CREATING AVERSIONS TO LOCOWEED IN NAIVE AND FAMILIAR CATTLE

The objective of this study was to determine if cattle that were famil iar with white locoweed (Oxytropis sericea Nutt, ex T&G) could be aver sively conditioned to avoid eating it, In the first preliminary trial, we tried to aversely condition native steers that were already eating locoweed Six of 12 steers were penned, fed fresh-picked locoweed, the n dosed via a stomach tube with lithium chloride (LiCl, 200mg/kg BW), When released into the locoweed-infested pasture, they gradually incre ased locoweed consumption over the next 5 days, The conditioning proce dure was repeated with a lower dose (100 mg/kg BW), but locoweed consu mption increased within 10 days until they were consuming as much as t he non-averted controls, In the second trial, we compared the strength and longevity of aversion between steers that were familiar with loco weed (n = 6) and naive steers (n = 6), Both groups were averted to loc oweed as described in Trial 1 and returned to locoweed-infested pastur e, The Familiar group decreased locoweed consumption for the first 2 d ays, then gradually increased locoweed consumption and extinguished th e aversion, The Naive group subsequently refused to graze locoweed, In the third trial, aversions were reinforced following grazing locoweed in the pasture, Three steers from the Familiar group were allowed to graze locoweed for 30 min, periods, then were returned to the pen and dosed with LiCl (100 mg/kg BW), These steers were kept in the pen and allowed to recover for 36 hours, This reinforcement process following grazing was repeated 4 times, Steers in the Reinforced group abstained from eating locoweed when released into the locoweed-infested pasture for the remainder of the trial, Reinforcement of aversions following field grazing of locoweed prevented cattle that were familiar with loc oweed from grazing it.