Digestive capacity in weanling and mature horses.

The research examines the ability of young (weanling) and mature horses to digest dry matter (DM), organic matter (OM), and neutral detergent fiber (NDF). The results showed that both types of horse exhibit similar digestibility for these components, demonstrating similar digestive capacities.

Methodology

• The study used a sample of six weanling colts and six mature geldings, each pair acclimatized to a diet of 67% alfalfa cubes and 33% concentrate for 21 days.
• During this adaptation period, horses were habituated to their housing and handling procedures.
• This period also served to balance the feed offered to minimize leftovers and sustain identical intake rates within each pair.
• Post-adaptation period, a 5-day fecal collection period was instigated. The horses wore fecal collection harnesses for this purpose.
• The colts’ mean age at the start of this collection period was approximately 182 days.
• Two markers, Co-EDTA (9 mg Co/kg body weight raised to the power of 0.75) and ytterbium-labeled hay fiber (9 mg Yb/kg body weight raised to the power of 0.75), were integrated into the horses’ diet prior to first collection day amid regular observation to ensure comprehensive marker consumption.
• Fecal collections were weighed and subsampled every 1 to 2 hours for later assessment of Co and Yb concentrations, to ascertain the mean retention time (MRT) of the fluid and particulate phases of digesta.
• Each horse’s leftover feces were composited daily and subsampled to quantify DM, NDF, and OM digestibility.

Results

• Over the fecal collection period, dry matter intake (DMI) was approximately equal for both colts and geldings.
• No significant differences in DM or NDF digestibility were observed between colts and mature geldings.
• Regardless of age, the MRT of the particulate phase was approximately 24.9 hours, contrasted with a slightly shorter 21.8 hours for the fluid phase.
• Again, no significant difference in the MRT of the fluid phase was seen between colts and mature geldings.

Conclusions

• This research suggests that in a diet of good-quality cubed forage and concentrate, both weanling colts and mature geldings have similar digestibility for DM, OM, and NDF, which indicates comparable digestive capabilities in both horse types.