Digestibility of a complete ration in horses fed once or three times a day and correlation with key blood parameters.

The research study explored whether feeding horses once or three times a day impacts the digestibility of their food and any key blood parameters. The team found no significant differences in terms of digestibility or blood metabolites between the two different feeding frequencies.

Study Design and Methodology

• The experiment was conducted using four geldings – castrated male horses – that were fed either once a day, at 08:00 h, or three times a day, at 08:00, 13:00, and 18:00 h.
• The feed given was a mix of cereals and chopped alfalfa hay, supplied at a maintenance level of energy at 344 kJ/kg BW(0.75) everyday.
• The researchers allowed the horses three weeks to adapt to the feeding regime before collection was initiated.
• For five consecutive days, the total amount of faeces and urine was collected using special harnesses, to measure the digestibility of the feed.
• Blood samples were taken at multiple time points before and after feeding, and were analysed for glucose, L-lactate, triglycerides (TG), non-esterified free fatty acids (NEFA), and triiodothyronine (T3) to assess metabolism.

Findings and Interpretation

• The digestibility coefficients of dry matter (DM), crude protein (CP), ether extract (EE), crude fibre (CF), ash and nitrogen-free extract (NFE) showed no significant differences regardless of whether the horses were fed once or thrice a day.
• Similarly, blood metabolites including basal plasma glucose, plasma glucose curves, and other entities did not show any impact due to the variability in feeding frequency.
• Interestingly, the horses that were fed once in the morning were observed not to consume the entire meal immediately but saved a portion for eating later in the day suggesting they self-regulated their eating cultural which may explain the lack of difference found in the study.
• Feeding frequency was not related with plasma glucose response, however, the area under curve (AUC) of glucose was inversely correlated with CP and CF digestibility. This means as the digestibility of CP and CF increases, glucose response tends to decrease.

Implications of the Study and Future Research

• The study concluded that changes in feeding frequency did not affect digestibility or plasma blood metabolites, suggesting that when to feed a horse may not significantly impact its nutritional status or metabolic processes.
• The correlations between glucose response and CP and CF digestibility suggest possible roles of digestion in glucose regulation. Future research could focus on exploring these apparent relationships, as well as potential differences in endocrine responses or passage rates that could further clarify these observations.