Permanent Transmission of Endoparasites in Large Herds of Catile

Bej§ovec, J.: Permanent Transmission of Endoparasites in Large Herds of Cattle. Acta vet. Bmo,60, 1991: 205-212. Calving houses were found to be cohtaminated with endoparasites by the first crop of pregnant cows arriving in the new premises. No significant differences were found in the incidence of endoparasite species between new and old calving houses by' artalysis of variance. The proportions of dams excreting coccidial oocysts and gastroenteronematode eggs were 97.2 % and 38.1 %,respectively. The calves became. infected with small numbers of endoparasites. After transfer to large-capacity calf houses coccidia and· gastroenteronematodes were found in 57.8 % and 7.1 % of them, respectively. The .intensity. of their infection was, for the most part,. weak. After being changed to plant nutrition all calves became infected with coccidia and. the intensity of their infection underwent a large temporary increase; some animaIsshowed clinical coccidiosis. From large-capacity calf houses a wide spectrum.of coccidial and geohelminth species was transmitted to further animal categories· including grazing cattle. The most frequently. transmitted parasites are highly pathogenic coccidia Eimma bwis and E. zuernii. The intensity of infection was, for the most part, weak. Cattle, large herds, animal category, coccidia, helminths,. transfer Bovine parasites in large. herds of cattle in the Czechoslovak Federati¥e Reput;lie hav.e keD: considerably affected by veterinary measures and modern animal husbandry and animal hygiene practices conducted there for several years. Helminthoses are now present mainly in the su~ nical form (Hovorka and. Corbal984). In his study on gastroenteroheIiDinthoses Chraust (1967) pointed out that" ••• besides clinically diseased animals it is mainly thepresenceofasymptomatic conditions which can worsen and accelerate processes of another aetiology, impair the immunity to infectious diseases and exert serious adverse effects on general perfOrmance of the animals". According to Supperer (1973), a.o.,helminth larvae parasitizing in the alimentary tract of calves may activate, in the process of their migration, latent viraI and bacterial infections of the respiratory tract. In recent years the interest in helminthoses in our country· receded· and it has become necessary to pay more attention to coccidiosis. The danger of coccidiosis was pointed out by Zaji(!ek (1962) as early as the first l8rge-capacity calf houses in our C'ountry were being designed. Put into operation, these large-capacity calf houses gave rise to conditions favourable to coccidia which infect calves very soon after birth (Bejlovtc 1985, 1986). Pavlasek (1985) found coccidia in barns housing dams. Coccidia cause mortality among calves and decrease their body mass, on average, by 12: to 20 kg (Chroust 1966). Aecording to Papa<!ek and Pavlasek (1984) the body mass of coccidia-infected calves was decreased by 10 to 50 %. Bedrnfk et aI. (1980) drew attention to the role of coccidia in the pathogenesis of diarrhoeal diseases among calves. Chroust (1964) examining dead calves found bronchopneumonia as a complication of coccidiosis. According to MenUlt et al. (1984), &.0., the morbidity and mortality of calves kept under intensive husbandry conditions are generally,the result of synergic action of many. microorganisms.