Improved stability and specificity of baits for oral administration of substances to wild boar.

ABSTRACT

Oral vaccination is one of the most effective interventions for disease control in wildlife. As a result of the recent global reemergence of African swine fever and ongoing classical swine fever and animal tuberculosis, oral vaccination of Eurasian wild boar (Sus scrofa) receives increased interest. Several baits for wild boar and feral pigs have been described, but developing more stable and personalized formulations is important. This paper proposes a new bait formulation primarily composed of corn flour, piglet feed, sugar, and honey as a binder to obtain improved elasticity. The bait consists of a matrix with no protective coats, has a hemispherical shape (ø 3.4 ×1.6 cm), and displays an anise aroma and blue color. The color and aroma did not affect bait choice by wild boar, while bait coloring contributed to avoid consumption by non-target species (corvids). Baits with the new formulation were significantly more resistant to humidity and high temperatures than previous versions. Simulations suggest that baits with the new formulation are elastic enough to resist impacts from a maximum altitude of 750 m. Thus, the new bait prototype solves several problems of previous bait formulations while keeping a format that can be selectively consumed by piglets and adult wild boar.