[Markers of nutritional risk for placental retention: use of blood analysis at the end of gestation].

A sample of 1,225 calvings was used to detect predictors for retained placenta before parturition: 300 with retention, 925 without. Biochemical analyses showed an increased energy mobilization, hypocalcemia, and lower levels of circulating amino acids and monocytes within the last 2 weeks of gestation in cows with a retained placenta. The results agree with the reported smaller quantity of concentrates supplied to these cows before parturition. More cows with retained placenta were fed cereals but received less phosphorus with the mineral supplementation.