Utilization of proteins by the equine species.

This research article investigates the digestion and utilization of different types of protein supplements in horses, and it reveals that the type of protein supplement used can significantly affect how horses digest protein and retain nitrogen.

Research Methodology

• The study focused on examining the effects of three different protein supplements on protein digestion, nitrogen retention, and plasma concentrations in ponies.
• The protein supplements tested were casein, corn gluten meal, and corn gluten meal supplemented with lysine.
• These were substituted for a portion of the cornstarch in a low-protein basal ration consumed by the ponies.

Key Findings

• The results showed that the substitution of the cornstarch with any of the protein supplements resulted in increased apparent digestion of protein. This means that the ponies were able to break down and absorb the protein more effectively when it was part of their diet.
• The study also noted a significant increase in nitrogen retention when either casein or corn gluten meal-plus-lysine were used as substitutes. However, the corn gluten meal on its own did not lead to a similar increase.
• Nitrogen retention, expressed as a percentage of nitrogen absorbed, was also significantly increased by the addition of casein to the basal ration.

Impact on Plasma Concentrations

• While the protein supplement substitutions did not result in any significant changes in plasma protein concentration, plasma urea nitrogen levels increased significantly in the ponies which were given the casein variation of the ration. This implies that the addition of casein to the diet affects urea nitrogen levels, potentially indicating greater protein breakdown.
• Interestingly, the study found a marked increase in plasma lysine concentration when lysine was added to the corn gluten meal. This suggests that lysine supplementation can significantly influence the concentration of this essential amino acid in the blood.

Conclusions

• This study infers that the equine species responds differently to variations in the quality of dietary protein, therefore, the choice of protein supplement could potentially impact protein digestion and utilization rates.
• The notable responses to casein and lysine supplementation suggest that these could be beneficial additions to equine feed regulations to optimize protein absorption and utilization.