Diets fed to veal calves seem to lead to frustration and chronic stress in the calves, due to the limited opportunity to chew and ruminate on solid feed (e.g. Veissier et al., 1998). Veal calves are typically fed only twice a day, and their meals comprise of large quantities of milk replacer supplemented by solid feed, with little structure to chew on (e.g. Brscic et al., 2011). The inability to perform highly-motivated natural behaviours, such as rumination in cattle, leads to the development of repetitive, invariant behaviours with no obvious function, termed stereotypies (e.g. Redbo et al., 1996). Stereotypies found in veal calves include for example tongue playing, the rolling and unrolling of the tongue inside or outside of the mouth. Tongue playing is thought to reflect a frustrated drive to eat and ruminate (e.g. Webb et al., 2012), but research also suggests that this behaviour is related to how milk is fed: in an open bucket or via a teat (Seo et al., 1998), and may, thus, reflect a frustrated drive to suck on a teat. Tongue playing levels were compared in veal calves fed different diets, varying in solid feed amount and composition, as well as in the method of feeding the milk replacer.
|Publication status||Published - 2015|