Ortega-Reyes L, Provenza F D
Department of Range Science, Utah State University, Logan 84322-5230.
J Anim Sci. 1993 Feb;71(2):380-3. doi: 10.2527/1993.712380x.
Generalization occurs when an animal responds to novel stimuli in much the same way it has responded to similar, familiar stimuli. Our objective was to determine whether goats generalized foraging skills from older growth blackbrush (Coleogyne ramosissima) to shrub live oak (Quercus turbinella). Blackbrush (OGBB) has small leaves that are difficult to ingest without the twigs, whereas shrub live oak (SLO) has larger leaves that can be ingested easily without twigs. In Yr 1, 6-mo-old goats and in Yr 2 18-mo-old goats were given experience browsing with OGBB for 0, 10, 20, or 30 d. They were next tested for 5 min/d for 2 d on OGBB, and then tested in the same way on SLO. The number of bites and bite rate increased significantly as goats of both ages gained experience browsing OGBB. Likewise, goats with more experience browsing OGBB took more bites during a 5-min period when foraging on SLO. Thus, goats generalized foraging skills from OGBB to SLO. Plant life form also affected the response of goats. Total intake, intake rate, and bite size were significantly higher for SLO than for OGBB. There was an interaction between level of experience and plant life form. The interaction occurred because goats with no experience browsing OGBB took more bites per 5 min of SLO than of OGBB, whereas goats with increasing levels of experience browsing OGBB generally took more bites of OGBB than of SLO. Controls took more bites per 5 min of SLO than of OGBB, because SLO leaves could be ingested (harvested and chewed) more easily than OGBB twigs.
当动物对新刺激的反应方式与它对类似的、熟悉的刺激的反应方式非常相似时,就会出现泛化现象。我们的目标是确定山羊是否能将从老龄黑刷子树(Coleogyne ramosissima)学到的觅食技能推广到灌木状活橡树(Quercus turbinella)上。黑刷子树(OGBB)的叶子很小,不带小枝就很难食用,而灌木状活橡树(SLO)的叶子较大,不带小枝就能轻松食用。在第1年,对6月龄的山羊进行试验,在第2年,对18月龄的山羊进行试验,让它们分别用OGBB进行0、10、20或30天的采食体验。接下来,让它们每天在OGBB上测试5分钟,持续2天,然后以同样的方式在SLO上进行测试。随着两个年龄段的山羊获得采食OGBB的经验,咬食次数和咬食速率显著增加。同样,有更多采食OGBB经验的山羊在采食SLO的5分钟内咬食次数更多。因此,山羊将觅食技能从OGBB推广到了SLO。植物的生活型也影响了山羊的反应。SLO的总摄入量、摄入速率和咬食大小显著高于OGBB。经验水平和植物生活型之间存在相互作用。之所以会出现这种相互作用,是因为没有采食OGBB经验的山羊在采食SLO的每5分钟内咬食次数比采食OGBB时多,而随着采食OGBB经验水平的提高,山羊通常采食OGBB的咬食次数比采食SLO时多。对照组在采食SLO的每5分钟内咬食次数比采食OGBB时多,因为SLO的叶子比OGBB的小枝更容易食用(采摘和咀嚼)。