Wallgren Per, Gunnarsson Stefan
Swedish Veterinary Agency, SVA, 751 89, Uppsala, Sweden.
Department of Clinical Sciences, Swedish University of Agricultural Sciences (SLU), Box 7054, 750 07, Uppsala, Sweden.
Acta Vet Scand. 2025 Aug 2;67(1):38. doi: 10.1186/s13028-025-00825-6.
Swedish animal welfare requirements exceed those of EU, which may have contributed to decreased pig production in Sweden since joining EU. On request from stakeholders, the Swedish Board of Agriculture allowed testing effects of reduced welfare demands on pig production for one year. This included weaning before 28 days at individual level, temporary confinements of sows during farrowing and mating, and increased stocking density of growers. The intervention period lasted for one year, and the productivity was compared with the preceding year.
A reduced mean weaning age from 32 to 27 days did not have a significant effect on piglet welfare measures but the annual number of piglets weaned per sow increased by 1.3. Temporary confinement of sows at farrowing had no significant effect on piglet mortality or productivity, but the confinement reduced sow welfare. Temporary confinement of sows during mating did not improve sow productivity. Instead, hygiene and welfare decreased due to the confinement. Decreased stocking density by 10% compared with Swedish requirements had no significant effect on welfare measures. Nor did weight gain differ from the previous year. However, increased batch size of fatteners increased the incidence of respiratory lesions at slaughter, impaired growth and feed conversion.
Simulations assured that over 90% of the piglets were older than 25 days in batches weaned at a mean age of 28 days. As piglets mature from three to four weeks of age, this was important for piglet welfare. Short-term confinement of sows at farrowing or mating decreased sow welfare due to the confinement while no significant increase in piglet productivity was found. An increased stocking density by 10% of weaners and growers did not affect welfare measures but increased the number of potential disease transmissions between pigs by 22% due to increased batch sizes. When batch size increased, respiratory lesions at slaughter increased and productivity decreased. Based on the results, the Board of Agriculture allowed herds to wean at a mean age of 28 days provided they complied with special requirements. Except for this, the minimal legal requirements of pig welfare in Sweden remained unchanged.
瑞典的动物福利要求高于欧盟，这可能是瑞典自加入欧盟以来生猪产量下降的原因之一。应利益相关者的要求，瑞典农业委员会允许对降低福利要求对生猪生产的影响进行为期一年的测试。这包括在个体层面28天前断奶、母猪分娩和配种期间的临时限制以及育肥猪饲养密度的增加。干预期持续一年，并将生产力与上一年进行比较。
平均断奶年龄从32天降至27天对仔猪福利指标没有显著影响，但每头母猪每年断奶仔猪数量增加了1.3头。母猪分娩时的临时限制对仔猪死亡率或生产力没有显著影响，但这种限制降低了母猪福利。母猪配种时的临时限制并未提高母猪生产力。相反，由于这种限制，卫生和福利下降。与瑞典的要求相比，饲养密度降低10%对福利指标没有显著影响。体重增加与上一年也没有差异。然而，育肥猪批次规模的增加增加了屠宰时呼吸道病变的发生率，影响了生长和饲料转化率。
模拟结果表明，平均断奶年龄为28天的批次中，超过90%的仔猪年龄超过25天。由于仔猪在三到四周龄时成熟，这对仔猪福利很重要。母猪在分娩或配种时的短期限制由于这种限制而降低了母猪福利，同时未发现仔猪生产力有显著提高。断奶仔猪和育肥猪饲养密度增加10%并未影响福利指标，但由于批次规模增加，猪之间潜在疾病传播数量增加了22%。当批次规模增加时，屠宰时的呼吸道病变增加，生产力下降。根据结果，农业委员会允许猪群在符合特殊要求的情况下平均28天断奶。除此之外，瑞典生猪福利的最低法律要求保持不变。
