Assessing the feasibility of targeted selective treatments for gastrointestinal nematodes in first-season grazing cattle based on mid-season daily weight gains.

A retrospective study was carried out to assess the possibility of using daily weight gain in first-season grazing cattle (FSG) as a marker for treatment decisions to prevent parasite-induced losses caused by gastrointestinal (GI) nematodes. This is intended as a proof of concept for using targeted selective treatments (TSTs) in the control of veterinary parasites. Historical data were combined from three independent grazing trials in Sweden, each of which was repeated over 2-3 years, in order to investigate the influences of parasites on the performance of FSG cattle subjected to different levels of parasite control.

Seasonal translation of infective larvae of gastrointestinal nematodes of cattle and the effect of Duddingtonia flagrans: a 3-year pilot study.

A study was conducted over 3 years (1998-2000) to investigate larval availability of gastrointestinal nematodes from faeces of cattle reared under different parasite control schemes. These cattle were part of a parallel, but separate grazing trial, and were used as donor animals for the faecal material used in this experiment. At monthly intervals, faeces were collected and pooled from three groups of first-season grazing cattle.

Evaluation of gastro-intestinal nematode parasite control strategies for first-season grazing cattle in Sweden.

A three-year grazing experiment (1998-2000) was conducted with first-season grazing cattle (FSGC) on improved pastures in central-eastern Sweden. Comparison was made between five groups with 10 calves in each group where four of these were set stocked and either (1) untreated, (2) ivermectin bolus treated, (3) subjected to biological control with the nematophagous fungus Duddingtonia flagrans, or (4) treated with a copper wire particle bolus. The fifth treatment was an evasive grazing strategy, whereby untreated calves were turned out onto pasture used by older cattle the previous year and then these calves were moved to silage aftermath in mid-July.