Munsterhjelm C, Nordgreen J, Aae F, Heinonen M, Olstad K, Aasmundstad T, Janczak A M, Valros A
Research Centre for Animal Welfare, Department of Production Animal Medicine, University of Helsinki, Finland.
Animal Welfare Research Group, Department of Production Animal Clinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences (NMBU), Oslo, Norway.
Physiol Behav. 2017 Oct 1;179:298-307. doi: 10.1016/j.physbeh.2017.06.024. Epub 2017 Jul 3.
Tail biting is detrimental to animal welfare and has negative consequences for producer economy. Poor health is one of the risk factors for tail biting. The first aim of this study was therefore to test for links between health status and behavior related to tail biting at the individual level. The second aim of this study was to test whether variation in cytokines was related to variation in social behavior. These small molecules produced upon immune activation are known to influence behavior both in the direction of withdrawal and increased aggression. This could potentially increase non-functional social behavior and thereby the risk of a tail biting outbreak. To investigate this, we collected behavioral data, health data, feeding data and blood samples from undocked boars at a test station farm in Norway. We compared groups with three different diagnoses: osteochondrosis diagnosed by computer tomography scanning (OCSAN), osteochondrosis diagnosed by clinical examination (OCCLIN) and respiratory tract disease (RESP), with healthy controls (CTR). We tested whether the diagnoses were associated with feeding and growth, social behavior and cytokine levels. We then tested whether there were correlations between cytokine levels and social behavior. We also provide raw data on cytokine levels in the extended sample (N=305) as there are few publications on cytokine levels measured in pigs living under commercial conditions. OCCLIN pigs visited the feeder less, and fed longer compared to CTR pigs. Pigs diagnosed with RESP showed a large drop in growth the first week after filming, which corresponds to the week they were likely to have been diagnosed with illness, and a tendency to compensatory increase in the week after that. Social behavior differed between experimental groups with OCSCAN pigs receiving more social behavior (both aggressive and non-aggressive) compared to CTR, and RESP pigs tending to perform more ear- and tail-biting than controls. There were no differences in absolute levels of cytokines between categories. However IL1-ra and IL-12 showed correlations with several behaviors that have been shown by others to be associated with current or future tail biting activity. To our knowledge, this is the first published study indicating a role for illness in non-functional social behavior in pigs and the first showing a correlation between cytokine levels and social behavior.
咬尾对动物福利有害，且会给养殖者的经济带来负面影响。健康状况不佳是咬尾的风险因素之一。因此，本研究的首要目的是在个体层面测试健康状况与咬尾相关行为之间的联系。本研究的第二个目的是测试细胞因子的变化是否与社会行为的变化有关。这些在免疫激活时产生的小分子已知会在退缩和攻击性增强两个方向上影响行为。这可能会潜在地增加无功能的社会行为，从而增加咬尾爆发的风险。为了对此进行研究，我们在挪威一个试验站农场收集了未断尾公猪的行为数据、健康数据、采食数据和血样。我们将三组不同诊断结果的猪与健康对照组（CTR）进行了比较：通过计算机断层扫描诊断的骨软骨病（OCSAN）、通过临床检查诊断的骨软骨病（OCCLIN）和呼吸道疾病（RESP）。我们测试了这些诊断结果是否与采食和生长、社会行为以及细胞因子水平相关。然后我们测试了细胞因子水平与社会行为之间是否存在相关性。我们还提供了扩展样本（N = 305）中细胞因子水平的原始数据，因为关于在商业条件下饲养的猪中测量细胞因子水平的出版物很少。与CTR猪相比，OCCLIN猪访问采食器的次数更少，采食时间更长。被诊断为RESP的猪在拍摄后的第一周生长大幅下降，这与它们可能被诊断出患病的那一周相对应，并且在之后的一周有代偿性增加的趋势。实验组之间的社会行为有所不同，与CTR相比，OCSAN猪接受更多的社会行为（包括攻击性和非攻击性），并且RESP猪比对照组更倾向于进行更多的耳部和尾部啃咬行为。不同类别之间细胞因子的绝对水平没有差异。然而，IL1 - ra和IL - 12与其他一些已被证明与当前或未来咬尾活动相关的行为存在相关性。据我们所知，这是第一项表明疾病在猪的无功能社会行为中起作用的已发表研究，也是第一项表明细胞因子水平与社会行为之间存在相关性的研究。
