The concentration of plasma triacylglycerols in horses fed diets containing either medium chain triacylglycerols or an isoenergetic amount of starch or cellulose.

The study investigates the impact of diets containing isoenergetic amounts of starch, cellulose, or medium chain triacylglycerols (MCT) on the plasma triacylglycerol levels in horses. The findings indicate that an MCT-rich diet significantly increases the plasma level of triacylglycerols, as compared to those of starch or cellulose.

Methodology

• The study was conducted using a Latin square design, involving six horses.
• The horses were fed hay and concentrates containing equal energy amounts of either starch, cellulose or MCT – the dietary variables provided on average 22% of total dietary net energy.
• Each experimental period lasted 21 days. Blood samples were collected before the morning meal, and then three and six hours later.

Findings

• The MCT-rich diet significantly increased the plasma levels of triacylglycerols when compared to diets rich in either starch or cellulose.
• There were also significant increases in the plasma concentrations of 3-hydroxybutyrate, total cholesterol, and phospholipids when the horses were fed with the MCT-rich diet as opposed to the cellulose or starch diets.
• The least postprandial insulin concentrations were observed in horses on the MCT diet.
• The concentrations of free fatty acids were the highest for the horses on the MCT diet.
• The activity of lipoprotein lipase was not significantly different across the three diets.

Implications

• The results contradict the previous assumption that cellulose feeding would generate enough acetic acid in the cecum and colon to enhance the provision of cytosolic acetyl-CoA, which would then stimulate hepatic fatty acid synthesis and consequently increase plasma triacylglycerols.
• This study shows that, instead, an MCT-rich diet appears to have the most significant impact on increasing the plasma triacylglycerol levels in horses.