All major livestock species are social animals requiring appropriate companionship. Isolation causes measurable welfare harm that social housing prevents at modest management cost.
Social housing is a welfare requirement for all major livestock and companion animal species that have evolved in social groups. Single housing — common in veal production, sow gestation, laboratory animal, and some horse management settings — denies the social interaction that these species require for normal behavioral and psychological welfare. Social isolation causes elevated stress hormones, abnormal behaviors, and impaired welfare across all social species studied. The management argument for single housing — easier monitoring, preventing disease transmission, and resource competition elimination — reflects operational convenience rather than genuine welfare justification. Social housing design that manages these practical concerns while allowing appropriate companionship is achievable and represents the welfare standard that evidence supports.