Fat and energy additives to molasses urea supplements for beef cattle fed a low quality roughage diet.

Abstract

26A 26A Fat and energy additives to molasses_urea supplements for beef cattle fed a low_quality roughage diet J.A. Lindsay1, J.F. Kidd2 and B.A. Gelling 1 1 2 Qld Beef Industry Institute, Dept of Primary Industries, Swan's Lagoon, Millaroo Qld 4807 Present address: DPI Animal Research Institute, Yeerongpilly Qld 4105 Molasses based mixtures are widely used in northern Australia to provide cost ef fective dry season supplements to remedy shortages of energy and protein in pasture (Lindsay and Laing 1996). However, there is a continued need for an energy dense additive to further boost production of cattle fed these molasses based supplements. A pen study was conducted using sixty Bos indicus crossbred steers (mean 142 kg liveweight) with twelve animals in three pens of four per treatment. The basal diet of native pasture hay (0.4% N, 45% DMD) was offered ad lib. The supplement, M8U, was molasses (100), urea (8) and salt (1) and was also fed ad lib. Energydense supplements of rice pollard (18% fat) were included at 10 or 20% and cotton oil was included at 2 or 4% to give a total of 5 different treatments. The steers on M8U+4CSO (40 g/kg cotton oil) performed poorly in the first 45 days. Hay intake was significantly reduced to 1 kg/d and fibre digestion would have been lower due to the high oil intake. The supplement was changed to 500 g/d whole cottonseed and LWG and hay intake increased markedly. The only significant increase in LWG was when 20% rice pollard was added. This supplement also improved FCR from 62:1 to 23:1. These results show that the addition of 20% rice pollard to an M8U mixture will improve both LWG and FCR. However adding cotton oil had a nil or detrimental effect on growth rate. The Meat Research Corporation partially funded this work through Project DAQ.065. Lindsay, J.A. and Laing, A.R. (1996) . In: A User s Guide to Drought Feeding Strategies, p. 55. University of New England Press, Armidale NSW. Table 1 Liveweight gain, feed intake, and feed conversion ratio (FCR) when lipid additives to a molasses-urea supplement were fed to steers in pens for 72 days. Feed intake (kg/day) Treatment M8U M8U+10RP M8U+20RP M8U+2CSO M8U+4CSO* s.e. LWG (kg/day) 0.06 0.10 0.18 0.04 0.09 0.03 M8U 1.14 1.29 1.53 1.15 1.12 0.08 Hay 2.56 2.71 2.59 2.51 1.98 0.12 FCR 62 40 23 92 34 _ * Changed to 500 g/day whole cottonseed at day 45. Recent Advances in Animal Nutrition in Australia, Volume 12 (1999)