Effect of meal frequency on fluid balance and behavior of ponies.

This research explored how meal frequency impacts fluid balance and behavior in ponies. The study tested ponies’ total daily rations, dividing it into one large meal versus six smaller meals, and recorded their behavior and blood samples pre and post-feeding.

Research Methodology

• The researchers conducted a study involving 12 ponies. Their daily rations were either given all at once in a single meal, or spread out over six smaller meals.
• The ponies’ behaviors were closely observed and recorded six times a day, before and after their meals.
• Blood samples were also collected 30 minutes before feeding and two hours after the meal. These samples were used to monitor changes in plasma protein, hematocrit, and plasma osmolality, which are indicators of fluid balance.

Key Findings

• Small meals led plasma protein to increase from 7.0 to a peak of 7.3 g/dl, and large meals increased plasma from 7.3 to 8.1 g/dl. However, these levels returned to pre-feeding sizes approximately 90 minutes after feeding.
• Hematocrit rose from 33.3 to 34.1% with small meals and from 33.0 to 36.0% with large meals. This increase in hematocrit, combined with the changes in plasma protein, suggest a decrease in plasma volume, indicating that meal size affects fluid balance.
• Plasma osmolality also increased upon feeding, climbing from 283 to 285 mosmoles/kg with small meals and from 281 to 288 mosmoles/kg with larger meals. The changes in plasma osmolality, an indicator of the body’s fluid balance, echo the other results and suggest meal size impacts fluid balance.
• Water availability was found to not have a significant impact on these changes in blood composition.
• There were no measurable differences in the rate of passage, or digestibility, as measured by chromic oxide.
• In terms of behavior, it was observed that ponies vocalized (neighed) and walked more often before feeding than afterward. Conversely, they were more likely to engage in behaviors such as eating bedding and other oral behaviors after being fed.