Effects of an optimized dairy calf-rearing protocol on performance and health in the subsequent fattening period on Swiss veal farms

We conducted a prospective field study to characterize the effects of an optimized rearing protocol of calves on dairy-farms on the subsequent performance, health and antimicrobial use (AMU) at the veal-farm. On 19 dairy-farms a total of 55 matched pairs of calves (same gender and breeding type, born within the same period and farm) were randomly assigned to the treatment group P (“preconditioned”) or C (“control”) during five two-week enrollment periods. The P-calves were fed milk ad libitum, received parenteral selenium and iron supplementation, wore calf jackets at low temperatures, and were vaccinated intranasally against bovine respiratory disease. The C-calves were fed restrictively and received no additional measures. At an average of 30 days of life, calves were transported directly to one of two veal-farms. Body weight and health score were determined between days 2 and 5 of life, at transport and in weeks 4 and 12 after arrival on the veal farm. All applications of antimicrobials were recorded. Mixed-effect models were applied for statistical analyses. While born with similar body weights, daily weight gain of the calves differed between groups on the dairy-farms (P: 1.10[0.96-1.25] vs. C: 0.70[0.55-0.84]kg/day; p