Food flavor and nutritional characteristics alter dynamics of food preference in lambs.

摘要

addressed two questions relating to the relationship between a food's flavor and its nutritional characteristics. First, I determined how a food's flavor and nutritional characteristics combine to influence food preference. I offered lambs three iso-nitrogenous foods differing in energy (90%, 100%, 110% TNC); each food was offered in two flavors (apple and maple). I hypothesized that preference for apple- or maple-flavored food would decrease with exposure (1, 2, 4 d), and I speculated that the change in preference would intensify when the food contained either inadequate or excessive levels of energy. I found that lambs preferred the alternative flavor, even after only 1 d exposure, and preference for the alternative flavor was greater when the animals were fed food containing inadequate or excessive energy (P ;The second experiment determined if lambs' food preferences in the evening changed after eating a food containing rapidly or slowly digestible sources of energy in the morning. I speculated that lambs fed a rapidly digestible food in the morning may switch to a slowly digestible food in the evening to take advantage of the available nutrients while ruminating overnight, or because preference for a food decreases after exposure in the morning. I offered lambs two foods (iso-nitrogenous and iso-caloric) that differed in rate of digestion (similar extent of digestion); both foods were offered in two flavors (apple and maple). Lambs fed rapidly digestible food in the morning preferred slowly digestible food in the alternative flavor in the evening. However, lambs fed slowly digestible food in apple or maple flavor in the morning continued to prefer slowly digestible food in both flavors in the evening (P