The objectives were (i) to compare the weaning performance of Simmental (S) and Holstein Friesian (H) female calves and (ii) to test a weaning scheme based on a standard milk replacer (MR) and whole S milk (SM). In a first trial two groups of S and H females (8 calves per group) were weaned with the same feeding programme based on milk replacer (150 g/L, 23% crude protein, 19% crude fat) and a concentrate mixture (compound feed : chopped alfalfa hay, 9:1). In a second trial, 20 S female calves were divided into two groups and weaned with the same feeding programme based on MR of the first trial or on SM. Both trials lasted 12 weeks and animals were reared in individual boxes, weighted at 3 weeks intervals with the milk fed till the 9 week of age. Blood samples were collected within 3 d after birth and analysed for haemoglobin (Hb) content. Data were analysed per trial, according to a one factor design y= \uf06d + \uf061i + \uf065 ij (\uf06d = overall mean; \uf061 = breed and milk type effect for trial 1 and 2, respectively).
In the first trial both groups received a total of 41 kg of milk powder and consumed the same concentrate mixture (102 kg). The S calves had a higher initial live weight and Hb contents than H (45 vs. 39 Kg and 7.3 vs. 6.1 mmol/L, P<0.05). The average daily gains in the whole trial were similar between breeds (740 and 717 g/d for H and S, respectively). In the second trial, the two groups had comparable initial live weights (42.5 + 3.3 Kg) and Hb contents (7.8 + 1.4 mmol/L). The two groups received the same amounts of milk (271 L), with similar protein contents (3.6-3.5 %) and higher fat contents for the SM than the MR group (4.3 vs 2.9 %). The concentrate mixture intake and the daily gains during the whole trial were higher for the SM than the MR calves (110 vs 97 Kg and 810 vs 740 g/d, P<0.05).
In conclusion the S and H females have the same performances in standard weaning programmes and the use of whole Simmental bovine milk allows to increase daily gains of S female calves
