Effect of age on serum metabolites of female Brahman crossbred cattle raised in an integration system of cattle-oil palm plantation in Central Kalimantan

The study was aimed to evaluate the effect of age on the serum metabolite of female Brahman crossbred cattle raised extensively under the cattle-oil palm integrated s ystem for 3 months. Thirty calves aged 3-6 months, 30 heifers aged 12-18 months, and 30 cows aged 48 months which were clinically healthy were selected and used in this study. Blood samples were collected from coccygeal vein. The serum was separated by centrifugation and stored at -20 o C until the time of analysis. Blood samples were collected from coccygeal vein as much as 4 mL. Serum metabolites were determined using an autoanalyzer (The Roche/Hitachi Cobas 6000 analyzer). Serum concentration of ALB, Ca, P, Na, K, and Cl in calves were higher than heifers and cows (P