Centre for Proper Housing of Ruminants and Pigs, Federal Food Safety and Veterinary Office, Agroscope, 8356 Ettenhausen, Switzerland; University of Bern, Veterinary Public Health Institute, Vetsuisse Faculty, 3012 Bern, Switzerland.
Centre for Proper Housing of Ruminants and Pigs, Federal Food Safety and Veterinary Office, Agroscope, 8356 Ettenhausen, Switzerland.
Animal. 2024 Oct;18(10):101325. doi: 10.1016/j.animal.2024.101325. Epub 2024 Sep 12.
Rooting is a strongly motivated, species-specific behaviour of pigs. Most housing systems do not provide appropriate materials that enable the full expression of this behaviour, and it remains unclear whether straw is suitable to entirely fulfil the rooting motivation of pigs. We therefore investigated the suitability of small (minimal) and large (deep) amounts of straw as well as large amounts of compost to satisfy rooting motivation in pigs. Fifty-seven growing-finishing pigs were housed in three pens, each providing permanent access to one of the three treatment substrates. Eight pigs per group were tested individually in a classical preference test (PT) and another eight pigs in a conditioned place preference test (CPPT). In the tests, pigs could show their preference to consume freely available feed ("feed") or feed hidden in sawdust ("root"). In the CPPT, feed was only present during training but not during testing. Pigs were exposed to the test situation twice, with approximately 72 kg and 115 kg BW. In both tests, the following variables were measured and used as outcome variables in linear mixed effect models: first decision to choose one of the two stimuli ("feed" or "root"), duration of time spent in proximity to "root", number of changes between stimuli, and latency to the first decision. Overall, the pigs' first decision (by tendency; P = 0.076) and the duration in proximity to "root" (P = 0.034) varied among treatments: Pigs housed with minimal straw tended to be more likely to choose "root" first (posthoc comparison; P = 0.090) and spent more time in proximity to "root" (P = 0.030) than pigs housed with compost, whereas pigs housed with deep straw were intermediate. Interestingly, the patterns of response to the treatment differed depending on the behavioural tests for both, first decision (interaction; P = 0.032) and duration in proximity to "root" (interaction; by tendency; P = 0.006). In addition, pigs in the PT changed more often between stimuli than pigs in the CPPT (P < 0.001). There was a tendency for an interactive effect between test and treatment for latency to first decision (interaction; P = 0.082), though pairwise comparisons did not reveal any differences. We concluded that in this study housing with permanent access to compost satisfied rooting motivation in pigs more than housing with minimal amounts of straw.
扎根是猪强烈的、特有的行为。大多数饲养系统没有提供适当的材料来充分表达这种行为，目前还不清楚稻草是否适合完全满足猪的扎根动机。因此，我们研究了少量（最小）和大量（深）稻草以及大量堆肥作为猪扎根动机的满足物的适宜性。57 头育肥-育肥猪被安置在三个围栏中，每个围栏都可以永久接触三种处理底物之一。每组有 8 头猪被单独进行经典偏好测试（PT）和条件位置偏好测试（CPPT）。在测试中，猪可以自由选择消耗可见饲料（“饲料”）或隐藏在木屑中的饲料（“根”）。在 CPPT 中，只有在训练期间才有饲料，但在测试期间没有。猪被暴露在测试情境中两次，体重约为 72 公斤和 115 公斤。在这两个测试中，测量了以下变量，并将其用作线性混合效应模型的结果变量：选择两种刺激物之一的第一决策（“饲料”或“根”）、接近“根”的时间长度、刺激物之间的变化次数，以及第一决策的潜伏期。总体而言，猪的第一决策（倾向；P=0.076）和接近“根”的时间长度（P=0.034）因处理而异：与堆肥相比，用最小量稻草饲养的猪更倾向于首先选择“根”（事后比较；P=0.090），并且更接近“根”（P=0.030），而用深稻草饲养的猪则处于中间位置。有趣的是，对处理的反应模式因行为测试而不同，包括第一决策（交互作用；P=0.032）和接近“根”的时间长度（交互作用；倾向；P=0.006）。此外，PT 中的猪比 CPPT 中的猪更频繁地在刺激物之间切换（P<0.001）。首次决策的潜伏期存在测试和处理之间的交互作用（交互作用；P=0.082）的趋势，尽管成对比较没有发现任何差异。我们得出结论，在这项研究中，与少量稻草相比，永久性接触堆肥的饲养方式更能满足猪的扎根动机。
