Responses of dairy heifers to the visual cliff formed by a herringbone milking pit: evidence of fear of heights in cows (Bos taurus)

The ability of cows (Bos taurus) to perceive depth has never been experimentally investigated. If cows can perceive depth, the milking pit in commercial milking facilities may be fear provoking for dairy cows, as past research has shown that most land-dwelling species possess an instinctive fear of heights. In the current study, 12 dairy heifers (1-year-old cows) were exposed to a milking pit (depth-exposed group) and 13 heifers (control group) were exposed to a standard change in the environment while they moved through a milking facility over a 5-day treatment period. Heifers in the depth-exposed group showed a higher heart rate (p < .05) and stopped more often (p < .05) than did those in the control group; persistence of heart rate but not of behavioral responses on repeated exposures indicated that some habituation to the depth stimulus had occurred. Depth exposure had no effect on cortisol concentrations or on ease of handling. These results indicate that heifers responded differently to a change in depth than they did to a standard change in the environment and provide evidence of both depth perception and acute fear of heights in cows.     

An Examination of Post-Traumatic Stress Symptoms and Aggression among Children with a History of Adverse Childhood Experiences

Childhood aggression is associated with many deleterious outcomes and is a common reason for psychiatric referral (Card & Little, 2006; Gurnani et al., 2016). One factor associated with childhood aggression is Adverse Childhood Experiences (ACEs; Felitti et al., 1998). However, existing research remains equivocal on which characteristics of ACEs (e.g., cumulative impact, typology, etc.) are significantly elated to aggression, especially when considering differential effects of ACEs on proactive aggression (PA) and reactive aggression (RA; Dodge & Coie, 1987). Post-traumatic stress symptoms (PTSS) are a common negative sequalae of ACEs and are characterized by disruptions in several cognitive, emotional, and behavioral processes similar to those associated with both RA and PA (e.g., Marsee, 2008). As such, the examination of PTSS as an underlying mechanism of influence on the relation between ACEs, PA, and RA is warranted. The present study fills several gaps in the literature by examining ACE characteristics that might be related to PTSS, PA, and RA while also examining direct and indirect effects on the relation between ACEs, PTSS and PA and RA. Results indicated the type of ACE, specifically child maltreatment ACEs (CM-ACEs), was most strongly related to all outcome variables. Therefore, CM-ACEs were included in a path analysis with PTSS, PA, and RA. Results indicated a significant indirect effect for PTSS on the relation between CM-ACEs and RA (β?=?.18, p?<?.01) but not PA. Findings have several implications for future research and clinical practice, especially for children with an extensive history of CM-ACEs.

     

Jeffrey P. Kahn,Anna C. Mastroianni,and Jeremy Sugarman (eds): Beyond consent: seeking justice in research, 2nd edition

Theoretical Medicine and Bioethics -