Economic evaluation of 4 bovine leukemia virus control strategies for Alberta dairy farms

摘要

Bovine leukemia virus (BLV) is a production-limitingdisease common in North American dairy herds. Tomake evidence-based recommendations to Canadiandairy producers and their consultants regarding costand financial benefits of BLV on-farm control, aneconomic model that takes the supply-managed milkquota system into account is necessary. Albertaspecificinput variables were used for the presentedanalysis. A decision tree model program was used toevaluate economic aspects of decreasing a 40% BLVwithin-herd prevalence on dairy farms by implementingvarious control strategies over 10 yr. Investigatedstrategies were (1) all management strategies, including3 options for colostrum management; (2) somemanagement strategies; (3) test and cull; and (4) testand segregate. Each of these strategies was comparedwith a no control on-farm approach. The prevalencefor this no-control approach was assumed to stay constantover time. Each control strategy incurred specificyearly cost and yielded yearly decreases in prevalence,thereby affecting yearly partial net revenue. Infectionwith BLV was assumed to decrease milk production,decrease cow longevity, and increase condemnation ofcarcasses at slaughter from cattle with enzootic bovineleukosis, thereby decreasing net revenue. Cows infectedwith BLV generated a yearly mean partial net revenueof Can$7,641, whereas noninfected cows generatedCan$8,276. Mean cost for the control strategies rangedfrom Can$193 to Can$847 per animal over 10 yr in a146-animal herd. Net benefits of controlling BLV onfarm, as compared with not controlling BLV, per cow ina 146-animal herd over a 10-yr period for each strategywas: Can$1,315 for all management strategies (freezer);Can$1,243 for all management strategies (pasteurizer);Can$785 for all management strategies (powdered colostrum);Can$1,028 for some management strategies;Can$1,592 for test and cull; and Can$1,594 for testand segregate. Consequently, on-farm BLV control wasfinancially beneficial. Even though negative net benefitswere possible and expected for some iterations, oursensitivity analysis highlighted the overall robustness ofour model. In summary, this model provided evidencethat Canadian dairy farmers should be encouraged tocontrol BLV on their farm.