Grass odor and flavor overcome feed neophobia in sheep

Abstract

This study was conducted to determine if the time taken by sheep to eat an unfamiliar feed might be reduced if it was offered in the presence of a taste or odor that was familiar to the animals, or extended if the odor was aversive to them. Each morning in a 5 min test, groups of sheep (already adapted to the testing procedures) were offered an unfamiliar feed (rice bran) in the presence or absence of a familiar grass odor or grass flavor. Another group was offered the rice bran in association with the odor of dog feces. When offered the rice bran in the presence of grass juice odor or flavor, sheep ate a small amount on Day 1, and progressively increased their intake to 35–40 g by Day 7. The control sheep did not ingest any rice bran until Day 5, then increased their intake to 35 g by Day 11. In contrast, sheep avoided the rice bran with the odor of dog feces for 13 days and the rice bran intake of sheep in this group never exceeded 10 g during the test. The more rapid acceptance of rice bran in the presence of either a familiar flavor or odor is argued to be a consequence of stimulus generalisation.