The potential effect of Garlium GEM HCTM as a tick control agent in cattle.

As resistance to chemical acaricides increases amongst tick populations, investigations of natural remedies that have acaricidal or tick-repellent effects have become essential in the search for alternatives for sustainable tick control. Garlium GEM HC (Garlium), a natural concentrated garlic product, was supplemented in-feed to beef cattle to determine if it could assist in reducing the number of attached ticks on cattle. Two grams of Garlium was supplemented daily to eight Bonsmara steers over 43 days. A second group of eight steers served as controls. All animals were infested with a similar number of Rhipicephalus appendiculatus adults and Rhipicephalus microplus larvae. Subsequently, the number of attached engorged ticks and the hatchability of the tick eggs were determined. Blood samples were collected from the steers for whole blood analyses. The results were analysed using a twosample t-test procedure. Due to large standard deviations observed, most of the tick parameters were only numerically improved. Although not significant, the number of larvae produced by female R. appendiculatus ticks per host was reduced by 23%. Estimated number of R. microplus larvae produced from ticks harvested from Garlium supplemented cattle were reduced by 42.3% (p = 0.10). No adverse effect was observed on haematocrits or haemoglobin concentrations. Garlium reduced segmented neutrophil count in the treatment group, suggesting that the immune system was less challenged. Although not statistically significant, the effect of reducing the number of larvae produced per host for the two tick species by approximately 20% and 40% respectively, may be of economic benefit to commercial cattle farmers.