The behavioural reactivity of two divergently selected lines of South African Merino sheep for an increased (HL: N = 1187) and reduced (LL: N = 285) number of lambs weaned per ewe mated was investigated using a docility test and a ‘scale’ test. The objective of this study was to determine whether these two lines, which differed significantly in terms of reproduction performance, would also react differently when exposed to novel and challenging situations. In the first test, an individual animal was moved to the test pen by an experienced handler then an unfamiliar or familiar human entered the test pen and tried to encourage the animal to move into a marked area for 3 min. The test was terminated if the animal could not be moved within 3 min, came out of the marked area or if the animal could be contained in the marked area for 30 s (successful test). The latency of the animal to enter and time contained in the square area was recorded as well as whether the animal was bleating or urinating/defecating during the test. No difference was found between production lines and handler in terms of the success of the test and latency to enter (P > 0.05). LL sheep were however contained for longer and bleated more than HL sheep (P < 0.05). Sex differences were also observed, with ewes being more difficult to successfully contain and bleating more than rams, especially when exposed to an unfamiliar human (P < 0.05). They also tended to urinate/defecate more than rams (P < 0.05). In the second test, behaviour response of animals was recorded using a 5-points score system (1 = calm; 5 = wild) while spending 30 s on a scale. We also recorded whether animals were bleating during the test. While there was no difference in average scores between selection lines (P> 0.05), inter-observer variability was observed (P < 0.05). Ewes were also observed to bleat more than rams (P < 0.05). Further research is needed to determine whether these and other behavioural tests are related to traits of economic importance in sheep.

使用柔韧性测试和“量表”调查了两只不同选择的南非美利奴绵羊品系对每只母羊断奶的羔羊数量的增加（HL：N = 1187）和减少（LL：N = 285）的行为反应性测试。这项研究的目的是确定这两条在繁殖性能方面有显着差异的品系在暴露于新颖而具有挑战性的情况下是否也会产生不同的反应。在第一个测试中，有经验的操作员将一只动物移到测试笔上，然后由陌生或熟悉的人进入测试笔，并尝试鼓励动物移入标记区域3分钟。如果动物在3分钟内无法移动，则测试将终止，从标记区域出来或是否可以将动物关在标记区域30秒钟（成功测试）。记录动物进入的潜伏时间和包含在正方形区域中的时间，以及在测试过程中动物是否正在起泡或排尿/排便。在测试成功与进入等待时间方面，生产线与操作人员之间没有发现差异（P> 0.05）。但是，LL绵羊比HL绵羊的收容时间更长，流血更多（P <0.05）。还观察到性别差异，母羊比公羊更难以成功地遏制和流血，尤其是当暴露于陌生的人时（P <0.05）。他们还比公羊更趋于排尿（P <0.05）。在第二项测试中，使用5分制评分系统记录动物的行为反应（1 =冷静；5 =野生），同时花费30秒。我们还记录了动物是否在测试过程中流血。选择线之间的平均得分没有差异（P> 0.05），但观察者之间存在差异（P <0.05）。还观察到母羊比公羊更臭（P <0.05）。需要进行进一步的研究以确定这些和其他行为测试是否与绵羊的经济重要性相关。