Effect of Chromium Propionate Supplementation on Biochemical and Hormonal Parameters of Sheep During Gestation and Lactation

Chromium (Cr) is a trace element that places a role in the insulin sensitivity mechanism and its supplementation can alter energy metabolism and related blood parameters. This study aimed to evaluate the effects of Cr propionate doses supplementation in ewes, during late pregnancy and lactation, on biochemical and hormonal parameters. Thirty-one ewes, Santa Inês and Dorper crossbreed, single gestation, 63 ± 10 kg of body weight, age 3 ± 2 years, were randomly assigned into 4 treatments: without supplementation (CR0) and daily supplementation of 0.5 mg (CR0.5), 1.0 mg (CR1.0) and 1.5 mg (CR1.5) of chromium per animal. Daily supplementation occurred from the 100th day of gestation to the 60th day after lambing, totalizing 110 days. Blood samples were collected five times during trial. Data were analyzed using SAS program, PROC MIXED and means compared by Tukey test with P ≤ 5% for significance and 5% < P ≤ 10% for tendency. During gestation, CR0.5 tended to decrease blood non-esterified fatty-acids levels (P < 0.1). During lactation, CR0.5 tended to present lower ß-hydroxybutyrate level compared to CR1.0 (P < 0.1) and had lower insulin:glucose ratio compared to CR0 (P < 0.05). Serum phosphorus levels increased with higher doses of Cr (P < 0.001). Therefore, the dose of 0.5 mg of Cr improved energy metabolism efficiency of ewes during high-demand periods. We concluded that the dose of 0.5 mg of Cr per animal per day altered energy metabolism during late pregnancy and lactation, and that doses above it altered phosphorus concentrations.