NONNUTRITIVE ORAL ACTIVITIES AND STRESS RESPONSES OF VEAL CALVES IN RELATION TO FEEDING AND HOUSING CONDITIONS

This study assessed the extent to which eating solid foods and social contacts influence nibbling objects and improve the welfare of veal ca lves, Animals were fed milk replacer only vs. supplemented with solid foods and were housed in individual stalls vs, together in pens, Time budget, reactions to handling in a weighing machine, growth, health (l ength of medical treatments) and abomasal lesions were assessed. In ad dition, chronic activation of the hypothalamo-pituitary-adrenocortical axis was evaluated after ACTH and CRF challenges, and that of the sym pathetic nervous system, through activities of catecholamine-synthesis ing enzymes. The provision of solid foods reduced time spent nibbling objects and being inactive in proportion to and at the time of the inc rease in time spent eating and chewing. The calves housed together in pens had higher basal cortisol levels and they reacted to weighing, He alth and physiological indices of chronic stress did not vary with fee ding or housing conditions. It is concluded that nibbling in veal calv es derives at least in part from a lack of development of feeding beha viour appropriate to ruminants. There was no clear evidence of poorer welfare due to feeding on milk replacer only or individual housing, bu t calves reared in groups seemed more stressed by handling than calves reared in individual stalls. (C) 1998 Elsevier Science B.V.