Imprinting refers to the process by which a young animal establishes a primary social bond with another animal (usually its mother) shortly after birth, from whom it will receive information about its environment and learn specific behaviours at critical periods of time and stages of development (Williams et al., 2003; Henry, Briefer, Richard-Yris, & Hausberger, 2007). The individual that the animal bonds to is one which regularly provides it with pleasure and comfort, thereby stimulating the production of endorphins and reinforcing the bond through an addiction-like process, a learning process that is not yet entirely understood. This process also applies to objects. Therefore, both unfamiliar individuals and unfamiliar objects may initially induce a fear response in the young animal. However, this can be overcome with sufficient exposure (Hoffman, 1996).
Imprint training in foals describes a process of forceful neonatal handling and exposure to aversive stimuli, which is often quite invasive and occurs almost immediately after birth. Proponents believe that such processes will condition a horse to be less reactive, more manageable, easier to handle and train, and result in a stronger horse-human bond (Henry, Richard-Yris, & Hausberger, 2006; McGreevy, 2012; Spier, Berger Pusterla, Villarroel & Pusterla, 2004; Williams et al., 2003). While there is some evidence that imprint training in foals is effective in the short-term, there is a lot of conflicting evidence about its long-term effectiveness and suitability as a training methodology (Lansade, Bertrand & Bouissou, 2005; Simpson, 2002).
Given the diversity of approaches to the process, it is no wonder results are inconclusive. The ideal time to start imprint training as suggested by 7 different authors ranges from birth or 10 minutes following birth to 14 days of age, with repetitions of the process and testing for results occurring at wildly varying frequencies (McGreevy, 2012). Furthermore, a critical learning period in foals has not yet been established, and despite Robert Miller’s claims, foals will not “imprint on” (establish a social preference for) a human over its dam (Lansade et al, 2005; Spier et al. 2004; Williams et al., 2003).
Imprint training, as espoused by veterinarian Robert Miller, advocates for the handling of the foal immediately following birth and continuing in a series of sessions occurring over a 48 hour period. The goal is to desensitize and habituate the foal to human contact with the belief that it is safer than training a larger, stronger and potentially dangerous youngster, and that such contact will have a long-lasting impact, making it easier to handle the foal when the time comes for more advanced training and routine veterinary procedures (McGreevy, 2012).
When following Miller’s program, the handler will physically separate the foal from the dam within 10 minutes of birth and restrain it to dry its body and cut the umbilical cord. The next step involves holding the foal before it stands, until it ceases to resist, and then rubbing the entire body until the foal shows relaxation, including the ears (inside and out), eyes, lips, tongue, face, neck, thorax, sides, stomach, rump, tail, perineum and external genitalia, lifting and handling each foot, and lifting and moving the tail up and down and from side to side (McGreevy, 2012; Spier et al., 2004; Williams et al. 2003).
Once the foal ceases to resist the handler’s touch, a number of aversive stimuli are introduced until signs of panic subside, such as clippers, a simulation of an anal exam, including insertion of a rectal thermometer, rubbing the foal’s entire body with a plastic bag, and spraying the foal with water from poll to tail. A number of unusual sounds and aversive visual stimuli are also presented, such as whistles, gunfire, loud music, waving flags and swinging ropes (McGreevy, 2012).
The handler then proceeds to apply pressure to the girth region by placing his or her arms around the foal and “compressing rhythmically until any resistance abates” (McGreevy, 2012, p.85). A halter is placed on the foal and the handler then attempts to lead it and teach it to stand still by holding it in place until it stops struggling. The handler may also push the foal from either side until it moves away in response to pressure (Williams et al. 2003). The initial imprinting session lasts for 45 to 60 minutes and the entire procedure is repeated when the foal is 24 hours old (Spier, et al., 2004).
Perceived benefits of imprint training
Studies conducted by Miller, Mal and McCall, and Simpson (see Lansade et al., 2005) all indicate that foals subjected to imprint training are more tractable and less reactive to stimuli to which they were introduced as neonates than non-handled foals. Experiments conducted by Simpson (2002) support these claims. She found significant differences in the calmness and perceived friendliness of handled foals, i.e. willingness to approach humans in the test paddock, and lower heart rates in comparison to the control foals when presented with stimuli when tested 4 months after the initial sessions. Whereas Lansade et al. (2005) state that handling from birth may be advantageous because “very young foals are weaker, have fewer defensive reactions and may be less fearful of humans than older foals,” however, they go on to say that “the effects of handling are only temporary” and that “the handling procedure needs to be repeated regularly until the horse is broken in” (p.156).
Despite the perceived benefits, the decision to engage in any neonatal handling procedure should be approached with caution. Handling a foal at birth does not fit within the equine ethogram (the catalogue of horse-specific behaviours) (McGreevy, 2012) and there is a risk that over-handling of the foal will interfere with the mare-foal bond (Simpson, 2002). Also of importance is the fact that the young of highly precocial species, such as horses, receive “little physical contact, apart from the very early licking at birth and later direct social interactions” with the dam, the frequency of which is low (Henry et al., 2007, p.712-713) especially when compared to the 30 to 50 interactions that Miller prescribes for imprint training. Miller’s techniques may, in fact, equate to a process of flooding, which leaves the foal in a state of learned helplessness rather than achieving true habituation or desensitization (McGreevy, 2012).
Many horses do not receive training until later in life and are still able to learn the skills and behaviours that are taught during imprint training, such as leading and acceptance of clippers (Williams et al., 2003).
It has been observed that even foals that have received imprint training are as difficult to approach as controls if they don’t receive regular handling after the initial sessions. Also, there has been little proof that acceptance of aversive stimuli is accomplished through imprint training, nor are reactions to isolation from conspecifics or learning abilities noticeably improved (Lansade et al., 2005; McGreevy, 2012).
Henry, S., Richard-Yris, M.A., & Hausberger, M. (2006). “Influence of Various Early Human-Foal Interferences on Subsequent Human-Foal Relationship.” Developmental Psychobiology, 48, p. 712-718.
Henry, S., Briefer, S., Richard-Yris, M.A., & Hausberger, M. (2007). “Are 6-Month-Old Foals Sensitive to a Dam’s Influence?” Developmental Psychobiology, 49, p. 514-521.
Hoffman, H.S. (1996). “Imprinting: A brief description.” Retrieved from http://www.animatedsoftware.com/family/howardsh/imprint.htm
Lansade, L. Bertrand, M., Bouissou, M.F. (2005). “Effects of neonatal handling on subsequent manageability, reactivity and learning ability of foals.” Applied Animal Behaviour Science, 92, p. 143-158.
McGreevy, P. (2012). Equine Behaviour: A Guide for Veterinarians and Equine Scientists, 2nd ed. Edinburgh: Elsevier.
Simpson, B.S. (2002). “Neonatal Foal Handling.” Applied Animal Behaviour Science, 78, p. 303-317.
Spier, S.J., Burger Puterla, J., Villarroel, A. & Pusterla, N. (2004). “Outcome of tactile conditioning of neonates, or ‘imprint training’ on selected handling measures in foals”. The Veterinary Journal, 168, p. 252-258.
Williams, J.L., Friend, T.H., Collins, M.N., Toscano, M.J., Sisto-Burt, A. & Nevill, C.H. (2003). “Effects of imprint training procedure at birth on the reactions of foals at age six months.” Equine Veterinary Journal, 35 (2), p. 127-132.