The value of the digestibility trial as an adjunct to growth trial data in indicating the efficiency of hog rations.

Digestibility experiments were conducted with swine using the rations fed during two growth trials. The calculated gross energies of the feeds were lower than the determined values and the digestible energy of a ground, balanced hog ration could be determined from a formula based upon its crude fibre content. The metabolizable energy was not found to be a more suitable evaluation of the diets than the digestible energy. Thus the latter figures were used when the effects of caloric intake upon carcass quality were studied. In that section the percentages of the variations in the carcass measurements attributable to the lengths of the fattening periods together with the total intakes of digestible therms during those periods, were determined. It was suggested that bacon quality might be controlled in practice by regulating the growth rates, and the applicability of a formula which estimates feed requirements for growth was discussed