Modeling Soluble Protein Fractionation in Feedstuffs in Equine Rations Using Crude Protein and Fiber Composition.

Area of Science:

• Animal Nutrition
• Equine Science
• Feedstuff Analysis

Background:

• Current equine protein requirements rely on crude protein (CP), overlooking its digestibility.
• Protein distribution within feedstuffs impacts foregut digestion and nutrient availability.
• Neutral detergent soluble crude protein (NDSCP) represents the readily digestible protein fraction crucial for equine needs.

Purpose of the Study:

• To develop linear regression models for predicting NDSCP and pre-cecal digestible crude protein (pcdCP).
• To utilize feedstuff crude protein (CP) and fiber components as predictors in these models.
• To enhance the accuracy of equine dietary protein assessment.

Main Methods:

• Data sourced from the 2023 Dairy One© Feedstuff Composition Library.
• Feedstuffs with n ≥ 50 analyses for CP, NDF, ADF, and ADL were selected and categorized.
• Multiple linear regression analysis was performed using R Statistical Program©, with model selection based on AICc, AICcWt, and Adjusted R².

Main Results:

• The model incorporating CP and neutral detergent fiber (NDF) provided the highest predictive accuracy for both NDSCP and pcdCP (AICcWt = 0.95; Adjusted R² = 0.9868 for NDSCP, 0.9867 for pcdCP).
• These findings indicate that CP and NDF effectively predict protein digestibility.
• The developed models demonstrated high precision in predicting available protein.

Conclusions:

• Linear models using CP and NDF accurately predict NDSCP and pcdCP in feedstuffs.
• Incorporating fiber fractionation improves the prediction of available dietary protein for horses.
• This approach offers a more precise method for formulating equine diets to meet protein requirements.