Holt Consulting, P.O. Box 869, Winterville, GA 30683, USA.
Poult Sci. 2021 Dec;100(12):101436. doi: 10.1016/j.psj.2021.101436. Epub 2021 Aug 20.
Mandating free range husbandry as a requirement for organic egg designation remains a prevailing sentiment within a segment of the organic community. The proponents maintain that such management practice ensures high hen welfare and enhanced wholesomeness of the egg. However, evidence from the field, especially in the European Union (EU), contradicts these assumptions. In many cases, hens allowed outdoor access were more subject to increased injury from predators and from flock mates, disease was more prevalent and generally more severe, and, as a result, higher mortality was routinely observed in these individuals compared with those raised indoors. The safety of eggs from free range hens is also questionable. Outdoor access compromises biosecurity efforts to curtail interaction of hens with rodents and wild birds, increasing the risk of flock Salmonella enterica serovar Enteritidis infection and consequent production of Salmonella-contaminated eggs. Even more serious, soil contaminated with dioxins and polychlorinated biphenyls, carcinogenic industrial by-products widespread in the environment, can be ingested by hens foraging outdoors. These compounds will subsequently be deposited into the egg yolks, many times at high levels, creating a serious food safety issue for the consuming public. Such findings provide evidence that hens exposed to a free-range environment may exhibit neither an enhanced welfare nor produce the safe wholesome egg that consumers expect.
将自由放养作为有机蛋指定的要求,在有机社区的一部分中仍然是一种流行的观点。支持者认为,这种管理实践确保了母鸡的高福利和鸡蛋的更高品质。然而,来自实地的证据,特别是在欧盟,与这些假设相矛盾。在许多情况下,允许户外活动的母鸡更容易受到捕食者和同群鸡的伤害,疾病更为普遍且通常更为严重,因此,与室内饲养的母鸡相比,这些母鸡的死亡率通常更高。自由放养母鸡所产鸡蛋的安全性也值得怀疑。户外接触会破坏生物安全措施,从而限制母鸡与啮齿动物和野鸟的接触,增加了禽类沙门氏菌肠炎血清型感染的风险,进而导致受沙门氏菌污染的鸡蛋的产生。更严重的是,土壤中会被二恶英和多氯联苯等致癌工业副产品污染,这些污染物在环境中广泛存在,母鸡在户外觅食时可能会摄入这些污染物。这些化合物随后会沉积到蛋黄中,很多时候含量很高,这对食用鸡蛋的公众构成了严重的食品安全问题。这些发现表明,暴露在自由放养环境中的母鸡既不能提高福利,也不能生产出消费者所期望的安全、健康的鸡蛋。