Free-choice Administration of Ronnel in Mineral Mixture for the Control of Cattle Grubs1

Abstract

Technical ronnel incorporated in a 3: 1 salt-bonemeal mixture was made available on a free-choice basis to cattle grub-infested calves for periods of 28 to 66 days. Outstanding control (100%) was achieved at concentrations of 48 and 40 grams ronnel per pound of mixture for 66 days. Inadequate control was obtained at lower levels (16 grams per pound) and over shorter periods (28 days). Six-fold variations in average total mineral consumption (0.31 to 1.88 oz. per day) were observed. Accompanying physiological events such as reduced erythrocyte cholinesterase activity (as low as 21% of pretreatment activity) and transient weight gain depression at higher levels of ingestion suggest that further research with this or other appropriate systemic chemicals- be pursued before general recommendations for use be made.