g 13-1096 i; March 1970 Y HEAT PROCESSING of Sorghum Grain for Beef Cattle TEXAS A&M UNIVERSITY TEXAS AGRICULTURAL EXPERIMENT STATION H. O. Kunkel, Acting Director, College Station, Texas IllllIllIllllllllIlllllllllHllIIlllllllllllllllllIIIIIlllllIllIlllllllllllllllllllllllllllllllllllllllllllllllIIIIIIIIIIIII|l||I|IllllllIllllIIllllIllIIIIIIlllllllllIIIIIllllllllllllIIIIIIIllllllllllillllllllllllll Q a R“ s. m LHH IHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHLH IHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH _to L. M. Schake for overall management { Acknowledgments _____________________________________ ,1 ______ ._ Summary _____________________________________________________ __ 7 Introduction _______________________ __________________ _. Equipment and Procedure ......................... .. Engineering Phase ______________________________ ._ A Reciprocating Table ....................... ..e._; Vibrating-Tray Conveyor .......... .. i Cattle Feeding and Nutrition Aspect Results and Discussion .............................. .. Engineering Phase _______ ____________________ __ Machine Operation and Capacity.....: Bulk Density .................................... Effect of Grain Moisture Content Popping Characteristics ................. _.Y Cattle Feeding and Nutrition Aspectsnf Feeding Experiment ........................ Rumen Volatile Fatty Acids ..... .. ' Digestibility of Grains ............... .. Discussion ............................................ .. Literature Cited .......................................... .. ACKNOWLEDGMENTS The reciprocating-table machine used I was designed by Mr. Chardo W. Pierce l; Texas and constructed in the Agricultural Research Shop. The authors express their‘. to Mr. Pierce for his assistance in constru chine and in conducting these tests. _ Appreciation is also expressed to Mr. ‘ Action Products Corporation, Dallas, Te 1 ing a vibrating-tray machine and for hisi’ in conducting the tests. The authors are especially indebted . Adame, who did the cattle feeding and and to I. J. Young for his assistance in c015: operating the reciprocating-table machine. ‘T '5, q . _, S, EAT PROCESSING 0]‘ Sorghum Grain for Beef Cattle IlllllllllllIllIIlllllllllllllllllllllllIIllllllllllllllllllIIIIlllllllllllIllllIlllIlllllllllll!llllllIlllIllllIlll1IllllllllIllllIllllllllIIIIIIIIIIllIIIIllllIIIHIIIIIIlllIllllIllIIIIIII!|IlIllIIIll]IIIIIIllIllllIIllIIlllllllllllllllIIlllllllllllllllllllllIIIllIllIllllllllllIllllIllllllllllIIIllllIlllllllIlllllIIIllllIIllllllllllllllllllllllllll J. W. Sorenson, Jr. and Price Hobgood* SUMMARY.‘ feasibility of using dry heat in a popping operation t0 process sorghum grain for finishing beef cattle. An infrared-heated reciprocating steel table machine and a gas-heated vibrating-tray conveyor machine were used in the study. The grain should be cleaned to assure an even flow free from foreign materials for efficient operation of the reciprocating-table machine. A grain moisture content of 15 percent was optimum for obtaining the highest percentage of completely popped grain. Maximum pop- ping achieved was 45 percent. Bulk density for loose- fill samples ranged from 49 pounds per cubic foot for the original whole grain to about 6 pounds per cubic foot for completely popped grain. Self-feeding popped - grain mixture, completely popped or partially and nonpopped grain, all crimped, in all-concentrate feed mixtures to finishing steers re- sulted in significantly reduced feed intake as compared with nonheated, dry-rolled grain. The reduced feed intake was accompanied by an increase in efficiency of feed utilization but a nonsignificant decrease in rate of gain, final weight, carcass weight, dressing percent, car- cass grade and fat thickness. Rumen samples showed significantly lower levels of acetic and isovaleric acids but higher levels of propionic acid in cattle fed the dry heat-treated grains than in _ those fed the nonheated grain. The resulting narrower aceticzpropionic acid ratio coincided with the greater efficiency of feed utilization observed in these cattle. Cattle fed the dry heat-treated grains showed sig- nificantly higher digestibility of dry matter, organic mat- ter, nonprotein organic matter and nitrogen-free extract, but not of fat, fiber or protein. An unknown part of the increased digestibility could be attributed to the lower level of feed intake. No differences in digestibility were found among cattle fed the three heat-treated grain frac- tions. This indicated that dry heat rather than popping per se was responsible for the changes in performance. INTRODUCTION The need for physically processing sorghum grain to improve its utilization by cattle has been recognized for a long time. During the past 4O years, grinding, dry rolling, steam rolling and steam flaking have been the methods used to prepare the grain for commercial cattle feeding operations. All of these methods have received attention by research workers (Jones et al., 1937; Smith and Parrish, 1953; Baker et al., 1955; Smith et al., 1960; Pope et al., 1962; Brethour and Duitsman, 1966; Hale et al., 1966; and Newsome et al., 1966). *Respectively, professor, Department of Animal Science, professor, and professor and head, Department of Agricultural Engineer- ing, Texas A&M University. 3 Research was conducted to determine the As technological developments in mechanical equip- ment have occurred, processing methods have become more sophisticated. Today dry grinding is considered inadequate preparation for sorghum grains by some feeders in the modern cattle feeding industry. The moist heat treatment of steam processing followed by flaking is widely accepted. Until the last 3 or 4 years, the use of dry heat, as in popping, has not been seriously considered as a means of processing grain for cattle feeding. Ellis and Car- penter (1966) reported slightly slower gains but 16.6 percent less feed per unit of gain when 40 percent of cracked milo was replaced by popped milo in an all- concentrate mixture for yearling steers. Durham, Ellis and Cude (1965) reported daily gains of 2.79, 2.4-6 and 2.70 pounds with almost identical feed conversions for cattle fed cracked, flaked and popped milo, respectively, in all-concentrate mixtures. Cattle fed flaked milo con- sumed significantly less feed daily than did those fed milo processed by the other two methods. During fall 1966, equipment became available at Texas A&M University with the capacity to dry heat process enough sorghum grain to feed 30 yearling steers on a continuing basis. A project was planned and en- acted during 1967 which provided opportunity to study the equipment requirements, the effect of initial moisture content on popping characteristics of sorghum e and the bulk densities of the various compone, popped grain mixtures. The study evaluated performance and carcass characteristics of cattle dry heat-processed and nonprocessed grain in centrate finishing mixtures. Rumen volatile fatty levels and grain digestibility were also determined; work was carried out cooperfatively by the Depa If, of Agricultural Engineering and Animal Science a lege Station. l EQUIPMENT AND PROCEDURE s Engineering Phase Two machines, a reciprocating steel table = vibrating-tray conveyor, were used to process so grain for this work. Reciprocating Table. The reciprocating-tabl chine, shown in Figure 1, consisted of a recipr steel table one-half inch thick, 34 inches wide feet long activated by a 1/2-horsepower electric ~!_ Six gas-fired infrared generators, rated at 50,000 p. per hour each and suspended about 6 inches abo table were used to heat the table and also the g1“. _ it was conveyed through the machine. The machine was equipped with a metering Figure l. Reciprocating-table machine used for the tests. Grain was stored in hopper-bottom bin (shown on the left) and automatic veyed into metering hopper installed on the popping machine. Grain was then metered onto the reciprocating table where it wo as it was conveyed under a bank of gas infrared burners and finally discharged from the machine as popped grain. 4 / juld be adjusted to feed grain onto the table ired rate. Grain was metered onto a vibrating ilhere sand, weed seed and broken grain were A The cleaned grain flowed onto one end of the 2 ting table, passed under the infrared generators ved along the table and was discharged from Tsite end as popped grain at a temperature of fT3l0°F. The rate at which the grain moved the machine could be varied by changing the inclination of the table, by changing the length i; iprocating stroke and by changing the rate of of the table. Stroke length for all tests i» in this study was eleven-sixteenths inch. i: machine was used to process approximately i“ unds of sorghum grain for use in cattle feeding ts conducted by the Department of Animal Experience in processing soon indicated that ‘bility in percentage of popped grain obtained l’ essitate separating the processed grain into two that which was completely popped and that not popped or was only partially popped, if iul results were to be obtained. Accordingly, ted-grain mixture coming from the machine was onto a 3/ 16-inch screen. The completely grain remained on and passed over the screen nonpopped and partially popped grain fell l Hence, three products, the popped-grain mix- completely popped grain only and a mixture ly-popped and nonpopped grain, were prepared in comparison with original grain. The components were discharged into roller mills '1 .. with the roillis“ set“ at l / 64-inch clearance where the ma- terial was crimped and conveyed into burlap bags, Figure 2. Under commercial operating conditions the popped- grain mixture could be conveyed directly into hopper bottom bins for automatic handling. Records were kept of the weight of whole grain supplied to the machine and of the processed material to determine the machine capacity. At various intervals during the operating period, tests were made to determine bulk densities of the various popped-grain components and the percentage of popped and partially-popped grain. Test samples were taken at random, placed in a 1-cubic foot capacity container and weighed to find the bulk density of the different components. These measurements were made for whole grain and for loose and packed fills of crimped and noncrimped samples of mixtures of the popped-grain components. For these tests, a loose fill was obtained by permitting the material to discharge from the machine directly into the container until it was filled to overflow- ing. It was then leveled off and weighed. A packed fill was obtained by catching the material from the machine until the container was full. The container was then dropped from a height of 4 inches onto a con- crete floor. Additional material was then added to refill the container, and the container was dropped again from the same height. This procedure was repeated three times before the container and its contents were weighed. V ibrating-Tray Conveyor. A vibrating-tray con- veyor used for these tests was similar to the machine The popped-grain mixture was separated into two components as it was discharged from the popping machine. The separate then passed through roller m-ills where the materials were crimped and then conveyed into burlap bags. The popped-grain Id be conveyed directly into hopper-bottom storage bins for automatic handling. 5 Figure 3. Cut-away view of a vibrating tray-conveyor. Vibrating motion is generated by an electric motor with eccentric weights. The product is metered onto the top tray and is conveyed through the machine as shown above. The number of trays used can be varied from one to three. In these tests, grain was processed on one tray only. shown in Figure 3. It consisted of a 5-foot diameter, heated, vibrating tray enclosed-in an insulated housing. A natural gas burner, mounted underneath the tray, was used to heat the tray t0 the desired temperature. A vibrating motion was imparted to the tray by a Z-horse- power electric motor equipped with eccentric weights. The motor was mounted vertically in a housing attached directly to the frame supporting the tray. The rate at which the grain was conveyed through the machine was controlled by positioning the eccentric weights on the motor shaft. Grain was metered onto the tray where it was heated and popped as it was conveyed a distance of 15.7 feet on the heated-tray surface. The popped- 5 grain mixture was then discharged from the; through an unloading spout. ‘i’ Tests were made with this machine to dete; effect of initial grain moisture content on the, characteristics of sorghum grain. Four lots of; with initial moisture contents ranging from percent, wet basis, were processed for these The processed material from each lot was p,“ No. 4 and No. 6 sieves in order to separate i following components: completely popped gr tially-popped grain; and nonpopped grain, The completely popped grain remained on F sieve. Material passing through the No. 4 remaining on the No. 6 sieve was designated as popped grain. The material passing through sieve was mostly whole grain and foreign materi stems and some charred grain). Cattle Feeding and Nutrition Aspects Sorghum grain of one kind from a sin, and processed in four ways was available for the processing effect on utilization of the grain ; original grain; popped-grain mixture; complet; grain only; and partially-popped and nonpopf Both the original and heat-treated grains ._ rolled before formulating into all-concentrate containing approximately 13 percent crude follows: 92 percent of the mixture was grain; was cottonseed meal; and l percent was mi salt. Aureomycin and vitamin A concentrate u to all mixtures at levels to provide 4.5 mg. and respectively, per pound of finished feed. Forty Santa Gertrudis yearling steers, approximately 750 pounds, were divided into; form groups of 10 each. Previously, the steer: self-fed a high concentrate mixture based on sorghum grain for about 9O days. One ; assigned to each type of grain indicated abov; fed in drylot for 84 days. All steers were i, with 3O mg. of diethylstilbestrol. i The steers were weighed individually f secutive days at the beginning and end of the and each 14 days during its course. Feed in were maintained on a group basis by Ill-did thus providing six records of mean intake. group for statistical analysis. The day after final weights were =