The Apparent Digestibility of the Crude Protein of the Pig Ration as a Function of Its Crude Protein and Crude Fiber Content

Increasing the protein percentage or decreasing the crude fiber percentage of the ration tends to increase the apparent digestibility of protein by pigs. The partial regression coefficients of protein percentage and of crude fiber percentage on apparent protein digestibility are approximately equal. Consequently, if in a practical pig ration the level of protein is three times as large as the crude fiber level, a change of 1 unit in ration crude fiber has 3 times the weight of a 1 unit change in ration protein on the apparent digestibility of protein.