Ivermectin treatment of horses: effect on the distribution of lawns and roughs in horse pastures.

The research article is about a study that used aerial surveys to understand how regular ivermectin treatment of horses affects the distribution of grazed and ungrazed areas in horse pastures.

Research Objectives and Methodology

• The main objective of the study was to assess the feasibility of pin-pointing the grazing patterns of horses through bimonthly aerial surveys and standard cartographic techniques.
• These grazing patterns were mapped in pastures where horses were treated bimonthly with either 200 micrograms of ivermectin per kg or 10 mg of oxibendazole per kg. The two compounds are commonly used as deworming agents in horses.
• These aerial surveys were conducted three times during a grazing season to monitor any changes in grazing patterns and overall distribution of “lawns” (areas in the pasture heavily grazed by horses) and “roughs” (areas left ungrazed or less grazed).

Key Findings

• The distribution patterns of “lawns” and “roughs” in the pastures remained consistent throughout the duration of the study, regardless of the type of deworming treatment used. This suggests that the habitual grazing behavior of the horses was not significantly altered by either ivermectin or oxibendazole treatments.
• The use of aerial surveys in combination with cartographic techniques proved to be an efficient and objective way to analyze and understand the composition of horse pastures. This method provides a broad, comprehensive view of the spatial layout and usage of the pasture by horses over time.

Significance of the Study

• The research provides insights into how deworming treatments might influence the grazing behavior of horses but found no substantial effect of either ivermectin or oxibendazole on such behavior.
• Meanwhile, the application of aerial survey as a method to observe grazing patterns validates its efficiency and acccuracy. This can open up opportunities to use this approach in future studies analysing grazing behaviour and pasture management.