FACTORS AFFECTING RYE (SECALE CEREALE L.) UTILIZATION IN GROWING CHICKS. III. THE INFLUENCE OF MILLING FRACTIONS

Abstract

Three experiments were conducted with growing chicks to study the influence of feeding diets containing different milling fractions of wheat and rye or combinations of these fractions. The diets were formulated to provide protein in excess of or below the minimum requirements of the chicks. The results of the feeding trials indicate that rye contained at least two detrimental factors: an appetite-depressing factor located primarily in the bran, and a growth-depressing factor present in all the fractions (bran, flour and middlings). This latter factor was also associated with the reduction in the efficiency of feed utilization, an increase in the excreta wetness and excreta volatile fatty acid concentration and consequent lowering of the excreta pH. The depression in the weight gain and the efficiency of feed utilization appeared to be accentuated by feeding low protein diets and was partially overcome by penicillin supplementation of the diets. Feeding a combination of two or more milling fractions of rye greatly magnified the detrimental effects as evidenced by marked depressions in weight gains and feed conversion efficiencies. Alkylresorcinols in rye did not appear to be detrimental to chick performance.