Prediction models for phosphorus excretion of pigs

Area of Science:

• Animal Science
• Environmental Science
• Nutritional Science

Background:

• Phosphorus (P) excretion from pigs is a significant environmental concern.
• Accurate estimation of P excretion is crucial for sustainable livestock farming.
• Exogenous phytase supplementation is common in pig diets to improve P utilization.

Purpose of the Study:

• To quantify fecal and urinary phosphorus (P) excretion in pigs.
• To establish predictive models for estimating P excretion based on pig body weight and dietary P concentration.

Main Methods:

• Utilized 96 data points from four experiments involving pigs (15-93 kg body weight) fed 12 different diets.
• All diets included exogenous phytase (500 units/kg).
• Developed regression models using pig body weight (BW) and dietary P concentration as independent variables.

Main Results:

• Total P excretion was positively correlated with BW, feed intake, and P intake (r=0.80-0.94, p<0.001).
• Prediction models were developed for fecal, urinary, and total P excretion (R²=0.83-0.86, p<0.001).
• Estimated annual P excretion for a market pig: 1.24 kg fecal P, 0.09 kg urinary P, and 1.33 kg total P.

Conclusions:

• Pig body weight and dietary P concentration are reliable predictors of P excretion.
• The developed models provide a practical tool for estimating P excretion in market pigs.
• Annual P excretion estimates (1.24 kg fecal, 0.09 kg urinary) are valuable for environmental impact assessments.