PSXI-33 Milk replacer formulation for dairy calves: substitution of some dairy protein by yeast-protein

Abstract Eighty dairy calves from birth (d1) to weaning (d64) were reared in individual pens. One feeding program was tested with 4 different milk replacers (MR), 3 included some yeast products (Table 1). The content of crude protein (22 %), crude fat (18 %) and concentration (140 g MR per liter milk feed) was similar for all MR. Calves were divided into 4 groups at 5-d of age: (i) Control, (ii) MR1, (iii) MR2 and (iv) MR3 milk replacers. Volume distributed per calf and per meal varied with age but did not differ between groups. All calves received water and a starter concentrate (19.0% CP) ad libitum. Diarrhea scoring per calf (0 to 4), individual MR and starter intake were recorded daily whereas BW was determined every two weeks. Data were evaluated by the MIXED procedure of SAS with group, breed and sex used as fixed effects. Quality (% brix) and intake of colostrum over d1 did not differ between groups. Growth performances are altered by treatment (P = 0.05): ADG over all the experimental period was significantly lower for MR2 (0.59 kg/d) whereas it resulted similar between the 3 other groups (0.67 kg/d on average). Starter feed intake over 64d did not differ significantly between groups: 526, 501, 475 and 555 g/d on average for Control, MR1, MR2 and MR3, respectively. The MR intake over 64d was lower for MR2 (5.48 L/d) compared to Control, MR1 and MR3 (5.64 L/d, on average). There was no difference regarding diarrhea score (0.26 on average) between groups. Globally, both MR1 and MR3 led to performances similar to control MR used as reference whereas MR2 resulted more challenging for calves. Therefore, using yeast product as part of protein source for MR formulation is achievable without compromising growth performances but type of product needs to be considered.