Veal calves are typically fed high quantities of milk replacer supplemented with solid feed, which tends to contain a relatively small portion of roughage. Feeding strategies used in veal production have been associated with welfare issues, including the development of abnormal oral behaviours (AOB) and poor gastrointestinal health. AOB mainly include tongue playing and excessive oral manipulation of the environment, and are thought to develop in calves when chewing activity (i.e. eating and rumination) is not adequately stimulated. The aim of this thesis was to develop novel feeding strategies to improve the welfare of veal calves, i.e. to minimise the development of AOB and gastrointestinal health disorders.
Calves preferred milk replacer, concentrate and hay over straw and maize silage, although preferences varied across age and depended on the variable considered to assess preference (i.e. intake, time spent eating or frequency of visits). Calves were willing to work for hay and straw, despite being fed a high-energy diet of milk replacer and concentrate. In addition, they showed a preference for long over chopped hay, but not long over chopped straw. Calves voluntarily selected an average of 1000 g DM roughage and 2000 g DM concentrate on top of milk replacer (provided ad libitum), and seemed to select a diet that enabled them to meet their needs in terms of chewing activity.
Novel feeding strategies aimed at improving the welfare of veal calves should comprise sufficient roughage to meet every individual's needs in terms of chewing activity, and this throughout their lifetime, whilst stimulating good gastrointestinal health.