Development of conditioned taste aversion to Mascagnia rigida in goats

Abstract

The aim of this study was to determine whether goats could be averted from consuming Mascagnia rigida, a toxic plant found in the semiarid region of northeastern Brazil. Fourteen male goats not previously familiarized to M. rigida were randomly allocated to two treatment groups: control (treated with 5.5mL water orally by a drenching gun) and lithium group (treated with 100mg LiCl/kg body weight orally by a drenching gun). For conditioning, goats were allowed to feed on M. rigida leaves for 15 min, followed by LiCl or water administration. The time spent on eating M. rigida leaves was measured. The conditioning was repeated daily until the LiCl-treated goats stopped eating M. rigida. On the 10th, 17th, and 24th day after conditioning, extinction trials of the M. rigida aversion were performed in goats by using single-choice tests. There was no difference between the two treatment groups with respect to the consumption of M. rigida on the first day of aversion conditioning, however, controls ingested increasing amounts of the plant on consecutive conditioning days. On the second day, five out of the seven goats in the lithium group did not eat the leaves, but on the third day, all the goats in the lithium group did not ingest M. rigida. This aversion persisted throughout all evaluated days. This indicates that goats can be easily conditioned by using lithium chloride to avoid eating M. rigida temporarily.