Crossbred heifer calves (n = 70) were used in a randomized complete block design to evaluate the effects of a feed supplement on growth performance in an individual outdoor hutches during winter (T = −35 to 4°C) at a commercial dairy farm in South Dakota. After birth calves were assigned to (1) Control with no supplement (CON; n = 35) and (2) supplemented with 3 g/d Probisan, a lactic acid bacteria and non-bitter fermented yeast product, added to milk from d 3 until weaning at d 56 (PRO; n = 35). Groups were balanced for birth date, weight and concentration of serum immunoglobulins. Calves in both groups were fed 2.6 L at 3x/d pasteurized milk/calf/d until wk 7. During wk 8 milk was fed once daily until weaning. A commercial nonmedicated starter (grain mix pellet) was fed ad libitum from d 14. Body weight was recorded at birth and weekly until weaning. Hip height and width were measured every other week until weaning. Individual starter DM intake was measured daily. Data were analyzed by MIXED procedures in SAS 9.4 with repeated measures. The model included the fixed effects of treatment, week, and interaction, and animal nested within treatment as random effect. No differences (P > 0.10) were found between treatment groups for average body weight (47 ± 0.8 kg), hip height (81 ± 0.5 cm), hip width (18.4 ± 0.2 cm), or body weight gain (0.634 ± 0.02 kg/d). Average values for body weight, hip height, hip width, and body weight gain increased (P < 0.001) from 32.3 ± 0.5 kg, 75 ± 0.4 cm, 17.1 ± 0.6 cm, and 0.272 ± 0.03 kg/d at wk 0 to 67.8 ± 0.8 kg, 88 ± 0.4 cm, 20.9 ± 0.1 cm, and 0.923 ± 0.03 kg/d at wk 8, respectively. For starter DM intake, both groups consumed similar amount (119 ± 19 g/d) during wk 2 and 3. However, from wk 4 until weaning PRO calves tended (P = 0.078) to consume less starter (CON = 574 ± 38 g/d and PRO = 477 ± 39 g/d). In conclusion, calves supplemented with Probisan consumed 17% less starter from wk 4 until weaning without reductions in body weight gain or body measurements.