Anderson Mallory G, Johnson Alexa M, Jacobs Leonie, Ali Ahmed B A
Department of Animal and Veterinary Sciences, Clemson University, Clemson, SC 29634, USA.
Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA 24061, USA.
Animals (Basel). 2023 Sep 23;13(19):3003. doi: 10.3390/ani13193003.
Perches can enhance laying hen welfare, but their effectiveness might be age-dependent. We investigated early and late perch access effects on anxiety and fear in pullets through attention bias (AB) and tonic immobility (TI) tests. Pullets ( = 728) were raised with or without multi-level perches: CP (continuous perch access: 0-37 weeks), EP (early perch access: 0-17 weeks), LP (late perch access: 17-37 weeks), and NP (no perch access). AB was conducted in weeks 21 and 37 ( = 84/week), and TI was performed in weeks 20, 25, and 37 ( = 112/week). CP hens fed quicker than EP, LP, and NP in AB at weeks 21 and 37 ( ≤ 0.05). CP and NP feeding latencies were stable, while EP and LP fed faster at week 37 ( ≤ 0.05). CP had the shortest TI at week 20 ( < 0.05). CP and LP had the shortest TI in weeks 25 and 37 (all ≤ 0.05). Unlike NP, CP reduced anxiety and fear. Adding perches during laying (LP) raised anxiety at week 21, adapting by week 37, and removing pre-laying perches (EP) worsened fear at weeks 20 and 25 and anxiety at week 21, recovering by week 37. Adding or removing perches prior to the lay phase increased fear and anxiety, an effect that disappeared by week 37 of age. Our study indicates that continuous perch access benefits animal welfare compared to no perch access at all.
栖木可以提高蛋鸡的福利，但它们的效果可能因年龄而异。我们通过注意力偏差（AB）和强直静止（TI）测试，研究了早期和晚期提供栖木对小母鸡焦虑和恐惧的影响。小母鸡（n = 728）在有或没有多层栖木的环境中饲养：CP（持续提供栖木：0至37周）、EP（早期提供栖木：0至17周）、LP（晚期提供栖木：17至37周）和NP（不提供栖木）。在第21周和第37周进行AB测试（每周n = 84），并在第20周、第25周和第37周进行TI测试（每周n = 112）。在第21周和第37周的AB测试中，CP组母鸡比EP、LP和NP组进食更快（P≤0.05）。CP组和NP组的进食潜伏期稳定，而EP组和LP组在第37周进食更快（P≤0.05）。CP组在第20周的TI时间最短（P<0.05）。CP组和LP组在第25周和第37周的TI时间最短（均P≤0.05）。与NP组不同，CP组减少了焦虑和恐惧。产蛋期添加栖木（LP）在第21周增加了焦虑，到第37周有所适应，而去除产蛋前的栖木（EP）在第20周和第25周加剧了恐惧，在第21周加剧了焦虑，到第37周恢复。在产蛋期之前添加或去除栖木会增加恐惧和焦虑，这种影响在37周龄时消失。我们的研究表明，与完全不提供栖木相比，持续提供栖木对动物福利有益。
