Social isolation can increase distress in goats, particularly when they cannot maintain visual contact with conspecifics. This experiment was conducted to determine the behavioral and physiological responses in goats during isolation with or without visual contact with conspecifics. Male Spanish goats (uncastrated, 8 mo old, average weight 29.4 ± 0.59 kg) were randomly assigned to a control (CO) group with no isolation or to one of four isolation treatment (TRT) pens (1.5 × 1.5 m) with: 1) open grill panels but with no visual contact with conspecifics (IO), 2) covered grill to prevent visual contact (IC), 3) open grill with visual contact (IV), or 4) covered grill with a 30 × 30 cm window to allow visual contact (IW), for 90 min of social isolation (n = 12 goats per TRT). Blood samples were collected at 0, 30, 60, and 90 min (Time) from isolated and control goats. The experiment was repeated 1 wk later using the same animals, with each goat being subjected to the same isolation TRT the second time to study the effect of prior exposure to isolation. Friedman’s two-way analysis of variance by Ranks test in SAS showed that the median frequency of vocalization (rank score) in goats was high in the IO group, low in the IV and IW groups, and intermediate in the IC group (P < 0.01). The vocalization rank score was also higher (P < 0.01) during the first 30 min of isolation in goats. The median frequency of visual contact was higher in the IW group than in the IV group (P < 0.01). The frequency of climbing behavior was high in the IC and IO groups, low in the IV group, and intermediate in the IW group (P < 0.01). Repeated measures analysis using general linear models procedures in SAS revealed that plasma cortisol and glucose concentrations tended (P < 0.1) to be the highest in the IO group than in CO, IC, IV, and IW groups. Cortisol levels were also higher (Time; P < 0.05) at 0 and 90 min compared with 30 and 60 min. Norepinephrine concentrations decreased (P < 0.05) with Time, and plasma nonesterified fatty acid (NEFA) levels were affected by TRT × Time interaction (P < 0.01). Overall, epinephrine, norepinephrine, glucose, and NEFA concentrations were lower (P < 0.01) and cortisol concentrations and lymphocyte counts were higher (P < 0.01) when goats were exposed to isolation the second time. The results showed that goats with no visual contact with conspecifics during social isolation had greater physiological stress responses and spent more time vocalizing or trying to escape the pen, which may indicate distress.

中文翻译：

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山羊的社会隔离：视觉接触对行为和生理反应的意义

社会孤立会增加山羊的痛苦，特别是当它们无法与同类保持视觉接触时。进行该实验是为了确定山羊在隔离期间与同种动物有或没有视觉接触的行为和生理反应。雄性西班牙山羊（未阉割，8 个月大，平均体重 29.4 ± 0.59 kg）被随机分配到没有隔离的对照组（CO）组或四个隔离处理（TRT）围栏（1.5 × 1.5 m）中的一个，其中：1 ) 开放式烤架面板，但不与同种动物进行视觉接触 (IO)，2) 有盖烤架以防止视觉接触 (IC)，3) 具有视觉接触的开放式烤架 (IV)，或 4) 有 30 × 30 厘米窗口的有盖烤架允许视觉接触 (IW)，进行 90 分钟的社会隔离（n = 12 只山羊/TRT）。在 0、30、60、和 90 分钟（时间）从隔离和控制山羊。1 周后使用相同的动物重复该实验，每只山羊第二次接受相同的隔离 TRT，以研究先前暴露于隔离的影响。Friedman 在 SAS 中通过 Ranks 检验进行的双向方差分析表明，山羊发声的中位频率（等级分数）在 IO 组中较高，在 IV 和 IW 组中较低，在 IC 组中居中（P < 0.001）。 0.01)。在山羊隔离的前 30 分钟内，发声等级得分也较高（P < 0.01）。IW 组的中位视觉接触频率高于 IV 组（P < 0.01）。IC组和IO组攀爬行为频率高，IV组低，IW组中等（P < 0.01）。在 SAS 中使用一般线性模型程序进行的重复测量分析显示，IO 组的血浆皮质醇和葡萄糖浓度趋于（P < 0.1）高于 CO、IC、IV 和 IW 组。与 30 和 60 分钟相比，0 和 90 分钟的皮质醇水平也更高（时间；P < 0.05）。去甲肾上腺素浓度随时间降低 (P < 0.05)，血浆非酯化脂肪酸 (NEFA) 水平受 TRT × 时间相互作用的影响 (P < 0.01)。总体而言，当山羊第二次进行隔离时，肾上腺素、去甲肾上腺素、葡萄糖和 NEFA 浓度较低（P < 0.01），皮质醇浓度和淋巴细胞计数较高（P < 0.01）。