Research note: adding coefficients for dietary protein and energy to equations for predicting the metabolizable energy intake of laying hens.

Abstract

The data from two published experiments were used to determine whether feed consumption prediction equations could be improved by the addition of coefficients for levels of protein and energy in the diet. The two experiments were conducted from 20 to 44 wk of age with hens housed in cages. Diets contained primarily corn, dehulled soybean meal, wheat middlings, and poultry oil. When the standard form of feed consumption prediction equations was fitted to the data, only the coefficient for egg mass (b3) was different from zero (P less than .10): MEI = b0 + b1 BWn + b2 delta g + b3 EM where MEI = metabolizable energy intake; BW = average body weight (kilograms), delta g = daily body weight change (grams); n = .65, .75, 1, or 2; and EM = daily egg mass output in grams. Three published equations that have been used to predict feed intake based on body weight and egg mass output were chosen for evaluation. For two equations the residual MEI (observed-predicted) was found to be predictable from protein or energy levels fed. Inserting dietary protein and dietary energy data for the feed decreased the observed error in equations to predict MEI, but the effect was small.