Fat feeding increases equine heparin-released lipoprotein lipase activity.

The research explored how varying levels of fat intake impact the activity of lipoprotein lipase (LPL), a crucial enzyme in lipid metabolism, in horses. The results showed that increased fat in their diet led to increased enzyme activity and also affected plasma concentrations of certain types of cholesterol and phospholipids.

Methodology

• The researchers used eight mature trotter horses for the study. They followed a 4×4 Latin square design.
• The horses were given four different diets, each with different fat levels—3.0, 5.0, 7.7, and 10.8% relative to dry matter content.
• The diets consisted of hay in combination with distinct concentrates. Added fat came from soybean oil, which replaced equal-energy quantities of glucose in the concentrates. Hay and concentrates were provided in a 3:1 energy ratio.
• Each dietary phase lasted for three weeks, after which blood samples were collected for analysis.

Findings

• The findings revealed an explicit dose-dependent relationship between fat intake and the activity of lipoprotein lipase (LPL), i.e., with the increase in fat intake, the activity of LPL also increased. Specifically, an intake increase of 1g/kg dry matter correlated with a 0.98 micromol fatty acid released-mL(-1) x h(-1) increase in LPL activity.
• The researchers also found elevations in plasma concentrations of total cholesterol, high-density lipoprotein cholesterol, and phospholipids following high-fat feeding.
• The diets, however, did not significantly influence plasma triacylglycerols concentrations.

Implication of the Results

• The results are interpreted in the context of the ability of fat feeding to potentially bolster the oxidative capacity of skeletal muscle.
• This is crucial as the metabolism and redistribution of lipids in the body are key to the overall health and energy utilization of horses, particularly in high-performance circumstances.