Abstract Provision of enrichment in welfare- and environmentally-friendly pig pens is important for sustainable pig production. The primary aim of the present experiment was to investigate the effects of maize silage as a singular enrichment compared to a combination of maize silage and chopped straw on behaviours important for determining pig welfare (play, locomotion, exploration, social contact, aggression, manipulation, eating, drinking, lying/sleeping, sitting/standing and nosing objects) in growing-finishing pigs (pigs, n = 432; batch, n = 2; pens n = 12 per batch). Secondly, the impact of drinker position (IN: two drinkers placed in the inside area; OUT: two drinkers in the outside area; IN_OUT: a drinker in each of the inside and outside areas; n = 8 pens per group) on pig behaviour was assessed. There were no statistically significant influences of enrichment treatments on behaviour. The OUT group performed less manipulation behaviour than the IN (mean difference = 2.65; 90 % highest density interval (HDI): 0.46, 4.84) and IN-OUT (mean difference = 2.88 HDI: 0.69, 5.15) groups, and drank more than the IN-OUT group (mean difference = -3.87; HDI: -6.76, -0.90). In addition, we found that a one standard deviation (∼ 2 days) increase in observation days/pig age significantly decreased manipulation (log coefficient = -0.32; HDI: -0.42, -0.22) and aggressive behaviours (log coefficient = -0.46; HDI: -0.57, -0.36), but there was an increase in drinking (log coefficient = 0.13; HDI: 0.09, 0.18) and nosing objects (log coefficient = 0.12; HDI: 0.06, 0.18). Significant associations were also found for batch (season), as well as correlations between behaviours. In summary, our results showed that pig behaviours during the growing-fattening period were similarly expressed in the maize silage and combined maize silage and chopped straw treatments, suggesting that maize silage in environmentally-friendly pig pens is adequate in ensuring welfare standards. Furthermore, placing drinkers in the outside area reduced manipulation between pen-mates, thus, could improve pig welfare.

中文翻译：

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玉米青贮作为增菌材料改善了环保猪舍中生长育肥猪的福利

摘要 在福利和环境友好的猪圈中提供富集对于可持续的养猪生产非常重要。本实验的主要目的是研究玉米青贮作为单一富集物与玉米青贮和切碎秸秆的组合相比对决定猪福利重要的行为（玩耍、运动、探索、社会接触、攻击、操纵、在生长育肥猪（猪，n = 432；批次，n = 2；围栏 n = 12 每批次）中吃、喝、躺/睡、坐/站和鼻子物体）。其次，饮水器位置（IN：内区放置两个饮水器；OUT：外区放置两个饮水器；IN_OUT：内外区各一个饮水器；n = 8 圈/组）对猪行为的影响被评估。富集治疗对行为没有统计学上的显着影响。OUT 组比 IN（平均差异 = 2.65；90% 最高密度区间 (HDI)：0.46、4.84）和 IN-OUT（平均差异 = 2.88 HDI：0.69、5.15）组执行的操作行为更少，并且饮酒量超过IN-OUT 组（平均差 = -3.87；HDI：-6.76，-0.90）。此外，我们发现观察天数/猪龄增加一个标准差（~2 天）显着降低操纵（对数系数 = -0.32；HDI：-0.42，-0.22）和攻击行为（对数系数 = -0.46； HDI：-0.57，-0.36），但饮酒（对数系数 = 0.13；HDI：0.09, 0.18）和鼻子物体（对数系数 = 0.12；HDI：0.06, 0.18）有所增加。还发现了批次（季节）的显着关联，以及行为之间的相关性。综上所述，我们的研究结果表明，生长期猪的行为在玉米青贮和玉米青贮与切碎秸秆联合处理中的表现相似，表明环保猪圈中的玉米青贮足以确保福利标准。此外，将饮水器放置在外部区域减少了围栏伙伴之间的操纵，因此可以改善猪的福利。