This study aimed to investigate the correlation between body condition score (BCS), blood biochemical metabolites, milk yield (MY) and quality (Mfat) in Montbéliarde cattle (31 cows) reared in 5 farms of Algerian semi arid area. The BCS was measured in dry and peak of lactation (6 weeks after calving). Blood samples were taken at the time of body condition (BC) measurement for determination of energy (Glucose, cholesterol, triglycerides and B-Hydroxybutyrate), nitrogen (urea and albumin) and mineral (calcium) metabolites.  Milk yield was recorded in the 6^th week of lactation (peak). A sample of milk for each cow was used to determinate milk fat, density and acidity. The results showed a significant decrease in postpartum BCS accompanied by an increase in cholesterol and B-Hydroxybutyrate (BHB) concentration. The correlation analysis showed that BHB concentration in pre calving was negatively correlated with BCS (r=-0.321; P<0.05) and cholesterol (r=-0.308; P<0.05). In postpartum, BCS was negatively correlated with cholesterol (r=-0.416; P<0.05), urea (r=-0.366; P<0.05) and BHB (r=-0.487; P<0.05). However, the level of milk production decreased significantly with high glucose (r=-0.449; P<0.05) and BHB (r=-0.514; P<0.05). The fat content increased significantly with blood triglycerides (r=0.681; P<0.05) and BHB (r=0.522; P<0.05) concentration, indicating a high mobilization of body reserves used for the synthesis of milk fat. In conclusion, it can be assumed that the rate of BHB seems to be the best indicator of the nutritional status of dairy cows that determines their production level and quality.

Key words: Body condition, Blood metabolites, Milk fat, Milk yield, Montbéliarde cattle