Search Results

You are looking at 1 - 3 of 3 items for

  • Author or Editor: L. E. Heider x
  • Refine by Access: All Content x
Clear All Modify Search

Summary

Forty-eight herds participating in the 1988/1989 Ohio National Animal Health Monitoring System dairy project were monitored for 1 year to determine the effects of environment and management on mortality in preweaned calves. Environmental factors were evaluated by veterinarians during monthly visits to the herds. Management procedures were measured through the use of a questionnaire administered near the end of the project. Mortality in preweaned calves was calculated for each herd by using data from project records on calf mortality and animal inventory, which were collected monthly by veterinarians. Relationships between the management/environment variables and calf mortality were examined by use of analysis of covariance. Herd size, days on a nipple feeder, navel disinfection, type of housing, and whether each calf observed with diarrhea was treated with antibiotics were the variables that had an impact on herd mortality. These variables explained approximately 39% of the variation in mortality among herds.

Free access
in Journal of the American Veterinary Medical Association

SUMMARY

A dot elisa was developed for detection of antibodies to Mycobacterium paratuberculosis. The assay was evaluated by testing sera from cattle that were determined, by bacteriologic culturing of feces, to be infected with M paratuberculosis and were suspected of having clinical disease. Further evaluation involved testing sera from cattle in which M paratuberculosis had not been isolated from feces on several attempts. Results of the dot elisa were positive for sera from 86 of 101 infected cattle, and results were negative for sera from 64 of 64 noninfected cattle. Results of conventional elisa and agar gel immunodiffusion (agid) tests were positive for 79 of 99 and for 51 of 101 infected cattle, respectively.

The dot elisa also was evaluated by comparing results of testing 708 sera with results of bacteriologic culturing of matched fecal samples from 262 cattle in 3 central Ohio dairy herds known to include cattle infected with M paratuberculosis. Results of the dot elisa were positive for 25 of 39 sera from cattle with positive results on culturing of concurrently obtained fecal specimens. The dot elisa results were negative for 661 of 669 sera from cattle with negative results to culturing of concurrently obtained fecal specimens. The 39 sera from cattle with positive results on bacteriologie culturing of matched fecal specimens had positive results for elisa and the agid test 25 and 14 times, respectively. The 669 sera from cattle with concurrently negative results on bacteriologie culturing of feces had negative results to elisa and the agid test 559 and 668 times, respectively.

Free access
in American Journal of Veterinary Research

Summary

Nine dairy herds (mean size, 149 cows) with bulk-tank milk somatic cell counts of < 300,000 cells/ml and > 80% of cows with Dairy Herd Improvement Association linear somatic cell counts ≤ 4 were selected for study. Each herd was monitored for 12 consecutive months. Duplicate quarter-milk specimens were collected from each cow for bacteriologic culturing at beginning of lactation, cessation of lactation, and at the time of each clinical episode of mastitis. Streptococcus agalactiae was never isolated and Staphylococcus aureus was isolated from < 1% of all quarters. There were 554 episodes of clinical mastitis. During the year of study, the incidence rate of clinical mastitis varied from 15.6 to 63.7% of cows among the 9 herds. Mean costs per cow per year in herd for mastitis prevention were: $10 for paper towels, $3 for nonlactating cow treatment, and $10 for teat disinfectants. Mean cost associated with clinical mastitis was $107/episode. Approximately 84% ($90) of the costs attributed to a clinical episode were associated with decreased milk production and nonsalable milk. Costs of medication and professional veterinary fees per clinical episode varied Significantly among the 9 herds. Three of the herds did not have a veterinarian treat a clinical episode of mastitis during the year of study even though 2 of these herds had the first and third highest incidence rates of clinical mastitis. When calculated on a per cow in herd basis, mean costs of $40/cow/year were attributed to clinical mastitis. Our findings suggest that herds that have effectively controlled mastitis caused by contagious pathogens may still have substantial economic losses as a result of clinical mastitis and that losses and even rates of clinical mastitis may vary considerably among such herds.

Free access
in Journal of the American Veterinary Medical Association