Abstract: Whereas mammalian mothers and young may retain long-term social affiliations in nature, the management of animals in captivity typically dictates that offspring are abruptly and permanently separated from their mothers at a relatively early age, often prior to the time of natural weaning. For animal breeders, this strategy can enhance the yield of offspring from a breeding population. Morbidity and mortality can also precipitate severance of mother-young bonds. Although it is recognized that early weaning provides nutritional challenges for the young, relatively little attention has been paid to the psychological consequences and long-term impacts of breaking the mother-young bond in non-human mammals. Furthermore, whereas great strides are being made in our understanding of the neurobiological and genetic underpinnings of social bonding, the mechanisms underlying the process of detachment following establishment of a mother-young bond remain relatively unexplored, although parallels can be drawn with processes involved in withdrawal from addictive substances. In this review, we outline mechanisms involved in social bonding. We consider the diversity in extent and duration of mother-young attachment across mammalian lineages and implications for predicting the outcome of severing ties between mothers and young at different times post-partum. We identify characteristics signalling emotional distress resulting from separation of mothers and young and discuss strategies for mitigating separation-induced distress. These include postponement of separation, ensuring high-quality maternal care of young prior to separation, providing bonded individuals with opportunities to separate voluntarily for brief periods prior to permanent separation, use of anti-suck devices prior to separation, allowing a period of partial (fence line) contact prior to full separation, providing substitutes for stimuli previously exchanged between mother and young, providing social buffers, gradual introduction to new housing arrangements, and pharmacological intervention. Areas for future research are proposed, including the use of functional neuroimaging technologies and functional genomics approaches, in combination with behavioural assessments of reinstatement motivation, individual recognition memory and long-term consequences of early separation, to shed further light on the nature of mother-young bonding and detachment in animals.

Abstract: Animal welfare, or well-being, is a social issue with ethical, scientific, political, and aesthetic properties. Answering questions about the welfare of animals requires scientific definition, assessment, solutions, and public acceptance. With respect to the actual well-being of the animal, most issues are centered on how the animal “feels” when managed within a specific level of confinement, during special agricultural practices (e.g., tail docking, beak trimming, etc.) and handling. Questions of this nature may require exploration of animal cognition, motivation, perception, and emotional states in addition to more commonly recognized indicators of well-being. Several general approaches have emerged for solving problems concerning animal well-being in intensive production systems: environmental, genetic, and therapeutic. Environmental approaches involve modifying existing systems to accommodate specific welfare concerns or development of alternative systems. Genetic approaches involve changing the behavioral and (or) physiological nature of the animal to reduce or eliminate behaviors that are undesirable within intensive system. Therapeutic approaches of a physical (tail docking, beak trimming) and physiological (drug and nutritional therapy) nature bring both concern and promise with regard to the reduction of confinement stress. Finally, the recent focus on commodity quality assurance programs may indirectly provide benefits for animal well-being. Although research in the area of animal well-being will provide important information for better animal management, handling, care, and the physical design of intensive production systems there is still some uncertainty regarding public acceptance. The aesthetics of modern intensive production systems may have as much to do with public acceptance as with science.