Preliminary Evaluation of the Effectiveness of the GAVACⓇ Immunogen and the Rational Use of Acaricides as an Alternative for an Integrated Tick Control Program in Ecuador

Abstract

Abstract Rhipicephalus microplus one of the ectoparasites with the most significant impact on livestock health and the economy in Ecuador and globally. Controlling ticks through chemical means has been demonstrated to be ineffective, resulting in acaricide resistance and increasing costs and health problems in tropical and subtropical livestock. Several tick control alternatives have been investigated to date, showing promising results under laboratory conditions but not in field applications. The use of multiple control alternatives in a comprehensive management plan for tick control has proven to be effective in reducing tick infestation. The objective of this study was to determine the effectiveness of immunization with the GavacⓇ vaccine and its effect on the rational use of acaricides. The study aimed to establish the impact of immunization on the biotic potential of Rhipicephalus microplus, the level of infestation, and the frequency of acaricidal baths. In a pilot farm, 176 bovines were vaccinated, and 30 animals were observed every 15 days for eight months, resulting in 18 observations. Observationally, a significant reduction in tick load on animals was identified, as well as a reduction in the use of acaricides by less than 10% (1 bath) compared to the farm's estimated use. On average, acaricidal baths were administered 23 days after vaccination. The study found a statistically significant decrease in the number of ticks on the animals, the weight of the eggs, and their hatching percentage after the inclusion of the vaccination program on the farm. However, no statistically significant effect on the weight of engorged ticks was observed. In conclusion, the GavacⓇ vaccine has a positive observational effect on controlling the presence of ticks in animals and a negative effect on their reproductive aspects.

Keywords

• rhipicephalus microplus
• vaccine
• bovines
• acaricide control
• integrated tick control program.