Battery cages for egg-laying hens were banned in 2012, for instance.

例如，2012年禁止对蛋鸡使用多层鸡笼。

Research by the Open Philanthropy Project, a group which funds animal-welfare activists, finds that such campaigns have prompted more than 200 American companies-including Mc- Donald's, Burger King and Walmart-to stop buying eggs from chicken raised in battery cages since 2015.

为动物福利活动人士提供资金的组织“开放慈善项目”的研究发现，自2015年以来，此类活动已促使包括麦当劳、汉堡王和沃尔玛在内的200多家美国公司停止购买电池笼饲养鸡产的鸡蛋。