Control of gastrointestinal parasitism in calves in Sweden over six years using the morantel sustained release bolus

摘要: During the 6 years 1979-1984, use of morantel sustained release bolus (MSRB) was monitored in first year grazing calves. Twenty-four to 30 calves each were allotted two groups (controls and MSRB-treated) turned out at end May on same pasture divided into equal areas. After housing October, group kept boxes fed concentrates, whey hay. The weighed monthly intervals until animals sent slaughter. No cases clinical ostertagiasis Type I observed control during seasons, but one (1983) signs occurred 2 weeks after housing. number overwintering larvae influenced by contamination previous season climatic conditions winter spring. fecal egg output did not reflect level turnout. build-up larval later part conditions. treated low entire resulting a significantly reduced contamination. A live-weight gain demonstrated five six years. When heavily infected housing, performance still negatively fattening period indoors.