Koret School of Veterinary Medicine, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel.
Department of Psychological and Brain Sciences, University of Massachusetts Amherst, MA 01003, USA.
Animal. 2021 Feb;15(2):100082. doi: 10.1016/j.animal.2020.100082. Epub 2021 Jan 26.
Food animal welfare is an issue of great concern, as society has a responsibility for animals under human care. Pork is the most consumed meat worldwide, with more than a billion pigs being slaughtered globally every year. Still, in most countries, sows are restrained in farrowing crates throughout lactation. In these crates, sows are confined with bars to an area that is just slightly larger than their body. Thus, moving and turning around, grooming, or expressing other natural behaviors are typically impossible. In this study, we utilized a simple and practical modification of conventional farrowing crates to designed farrowing pens, by removable confinement bars, which provide the flexibility to change the housing system from one to another. Our objective was to examine the parameters of production and hair cortisol concentrations after different restraint periods during lactation. Analyses included data from 77 sows and their 997 piglets. Sows were housed in farrowing crates, but the confinement bars were removed after different periods, from 3 days post-farrowing to full restraint. For certain analyses, sows were grouped into Short or Long Restraint groups (3-10 days vs 13-24 days, respectively). Multiple linear regression revealed that for any additional day in restraint of the sows, piglets' weaning rate decreases by 0.4% (P < 0.05). Moreover, the total number of weaned piglets per litter was higher in the Short Restraint group as compared to the Long Restraint group (10.4 ± 0.3 vs 9.7 ± 0.3, respectively; P < 0.05). Accordingly, total litter weight on the weaning day tended to be higher in the Short Restraint group (68.8 ± 2.2 vs 64.9 ± 1.8 kg; P = 0.1210). The requirement for medical treatments during lactation (e.g., antibiotics, NSAID) tended to be less frequent in the Short Restraint group (Sows: 21.9% vs 40%; P = 0.1219. Piglets: 2.4% vs 17.1%; P = 0.0609). Hair cortisol as a marker for chronic stress during lactation decreased when the restraint period was shortened in both sows and piglets. Our analysis revealed that sows' hair cortisol is a significant mediator between the restraint of the sow and its piglets' hair cortisol (Sobel test; P < 0.05). For every day of sows' restraint, sows' hair cortisol increased by 0.5 pg/mg, and for any additional unit of sows' hair cortisol, piglets' hair cortisol increased by 0.36 pg/mg. In conclusion, sustainable swine farming management can be beneficial for both animals and farmers; limiting sow restraint during lactation is expected to reduce stress, enhance welfare and production, and potentially improve the economics of swine operations.
动物福利是一个备受关注的问题，因为社会有责任照顾人类所照顾的动物。猪肉是全球消费最多的肉类，每年有超过 10 亿头猪被屠宰。尽管如此，在大多数国家，母猪在哺乳期仍被限制在产仔箱中。在这些产仔箱中，母猪被限制在与身体仅稍大一点的栏中。因此，移动、转身、梳理或表达其他自然行为通常是不可能的。在这项研究中，我们通过可移动的限制栏对传统产仔箱进行了简单实用的改进，设计了产仔围栏，从而可以灵活地在不同的产仔系统之间进行转换。我们的目的是研究哺乳期不同限制期后的生产参数和皮质醇浓度。分析包括 77 头母猪及其 997 头仔猪的数据。母猪被安置在产仔箱中，但在产仔后的不同时期（3 天至 24 天）去除限制栏。对于某些分析，将母猪分为短时间限制组（3-10 天）和长时间限制组（13-24 天）。多元线性回归显示，母猪每多限制一天，仔猪断奶率就会下降 0.4%（P<0.05）。此外，短时间限制组的每窝断奶仔猪数量高于长时间限制组（分别为 10.4±0.3 和 9.7±0.3；P<0.05）。相应地，短时间限制组的断奶日总窝重也更高（分别为 68.8±2.2 和 64.9±1.8 公斤；P=0.1210）。哺乳期的医疗治疗（例如抗生素、非甾体抗炎药）需求在短时间限制组中也趋于减少（母猪：21.9%对 40%；P=0.1219.仔猪：2.4%对 17.1%；P=0.0609）。当限制期缩短时，母猪和仔猪的皮质醇作为哺乳期慢性应激的标志物均下降。我们的分析表明，母猪的皮质醇是母猪限制及其仔猪皮质醇之间的一个重要中介（Sobel 检验；P<0.05）。母猪每限制一天，其皮质醇就会增加 0.5 pg/mg，母猪每增加一个单位的皮质醇，其仔猪的皮质醇就会增加 0.36 pg/mg。总之，可持续的养猪管理对动物和农民都有益；限制母猪哺乳期的限制预计会减轻压力，提高福利和生产水平，并可能改善养猪业务的经济效益。
