Effect of withholding feed on concentration and composition of plasma very low density lipoprotein and serum nonesterified fatty acids in horses.

The research study looks into the effects of withholding feed on the concentration and composition of very low-density lipoprotein (VLDL) and serum nonesterified fatty acids in horses. The results show that denying food significantly increases blood lipid concentrations in horses but results vary for individual horses.

Methodology

• The researchers carried out their study on four healthy adult mares. These mares were either fed mixed grass hay freely or denied feed for a period of 36 hours commencing at 8:00 AM.
• Blood samples were collected every 2 hours during the study duration. These samples were analyzed for different aspects such as the concentration and composition of very low-density lipoprotein (VLDL), nonesterified fatty acid (NEFA), triglyceride (TG), and glucose.

Key Findings

• The study observed that withholding feed led to a significant rise in the mean serum concentrations of NEFA in horses. 36 hours without feed resulted in a 16-fold increase in the mean serum NEFA concentration and a 2-fold increase in the mean plasma VLDL concentration compared to the baseline units.
• The research showed that the concentrations of triglycerides in plasma significantly increased over time in horses deprived of feed.
• Feed-deprived horses were found to have considerably lower mean plasma glucose concentrations overall. The percentage of protein in VLDL was significantly lower as well in these horses.
• The concentrations of plasma VLDL differed extensively among horses when feed was withheld. For two horses, the concentrations of plasma triglycerides and VLDL remained unaffected.

Conclusions

• The study concludes that the act of withholding food leads to a significant increase in the concentrations of blood lipids in horses. However, the response to feed deprivation varies across individual horses.
• All horses that were denied feed showed an increase in serum NEFA concentrations, which is a signal of the mobilization of triglyceride stores in the tissue.
• The variation in the concentration of plasma VLDL due to feed deprivation indicates that its metabolism could be strongly influenced by other unidentified factors in horses.
• The differences seen in plasma VLDL concentrations in horses due to withholding feed potentially serve as an indication of susceptibility to the hyperlipemic syndrome of Equidae.