Dr. Murai Éva szerk.: Parasitologia Hungarica 22. (Budapest, 1989)
Gastrointestinal helminth prevalence, and intensity of infection, in dairy cattle from Avalon Peninsula, Newfoundland Dr. Richard M. HARDING and Dr. William THRELFALL Department of Biology, Memorial University of Newfoundland, St. John's, Canada "Gastrointestinal helminth prevalence, and intensity of Infection, In dairy cattle from the Avalon Peninsula, Newfoundland".-Harding, R.M. and Threlfall, W. - Parasit. hung. 22_: 67-74. 1989. ABSTRACT. A study was conducted in 1985 to determine gastrointestinal helminth prevalence, and intensity of Infection, In dairy cattle on farms and pastures on the Avalon Peninsula, Newfoundland, using a fecal egg count technique. It was found that 55% of adult dairy cattle on ten farms in the St. John's area were positive for helminth eggs. The mean egg count for the area was 1.2 eggs per gram of feces. The majority of the eggs (60%) were from a group containing the genera Ostertagia-TrlchostrongylusCooperia , with 30 % from Haemon- c h usOe s op hagos t om urn , 5% Bunostomum , and 5% trematodes. Trlchuris eggs were noted in only one sample. Bovine fecal samples from community pastures showed a 39% prevalence with 50% of the eggs being from the Ostertagia-Trlchostrongylus-Cooperia group. 22 % Haemonchus-Oesophagostomum. 16 % Bunostomum and 2 % for each of Nematodlrus . Trlchuris and trematodes. KEY WORDS: Newfoundland, dairy cattle, nematodes, flukes, feces, prevalence, eggs per gram. Production losses can occur in domestic livestock harbouring subclinical levels of parasites (12) . In dairy cattle losses include decreased milk yield (3) and milk fat production (7). Subclinical parasitism can be controlled by anthelmintic treatment; alone, this strategy provides only a short-term relief (11). Despite the fact that anthelmintic administration at parturition results In an Increased milk production (20) many farmers still do not Include deworming programs In their herd health programs. In a survey in southwestern Ontario, 26 out'of 28 farms reported no use of anthelmintics and only one farm submitted fecal samples for laboratory examination routinely (16). There are no reports of studies of helminths of Newfoundland dairy cattle. This study was initiated In 1985 to determine the prevalence of, and intensity of infection with, gastrointestinal helminths in two groups of cattle, (1, lactatIng; 2, pastured for the summer) using a fecal egg counting technique. MATERIALS AND METHODS Sampling provided data on the gastrointestinal helminths in two different groups of cattle, namely 1) those on ten dairy farms In the St. John's area; and 2) those cattle (heifers and dry cows) grazing for the summer on four nearby community pastures (Fig. 1).
