In a longitudinal investigation (3 points of time n = 214, 206 resp. 202) the hemoglobin quota (Hb), the hematocrit (Hct) resp. the average corpuscular hemoglobin concentration (MCHC) were analysed at male calves receiving semi-liquid feed in the transitional period from pre-ruminal to ruminal digestion (56d). Breed, live weight development, consumption of milk, concentrated feed resp. dried forage, diseases of the calves as well as the father and the milk yield resp. the lactation age of the mother were registered as reference conditions. The percentage of calves with an Hb less than 10.5 g/dl was at the three points of time 50.00%, 86.41% resp. 41.58%, of calves with an Hct less than 33,5% it was 43.46%, 66.02% resp. 31.68% and of calves with an MCHC less than 30.5 g Hg/dl erythrocytes 51.87%, 76,21 resp. 47,03%. 21.50%, 33.50% resp. 4.46% of all test animals even had an Hb of less than 8.5 g/dl.