Center for Welfare Metrics, Sao Paulo, Sao Paulo, 04795-100, Brazil.
F1000Res. 2022 May 24;11:564. doi: 10.12688/f1000research.122042.2. eCollection 2022.
: For decades, pig farmers have used gestation crates to confine pregnant sows. Gestation crates physically restrain sows for most of their life, preventing them from walking or turning around. Growing concern about animal welfare has been pressuring the industry for change, with recent legislation in several countries restricting the use of crates. Still, the notion that gestation crates negatively affect sow welfare has been challenged by producers in regions where crates are still used, who argue that, by facilitating health monitoring and preventing aggression, crates lead to lower sow mortality and higher piglet outputs per sow. We test whether these claims are valid by comparing these parameters across countries with different housing systems. : We use publicly available data from InterPig, a network of pig production economists in 17 countries that provides harmonized methods for meaningful comparisons of production and cost indicators. We focus on the last five years (2015-2019) of data available. Annual sow mortality and the number of pigs sold per sow were compared among (1) countries where gestation crates are the norm (CRATE), (2) countries where gestation crates are restricted to four weeks after insemination (RESTRICTED), and (3) countries where gestation crates are banned (BANNED). : Sow mortality was significantly higher (F =5.03; =0.009), and annual pig production per sow significantly lower (F =5.99; =0.004), in the CRATE than in the RESTRICTED group. : Claims of higher mortality and reduced productivity per sow in crate-free systems are not substantiated by this industry-validated dataset. While many factors differ among the country groups (e.g., genetics, nutrition, climate), the observation that factors other than crating have a greater influence on performance challenges claims of an overall negative effect of loose housing on the parameters investigated. This evidence should be considered in policies affecting the welfare of breeding pigs.
几十年来，养猪户一直使用妊娠栏来限制怀孕母猪。妊娠栏在母猪的大部分生命中限制了它们的身体活动，使它们无法行走或转身。对动物福利的日益关注给该行业带来了变革的压力，最近几个国家的立法限制了妊娠栏的使用。然而，在仍在使用妊娠栏的地区，一些生产者对妊娠栏会对母猪福利产生负面影响的观点提出了质疑，他们认为，通过促进健康监测和防止攻击，妊娠栏降低了母猪死亡率，并提高了每头母猪的产仔量。我们通过比较不同饲养系统的国家的这些参数来检验这些说法是否成立。
我们使用了来自 InterPig 的公开数据，InterPig 是一个由 17 个国家的猪生产经济学家组成的网络，该网络提供了用于对生产和成本指标进行有意义比较的协调方法。我们重点关注了过去五年（2015-2019 年）的数据。在（1）妊娠栏是常态的国家，（2）妊娠栏限制在授精后四周的国家，（3）妊娠栏被禁止的国家，我们比较了每年的母猪死亡率和每头母猪出售的仔猪数量。
母猪死亡率在 CRATE 组中显著更高（F =5.03；=0.009），每头母猪的年猪产量显著更低（F =5.99；=0.004）。
在无笼系统中，更高的死亡率和每头母猪的生产率降低的说法并没有得到这个经过行业验证的数据的支持。虽然各国之间存在许多差异（例如，遗传、营养、气候），但除了笼养以外，其他因素对性能的影响更大，这一观察结果挑战了笼养对所研究参数的整体负面影响的说法。在影响种猪福利的政策中，应该考虑到这一证据。
