Abstract:
Commercial laying hen housing is shifting from traditional cages to non-cage housing systems, such as the aviary, which has gained popularity due to potential for more species-typical behavior. However, birds housed in aviaries may have difficulties moving through the vertical tiers of the system leading to health problems such as keel bone fracture (KBF). One possible way to improve movement is to add ramps into an aviary system, allowing hens to walk between tiers rather than jump or fly. The objective of this study was to evaluate the impact of adding ramps to rearing and laying aviaries on bird health, production, and movement across vertical tiers of the aviary. Lohmann Selected Leghorn pullets were raised in 2 treatments: 4 pens (600 birds/pen) were raised with wire mesh ramps to aid movement between aviary tiers (RR) and 4 pens (600 birds/pen) were raised without ramps (RO). At 17 wk of age (WOA), birds were moved to the laying facility, in which 16 aviary pens with 225 birds/pen were populated. Half the pens (n = 8) were supplemented with wire mesh ramps (LR) and the other half were not (LO). Within each laying treatment group, 4 pens were populated with RR hens and 4 pens were populated with RO hens, creating 4 treatment combinations (RRLR, RRLO, ROLR, ROLO). From each pen, 15 focal hens were selected for radiographic imaging of their keel bones taken at 21, 36, 45, and 60 WOA and the images were subsequently scored for KBF severity. Focal hens were also scored for feather condition and footpad quality at 36 and 60 WOA using a standardized welfare assessment protocol. The number of downward transitions among aviary areas and falls were recorded at 19 to 20 and 30 to 31 WOA. Data were analyzed using (generalized) linear mixed models in R software. When ramps were available, they were used in most of the observed downward transitions (79% in ROLR and 86% in RRLR). Hens who received ramps in lay (i.e., RRLR and ROLR) showed more transitions immediately after lights on compared to midday or dusk phases (p < 0.001), performed more transitions from the first aviary tier compared to nest or top tier (p = 0.013) and had lower KBF severity than those who did not receive ramps in the laying aviaries (ROLO, RRLO; p < 0.001). At 60 WOA, hens in the RRLR treatment had greater feather coverage than those in ROLR and RRLO treatments (p < 0.001). Birds in the RRLR treatment had better foot health overall than those in treatments without ramps in lay (p = 0.018). Providing ramps to hens in aviaries appeared to be the preferred means of transitioning between aviary tiers though had positive effects on welfare parameters such as food health, feather coverage, and KBF severity, without negative impacts on production. Benefits were seen primarily when ramps were provided in lay, though their installation in rearing provided evidence of easier adaptation to the laying barn. Our study supports providing ramps throughout the lifetime of the bird to accommodate hens\' preferred means of moving vertically in aviaries and deliver consequent benefits to health and welfare.
摘要:
商业蛋鸡住房正在从传统的笼子转向非笼子住房系统,比如鸟舍,由于具有更多物种典型行为的潜力而受到欢迎。然而,饲养在鸟舍中的鸟类可能难以通过系统的垂直层移动,从而导致健康问题,例如龙骨骨折(KBF)。改善运动的一种可能方法是在鸟舍系统中添加坡道,允许母鸡在各层之间行走,而不是跳跃或飞翔。这项研究的目的是评估增加斜坡饲养和铺设鸟舍对鸟类健康的影响,生产,以及跨越鸟舍垂直层的运动。LohmannSelectedLeghorn小母鸡在2种处理中饲养:用金属丝网坡道饲养4支钢笔(600只鸟/笔),以帮助在鸟舍层(RR)之间移动,并在没有坡道(RO)的情况下饲养4支钢笔(600只鸟/笔)。17周龄(WOA),鸟被转移到铺设设施,其中有16个鸟舍围栏,225只鸟/围栏。一半的笔(n=8)补充了金属丝网斜坡(LR),另一半没有(LO)。在每个铺设治疗组中,用RR母鸡填充4个围栏,用RO母鸡填充4个围栏,创建4种治疗组合(RRLR,RRLO,ROLR,ROLO).从每一支钢笔,选择15只局灶性母鸡在21、36、45和60WOA时对其龙骨进行放射学成像,随后对图像进行KBF严重程度评分。还使用标准化的福利评估方案在36和60WOA时对局灶性母鸡的羽毛状况和脚垫质量进行了评分。鸟舍区域和瀑布之间的向下过渡次数记录为19至20和30至31WOA。使用R软件中的(广义)线性混合模型分析数据。当坡道可用时,它们用于观察到的大多数向下过渡(ROLR为79%,RRLR为86%).在躺下接受坡道的母鸡(即,与中午或黄昏阶段相比,RRLR和ROLR)在亮灯后立即显示出更多的过渡(p<0.001),与巢穴或顶层相比,从第一鸟舍层进行了更多的过渡(p=0.013),并且KBF严重程度低于未在放生鸟舍中接受斜坡的人(ROLO,RRLO;p<0.001)。在60WOA时,RRLR治疗的母鸡比ROLR和RRLO治疗的母鸡具有更大的羽毛覆盖率(p<0.001)。RRLR治疗中的鸟类的足部健康状况总体上优于无斜坡的治疗中的鸟类(p=0.018)。向鸟舍中的母鸡提供坡道似乎是在鸟舍层之间过渡的首选手段,尽管对诸如食品健康等福利参数有积极影响,羽毛覆盖,和KBF严重性,对生产没有负面影响。好处主要是在提供坡道时看到的,尽管他们在饲养中的安装提供了更容易适应下料谷仓的证据。我们的研究支持在鸟类的一生中提供坡道,以适应母鸡在鸟舍中垂直移动的首选方式,并为健康和福利带来随之而来的好处。