Effect of vaccination with an Escherichia coli bacterin-toxoid on milk production in dairy cattle |
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Authors: | JM Musser KL Anderson |
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Affiliation: | Department of Food Animal and Equine Medicine, College of Veterinary Medicine, North Carolina State University, Raleigh 27606, USA. |
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Abstract: | OBJECTIVE: To determine whether vaccination of lactating cattle with an Escherichia coli J5 bacterin-toxoid would produce a significant short-term change in milk production. DESIGN: Randomized, controlled clinical trial. ANIMALS: 84 healthy, lactating cows (42 Holsteins and 42 Jerseys). PROCEDURE: Control and vaccinated cows were paired on the basis of breed, days in milk, daily milk production 1 week prior to vaccination, and parity. One cow in each pair was inoculated IM with a commercially available bacterin-toxoid according to label directions; the other cow was given saline solution. Cows were milked twice daily for 5 days before and 5 days after inoculation. Milk production was compared by ANCOVA. RESULTS: Vaccinated cows produced significantly less milk than did control cows at the second and third milkings after inoculation. At these milkings, milk production in vaccinated cows was approximately 7% less than that of controls. CLINICAL IMPLICATIONS: Vaccination of lactating cattle with an E coli J5 bacterin-toxoid may cause a significant short-term decrease in milk production. |
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