BLOOD SERUM LEVELS OF MACRO - AND MICRONUTRIENTS IN TRANSITION AND FULL LACTATION COWS

摘要

The objective of this study was to determine blood levels of macro- and micronutrients in Simmental cows (n=45) during the transition period and full lactation. The experimental cows were assigned to three groups; Group A (n=15) including clinically healthy late gestation cows, Group B (n=15) comprising clinically healthy cows in the puerperium, and Group C (n=15) made up of clinically healthy full lactation cows. Blood samples were collected from all experimental cows. Blood serum samples were analysed for calcium, magnesium, inorganic phosphorus, iron, copper, manganese, zinc and cobalt levels using spectrophotometry. Blood levels of macro- and micronutrients were within the physiological range in all experimental cows. Blood concentrations of calcium, magnesium and inorganic phosphorus in cows in the puerperium were statistically significantly lower (p<0.05) compared with those in dairy cows during late gestation, and full lactation, which may indicate the increased use of these macronutrients in early lactation for the mammary gland. Serum levels of iron, copper, manganese and cobalt showed no significant variation (p>0.05) across cows, whereas serum zinc level were significantly lower (p<0.05) in puerperium cows compared with late gestation and full lactation cows. The results show that the homeostasis of the macro-and micronutrients tested in the blood of transition and full lactation dairy cows was maintained, suggesting their adequate supply from alimentary sources.