Changes in blood glucose, plasma non-esterified fatty acids and insulin in pregnant and non-pregnant goats

The blood glucose and the plasma non-esterified fatty acids (NEFA) and insulin concentrations were estimated in jugular blood samples from 18 Alpine x Beetal and Sannen x Beetal goats during pregnancy and compared with samples from non-pregnant goats and from goats during the periparturient period. The blood glucose levels in the pregnant goats rose to a peak of about 60 +/- 1.36 mg/ml at 42-56 days and then declined to about 46+/-2.37 mg/ml at 112-126 days. In non-pregnant goats, the blood glucose levels were significantly (p<0.01) higher than in pregnant goats, except between days 42 and 70 (59 +/- 1.36 mg/ml). On the day of kidding, the levels declined significantly (p<0.01), increasing again thereafter. The plasma NEFA concentrations were significantly higher in pregnant than in non-pregnant goats from days 56 to 126. The NEFA concentration increased on the day of kidding, followed by a transient fall by day 3. The plasma insulin concentration was usually higher in pregnant than in non-pregnant goats, except between days 56 and 70 and from day 126 onwards. The insulin concentration fell late in pregnancy, but there was a transient increase 2 days after parturition. The blood glucose and plasma NEFA concentrations can be used as indices of nutritional status during pregnancy in goats.