Recipient Organization
UNIVERSITY OF CALIFORNIA, DAVIS
410 MRAK HALL
DAVIS,CA 95616-8671
Performing Department
Population Health & Reproduction
Non Technical Summary
Treatment for intestinal parasites (deworming) is commonly practiced on beef cattle operations as part of herd health management and to increase efficiency of the herd. Among the perceived benefits of anthelmintic treatment are improved immune status, increased weight gain and better reproductive performance. Today, as has been the case for the last thirty years, there are three primary classes of dewormers available for the treatment of beef cattle and no new anthelmintic class or specific drug has been approved by the FDA in many years. Recently, the FDA has started requesting drug companies to add information about antiparasitic resistance on dewormers due to increasing concerns about possible resistance to these drugs. There is also evidence that efficacy of different routes of administration (given by mouth, as an injection or on the skin) may be variable. California is the fourth largest beef cattle producer in the United States with 5.2 million head of cattle. Surveys on the practices of usage and effectiveness of anthelmintics across the state are missing, in particular, there is very little knowledge on any trends in resistance to the common dewormers used in cow-calf operations in California or the Western United States. The last survey on anthelmintic efficacy across the United States was performed as part of the 2007-2008 NAHMS beef study but included only one ranch in California. Although evidence on the resistance of intestinal parasites to dewormers, especially to the class of macrocyclic lactones exists, no recent data in California is available on the practices, uses and efficacies of these drugs. The objective of this study is to gain insight into the usage patterns and efficacy of anthelmintic treatments on beef cattle operations in California.
Animal Health Component
100%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Goals / Objectives
The major goals of this project are to evaluate the need for and efficacy of commonly used dewormers on beef cattle ranches in California. There is growing concern about resistance to anthelmintics used in livestock species but recent data from the western US on efficacy or parasite load are missing. It is difficult to formulate recommendations to ranchers on judicious use of anthelmintics in this region with a drastically different climate than other regions in the U.S. without supporting data.
Project Methods
A convenience sample of a target of 50 cow-calf ranches in California will be enrolled through the network of livestock advisors in the UCCE network with approximately 40 of the herds grazing irrigated pasture. Enrollment criteria are pasture exposure during the previous six months and no treatment with anthelmintics in the 45 days prior to the visit, or not within the previous 150 days with long-acting eprinomectin. Participating herds will be visited at the time of planned treatment with anthelmintics by producers. Producers may use the anthelmintic drug of their choice as we intend to capture and analyze data on current deworming practices as well as on efficacy of the drugs used on California ranches. Feces from a random sample of 10 animals will be sampled.An additional 5 animals will be sampled but left untreated at the time of enrollment. Fecal samples of at least 50 g each will be collected from the rectum of cattle using fresh gloves for each animal as they are moved through a chute system and before the anthelmintic is applied. Samples will be stored in labelled plastic bags on ice for delivery or shipment to the lab. Study personnel will be conducting a survey of the deworming practices on the ranch via an in-person questionnaire. The type of anthelmintic drug(s) (brand name, dose used, method of determining dosage, duration of usage), regimen of drug rotation if any, breed of cattle, age range of cattle in the sampled group, type of pasture, and date and location of treatment will be recorded via the questionnaire. For cattle on irrigated pasture, a second round of samples will be collected from the same animals 14-16 days after the first collection date. The outcome measure is the change in fecal egg count (FEC) post treatment. We will be using the mini Flotac system, which has greater sensitivity than the McMaster technique to assess FEC. In addition, pooled samples will be sent out to California Animal Health and Food Safety lab for fecal sedimentation to detect fluke eggs for pretreatment samples and to Texas A&M veterinary diagnostic lab for coproculture for both pre and post treated samples to determine gastrointestinal parasite species susceptibility.