MODEL FOR PREDICTING THE EFFECT OF NITROGEN INTAKE, BODY MASS, AND DIETARY CALCIUM AND PHOSPHORUS ON MANURE NITROGEN CONTENT.

This study describes a method of predicting voided manure constituents based on animal mass and diet. Male laboratory rats used to test the model were grown from weaning to puberty. Nitrogen excreted followed the consumption pattern very closely. Prediction equations using mass and dietary nitrogen, phosphorus and calcium were more accurate for predicting fecal, urinary and body nitrogen than relationships developed from mass only. Nitrogen in the feces, urine and body can be estimated accurately when constituents of the diet are known.