Effects of processing barley on its digestion by horses.

The research article explores the impact of different processing methods of barley on its digestion by horses. Four horses were fed rolled, micronised, or extruded barley, and afterwards, their glycaemic and insulinaemic responses were measured along with their breath hydrogen and methane levels.

Methodology

• The experiment involved four horses that were randomly given diets containing rolled, micronised, or extruded barley. The barley intake was carefully calibrated to provide 2 g of starch per kg of body weight per day.
• Alongside the barley, horses were also provided with 1 kg of grass hay per 100 kg of bodyweight daily for a 10-day acclimatisation period.

Data Collection

• After each feeding period, blood and breath samples were taken from the horses. The horses were given their test meal of variously processed barley after a 12-hour overnight fast to ensure that the results were not influenced by other dietary factors.

Measurements

• Glycaemic and insulinaemic responses of the horses were measured as an indicator of the pre-caecal digestibility of starch. Basically, the researchers were trying to see how quickly and effectively the horses’ bodies were able to break down and absorb the starch in the barley.
• The horses’ breath hydrogen and methane levels were also tested after feeding. These gases indicate microbial fermentation of the starch, which is another important aspect of digestion.

Results

• The study found that the highest peak serum glucose and serum insulin concentrations occurred after the horses ate the extruded barley. Micronised barley resulted in lower concentrations, and the lowest concentrations were noted after the horses consumed the rolled barley.
• Analysis of the breath gas showed increased hydrogen levels within four hours of feeding all types of barley diets. However, the differences in peak hydrogen concentrations between the various processing methods were not statistically significant.
• The study found a varying methane concentration level. Though not significantly different, it appeared to be a trend for higher methane concentrations after the consumption of rolled barley.

Conclusion

• The results of the study suggest that the processing method of barley can have an impact on its digestibility by horses and the subsequent metabolic responses. However, more research is needed, given the variability in the results obtained in this particular study, to conclusively determine the best processing method for optimal digestive efficiency in horses.