Changes in Hepatic Key Enzymes of Dairy Calves in Early Weaning Production Systems

Abstract

The objective of the present study was to describe plasma hormonal and metabolite profile and mRNA expression levels and activities of the enzymes pyruvate carboxylase (PC), phosphoenolpyruvate carboxykinase (PEPCK), and acetyl-coenzyme A (CoA) carboxylase in the liver of male Holstein calves before (1 and 3 wk of age) and after (8, 13, and 19 wk of age) weaning at 6 wk of age. The mean plasma concentration of acetate and beta-hydroxybutyrate increased, and that of plasma lactate and nonesterified fatty acids decreased with week, particularly after weaning. Plasma glucose concentration was lowest at 8 wk of age. The mean plasma concentration of insulin and glucagon did not change with time, and that of cortisol was greatest at 1 wk of age. In the liver, enzyme activity of PC was greatest at 1 wk of age and decreased with time. There was a significant relationship between the activity and the mRNA level for PC. Activity of PEPCK also decreased with week. Acetyl-CoA carboxylase activity tended to decrease with week, and activity at 13 wk of age was lower than that at other times. Expression of PC mRNA, but not that of PEPCK and acetyl-CoA carboxylase alpha, decreased with week. We conclude that the hepatic gluconeogenic enzymes and acetyl-CoA carboxylase activities tend to decrease with age, reflecting changes in plasma metabolites in early weaning production systems.

Limiting Concentrate during Growing Period Affect Performance and Gene Expression of Hepatic Gluconeogenic Enzymes and Visfatin in Korean Native Beef Calves

“…There was an increase in serum glucose levels in both groups with increasing age (period effect, p<0.0001), in our earlier study (Lohakare et al, 2012). Haga et al (2008) reported that plasma glucose levels were lower around weaning (8 wk) but then increased at 13 and 19 wk of age that corresponds well with the present results. The weaning stress along with lower feed intake could be the reason for lower plasma glucose in both groups at this time period.…”

“…Glucose serves as the main energy source in neonatal and pre-ruminant calves, but the lactose intake/milk intake does not meet glucose demands in very young calves (Girard et al, 1992). Also, the reduction in milk intake and the introduction of solid food cannot meet glucose demands; hence for carbohydrate homeostasis, glycogenolysis and gluconeogenesis become important in the liver (Girard et al, 1992; Hammon and Blum, 1998; Haga et al, 2008). Feeding and managing calves is expensive, requires extensive labour and contributes significantly to farm expenses.…”

Anaerobically fermented colostrum: an alternative for feeding calves

“…metabolism of lactose, which after 60 days of fermentation was no longer detected. Although HAGA et al (2008) have reported that lactose is the main energy source for pre-ruminants, in this work we infer that the fat and lactic acid present in the silage are suffi cient to provide energy for animal growth. This was evident in the weight gain of the animals fed with colostrum silage which was higher than the recommended by NRC (2001).…”

Clinical, blood gas and biochemical profile of diarrheic dairy calves fed starter concentrate containing citrus pulp as a replacement for corn

“…According to Haga et al (2008), the main energy source for young calves is glucose from lactose present in milk or milk replacer, however with advancing age and rumen development, glucose concentrations tend to decrease. Blood glucose values for calves vary from 80 to 120mg/ dL; however, diarrheic calves may have hypoglycemia due to anorexia, poor digestion and absorption and therefore reducing hepatic gluconeogenesis and increased anaerobic glycolysis.…”