Glycaemic and insulinaemic response of quarter horses to concentrates high in fat and low in soluble carbohydrates.

The research investigates how glycemic and insulinaemic responses in healthy Quarter Horses are affected by feeds high in fat and low in starch. The study results suggest that such diet may prevent future discomfort associated with Polysaccharide Storage Myopathy (PSSM), a common horse ailment.

Study Objective and Methodology

• The aim of the study was to understand how the blood sugar and insulin levels of Quarter Horses respond to high fat, low starch feeds, given that these horses are more prone to PSSM.
• Twelve clinically healthy Quarter Horses were observed. All of these horses had no prior signs of myopathy, a muscle disease which PSSM is a type of.
• The horses were fed on a 4 x 4 Latin square design haylage along with isocaloric concentrates based on barley and oats as a control diet (CO). Additionally, they also received diets high in sugar beet pulp, grass meal, and soybean oil (SB), rice bran and grass meal (RB), and rice bran, grass meal, sugar beet pulp and soybean oil (CP).
• The feeds were given over two weeks after a week of acclimatization. At the end of each period, blood samples were collected at intervals – 0, 30, 60, 90, 120, 180, 240, and 300 minutes after feeding.
• Blood test parameters included creatine kinase level (muscle damage indicator), glucose and insulin levels.

Results and Findings

• It was observed that the horses initially resisted rice bran containing feeds, but gradually accepted them over time.
• The assessments of creatine kinase activity, glucose and insulin levels were highest with the control diet (CO).
• The correlation between glucose and insulin levels varied with the type of feed but was significant overall, suggesting that the type of feed influenced the relationship between glucose and insulin.
• Moreover, the researchers found a strong correlation between the creatine kinase levels at feeding time and the mean post-prandial plasma glucose levels.

Conclusions

• The study concludes that feeds inclusive of rice bran, sugar beet pulp, grass meal and soybean oil are effective in inducing low glycaemic and insulinaemic responses. However, a degree of acclimation is required for the horses to accept such feeds.
• Though the underlying mechanism is not completely understood, the researchers found that the type of feed affects both glucose patterns and basal creatine kinase activity.
• The results from the study support the idea that low-starch, high-fat feeding may not only be beneficial for affected horses but could also act as a preventive measure against PSSM in susceptible horses.