Effects of a Flavor and Food Restriction on the Response of Sheep to Novel Foods

Two methods were used to encourage sheep to eat unfamiliar foods quickly. The first method entailed restricting the amount of food offered. Lambs were fed either 750 g day−1 alfalfa pellets (slightly in excess of maintenance and 34% of ad libitum), or 1500 g day−1 (sufficient for 250 g day−1 growth and 68% of ad libitum) for 10 days and then offered a novel food (split peas). Food restriction did not increase the rate of acceptance of peas. The second method involved increasing familiarity with a flavor (onion) added to novel foods. Lambs drank water, water with 1% onion powder, water with 7% glucose, or water with 1% onion powder and 7% glucose. By day 2, intake did not differ among groups, so lambs were offered a novel food (rice) with 1% onion from days 3 to 7. There was no increase in speed of acceptance of rice with onion by lambs that drank onion-flavored solutions. Nor was there an increase in acceptance of rye (novel grain) with 1% onion when it was offered on days 8 to 11. However, on days 12–15, lambs ate more lentils (a novel food) with than without onion, and they ate corn (a familiar food) readily with or without onion. Conversely, intake dropped sharply when lambs were given a familiar food (rice) with a novel flavor (onion). Thus, lambs were reluctant to eat foods with unfamiliar flavors, whether they were added or occurred in novel foods. Food neophobia is likely to be one facet of the general phenomenon of fear exhibited in new situations, which ensures ruminants do not over-ingest toxic or nutrient-rich foods