Nutrient supply to dairy cows from processed white lupines

Area of Science:

• Animal Nutrition
• Ruminant Physiology
• Agricultural Science

Background:

• Accurate prediction of protein supply is crucial for dairy cow nutrition.
• White lupines are a potential protein source, but processing affects their nutritional value.
• Existing models like DVE/OEB and NRC-2001 have different approaches to protein evaluation.

Purpose of the Study:

• Compare the DVE/OEB system and NRC-2001 model for predicting protein supply from processed white lupines.
• Investigate the effect of roasting temperature and time on white lupine's digestive behavior and nutrient supply.
• Determine optimal processing conditions for white lupines as an intestinal protein source.

Main Methods:

• Compared predictions of ruminally synthesized microbial crude protein (CP), truly absorbed protein, and degraded protein balance (DPB) between DVE/OEB and NRC-2001.
• Systematically roasted white lupines at 110, 130, or 150°C for 15, 30, or 45 minutes.
• Evaluated changes in digestive behavior and nutrient supply based on processing parameters.

Main Results:

• Both DVE/OEB and NRC-2001 models showed high correlations (R > 0.83) in predictions.
• DVE/OEB predicted 11% higher microbial protein and 7% higher truly absorbed protein than NRC-2001.
• NRC-2001 predicted 8% higher DPB than DVE/OEB, indicating model-specific calculation differences.
• Roasting effectively shifted protein degradation from the rumen to the intestines, increasing DVE/MP values.
• Processing at 130°C for 30 or 45 minutes yielded optimal DVE/MP and low DPB values.

Conclusions:

• The DVE/OEB and NRC-2001 models provide comparable, yet distinct, predictions for dairy cow protein supply.
• Refinement of protein evaluation systems is necessary for improved accuracy.
• Roasting is an effective method to enhance the intestinal protein value of white lupines.
• Optimal roasting conditions (130°C for 30-45 min) maximize protein availability and minimize nitrogen loss.