The effects of fasting on some biochemical factors of liver, serum and clinical signs in cattle

BACKGROUND: Fasting is an alternative method to induce anorexia. OBJECTIVES: The biochemical factors of liver and serum and clinical signs were measured and documented in five non-lactating, non-pregnant cows following eight days of fast-ing. METHODS: Five crossbred, non-lactating, and non-pregnant cattle were used in this study. They were fasted for 8 days_ total food deprivation; however, they had free access to water. Liver biopsies were carried out one day before food deprivation (day 0) and 8 days after food deprivation by ultrasound-guided biopsy. Blood samples were taken from the jugular vein before and during fasting. The concentrations of triglyceride (TG), total lipids, glycogen, phospholipids, and total protein in liver and NEFA, BHBA, TG, total cholesterol, glucose, total lipid, APO A1, and APO B in blood serum were measured and compared. RESULTS: The results of this study showed that fasting for 8 days reduces respiratory rate by 52% and heart rate by 12.5% and has no significant effect on rectal temperature. The concentrations of the liver triglyceride (TG) and glycogen significantly increased (p=0.046) and decreased (p=0.007) on day 8, respectively. There were no significant differences in the content of liver phospholipids (p=0.83), total lipids (p=0.29), and total protein (p=0.23). The serum concentrations of NEFA and BHBA increased significantly (p=0.008) at the end of fasting period. No significant differences in the concentrations of serum TG (p=0.057), total cholesterol (p=0.93), glucose (p=0.108), total lipid (p=0.27), APO A1 (p=0.762), and APO B (p=0.92) were noticed on days 0 and 8. CONCLUSIONS: The results of the present study showed that fasting, like anorexia (as a result of diseases), induces fat mobilization from adipose tissue in response to the induced negative energy balance.