wild ruminants502202236.DehorityB.ATirabassoP.A2001Effect of feeding frequency on bacterial and fungal concentrations, pH and other parameters in the rumen7929082912117681217.DogielV1925Nouveaux infusoires de la famille des Ophryoscolécidés parasites d’antilopes Africaines’ [New infusoria of the family of ophryoscolecid parasites in African antelope]21161428.DogielV1932Beschreibung einiger neuer Vertreter der Familie Ophryoscolecidae aus afrikanischen Antilopen nebst Revision der Infusorienfauna afrikanischer Wiederkäuer‘ [Description of some new representatives of the family Ophryoscolecidae from African antelope together with a revision of the infusorial fauna of African ruminants]77921079.El-ShazleyKHungateR.E1965Fermentation capacity as a measure of net growth of rumen organisms13626914269247105819110.KleynhansC.J1977The rumen protozoa of the impala (Aepyceros melampus) Lichtenstein, and the kudu (Tragelaphus strepsiceros) Pallas11.KleynhansC.JVan HovenW1976Rumen protozoa of the giraffe with a description of two new species1420321412.Van der WathJ.GMyburghS.J1941Studies on the alimentary tract of merino sheep in South Africa. VI. The role of infusoria in ruminal digestion with some remarks on ruminant bacteria17618513.Van HovenW1975Rumen ciliates of the Tsessebe (Damaliscus lunatus lunatus) in South Africa2245746281178814.Van HovenW1978Development and seasonal changes in the rumen protozoan population in young blesbok (Damaliscus dorcas Phillipsi Harper 1939)812713015.Van HovenW1983Rumen ciliates with descriptions of two new species from three African reedbuck species30688691