Dr. Murai Éva szerk.: Parasitologia Hungarica 21. (Budapest, 1988)

POWERS, WOOD, ECKERT, GIBSON and SMITH, 1982; DOWNEY, 1981) an enzyme digestion method described in a British methodological publication (Tech. Bull. No. 18, 1971) was chosen. After careful removal of their contents by washing, the abomasa were weighed to determine the volume of digestive fluid required. Subsequently the entire abomasa were digested in a digestive fluid preheated in a water-bath of 37 °C. The composition of the digestive fluid was as follows: 940 ml distilled water, 8 g pepsin, 20 ml cc. HCl, and 23 ml cc. NaCl solution. One litre of digestive fluid was sufficient for digesting 500 g of abomasum. The abomasa were digested at 37 °C for 8 hours by mixing at 15- to 20-minute intervals. Undigested tissues were removed and the fluid containing the digested mucosa was filtered through two filters: ths pore size of the upppr and lower filter was 125 and 71 _um, respectively. The upper filter retained undigested tissues, fat and sometimes one or two mature worms, while on the lower filter immature worms inhabiting the abomasal wall and colloidal fat were left over. The material retained by the lower filter was washed down with physiological saline, made up to 100 ml, and preserved with formalin. The lipid layer formed a few days later was removed with a blast pump. One-tenth and one-fifth of the decanted and digested sample, was examined, respectively. From the results the total worm and larval counts were estimated. Generic identification of the worms was carried out under a microscope. Some of the abomasa examined (n = 26) were derived from the Budapest Abattoir from cattle slaughtered normally or in an isolated manner. No data are available on the provenience or managemental conditions of these animals. The abomasa of five growing heifers were obtained from the slaughter-house of the State Farm of Izsák. These heifers had been kept under semi-intensive conditions exclusively on pasture before slaughtered. A total of 31 slaughter cattle were examined. 2. Coprological examination of cattle herds To determine the prevalence and intensity of infection, faecal samples collected from cattle of both sexes and different ages and state farms in several agricultural co-operatives were examined by quantitative ovoscopy. Freshly excreted individual faecal samples collected on the pasture were used. Whenever possible, individual faecal samples taken from the rectum were examined. Egg counts per gram of faeces (EPG) were determined by individual examination of faecal samples by McMaster's method. Fresh faecal samples or those stored at most for 24 hours at+4°C were used for the determinations. The percentual proportion of infected animals and the degree oi egg shedding were determined by quantitative faecal examination. Faecal samples from a total of 1 158 cattle of 18 agricultural farms in six counties (BácsKiskun, Fejér, Komárom, Nógrád. Somogy and Szolnok) of Hungary were examined. RESULTS 1. Survey of the prevalence of gastrointestinal helminthosis in slaughter cattle a) Study of helminths parasitizing the abomasum and small intestine A total of 58 cattle (16, 7, 16, 6 and 13 from the counties Borsod-Abaúj-Zemplén (BAZ), Csongrád, Nógrád, Tolna and Veszprém, respectively) were examined. In 55 out of these 58 animals (94. 8%) one or more helminth species were found. Fifty of the 55 parasitized cattle (90.9%) harboured two or more helminth species (Table 2). The prevalence and number of gastrointestinal nematodes in the cattle examined are shown