One of the challenges for veterinarians serving the food animal industries is to enhance value for producers whose profit margins have been under considerable economic pressure for the past half century Decreasing profit margins and relative animal value have limited the scope of cost-effective interventions veterinarians can provide for producers that are also profitable for the veterinarians. In response to these economic forces, larger farms employ unlicensed, fulltime health-care providers to deliver many services previously provided by licensed veterinarians. The common endemic nature of diseases on dairy farms likely contributes to this trend because common conditions are amenable to prescriptive diagnosis and treatments. Although the incidence of disease conditions is similar on farms of various sizes,1 larger farms manage more cows. Therefore, a similar disease incidence provides dairy producers on larger farms more exposure to an absolute number of routine disease conditions. Conversely, smaller farms lack the number of affected cattle to successfully train and employ a dedicated health-care provider for their herds. This places smaller farms at an economic disadvantage and may be one of the factors that favor the consolidation of food animal production into larger production units.
Correction of an LDA is the most common surgical procedure in dairy cattle.2 Numerous techniques have been described for the correction of this condition, including medical management, abomasopexy or omentopexy via laparotomy or laparoscopy, and percutaneous abomasopexy (such as the R&T procedure).2 Originally used as a salvage procedure, the R&T technique for correction of LDAs has been found to have outcomes similar to those for laparotomy or laparoscopy.3,4 The simplicity of the R&T procedure has enabled correction by on-farm health-care providers in place of surgical correction by licensed veterinarians in an attempt to reduce cost of correction.
Survival outcomes after LDA correction provided by veterinarians and LDA correction provided by herd personnel have been compared.4 In that study,4 veterinarians used the R&T method or laparotomy. The 60-day postintervention survival rate was 79% and 73% for veterinarian-provided R&T and laparotomy interventions, respectively. All LDA corrections performed by herd personnel were via the R&T method, with a 60-day postintervention survival rate of 71%, which was similar to the rate for veterinarian-provided corrections via the R&T procedure. A similar survival rate (76.6%) at 70 days of lactation was reported for herd personnel performing the R&T procedure.5 In other studies,6–8 survival data for LDA corrections performed by veterinarians via the R&T procedure ranged from 52% to 92%. Given the variation possible in outcome reported for correction via the R&T procedure, producers need to make informed decisions on whether to have herd personnel perform the procedure on the farm or to have a veterinarian perform this procedure. Veterinarians need to determine whether they should offer this procedure to producers or, instead, should train and oversee herd personnel to perform this procedure.
Decision analysis is a common technique used in business and medical practice to examine a range of outcomes that have associated probabilities of occurrence. The construction and use of a decision tree in veterinary medicine have been described elsewhere.9–11 Decision analysis has been used in food supply veterinary medicine to determine whether treatment or salvage has greater economic value10 as well as to identify the treatment with the best economic outcome.11,12
Briefly, a decision tree is constructed of decision nodes (represented as squares) and chance nodes (represented as circles) that follow mutually exclusive decision choice paths and associated probability attributes. The decision nodes represent points at which a veterinarian or producer makes a decision about who will be involved in the treatment of the animal. The chance nodes represent the probability of each outcome along with its associated cost. The expected value of each decision is calculated by weighting the value of each outcome by its expected probability and summing the branches within the same chance node. The resulting values are compared for each alternative, and choosing the branch with the highest value will maximize economic return over a series of choices. In the study reported here, we used decision analysis to evaluate the economic outcomes for health-care services provided by a licensed veterinarian or herd personnel as measured by comparison of outcomes for correction of an LDA.
American College of Veterinary Surgeons
Cost of herd personnel-provided intervention
Cost of veterinarian-provided intervention
Credentialed veterinary technician
Left displaced abomasum
Probability of a successful outcome with herd personnel-provided service
Probability of a successful outcome with veterinarian-provided service
Value of a dairy cow after a favorable outcome
Value of a dairy cow after an unfavorable outcome
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