Rotational Grazing Modifies Rhipicephalus microplus Infestation in Cattle in the Humid Tropics

SIMPLE SUMMARY: Ticks are one of the main problems in production units, mainly because they have become resistant to the chemicals used to control them. Several alternative methods to chemicals have been sought to control tick infestations in cattle, which are practical and friendly to the environment. In this work, we implement rotational grazing to combat ticks at the pasture level. We found that a 30-day rest period for pastures (without animals) is not enough to reduce the presence of ticks in animals but that a 45-day rest period does reduce the presence of ticks in cattle. These studies are critical since they would help cattle producers design better strategies that help reduce the use of chemical acaricides and the presence of chemicals in milk, meat, and the environment. ABSTRACT: Rotational grazing has been mentioned as a potential tool to reduce losses caused by high tick loads. This study aimed: (1) to evaluate the effect of three grazing modalities (rotational grazing with 30- and 45-day pasture rest and continuous grazing) on Rhipicephalus microplus infestation in cattle, (2) to determine population dynamics of R. microplus in cattle under the three grazing modalities mentioned in the humid tropics. The experiment was carried out from April 2021 to March 2022 and consisted of 3 treatments of grazing with pastures of African Stargrass of 2 ha each. T1 was continuous grazing (CG00), and T2 and T3 were rotational grazing with 30 (RG30) and 45 d of recovery (RG45), respectively. Thirty calves of 8–12 months of age were distributed to each treatment (n = 10). Every 14 days, ticks larger than 4.5 mm were counted on the animals. Concomitantly, temperature (°C), relative humidity (RH), and rainfall (RNFL) were recorded. Animals in the RG45 group had the lowest count of R. microplus compared to the RG30 and CG00 groups; these results suggest that RG45 days of rest could be a potential tool to control R. microplus in cattle. Yet, we also observed the highest population of ticks on the animals under rotational grazing with a 30-day pasture rest. A low tick infestation characterized rotational grazing at 45 days of rest throughout the experiment. The association between the degree of tick infestation by R. microplus and the climatic variables was nil (p > 0.05).