Variations of energy biochemical metabolites in periparturient dairy Saanen goats.

The Saanen goat is one of the highest milk-producing goat breeds and has a high reproductive yield. Twelve pregnant dairy Saanen does were selected to study the variations in energy-related blood metabolites during periparturition and to highlight the negative energy balance (NEB) rate during this critical period. Blood from the jugular vein was collected from each doe on days 29, 14 and 6 before the expected kidding time and also 12 h and on days 7, 13, 19, 21, 28, 35 and 42 postpartum. The concentrations of β-hydroxybutyrate (BHBA), non-esterified fatty acid (NEFA), cholesterol, triglyceride, glucose, total protein, albumin, blood urea nitrogen and aspartate aminotransferase (AST) activity were determined. Since serum metabolites were measured over time, a repeated measures approach using ANOVA with mixed linear models was used. The results of our study indicated that the changes in BHBA concentrations were between 134 and 375 μmol/l. There was a low number of does with BHBA concentrations above 1,000 μmol/l. However, the number of does with abnormal NEFA concentrations (≥0.6 mmol/l) was high. The NEFA results were in agreement with the increased proportion of does with AST concentrations greater than the cutoff level (≥100 U/l). We conclude that similar to dairy cows, NEB occurs in dairy Saanen goats during the periparturition period. NEFA concentration reflected a NEB better than BHBA in dairy Saanen goats. [ABSTRACT FROM AUTHOR]