Wang B, Rathgeber B M, Astatkie T, MacIsaac J L
Plant & Animal Sciences, Nova Scotia Agricultural College, Truro, Nova Scotia, Canada.
Poult Sci. 2008 Jul;87(7):1248-52. doi: 10.3382/ps.2006-00440.
The current study was conducted to investigate the influence of microwave toe treatment and an increasing photoperiod on stress and fear levels in broiler chickens. Upon delivery from the hatchery, the toe tips of 364 male and 364 female broilers were exposed to microwave energy to restrict claw growth, whereas the same numbers of birds retained intact toes. Birds from each sex and toe treatment were grown under 23 h of light or increasing photoperiods, with 4 replicates of each treatment combination. Elevated activity of plasma creatine kinase (CK) and increased heterophil to lymphocyte (H/L) ratios were employed as indicators of stress. Tonic immobility (TI) was conducted on d 10, 22, and 36 and used as an index of fear response. Males had lower plasma CK activity and H/L ratios (P < 0.05). Birds on 23 h of light had a higher activity of plasma CK (P < 0.05) but similar H/L ratios compared with birds on the increasing photoperiod. Microwave toe treatment did not affect the activity of plasma CK or H/L ratios. Photoperiod, microwave toe treatment, or sex did not affect the number of attempts required to induce TI. The increasing lighting program decreased the duration of TI on d 10 (P < 0.05), had no effect on d 22, and increased duration of TI on d 36 (P < 0.05). There was no microwave toe treatment or sex effect on the duration of TI at any ages tested.
本研究旨在探讨微波处理鸡趾及延长光照周期对肉鸡应激和恐惧水平的影响。从孵化场运来后，对364只雄性和364只雌性肉鸡的趾尖进行微波照射以限制爪的生长，而同样数量的鸡保留完整的趾。每种性别和趾处理的鸡在23小时光照或延长光照周期下饲养，每种处理组合有4个重复。血浆肌酸激酶（CK）活性升高和异嗜性粒细胞与淋巴细胞（H/L）比值增加被用作应激指标。在第10、22和36天进行强直静止试验（TI），并将其用作恐惧反应指标。雄性鸡的血浆CK活性和H/L比值较低（P<0.05）。与光照周期延长的鸡相比，接受23小时光照的鸡血浆CK活性较高（P<0.05），但H/L比值相似。微波处理鸡趾对血浆CK活性或H/L比值没有影响。光照周期、微波处理鸡趾或性别对诱导TI所需的尝试次数没有影响。延长光照程序在第10天缩短了TI的持续时间（P<0.05），在第22天没有影响，在第36天延长了TI的持续时间（P<0.05）。在任何测试年龄，微波处理鸡趾或性别对TI的持续时间均无影响。
