Use of insecticide-impregnated ear tags for the control of face flies and horn-flies on pastured cattle

Efficacy of topical administration of prallethrin-permethrin-piperonyl butoxide (Bronco® Equine Fly Spray) for the treatment and control of flies and other nuisance insects of horses

Numerous biting and nuisance insects are a noted cause of discomfort and stress to horses. Pyrethrins and pyrethroids have been used for many years in numerous formulations for the control of insect pests in animals, humans and environment. There are, however, few studies reporting their field efficacy in horses. The aim of the present study was to evaluate the repellent activity of a spray formulation based on prallethrin and permethrin synergized with piperonyl butoxide (BRONCO® Equine Fly Spray, Farnam Companies, Inc., USA) against annoying and harmful insects for horses in field conditions. Nine horses of mixed breed were divided into 2 groups (treatment and control). Pre-treatment insect counts were compared to daily counts for 4 days post-treatment (pt). One minute after the administration of the product (day 0), all the horses were negative for the presence of insects. All counts up to the 6-h pt check remained negative for Hippobosca equina, tabanid flies and Simulium spp., showing 100% efficacy. This remained above 90% throughout the study. For the H. equina, the repellent efficacy remained > 99.7% for all 4 days pt, for tabanid flies > 93.3% and for Simulium spp. > 97.4%. The efficacy against Musca spp. decreased from 82.2% at day 0 to 62.2% at day 3. Treatment was well-tolerated. In conclusion, despite the low number of tested horses, Bronco® has demonstrated high insecticide and repellent efficacy and a good persistence, maintained for up to 4 days post-treatment, against the most common species of insects harmful for horses.

Development and application of a novel approach to scoring ear tag wounds in dairy calves

Application of ear tags in cattle is a common husbandry practice for identification purposes. Although it is known that ear tag application causes damage, little is known about the duration and process of wound healing associated with this procedure. Our objective was to develop a detailed scoring system and use it to quantify wound healing in dairy calves with plastic identification tags. Calves (n = 33) were ear tagged at 2 d of age, and wound photos were taken weekly until 9 to 22 wk of age. This approach generated 10 to 22 observations per calf that were analyzed using a novel wound scoring system. We developed this system to score the presence or absence of external tissue types related to piercing trauma or mechanical irritation along the top of the tag (impressions, crust, and desquamation) and around the piercing (exudate, crust, tissue growth, and desquamation). Ears were scored as "piercing only" when tissue around the ear tag was intact. We found that impressions, crust, tissue growth, and desquamation were still seen in many calves by 12 wk of age. This suggests that extrinsic factors, such as mechanical disturbance and irritation, may have contributed to prolonged wound healing. Indeed, impressions along the top of tag, likely caused by rubbing against the ear, were observed for nearly the full duration of the study. Further research is warranted to understand ways to improve the ear-tagging process.

Potential of ear tags impregnated with acaricides for control of the brown ear tick (Rhipicephalus appendiculatus) infesting cattle

Plastic ear tags impregnated with acaricides (synthetic pyrethroids; fenvalerate, 10% (w/w); fenpropathrin, 10% (w/w); fiuvalinate, 10% (w/w); and permethrin, 8% (w/w)) were evaluated for the control of Rhipicephalus appendiculatus infesting cattle in the laboratory and field in Kenya. These controlled release devices gave excellent control of R. appendiculatus for over 20 weeks on cattle in the laboratory where they were housed mostly indoors. Fluvalinate-impregnated tags gave consistently the most rapid control of ticks, but all of the tags normally prevented feeding of the ticks on the ears of cattle. Under field conditions in the Trans-Mara Division of Kenya, excellent control of R. appendiculatus naturally infested cattle was obtained by fluvalinate-impregnated tags followed by fenpropathrin. Less impressive control was obtained by fenvalerate- and permethrin-impregnated tags, but this control was more effective than immersion of cattle in toxaphene. In contrast to the laboratory experiments, the effect of the tags on R. appendiculatus infestation waned by 58 days after application. The potential of synthetic pyrethroid-impregnated tags for the control of ticks infesting cattle in Africa was demonstrated, but a more prolonged release of the active ingredients at an effective level in the field and, in some cases, a more robust tag design will have to be achieved before tick control with impregnated tags becomes a practical proposition.