The aim of the study was to investigate the effects of a product ‘ZooLac Bovimix’, containing yeast (Saccharomyces cerevisiae) and a postbiotic product from Lactobacillus acidophilus, on the performance and health of young rosé veal calves. In total 120, mainly Holsteins, bull calves arrived at a Danish rosé veal production over a period of three months. On arrival, the calves were either allocated to a control diet (CON) (25.3 ± 1.3 days and 55.1 ± 1.3 kg) or a diet with the yeast/lactobaccilus (PRO) (25.3 ± 1.0 days and 55.3 ± 0.8 kg) for six weeks. PRO calves received the yeast/lactobacillus product in the milk replacer and the concentrate. The product constituted 0.09% of dry matter (DM) in the concentrate and 1.5% of DM in the milk replacer. All calves were fed milk replacer for four weeks and had access to concentrates for all six weeks. Manure was sampled twice, around days 14–17 and 28–31, and blood was sampled on days 3 and 28–35. The growth performance was significantly higher for PRO calves, while the product did not affect the number of veterinary treatments and DM content in the manure. Serum metabolites were similar between the treatments at the first sampling. However, the concentrations of total protein and immunoglobulin G were significantly higher in the serum from PRO calves at the second sampling. Thus, supplementation of the yeast/lactobacillus product in the diet of young rosé veal calves did not affect the overall health but had a positive effect on growth performance.