Gastrointestinal nematodes of cattle in the northeastern US: results of a producer survey

A questionnaire covering management practices and producer perception of th e effects of gastrointestinal nematode infections was sent to dairy and bee f producers in the northeastern US. The mailing list was derived from membe rship in grazing groups and attendance at grazing events. A final total of 474 responses were suitable for analyses. These responses covered 14 states , but for the purpose of analysis were broken into five groups: New England (NE), Vermont (VT), New York (NY), Pennsylvania (PA), and south and west ( S and W) of Pennsylvania. Two-thirds of the responses were from dairy produ cers. The average number of animals for the farms was 50 cows, 27 heifers, and 20 calves. The average acreage used for grazing was 70 acres, and about two-thirds of the responses used rotational grazing for at least the cows. About one-half of the rotational grazers had been practicing rotational gr azing for more than 5 years. Most rotational programs for cows involved a d aily rotation, but the rotational interval for other age groups was longer. There was a difference of about 2 months (5.25-7.27) in the length of the grazing season as one moved from New England to south and west of Pennsylva nia. Parasite control practices varied greatly by location and animal class . Most producers used anthelmintics one to two times per year, but 10-30% o f responses said they did not deworm their cattle. The most common time to deworm was in the spring, and the second most common time was the fall. Bet ween 10 and 20% of respondents reported deworming as a response to decrease d productivity or body condition. The use of anthelmintics increased as the location moved from New England to south and west of Pennsylvania. Produce r perception of parasite effects was closely related to their anthelmintic use, and also increased as the location moved to the south, and is most lik ely the result of the increased length of the grazing season. Of producers who ascribed estimated a cost of the parasite, the majority estimated this cost to be between US$ 5 and 20 per animal per year. (C) 2001 Elsevier Scie nce B.V. All rights reserved.