Dr. Murai Éva szerk.: Parasitologia Hungarica 21. (Budapest, 1988)
in Table 3. The results have confirmed the data in the literature that in the bovine abomasum Ostertagia spp. are the most prevalent helminths. In the present study 53 out of the 58 animals (91. 3%) were parasitized by Ostertagia ostertagi (Stiles, 1892). More than half of all helminths found were O. ostertagi. It should be mentioned that in the five animals in which only one helminth species was found (Table 2), it was always Q. ostertagi . .Grosspiculagia podjapolskyi (Schulz, 1954), a nematode belonging to a subgenus of the genus Ostertagia, was also prevalent (55. 1%): however, this helminth, occurred in very low numbers. Trichostrongylus axei (Cobbold, 1879) and Haemonchus contortus (Rudolphi, 1803) also belong to common parasites of the abomasum. Of nematodes parasitizing the small intestine, Cooperia spp. (C. punctata (Linstow, 1907) and C. oncophora (Railliet, 1898) occurred most frequently. A total of 33 cattle (56.8%) were infected by this helminth species. In 16 animals these two Cooperia species occurred simultaneously. Nematodirus helvetianus (May, 1920) and Bunostomum phlebotomum (Railliet, 1900) was found in 6 and 5 animals, respectively: these worms do not seem to have great importance in the age group studied. Other helminth species occurred sporadically in small numbers. b) Sedimentation of the abomasal contents and enzyme digestion study of the abomasal mucosa for helminths and their larvae The abomasum of 16 out of 31 randomly selected slaughter cattle yielded trichostrongylid worms. This corresponds to a prevalence of 51%. The results are summarized in Table 4. The average mature worm count of the infected samples was 2 250 (range: 100-6 800). Such a mild infection can usually be regarded as subclinical. Analysis of the mature worms inhabiting the lumen of the abomasum revealed that members of the genus Ostertagia, a trichostrongylid genus considered pathogenic, were the most prevalent (63.6%) in the abomasa examined. Trichostrongylus spp. (33.5%) were also common, whereas the prevalence of Hae monchus was negligible in this test sample. Studies on the sex distribution of abomasal helminths revealed that 28. 3% and 71. 6% of Ostertagia worms were males and females, respectively. For Trichostrongylus spp. the proportion of males and females was 30. 3 and 69.4%, respectively. Fifteen out of the 31 abomasal samples contained larvae of histotropic stage. The average number of larvae was 332. The number of larvae varied widely in the parasite-containing samples, the range being 28- 1 224 (Table 4). There were only two samples in which only larvae were demonstrable. In all samples but one besides the mature worms there were always larval stages in the abomasal mucosa. 31. 1 % of the larvae-and immature stages was found in the decanted supernatant and 68. 9% in the wall of abomasum, in histotropic phase. 2. Coprological examination of cattle herds Faecal samples taken from a total of 1 158 cattle (344 cows. 42 breeding bulls, 170 calves, 410 growing heifers, 92 fattening bulls and 100 fattening heifers) were examined. The results are summarized in Table 5. On the basis of a single examination 69.9% of the cattle examined proved to be parasitized by gastrointestinal nematodes. The percentage of infected animals and EPG counts were the lowest in cows and breeding bulls. In younger animals these indices were higher and showed larger variation. The differences are presumably due to the local conditions (start of grazing, contamination of pasture, animal density on pasture, age of the animals, etc.). Prevalencp of infection was rather high in earlier grazed animals that were fattened after weaning, indicating that the animals had become infected on the pasture and this infection, together with its consequences, was still demonstrable during fattening.
