Gait defects, assessed as gait score (GS), is a common welfare problem in broiler chicken production. The aim of this study was to examine whether birds with GS2 experience pain and poor locomotor ability compared to birds of lower GS. From day 0-27 of age, 600 Ross 308 birds were housed in simulated commercial conditions (stocking density 40 kg/m²). On day 27, all birds were gait scored and 192 birds (4 blocks of 48 birds) were selected as experimental birds based on gait score (GS0 or GS2). On day 28, a runway test with and without obstacles was performed to examine the locomotor ability of the birds. Approximately 3 hours before testing, the experimental birds were injected with the NSAID carprofen (25 mg/kg s.c.) or saline (equivalent volume). A Conditioned Place Preference (CPP) test was conducted on day 38, after 4 days of conditioning to a chamber (70 × 70 cm; painted either green with vertical stripes or orange with horizontal stripes) after injection with carprofen or saline. The broilers were expected to show a preference for the place in which they experienced a positive emotional state as induced by the mitigation of pain by carprofen. In the runway test, GS0 birds reached the end of the runway with obstacles faster compared to GS2 birds (P = 0.04) and tended to be faster than GS1 birds (P = 0.08). No effect of carprofen was found on the behaviour in the runway and no effect of GS on the behaviour in the runway without obstacles. In the CPP test, there was no effect of GS or carprofen on chamber preference (P > 0.05). The results showed clear differences between birds of GS2 and lower GSs in terms of locomotor response in the runway, indicating that locomotor ability was compromised with increased GS. The results could not confirm whether these differences in locomotor ability are related to or due to increased pain with increased GS.

步态缺陷（以步态评分（GS）评估）是肉鸡生产中常见的福利问题。这项研究的目的是检查与GS较低的鸟类相比，GS2的鸟类是否经历疼痛和运动能力差。从0-27日龄开始，在模拟商业条件下圈养600头罗斯308鸟（饲养密度40 kg / m ²）。在第27天，对所有鸟类进行步态评分，并根据步态评分（GS0或GS2）选择192羽鸟类（4羽48羽）。在第28天，进行了有无障碍物的跑道测试，以检查鸟类的运动能力。在测试前大约3小时，给实验鸡注射NSAID卡洛芬（25 mg / kg sc）或生理盐水（当量）。注射卡洛芬或生理盐水后，对第4天进行适应性试验的房间（70×70 cm；涂成带有垂直条纹的绿色或带有水平条纹的橙色）后，在第38天进行了条件放置偏好（CPP）测试。期望肉鸡表现出对他们因卡洛芬缓解疼痛而经历积极情绪状态的偏好。在跑道测试中 与GS2鸟相比（P = 0.04），GS0鸟到达跑道尽头时有障碍物，并且比GS1鸟（P = 0.08）更快。没有发现卡洛芬对跑道行为的影响，而GS对无障碍跑道行为的影响也没有。在CPP测试中，GS或卡洛芬对房室偏爱没有影响（P> 0.05）。结果表明，GS2禽类和较低GS禽类在跑道中的运动反应方面存在明显差异，表明运动能力受到GS升高的损害。结果不能证实这些运动能力的差异是否与GS增加引起的疼痛增加有关或是由于疼痛增加引起的。没有发现卡洛芬对跑道行为的影响，而GS对无障碍跑道行为的影响也没有。在CPP测试中，GS或卡洛芬对房室偏爱没有影响（P> 0.05）。结果表明，GS2禽类和较低GS禽类在跑道中的运动反应方面存在明显差异，表明运动能力受到GS升高的损害。结果不能确定这些运动能力的差异是否与GS增加引起的疼痛增加有关或是由于疼痛增加引起的。没有发现卡洛芬对跑道的行为没有影响，GS对无障碍的跑道的行为也没有影响。在CPP测试中，GS或卡洛芬对房室偏爱没有影响（P> 0.05）。结果表明，GS2禽类和较低GS禽类在跑道中的运动反应方面存在明显差异，表明运动能力受到GS升高的损害。结果不能确定这些运动能力的差异是否与GS增加引起的疼痛增加有关或是由于疼痛增加引起的。表明运动能力受到GS增加的损害。结果不能确定这些运动能力的差异是否与GS增加引起的疼痛增加有关或是由于疼痛增加引起的。表明运动能力受到GS增加的损害。结果不能确定这些运动能力的差异是否与GS增加引起的疼痛增加有关或是由于疼痛增加引起的。