The objective of the present research was to determine
the insulin response of the glucose and fatty acid
metabolism in dry dairy cows with a variable body
condition score (BCS). Ten pregnant Holstein Friesian
dairy cows (upcoming parity 2 to 5) were selected based
on BCS at the beginning of the study (2 mo before
expected parturition date). During the study, animals
were monitored weekly for BCS and backfat thickness
and in the last 2 wk, blood samples were taken for determination
of serum nonesterified fatty acid (NEFA)
concentration. Animals underwent a hyperinsulinemic
euglycemic clamp test in the third week before the
expected parturition date. The hyperinsulinemic euglycemic
clamp test consisted of 4 consecutive insulin
infusions with increasing insulin doses: 0.1, 0.5, 2, and
5 mIU/kg per minute. For each insulin infusion period,
a steady state was defined as a period of 30 min where
no or minor changes of the glucose infusion were necessary
to keep the blood glucose concentration constant
and near basal levels. During the steady state, the
glucose infusion rate [steady state glucose infusion rate
(SSGIR) in μmol/kg per minute] and NEFA concentration
[steady state NEFA concentration (SSNEFA)
in mmol/L] were determined and reflect the insulin
response of the glucose and fatty acid metabolism.
Dose response curves were created based on the insulin
concentrations during the steady state and the SSGIR
or SSNEFA. The shape of the dose response curves is
determined by the concentration of insulin needed to
elicit the half maximal effect (EC50) and the maximal
SSGIR or the minimal SSNEFA for the glucose or fatty
acid metabolism, respectively. The maximal SSGIR was
negatively associated with variables reflecting adiposity
of the cows (BCS, backfat thickness, NEFA concentration
during the dry period
The objective of the present research was to determinethe insulin response of the glucose and fatty acidmetabolism in dry dairy cows with a variable bodycondition score (BCS). Ten pregnant Holstein Friesiandairy cows (upcoming parity 2 to 5) were selected basedon BCS at the beginning of the study (2 mo beforeexpected parturition date). During the study, animalswere monitored weekly for BCS and backfat thicknessand in the last 2 wk, blood samples were taken for determinationof serum nonesterified fatty acid (NEFA)concentration. Animals underwent a hyperinsulinemiceuglycemic clamp test in the third week before theexpected parturition date. The hyperinsulinemic euglycemicclamp test consisted of 4 consecutive insulininfusions with increasing insulin doses: 0.1, 0.5, 2, and5 mIU/kg per minute. For each insulin infusion period,a steady state was defined as a period of 30 min whereno or minor changes of the glucose infusion were necessaryto keep the blood glucose concentration constantand near basal levels. During the steady state, theglucose infusion rate [steady state glucose infusion rate(SSGIR) in μmol/kg per minute] and NEFA concentration[steady state NEFA concentration (SSNEFA)in mmol/L] were determined and reflect the insulinresponse of the glucose and fatty acid metabolism.Dose response curves were created based on the insulinconcentrations during the steady state and the SSGIRor SSNEFA. The shape of the dose response curves is
determined by the concentration of insulin needed to
elicit the half maximal effect (EC50) and the maximal
SSGIR or the minimal SSNEFA for the glucose or fatty
acid metabolism, respectively. The maximal SSGIR was
negatively associated with variables reflecting adiposity
of the cows (BCS, backfat thickness, NEFA concentration
during the dry period
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