Epidemiology of gastrointestinal nematode infections in grazing yearling beef cattle in Saskatchewan.

The objective of this study was to provide contemporary data on the epidemiology of gastrointestinal nematode parasite infections of grazing yearling beef cattle in the province of Saskatchewan. Fecal samples (n = 1290) were collected over 4 time periods during the summer grazing season from 21 separately managed groups of cattle. Fecal egg counts (FEC) were estimated using generalized estimating equations with a negative binomial distribution with log link function, adjusting for clustering of samples within each herd for each time period. Nematodirus spp. and Trichuris spp. eggs were enumerated separately and were detected in 5.7% (73/1290) and 1.7% (22/1290) of samples, respectively. One or more strongyle-type eggs were detected in 79.5% (1025/1290) of the samples and FEC increased by 2.8 times over the summer grazing season. Interestingly, FEC were ~3.4 times higher on pastures located in dark brown versus brown soil zones, a finding that warrants further investigation.