Red Brazilian Propolis (RBP) is a new type of propolis with distinct chemical compounds, especially isoflavones, which can enhance the immune system and act against several diseases. The objective of this study was to evaluate the effects of RBP supplementation trough milk on animal performance, metabolism, and health. Thirty-two newborn calves were individually housed, with free access to water and concentrate, and fed 6 L/d of milk. The animals were blocked according to birth weight and distributed in 2 treatments: (1) Control; (2) daily supplementation of milk with 4mL/d of RBP ethanoic extract (30%; 300 mg of RBP/mL). Feed intake and fecal scores were monitored daily; weight was measured weekly. Blood samples were collected weekly for metabolites determination. Data were analyzed as repeated measures using a mixed model. Supplementation of RBP in milk had no effect on average feed intake, weight gain, and final weight (P > 0.05), however there was a significant age effect (P < 0.05). Supplementation of RBP had a positive effect on fecal score (P < 0.05), reducing the feces fluidity and clinical signs of diarrheic animals. No effects of supplementation were observed for blood metabolites or hematocrit. Nevertheless, there was an age effect for those parameters, associated with rumen development, and an interaction of supplementation and age for glucose (higher at wk 5 and 7) and ΒHB (higher at wk 5 and lower at wk 7). RBP supplementation had no effect on performance but decrease diarrhea severity. Results are shown in Table 1. Table 1. Performace and blood parameters of calves supplemented or not with Red Brazilian Propolis (RBP)

Item	Control	RBP	SEM	P-value
Treatment	Age	Treatment × Age
Feed intake, g/d	259.6	245.8	36.62	0.79	<0.0001	0.50
Initial BW, kg	35.8	35.1	1.21	0.89	—	—
Final BW, kg	72.5	73.6	1.64	0.89	—	—
BW gain, g/d	654.5	694.2	23.47	0.17	<0.0001	0.27
Fecal score	1.8	1.6	0.07	0.02	<0.0001	0.76
Hematocrit, %	22.5	23.2	0.64	0.36	0.006	0.93
Glucose, mg/dL	125.5	127.9	2.37	0.15	0.002	0.01
Urea, mg/dL	17.3	17.5	0.58	0.75	0.009	0.71
Lactate, mg/dL	14.0	14.3	0.72	0.81	<0.0001	0.69
Total protein, g/dL	6.9	6.9	0.14	0.85	<0.0001	0.35
Β-hydroxybutyrate, mmol/L	0.1	0.1	0.01	0.83	0.002	0.04