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Unformatted text preview: Source and level of energy supplementation for yearling cattle fed ammoniated hay 1 J. B. Royes* ,2 , W. F. Brown*, F. G. Martin†, and D. B. Bates‡ *University of Florida, Range Cattle Research and Education Center, Ona 33865; †Department of Statistics, University of Florida, Gainesville 32611; and ‡Animal Science Department, University of Florida, Gainesville 32611 ABSTRACT: Brahman × British crossbred steers were used in growth and digestion trials to evaluate the response of source (corn, sugar cane molasses, or soybean hulls) and feeding rate (0, 1.4, or 2.8 kg DM per steer daily in the growth trials; 0, 15, or 30% of the ration DM in the digestion trial) of energy supplementa- tion in cattle fed ammoniated (4% of forage DM) star- grass ( Cynodon nlemfuensis Vanderyst var. nlem- fuensis ) hay. Cattle on all treatments were fed 0.5 kg cottonseed meal daily. In the growth trials, steers grazed dormant bahiagrass ( Paspalum notatum ) pas- ture. Increasing the levels of supplementation de- creased hay intake but increased total dietary intake for all diets ( P < 0.07). Daily gain and feed efficiency of steers were improved ( P < 0.03) with supplementation. Steers supplemented with corn or soybean hulls at 2.8 kg DM/d had a higher ADG (0.92 kg) and gain/feed (0.103) than steers supplemented with molasses (0.78 kg, 0.08, respectively) at the same level. Seven cross- bred steers (200 kg) were used in a five-period digestion trial to evaluate apparent OM, NDF, ADF, and hemicel- lulose digestibility. Apparent OM digestibility of all diets increased linearly ( P = 0.02) as the level of supple- mentation increased. Apparent NDF and ADF digest- Key Words: Ammoniated Feeds, Cattle, Digestibility, Maize, Molasses, Soybean Husks 2001 American Society of Animal Science. All rights reserved. J. Anim. Sci. 2001. 79:1313–1321 Introduction Due to seasonal productivity, deficiencies in forage availability and quality are a constant limitation to livestock production in tropical regions. Mature tropical grasses are high in fiber and low in CP and TDN, re- sulting in situations in which cattle are unable to con- 1 This work was supported by the Florida Agric. Exp. Sta. and is reported as Journal Series No. R-0789. 2 Correspondence: Dept. of Fisheries and Aquatic Sciences, Box 110600 (E-mail: [email protected]). Received August 3, 2000. Accepted January 5, 2001. 1313 ibility decreased ( P < 0.03) as the level of supplementa- tion with corn or molasses increased, whereas increas- ing the level of soybean hulls in the diet increased ( P < 0.06) apparent NDF and ADF digestibility. Four rumi- nally fistulated crossbred steers (472 kg) were used in a 4 × 4 latin square design to investigate ruminal characteristics with energy supplementation at 30% of ration DM. Ruminal pH in steers supplemented with soybean hulls or corn declined after feeding. Ruminal pH decreased more rapidly with corn supplementation and remained below 6.2 for a longer period of time thanand remained below 6....
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- Spring '08
- Maize, Fodder, Ethanol fuel, soybean hulls