The economic impact of malignant catarrhal fever on pastoralist livelihoods

Abstract

This study is the first to partially quantify the potential economic benefits that a vaccine, effective at protecting cattle against malignant catarrhal fever (MCF), could accrue to pastoralists living in East Africa. The benefits would result from the removal of household resource and management costs that are traditionally incurred avoiding the disease. MCF, a fatal disease of cattle caused by a virus transmitted from wildebeest calves, has plagued Maasai communities in East Africa for generations. The threat of the disease forces the Maasai to move cattle to less productive grazing areas to avoid wildebeest during calving season when forage quality is critical. To assess the management and resource costs associated with moving, we used household survey data. To estimate the costs associated with changes in livestock body condition that result from being herded away from wildebeest calving grounds, we exploited an ongoing MCF vaccine field trial and we used a hedonic price regression, a statistical model that allows estimation of the marginal contribution of a good's attributes to its market price. We found that 90 percent of households move, on average, 82 percent of all cattle away from home to avoid MCF. In doing so, a herd's productive contributions to the household was reduced, with 64 percent of milk being unavailable for sale or consumption by the family members remaining at the boma (the children, women, and the elderly). In contrast cattle that remained on the wildebeest calving grounds during the calving season (and survived MCF) remained fully productive to the family and gained body condition compared to cattle that moved away. This gain was, however, short-lived. We estimated the market value of these condition gains and losses using hedonic regression. The value of a vaccine for MCF is the removal of the costs incurred in avoiding the disease.

Figure 1. A map of the study site.

Indicated are the location of Tarangire National Park (TNP), the Simanjiro Plain (SP), Emboreet Village (pink triangle), the wildebeest migration routes (blue broken line) and the direction the cattle travel (black solid line) to find substitute grazing pastures (orange area). Source: Map created by Thomas Morrison and Felix Lankester

Figure 2. Density plot illustrating the distance (km) that cattle herds travelled to avoid wildebeest calves and MCF virus.

Dashed red line indicates the mean

Figure 3. Density plot illustrating the length of time (days) cattle herds spend avoiding wildebeest calves and infection with the MCF virus.

Dashed red line indicates the mean

Figure 4. Scatter plot of the length of time (days) plotted against the distance travelled (km).

The blue line and the grey areas indicate the regression line (p-value < 0.03, r = 0.4) and its confidence intervals respectively.

Figure 5. Bar chart of the proportion of the treatment herd cattle recorded sick during the study period.

Data collection points were either 2 or 3 days apart and this accounts for the variation of the spacing of the bars. The plot is annotated with lines indicating the position of time periods 1–3.