Glucagon, @entity8788 , growth hormone, and some blood metabolites during energy restriction XXXX of lactating @entity291 .

@entity4323 @entity1522 @entity8788 @entity4322 @entity1270 @entity1718 @entity291 @entity413
Six Holstein @entity291 were sampled hourly for 24 h for plasma concentrations of hormones and metabolites. @entity291 were sampled at about 2 wk prepartum, at 3 wk postpartum, during a @entity1270 induced by feed restriction to 54% of ad libitum intake, and after a recovery period. They were fed long alfalfa hay postpartum. The onset of lactation caused concentrations of growth hormone, glucagon, @entity4323 , @entity4322 , and total @entity1522 of plasma to increase and those of @entity413 and @entity8788 to decrease. Feed restriction exacerbated changes at 3 wk postpartum except for total @entity1522 and glucagon, which both decreased to prepartal concentrations. Resumption of ad libitum feeding caused most hormones and metabolites to return to prepartum concentrations. Diurnal variations in response to feeding twice daily were most evident for growth hormone, free @entity1718 , and total @entity1522 . The 3-wk postpartum and ketonemic periods gave the greatest responses to feeding. Molar ratios of @entity8788 to glucagon and @entity8788 to growth hormone tended to decrease at 3 wk postpartum and decreased further in @entity1270 , demonstrating hormonal adaptations to decreased energy intake during lactation. Lactation ketosis results from more than severe energy deficit.
