Abstract:
RICE HULLS AS THE ONLY ROUGHAGE IN CATTLE FEEDLOT RATIONS KEITH HUTTON* and JOCK HAMILTON** Rice hulls are a low energy roughage of consistent quality freely available as a by-product of rice milling. They are available year round and store well with little risk of spoilage or spontaneous combustion and are very resistant to fire. Ground rice hulls have been successfully used as a least cost ingredient for many years in supplementary feeds for horses and ruminants, and in complete feeds for poultry, pigs and live export sheep. More recently ground rice hulls have been used commercially in large quantities in total mixed rations for finishing beef cattle. Following establishment of a low cost opportunity beef cattle feedlot at Yanco Agricultural High School in the ' Murrumbidgee Irrigation Area whole unground rice hulls have been compared with tub ground barley straw as a roughage Feedlot finishing rations were 76% crushed barley, source. 5% crushed lupins, 15% roughage, with 4% of a protein concentrate pellet containing monensin and vitamins, minerals and trace elements to adequately cover NAS-NRC requirements. The trial involved a total of 30 crossbred steers with 15 which randomly allocated to each treatment for 92 days The results are shown included a 28 day introductory period. in the table. TABLE 1 Liveweight and feed conversion data for 'steers fed rice hulls or barley straw as roughage Acceptance of rations was good and management was the same as in a traditional feedlot. Use of whole unground rice hulls as the sole source of roughage resulted in no significant difference in liveweight gain and feed conversion efficiency. However labour and machinery costs were reduced as a result of less roughage processing, a denser total mixed ration and therefore reduced mixing time. Whole unground rice hulls can be used in total mixed feedlot rations with no further processing and offer considerable advantages over traditional roughage sources. * Ricegrowers' Co-operative Limited, Leeton, NSW 2705 ** Yanco Agricultural High School, Yanco, NSW 2703
