Preference for flavoured foods by lambs conditioned with intraruminal administration of nitrogen.
标题 | Preference for flavoured foods by lambs conditioned with intraruminal administration of nitrogen. |
文章类型 | Journal Article |
发表年度 | 1997 |
作者 | Villalba, J. J., & Provenza F. D. |
期刊 | The British journal of nutrition |
卷 | 78 |
期 | 4 |
页码 | 545-61 |
发表日期 | 1997 Oct |
关键词 | Animals, Caseins, Female, Flavoring Agents, Food Preferences, Glutens, Hydrogen-Ion Concentration, Male, Nitrogen, Protein Deficiency, Rumen, Sheep, Taste, Urea, 调味剂/香料 |
摘要 | We suggested that food preference depends on the interplay between flavour and post-ingestive effects, and we predicted that protein-restricted lambs would acquire preferences for foods paired with supplemental sources of N, including urea (Expts 1 and 2), casein (Expt 3), and gluten (Expt 4). In each experiment, twenty lambs, in two groups of ten, were conditioned as follows: on odd-numbered days, lambs in group 1 received wheat straw (Expts 1, 3, and 4) or ground barley (Expt 2) flavoured with a distinctive flavour, and lambs in group 2 received the same food but with a different flavour. On even-numbered days, flavours were switched and lambs received capsules containing different amounts of urea (ranging from 0.12 to 0.92 g N/d), casein (ranging from 0.23 to 0.69 g N/d), or gluten (ranging from 0.23 to 0.69 g N/d). After conditioning period of 8 d, lambs were given a two-choice test to determine preference for flavours paired with N. In Expts 1 and 2, lambs preferred the flavours conditioned with urea at lower doses (0.12 g N/d in Expt 1, 0.23 and 0.46 g N/d in Expt 2), but they avoided the flavour associated with urea at the highest dose (0.23 g N/d in Expt 1 and 0.92 g N/d in Expt 2). In Expts 3 and 4, lambs avoided the flavours associated with the lowest doses of casein or gluten (0.23 g N/d), but they preferred the flavours paired with casein or gluten at higher doses (0.46 and 0.69 g N/d). After conditioning, N administrations were suspended and lambs in Expts 3 and 4 were offered a choice of the two flavours at weekly intervals for 2 weeks (extinction); preferences persisted during extinction. Collectively, these results suggest that the post-ingestive effects of N in different forms and concentrations influenced the development of food preferences by lambs. |
Alternate Journal | Br. J. Nutr. |