FACTORS AFFECTING RYE (SECALE CEREALE L.) UTILIZATION IN GROWING CHICKS. IV. THE INFLUENCE OF AUTOCLAVE TREATMENT, PELLETING, WATER EXTRACTION AND PENICILLIN SUPPLEMENTATION

Abstract

Three experiments were conducted with growing chicks to study the influence of autoclave treatment, pelleting, water extraction and penicillin supplementation on the nutritional value of rye. The diets were formulated to provide protein above, at or below the minimum requirements of the chicks. The results of the feeding trials indicate that rye contained a water-extractable growth depressing factor which was also associated with a reduction in the efficiency of feed utilization, beak impaction and an increase in the excreta wetness. Water extraction improved the nutritional value of rye by the removal of the growth depressing factor. Penicillin supplementation of whole rye diets also improved chick growth and feed conversion efficiency but to a lesser extent than water extraction. Autoclave treatment of rye and pelleting of a rye-containing diet had no influence on weight gain and the feed:gain ratio. However, the 10-min autoclave treatment increased appetite. Autoclaving for 30 min and pelleting reduced beak impaction. It may be concluded that rye contains a water-soluble factor which reduces nutrient utilization. An improvement in the nutritional value of rye can be accomplished by water extraction and supplementation with a high level of penicillin, but not by autoclave treatment or pelleting.