Assessment of gastrointestinal nematode parasitism in dairy calves housed in calf hutches

摘要

Gastrointestinal nematodes [GIN] are an important cause of morbidity and production losses in cattle. Clinical infection with GIN can cause diarrhea and hypoalbuminemia, but subclinical infections are more prevalent, harder to recognize, and a greaterthreat to productivity. Emphasis in the dairy industry has been placed on management strategies to mitigate disease and productive losses caused by GIN infections in grazing heifers and adult cattle, but hutch calves have largely been left out of this discussion. Milk-fed dairy calves housed in hutches are presumed not to acquire GIN infection because transmission of GIN is thought to require exposure to a pasture environment and subsequent ingestion of contaminated forage. However, a recent assessmentof fecal egg counts (FEC) in hutch calves for another research project revealed calves raised in hutches with unexpectedly high FEC. The objective of this study was to estimate the prevalence and magnitude of GIN in hutch calves on two calf ranches andto evaluate factors associated with the probability for calves to be parasitized.