How goats learn to distinguish between novel foods that differ in postingestive consequences
How goats learn to distinguish between novel foods that differ in postingestive consequences
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山羊如何学会区分食后后果不同的新食物
DOI：
10.1007/bf02059601
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发表时间：
1994
影响因子：
2.3
通讯作者：
C. Scott
中科院分区：
文献类型：
--
作者：
F. Provenza;J. J. Lynch;E. A. Burritt;C. Scott
为了更好地了解控制新食物选择的一些机制，这些食物在采后后果方面有所不同，我们提供了来自灌木黑刷（Coleogyne ramosissima）的当季山羊（CSG）和较老的（OG）生长细枝。 CSG 的氮含量高于 OG（1.04% vs. 0.74%），并且在山羊瘤胃液中更易消化（48% vs. 38%）。尽管如此，山羊还是偏爱 OG，因为 CSG 含有更高水平的缩合单宁，会导致习得性食物厌恶。当向对黑刷幼稚的山羊提供CSG和OG时，山羊不会专门选择OG或CSG，但当它们最终（1）在一顿饭中吃了比OG更多的CSG（平均分别为44克和16克）和（2）在一顿饭中吃了足够的CSG以获得厌恶（平均44克）时，从那时起它们摄入的CSG比OG少。因此，由摄入后反馈引起的食物选择的变化受到膳食中摄入的每种食物的量的影响。当我们改变山羊在膳食中摄入的 CSG 和 OG 的量，然后通过灌胃给它们有毒的氯化锂 (LiCl) 时，进一步证明了这一点。随后，无论是CSG还是OG，他们吃得最多的食物都少了。 CSG 和 OG 的风味（即味道和气味）的显着性也在对 CSG 的后天厌恶中发挥了作用。显着性显然是由于 OG 和 CSG 共有的风味，其中 CSG 更集中。我们得出的结论是，一顿饭中摄入的不同食物的相对量，以及这些食物味道的显着程度，都是重要的变量，可以使山羊区分出食后后果不同的新食物。
To better understand some of the mechanisms that control selection of novel foods differing in postingestive consequences, we offered goats current season's (CSG) and older (OG) growth twigs from the shrub blackbrush (Coleogyne ramosissima). CSG is higher than OG in nitrogen (1.04% v. 0.74%) and it is more digestible in vitro in goat rumen fluid (48% v. 38%). Nevertheless, goats acquire a preference for OG because CSG contains much higher levels of a condensed tannin that causes a learned food aversion. When CSG and OG were offered to goat naive to blackbrush, the goats did not choose either OG or CSG exclusively, but when they finally (1) ate more CSG than OG within a meal (averages of 44 g and 16 g, respectively) and (2) ate enough CSG within the meal to acquire an aversion (average of 44 g), they ingested less CSG than OG from then onward. Accordingly, the change in food selection resulting from postingestive feedback was influenced by the amount of each food ingested within a meal. This was further shown when we varied the amounts of CSG and OG that goats ingested within a meal, and then gave them by gavage the toxin lithium chloride (LiCl). They subsequently ate less of the food eaten in the greatest amount, regardless of whether it was CSG or OG. The salience of the flavor (i.e., taste and odor) of CSG and OG also played a role in the acquired aversion to CSG. Salience evidently was due to a flavor common to both OG and CSG that was more concentrated in CSG. We conclude that the relative amounts of different foods ingested within a meal, and the salience of the flavors of those foods, are both important variables that cause goats to distinguish between novel foods that differ in postingestive consequences.