Clopyralid excretion in feces and urine of beef cattle

Abstract

To clarify the excretion of clopyralid in feces and urine of beef cattle, four Japanese Black beef cattle (14 months old on average, body weight 425kg on average) were used for balance trial (16 days for treatment adaptation period and 5 days for sampling period). The experimental feed contained almost 20% of Colored Guinea grass hay and 80% of commercial concentrate which was designed to achieve average daily weight gains of 0.2kg/day. Commercial clopyralid reagent was added to commercial concentrates (1mg/kg). All feces and urine were collected daily using an automatic feces-urine separating machine and weighed in the sampling period. The amount of feed and orts were also weighed daily. The excretion of clopyralid into feces and urine of experimental cattle were examined based on clopyralid concentrations in feed, feces and urine and feed intake, total feces and total urine. As a result, of all the excreted clopyralid, almost 91% was excreted in urine and 9% was excreted in feces, which was similar to the previous reports of lactating cows and ruminants.