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Summary:

The value of the marginal product (vmp) for veterinary services and medical supplies (vetmed), and the profit maximizing level of vetmed were estimated for dairy producers. Data from the Pennsylvania Farmers Association-Dairy Farm Business Analysis system during the years of 1986 to 1990 were used to evaluate the functional relationship between production and expenditures for vetmed. Other input variables examined were man-year equivalents of labor, asset values, value of feed fed, and culling rate. Data were screened to reflect economically viable dairy farms in Pennsylvania, and 173 such farms participated for each of the 5 years analyzed. The vmp was estimated for 1990. Profit maximizing levels for vetmed were estimated for 1990 holding other input variables at their mean values.

Mean expenditures for vetmed were $2,606/farm, or $43/cow in 1990. The vmp for vetmed was estimated to be $3.22 or $4.98, depending on the method of calculation. In other words, the marginal dollar spent on vetmed generated $3.22 ($4.98) in additional revenue from milk production. The profit maximizing level of expenditures for vetmed was $138/cow, substantially more than the mean, indicating the potential for farms in this data set to improve profitability through additional expenditures on vetmed.

Free access
in Journal of the American Veterinary Medical Association

Summary

Efforts to reduce the prevalence of Staphylococcus aureus intramammary infection were monitored in 3 Ohio dairy herds. Bacteriologic culturing of milk from all lactating cows in each herd was completed multiple times to identify infected cows and monitor reduction. Partial budgeting techniques were used to determine the economic outcome of the reduction program. Of particular emphasis was the economic impact of culling to maintain or achieve milk quality premium payments on the basis of bulk tank somatic cell counts. The prevalence of S aureus-infected cows was reduced in each herd. Culturing of milk from all lactating cows appeared to be an effective method to identify infected cows. Although numbers were limited, it also appeared that culturing of composite quarter samples was effective as a herd screening test to identify S aureus-infected cows. Bacteriologic culturing had a negative financial impact in all 3 herds. Using partial budgeting to assess the economic impact of the programs, it was determined that 2 herds experienced negative financial impacts as a result of an excess culling rate when compared with a 12-month baseline period prior to the initiation of the project. All herds had increased milk production per cow during the study as measured by the mature-equivalent method. However, when actual production was considered, increased milk production in each herd was not as great as that of other Ohio herds enrolled on Dairy Herd Improvement Association testing programs. Thus, each herd had a slight negative impact in revenues as a result of lower than expected increased production. Two herds received milk quality premiums. Although quality premiums were as great as $70 per cow per year, excess culling costs resulted in a negative net financial impact during the first 2 full years of the project in 1 herd and the first full year of the other herd that received a quality premium. Overall results of this study suggest that although quality premiums may be substantial, excessive culling is expensive, particularly in the short run.

Free access
in Journal of the American Veterinary Medical Association

Summary

Productivity and economic effects of pseudorabies were estimated for a mean-size, farrow-tofinish swine enterprise. A Delphi technique was used to elicit productivity effects from an expert panel. Enterprise budgets for pseudorabies-infected and noninfected herds were constructed by use of these productivity estimates, as well as by use of economic data from secondary sources. Data examined to determine effects on productivity included preweaning, nursery, and growing/ finishing pig mortality; breeding hog mortality; feed conversion; labor; and veterinary services and medication expenses. Results indicated that profitability was lowered in infected herds by approximately $6/cwt of swine produced.

Free access
in Journal of the American Veterinary Medical Association

Summary

Epidemiologic modeling of the likely herd-to-herd transmission of pseudorabies virus (prv) was developed to assess the progress and potential for the prv-eradication program in the United States. The herd-to-herd transmission of prv over a 20-year period (1993 to 2012) in the United States was simulated under various scenarios, which included variable program-funding levels and variable prevalences. A transition model (Markov process model) was used to predict yearly changes in herd prevalence of prv infection. Five mutually exclusive states of nature for herds were assumed: uninfected and not vaccinated; uninfected and vaccinated; known to be infected and not vaccinated; known to be infected and vaccinated; and infected, but not known to be infected. Three prevalences for states in the United States were assumed: higher prevalence, moderate prevalence, and lower prevalence. Three funding levels were assumed: no eradication program, continued funding at the current level, and increased funding of 25%. Estimates made by an expert panel for determining probabilities in the state-transition matrices were used. A model also was developed, and was considered to be the most optimistic scenario likely under increased funding of 25%. The most optimistic estimates of the probabilities that still lay within the range of estimates made by the expert panel were used for this model. Only the optimistic transmission matrices allowed for total eradication of prv. Using the optimistic matrices, all states in the United States of America had moved into the moderate- or low-level risk status by the year 2000. The longest time taken to achieve eradication was for the state of Iowa, where eradication was not achieved until 2012.

Free access
in American Journal of Veterinary Research

Summary

A telephone survey was conducted of 50 randomly selected Ohio-licensed veterinarians engaged in dairy practice. The survey's purpose was to determine the extent of mastitis control services offered by practitioners and to assess their utilization of milk somatic cell count (scc) data on individual cows available from the Dairy Herd Improvement Association (DHIA). During the preceding year, 96% (48/50) of practitioners surveyed had performed bacteriologic culture of milk samples. Practitioners were twice as likely to have performed culture on milk from mastitic cows that failed to respond to treatment as they were to have performed culture for purposes of identifying pathogen trends within a herd. Veterinarians in predominantly dairy practices were more likely to have completed bacteriologic examination of milk in their own laboratories than were veterinarians who were engaged in <50% dairy practice (P = 0.016). Most veterinarians (83%) reported that coagulase test results were available or that Staphylococcus aureus was differentiated from other staphylococcal species. Streptococcus agalactiae was not differentiated from other streptococcal species by 35% of practitioners surveyed.

For veterinarians with clients enrolled in the dhia, 91% (43/47) reported looking at, discussing, or otherwise using the dhia records. Eighty-one percent (35/43) of veterinarians who had clients using services from the dhia reported that clients also received individual cow milk scc results. Veterinarians engaged in predominantly dairy practice expressed a greater familiarity with the linear score method of scc reporting than did veterinarians whose practices were <50% dairy (P = 0.085); however, both groups reported a preference for raw scc data. Veterinarian response regarding potential use of dhia scc data was compared with that obtained in a companion survey of Ohio dairy producers. Veterinarians were more likely than producers to consider use of scc from individual cows to select cows for culture and to establish a milking order. Although several results of our survey indicated current high veterinary involvement in mastitis control and dhia record utilization, other trends supported concerns regarding the future of veterinarian involvement in food animal health management.

Free access
in Journal of the American Veterinary Medical Association

Summary

Fecal samples were collected from 450 neonatal calves ranging from 1 to 30 days old, between May, 1988 and May, 1989 to estimate the prevalence of bovine group A rotavirus in a stratified random sample of Ohio daily herds. Calves were from 47 dairy herds chosen to be representative of Ohio herds. Bovine group A rotavirus was detected in fecal samples by a cell culture immunofluorescence test (ccif) and elisa. Of 450 samples tested, 46 (10%) were positive by ccif and 67 (15%) were positive by elisa. The agreement beyond chance between the 2 assays was good (kappa = 0.65). The overall prevalence rate of rotavirus shedding was 16.4% (74/450). Forty-three percent (29/67) of the samples positive by elisa were subgroup 1, none were subgroup 2, and the remaining 57% (38/67) could not be assigned to either subgroups 1 or 2. Thirty herds (62.5%) had at least 1 group A rotavirus-positive calf (mean number of samples per positive herd = 12.4), and 17 herds (37.5%) had no rotavirus-positive calves (mean number of samples per negative herd = 6.0). A live oral rotacoronavirus vaccine was used in neonatal calves of only 1 herd and 3 of 17 (17.6%) calves from this herd were positive for group A rotavirus. The percentage of the rotavirus-positive fecal samples from all calves (n = 450) when stratified by fecal consistency was as follows: 28.3% (13/46) had liquid feces; 25.6% (10/39) had semiliquid feces; 23.4% (22/94) had pasty feces; and 10.7% (29/271) had firm feces. Of the rotavirus-positive calves (n = 74), 17.6% (13/74) had liquid feces; 13.5% (10/74) had semiliquid feces; 29.7% (22/74) had pasty feces; and 39.2% (29/74) had firm feces. The average age of calves shedding rotavirus was 14 days (range, 1 to 30 days). Double-stranded (ds) rna extracted from 36 samples positive by 1 or both tests was examined by polyacrylamide gel electrophoresis. All samples positive by this technique (30/36) had long dsrna migration patterns, typical of group A rotaviruses, including samples from calves in the herd in which the oral vaccine was used. Moreover, the electrophoretic migration pattern of group A rotavirus dsrna in these vaccinated calves differed from that of the rotavirus vaccine strain, suggesting the rotavirus strain circulating in this herd was not the vaccine strain. All samples negative by ccif or elisa that had volumes > 5 ml (n = 323) were also subjected to dsrna extraction and polyacrylamide gel electrophoresis for detection of additional group A or nongroup A rotaviruses; none of them were positive by this technique.

Free access
in American Journal of Veterinary Research