UTILIZATION OF PROCESSED GRAIN SORGHUM AND CORN BY RUMINANTS. by KYLE RHEA MCLEOD, B.S. A THESIS IN ANIMAL NUTRITION

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2 UTILIZATION OF PROCESSED GRAIN SORGHUM AND CORN BY RUMINANTS by KYLE RHEA MCLEOD, B.S. A THESIS IN ANIMAL NUTRITION Submitted t the Graduate Faculty f Texas Tech University in Partial Fulfillment f the Requirements fr the Degree f MASTER OF SCIENCE Apprved Accepted August, 1987

3 ACKNOWLEDGMENTS The authr wuld like t thank Dr. C. R. Richardsn fr his advice, encuragement and friendship. I wuld als like t thank Drs. R. A. Lng, R. W. Tack and C. R. Knaff fr serving n my cmmittee. My gratitude is als expressed t my fellw graduate students and Ray "Fecal" McPhersn. Their help and friendship will lng be remembered, as well as thse lng lunch hurs spent discussing ruminant nutritin and life. Mre imprtantly, I am grateful t my family. The supprt and inspiratin f my parents, Wesley and Linda McLed, has been an essential factr in reaching this and ther gals. My deepest appreciatin and gratitude is extended t my clsest friend and supprter, my wife, Rhnda Battin-McLed. Withut her patience, understanding, and encuragement my prgram culd nt have been cmpleted. n

4 TABLE OF CONTENTS ACKNOWLEDGMENTS LIST OF TABLES LIST OF FIGURES ii v vi CHAPTER I. INTRODUCTION 1 II. REVIEW OF LITERATURE 3 General Cncepts f Grain Prcessing 3 III. Cmparisn f Feeding Value and Kernel Structure f Grain Srghum and Crn 5 Effects f Prcessing Grain Srghum n Feedlt Perfrmance f Cattle 8 Effects f Prcessing Methd n Digestibility 13 The Effects f Prcessing n the Physi-chemical Structure f Starch 21 Effects f Chemical Cnditining Grain Srghum 25 LABORATORY EVALUATION OF PROCESSED GRAIN SORGHUM AND CORN 28 Abstract 28 Intrductin 29 Experimental Prcedures 30 Chemical analysis 30 Experiments 1 and 2 32 Experiment 3 32 Experiment 4 32 Statistical analysis 33 iii

5 Results and Discussin 33 Experiment 1 33 Experiment 2 33 Experiment 3 35 Experiment 4 37 IV. EFFECTS OF ADDED MOISTURE, OR ADDED MOISTURE PLUS HEAT ON GRAIN SORGHUM UTILIZATION 41 Abstract 41 Intrductin 42 Experimental Prcedures 43 Grain preparatin 43 Grwth assay 44 Labratry experiments 46 Statistical analysis 46 Results and Discussin 46 Experiment 1 46 Experiment 2 49 V. EFFECTS OF MOISTURE OR MOISTURE PLUS A CONDITIONING AGENT ON THE UTILIZATION OF PROCESSED GRAIN SORGHUM 63 Abstract 63 I ntrducti n 64 Experimental Prcedures 65 Grain prcessing 65 Experiment 1 66 Experiment 2 68 Experiment 3 68 Statistical analysis 69 Experiment 1 69 Experiment 2 72 Experiment 3 72 REFERENCES 76 IV

6 LIST OF TABLES 1. Chemical cmpsitin f prcessed grain srghum and crn In vitr dry matter and rganic matter digestibility f prcessed srghum and crn Prtein slubility fr prcessed grain srghum and crn In vitr gas prductin fr prcessed grain srghum and crn Experimental diet fr rats (Experiments 1 and 2) Dry matter intake (Experiments 1 and 2) In vitr dry matter digestibility (Experiments 1 and 2) Cmpsitin f basal ratin Intake, apparent digestibilities, nitrgen retentin and fecal ph In situ nyln bag dry matter disappearance Susceptibility f prcessed grain srghum t amylglucsidase 74

7 LIST OF FIGURES 1. Average daily gain as affected by misture level (Exp. 1) Efficiency f gain as affected by misture level (Exp. 1) Tw-hur in vitr gas prductin as affected by misture level (Exp. 1) Fur-hur in vitr gas prductin as affected by misture level (Exp. 1) Eight-hur in vitr gas prductin as affected by misture level (Exp. 1) Average daily gain as affected by misture level (Exp. 2) Efficiency f gain as affected by misture level (Exp. 2) Tw-hur in vitr gas prductin as affected by misture level (Exp. 2) Fur-hur in vitr gas prductin as affected by misture level (Exp. 2) Eight-hur in vitr gas prductin as affected by misture level (Exp. 2) 60 VI

8 CHAPTER I INTRODUCTION Grain srghum and crn are the primary energy feedstuffs fr grwing-finishing cattle. The decisin t chse between these tw grain surces is based upn cst f grain, perfrmance f animals cnsuming these grains and the availability f the grain surces t the feedlt. Grain srghum is the principle feed crp prduced in the high plains and suthern regins f the United States. Therefre, feedlts lcated in these regins use grain srghum as the principle dietary cmpnent fr feedlt cattle diets. Grain srghum is generally cnsidered t have a lwer feeding value than crn. The lwer feeding value f srghum has been attributed t the presence f a hard regin at the periphery f the endsperm. Rney and Sullins (1973) and Rney and Killer (1982) bserved that srghum had a much higher prprtin f peripheral endsperm than did crn. These same researchers als fund this regin t be extremely dense and resistant t water penetratin. Wagner (1984) cncluded this hard endsperm regin results in lwer digestibilities and feeding value fr grain srghum as cmpared t crn. Therefre, t effectively utilize grain srghum as a primary dietary cmpnent, the feeding value f grain srghum must be increased t levels cmparable t crn. 1

9 Disruptin f the hard peripheral endsperm shuld increase the availability f nutrients in grain srghum thereby increasing the feeding value. Prcessing methds such as steam flaking and recnstituting have been shwn t effectively breakdwn the srghum endsperm, thus enhancing the nutrient availibi11ty f srghum (Sullins and Rney, 1971 and Harbers, 1974). Thus the bjectives f these investigatins were t evaluate: (1) The effects f grain prcessing n in vitr digestin, nitrgen slubility and starch availability. (2) The effects f additinal misture r misture plus heat n in vitr digestin and starch availability. (3) The effects misture r misture plus cnditining agent n in viv digestin, ruminal degradatin, and starch availability.

10 CHAPTER II REVIEW OF LITERATURE General Cncepts f Grain Prcessing Fr many years livestck feeders have prcessed grains in rder t imprve utilizatin. There are numerus methds f prcessing grains fr livestck with each methd varying t sme extent in cmplexity, amunt f heat and misture applied, physical disruptin f the kernel and extent f imprvement. These prcessing methds have been classified by Hale (1973) as being either dry r wet prcesses. Dry prcessing methds include whle grain, grinding, dry rlling r cracking, ppping, extruding, micrnizing, rasting, pelleting and thermalizing. Wet prcessing methds include steam prcessing and flaking, recnstitutin, explding, pressure cking, early harvested, ear crn silage and srghum head silage. In a review by Orskv (1979) n the prcessing f grains fr ruminants, he cncludes that the ptimum extent f prcessing appears t be the minimum required t avid an unacceptably lw digestibility. Hwever, the severity f prcessing required t achieve adequate digestibilities varies between grain types. It is well dcumented that srghum must be prcessed mre vigrusly than crn, barley r wheat t achieve ptimum digestibility (Rney and Riggs, 1971; Hale, 1973; Barns and Orskv, 1982; Theurer,

11 1984). Hale (1984) cncluded that it is abslutely essential that grain srghum be prcessed by sme sphisticated system r methd if it is t be used in the mdern day high grain diets fr finishing cattle. The extent f imprvement and severity f prcessing required is als dependent upn ruminant species. Small ruminants, such as sheep, receive less benefit frm prcessing than d larger ruminants such as cattle (Buchanan-Smith et [., 1968; Theurer, 1984; Orskv, 1986; Theurer, 1986). Barns and Orskv (1982) attributed this t differences in ruminatin. In sheep, large particles similar in size t whle grains d nt easily pass thrugh the small reticul-masal rifice; cnsequently, grains that have nt been cracked during eating are returned t the muth and are brken during ruminatin. In cntrast, cattle have large reticul-masal rifices by which whle grains can easily pass. Steam flaking, recnstituting and early harvesting are wet prcessing methds that are cmmnly used in the cattle feeding industry. Steam "cking" and flaking f cereal grain may be accmplished by tw different prcedures prir t flaking. One prcedure invlves steam cnditining the grain in a tempering chamber at atmspheric pressure fr 15 t 30 minutes. The secnd prcedure includes the use f a steam pressure chamber t achieve the same apprximate amunt f cnditining. Steam pressures range frm 1.9 t 5.3 kg cm and cnditining time can be reduced t 1 t 5 minutes. In bth prcedures, a gd flake requires that

12 the grain reach a temperature f 96 t 99 C and a misture cntent f 15-18% (Penner, 1976). Recnstitutin f grains invlves the additin f water t mature dry grain t raise the misture cntent 25 t 30% and stred in an xygen-limiting sil fr days prir t feeding. High-misture grains are harvested at a misture cntent f 20-35% and stred. Bth recnstitutin and high-misture grains are usually rlled r grund befre feeding (Church, 1979). Cmparisn f Feeding Value and Kernel Structure f Grain Srghum and Crn Grain srghum is an imprtant crp and feed grain in the high plains and suthern regins f the United States. There is a great ptential fr grain srghum in these regins as well as many ther areas because f diminishing water supplies and irrigatin cst. These cnditins favr the prductin f grain srghum as cmpared t crn, because f its relative misture and drught tlerance. Grain srghum is usually sld at 85% f the price f crn in the United States. This discunt results frm srghum having a lwer feeding value, being mre variable, cntaining mre freign matter within a grade and with sme varieties being high in tannin (Wagner, 1984). Riley (1984) in review f research trials in which nutritinal values f feed grains were cmpared, cncluded that prcessed srghum had abut 93 t 96% the value f crn. This is cnsistent with the findings f Rney and Pflugfelder (1986) in which he cncluded in a review f research trials that prcessing methds such as steam flaking and recnstitutin are effective in raising grain srghum digestibility t near that f crn.

13 The grss cmpsitin and physical structure f grain srghum is similar t that f crn (Rney et al., 1980). Prximate analysis indicates nly slight differences in nutrient cmpsitin between the tw grains. Rney and Clark (1968) reprted that grain srghum has a slightly higher starch and prtein cntent with crn being slightly higher in fat cntent. Wald (1973) in a review, fund that starch cntent ranged frm 70-77% fr grain srghum and 70-78% fr crn. In cmparisn f grain srghum and crn starches, the physical structure (size and shape) and prperties f the starch granules have been reprted t be similar with srghum granules being slightly larger than thse f crn (Rney and Clark, 1968 and American Assciatin f Feed Micrscpist, 1978). Hwever, this is incnsistent with the findings f Wagner (1984) wh cncluded that ne f the majr differences between srghum and crn starch is the size and shape f the granules. Wagner (1984) reprted that srghum starch granules were spherical and irregular in shape and size with crn starch granules being mre hexagnal, larger and unifrm. Histlgical studies f grain srghum and crn have shwn that the starchy cnstituents r starch granules are fund in the endsperm layers belw the prteinaceus aleurne layer (American Assciatin f Feed Micrscpist, 1978). The endsperm is subdivided int peripheral, crneus and flury layers (Rney and Pflugfelder, 1986). Hwever, the prprtin f these endsperm layers are different fr grain srghum and crn. Rney and Sullins (1973) and

14 Rney and Miller (1982) fund that grain srghum generally is much higher In prprtin f peripheral endsperm than crn and that the peripheral layer is resistant t water penetratin and digestin. This Is cnsistent with the findings f Wagner (1984) in which he reprted that the peripheral endsperm cell cntent is generally much higher (apprximately fur times) in srghum than crn. Hseney et al^. (1974) by the use f electrn micrscpy characterized the endsperm layers. The sft flury endsperm f grain srghum is characterized by large intergranular air spaces. Starch in this prtin f the endsperm is essentially rund and cvered by a thin layer f prtein with small spherical prtein bdies (prlamines) ccasinally embedded in the prtein layer. In cntrast, crn has extremely small prtein bdies r they are absent. The hard peripheral endsperm prtin f grain srghum Is characterized by a tightly packed structure with n air spaces. The starch granules are plygnal and appear t be cvered with a thin prtein matrix. Embedded Int this prtein matrix are numerus amunts f prlamines. Rney and Pflugfelder (1986) stated in review that sme srghum prlamines have intermlecular crsslinks (crss-linked Kafirlns) and that these crsslinkages decrease digestibility f bth the prtein and starch granules enmeshed in it. Rney and Riggs (1971) pstulated a direct relatinship between starch recvery frm wet milling and ruminal digestibility f grain srghum. Watsn et al^. (1955) fund that starch recvery and

15 8 purificatin frm grain srghum by wet milling was mre difficult than crn, because f the larger prprtin f hard endsperm and a layer f dense cells rich in prtein at the periphery f the endsperm just inside the aleurne layer. Hseney (1974) cncluded that hard endsperm is a result f strng adhesin between prtein and starch which results frm water lss during maturatin. This is similar t the findings f Rney and Miller (1982) which related the hardness t prtein cntent and cntinuity f the prtein matrix. Wagner (1984) attributed lwer digestibilities and feeding values f grain srghum t this heavy shruding f the prtein matrix. Effects f Prcessing Grain Srghum n Feedlt Perfrmance f Cattle Hydrthermal prcessing r mist-heat treatment f grain srghum is used extensively thrughut the cattle feeding industry. Hale et aj. (1966) cnducted three cattle feeding experiments t determine the utilizatin f steam prcessed and flaked grain srghum as cmpared t dry rlled grain srghum. Steam prcessed srghum was prepared by subjecting the grain srghum t lw pressure, high misture steam, fr apprximately 25 minutes at 99 C prir t rlling. Results frm Experiment 1 indicated that steam prcessing and flaking tended t increase average daily gain and efficiency f gain ver dry rlled grain srghum. Hwever, differences due t treatment were nt fund t be significant (p<.05). Results frm Experiments 2 and 3 cmbined shwed that steam prcessing and flaking Increased (p<.05) average daily gain and decreased (0<.05) feed

16 required per unit f gain as cmpared t dry rlled grain srghum. Similar results were reprted by Wagner et Q\_. (1970) in cmparing five methds f prcessing grain srghum t determine the effects f steaming time under atmspheric cnditins n the feeding value f steam flaked grain srghum in high cncentrate feedlt ratins. Dry rlled srghum was used as a cntrl. The hydrthermal treatments evaluated were: srghum steamed 15 minutes then rlled; srghum steamed 25 minutes then rlled; srghum steamed 35 minutes then rlled; and srghum steamed 45 minutes then rlled. In a 112 day feeding trial utilizing 12 steers per treatment, the steam flaked treatments each prduced an imprvement in feed efficiency (p<.05) ver dry rlled grain srghum. Garrett et al^. (1971) cnducted tw feeding experiments cmparing mist-heat treatment f grain srghum at varied steam pressures t dry rlled and grund grain srghum t determine the effects f mist-heat treatment and steam pressure n the utilizatin f srghum by cattle. Treatments fr Experiment 1 Included: srghum dry rlled; srghum steamed fr 8 minutes at atmspheric pressure; srghum steam-pressured fr 1.5 minutes at kg/cm r 4.2 kg/cm. Treatments evaluated in Experiment 2 included: srghum grund, 0.64 mm screen; srghum steamed fr 8 r 20 minutes at atmspheric pressure, srghum steamed-pressured fr 1 minute at p p 1.8 kg/cm, 3.5 kg/cm*^ r 5.3 kg/cm. Results frm Experiment 1 indicated that rate f gain and efficiency f gain was greater fr 2 the srghum steam- pressured fr 1.5 minutes at 1.4 kg/cm than dry rlled srghum r the ther mist-heat treatments. In Experiment 2

17 10 rate and efficiency f gain were imprved (p<.05) when srghum was 2 steam-pressured at 3.5 kg/cm as cmpared t dry grund srghum. A third feeding experiment suggested that rlling was preferable ver grinding after mist heat treatment. Hale, (1984) In a feed grains utilizatin sympsium at Lubbck reviewed past feeding trails which cmpared recnstituted and early harvested grain srghum t dry rlled grain srghum. Tw 130 day feeding experiments reviewed cmpared recnstituted grain srghum t dry rlled grain srghum. Diet cmpsitin was the same fr bth experiments with grain level at 80% and alfalfa level 10%. Results frm bth experiments cmbined shwed that recnstituted grain srghum increased rate f gain and feed efficiency ver dry rlled grain srghum. Data frm ther studies utilizing early harvested grain srghum shwed similar imprvements in rate f gain and feed efficiency fr early harvested srghum ver dry rlled srghum. McGlnty and Riggs (1967) cnducted seven experiments invlving 273 cattle cmparing the utilizatin f mist grund grain srghum cntaining 23 t 32% misture, either recnstituted r early harvested, t dry grund grain srghum. Results frm the seven experiments shwed n significant difference in daily gains between mist grund srghum r dry rlled srghum. Hwever, feed required per unit f gain was apprximately 21% lwer fr the mist srghum than dry grund srghum with imprvements being similar fr recnstituted and early harvested srghum as cmpared t dry grund srghum. Wagner and Schneider (1970) cmpared five methds f

18 11 prcessing grain srghum that were used in high cncentrate feedlt ratins t study the Influence f strage time n the feeding value f recnstituted grain srghum and t determine the value f steeping whle grain srghum. Treatments evaluated cnsisted f: grain srghum dry rlled; grain srghum recnstituted whle t 30% misture and stred fr 5, 10, r 20 days and whle srghum steeped in water fr 48 hurs, fllwed by draining 24 hurs prir t feeding. All treatments were rlled prir t feeding. Results indicated a slight Imprvement in feed efficiency fr steeped srghum and recnstituted srghum stred fr 5 and 10 days ver dry rlled srghum. Larger imprvements In feed efficiency resulted frm srghum recnstituted and stred fr 20 days. There was little difference bserved in rate f gain acrss all treatments. McGlnty et al^. (1968) cnducted tw feeding experiments t determine the effect f pre-grund recnstituted and pst-grund recnstituted grain srghum n feedlt perfrmance f cattle. Treatments were recnstituted by adding water t grund and ungrund srghum t increase the misture cntent t 30%. The mist grains were stred in plastic bags fr 21 days. After strage, the ungrund srghum was grund befre feeding. Dry grund grain srghum was fed as a cntrl. Frty-eight cattle were altted t treatments and fed fr 100 days. Results shwed n differences In daily gain acrss all treatments. Hwever, cattle fed dry grund r pre-grund recnstituted srghum required 13% and 18%, respectively, mre dry matter per unit f gain than did pst-grund recnstituted srghum.

19 12 A secnd experiment using the same treatments resulted In smaller differences in feed efficiency; hwever, trends were similar t Experiment 1. The Influence f varius prcessing methds n perfrmance and feed efficiency by cattle has been cmpared in several studies. Hale (1980) in review f such studies demnstrated that feed efficiency as cmpared t dry rlled was Increased by steam flaking, recnstituting, micrnizing, explding and ppping. Each f these prcessing methds appeared t be equally effective In imprving feed efficiency with little effect n average daily gain. Schake et [. (1970) cnducted a feeding experiment In a cmmercial feedlt t evaluate cncentrate feedlt ratins cntaining either steam flaked r micrnized grain srghum n cattle perfrmance and carcass traits. Tw lts f 100 steers served as replicates fr each f the prcessing treatments. Results Indicated that animal perfrmance and carcass characteristics were similar fr bth treatments. Martin and Wagner (1974) cnducted a 136 day feeding experiment, invlving tw wet prcessing methds, t evaluate methd f prcessing n cattle perfrmance and carcass traits. Dry rlled grain srghum was used a cntrl. The wet prcessing treatments evaluated were: steam flaked and high misture early harvested grain. The steam flaking treatment included the steaming f grain srghum fr 25 minutes at atmspheric pressure prir t rlling. The high misture grain srghum was harvested cntaining apprximately 30% misture and stred in a xygen limiting sil. Results fr perfrmance data shwed n

20 13 differences (p<.05) due t prcessing. Hwever, feed required per unit f gain was lwer (p<.05) fr steam flaked and early harvested srghum than dry rlled srghum with steam flaking resulting In mre Imprvement (p<.05) than high misture harvesting. Carcass traits were similar fr all three treatments with the exceptin f kidney, heart and pelvic fat which was lwer (p<.05) fr steam flaked and high misture harvested srghum. Liver-abscesses were mre prevalent in the cattle receiving the tw wet prcessed treatments than dry rlled srghum. Effects f Prcessing Methd n Digestibility Many researchers have studied the effects f prcessing n the digestibility f grain srghum. Evans and Clburn (1967) used a in vitr bag technique t demnstrate ruminal dry matter and ttal digestible nutrient disappearance. Results shwed that dry matter and ttal digestible nutrient disappearance was greater (P<.05) fr grund srghum than srghum in the whle frm. Hale et al^. (1966) fund that steam flaked srghum had higher (P<.05) dry matter, ether extract, nitrgen free extract and ttal digestible nutrient digestibilities than did dry rlled srghum when fed t cattle. Prasad et [. (1975) als fund that steam flaked as well as extruded grain srghum had higher (P<.05) nitrgen free extract digestibilities than did dry rlled srghum. Buchanan-Smith et a^. (1968) als demnstrated imprvements in the digestibility cf grain srghum due t prcessing. Prcessing methds that were evaluated

21 14 included: steam flaking, recnstituting and either carsely r finely grund. Dry matter and rganic matter digestibilities were higher (P<.05) fr recnstituted diets than carsely f finely grund srghum diets, with n differences (P<.05) between recnstituted and steam flaked diets r steam flaked and the tw grund srghum diets. Digestible energy was als greater (P<.05) fr the recnstituted diet than either f the grund diets, with the steam flaked diet being greater (P<.05) than the carsely grund srghum diet. Husted et al^. (1968) cnducted tw digestin trials t determine the effects f prcessing n the digestibility f grain srghum. In the first trial prcessing methds cnsisted f: steam flaking, pressure cking and then flaking, dry rlling and grinding. The results shwed that digestibilities f dry matter, ether extract, nitrgen free extract, ttal digestible nutrients and grss energy t be higher (P<.05) fr steam flaked and pressure cked flaked srghum than either dry rlled r grund srghum. In the secnd trial prcessing treatments were dry rlled, steam flaked, steam prcessed cut and water saked cut. In the latter tw treatments a decrticatr cut the grain in 6 t 10 pieces but did nt apply pressure at the time the grain was cut. Results were similar t thse in trial ne, in that steam flaked srghum had higher (P<.05) digestibilities than did either steam prcessed cut and water saked cut srghum. In vitr prcedures have further cnfirmed the imprvement in grain srghum digestibility resulting frm prcessing. McNeill et a^

22 15 al (1970) fund in vitr dry matter digestibility t be higher (P<.05) fr steam flaked srghum than either recnstituted, micrnized r grund srghum, with recnstituted srghum being higher (P<.05) than micrnized r grund srghum. Hinman and Jhnsn (1974a) cmpared in vitr dry matter digestibilities f several prcessing methds after 12 and 24 hur incubatin perids. Dry matter digestibility after 12 hurs f incubatin was higher (P<.05) fr steam flaked and micrnized srghum than dry rlled srghum; hwever, grund srghum was nt different (P<.05) frm steam flaked r dry rlled srghum. Dry matter digestibility after 24 hurs f incubatin was similar t the 12 hur incubatin perid. Dry matter digestibility was higher (P<.05) fr steam flaked srghum than dry rlled srghum. Micrnizing was nt different (P<.05) frm any f the ther prcessing methds. In a secnd study Hinman and Jhnsn (1974b) utilizing the same Incubatin perids, cmpared varying degrees f micrnizatin t dry rlled grain srghum. In vitr dry matter digestibility after 12 hurs was higher (P<.05) fr the micrnized srghum than dry rlled srghum with n differences (P<.05) bserved between degrees f micrnizatin. The 24 hur incubatin perid shwed that nly the highest degree f micrnizatin increased (P<.05) in vitr dry matter digestibility ver that f dry rlled srghum. Imprvements in labratry technlgy have allwed researchers t partitin the effects f prcessing tc the

23 16 macrnutrients, starch and prtein. McNeill et a}^, (1971) cnducted a digestin trial t measure the effects f prcessing n site and extent f starch digestin. Results shwed that steers fed steam flaked r recnstituted srghum had higher (P<.05) ttal-tract starch digestibilities than steers fed either dry rlled r micrnized srghum. Ruminal starch digestin was greater (P<.05) fr steers fed steam flaked and recnstituted srghum than steers fed dry rlled r micrnized, with steam flaked srghum being greater (P<.05) than recnstituted. Pstruminal starch digestin was als greater (P<.05) fr steers fed steam flaked and recnstituted srghum than steers fed dry rlled r micrnized; n differences (P<.05) were bserved between steam flaked and recnstituted srghum. Buchanan-Smith et al^. (1968) shwed n differences (P<.05) in ttal-tract starch digestin fr steers fed steam flaked, recnstituted and carsely r finely grund srghum. Hwever, the ttal-tract digestin f starch plus reducing sugars were greater (P<.05) fr cattle fed steam flaked and recnstituted srghum than carsely grund srghum. Hinman and Jhnsn (1974a) used steers fitted with permanent rumen and abmasal cannulas t determine the effects f prcessing n site and extent f starch digestin. Steers were fed high cncentrate ratins cntaining grain srghum that had been prcessed by either dry rlling, grinding, steam flaking r micrnizing. Ruminal starch digestin was nt affected (P<.05) by methd f prcessing. Hwever, intestinal and ttal-tract starch digestin were greater (P<.05) fr steers fed steam

24 17 flaked, micrnized r grund srghum than steers fed dry rlled srghum; n differences (P<.05) were bserved between steam flaked, micrnized r grund srghum. Hinman and Jhnsn (1974b) utilizing the same techniques cmpared varius degrees f micrnizatin t dry rlled srghum. Results shwed intestinal and ttal-tract starch digestin t be increased (p<.05) by micrnizatin, with n differences (P<.05) in degree f micrnizatin. Hmes et a\_. (1970) cmpared the effects f steam prcessing at atmspheric pressure fr 8 minutes then flaking t steam prcessing at 3.5 Kg/cm f 1.5 minutes then flaking. Ruminal starch digestin was greater (P<.05) fr steers fed srghum steam prcessed at 3.5 Kg/cm than steers fed srghum steam at atmspheric pressure. Ttal-tract starch digestin was nt affected (P<.05) by steam prcessing methd. Hibbered et a^. (1985) cnducted an experiment utilizing tw varieties f grain srghum (i.e., red and brwn) t study the effects f variety and recnstitutin n site and extent f starch digestin. Ruminal starchy digestin was greater (P<.10) fr steers fed recnstituted red srghum than steers fed dry rlled red srghum; hwever, recnstitutin had n effect (P<.10) n brwn srghum. Starch digestin in the small Intestine was greater (P<.05) fr steers fed recnstituted srghum than steer fed dry rlled srghum. Recnstitutin increased (P<.05) ttal-tract starch digestin and disappearance f digestible starch prir t the terminal ileum fr red srghum and tended t increase ttal-tract starch digestin fr brwn srghum as well.

25 18 Labratry studies utilizing in vitr gas prductin and enzyme susceptibility techniques have been used t study the effects f prcessing n srghum starch. Trei et al^. (1970) using rumen micrbes develped an in vitr gas prductin prcedure t determine the effects f prcessing n starch availability. Results shwed that in vitr gas prductin was greater (P<.05) fr steam flaked than unprcessed grain srghum. In vitr gas prductin was fund t have a psitive crrelatin (r=.99) t starch digestin. Prasad et aj^. (1975) cnducted an experiment using amylglucsidase t determine the effects f prcessing n starch susceptibility t enzymatic attack. Results shwed that enzymatic attack was greater (P<.05) fr expanded than either steam flaked, extracted r dry rlled srghum. Enzymatic attack was similar (P<.05) fr steam flaked and extruded, with bth being greater (P<.05) than dry rlled srghum. McNeill et aj^. (1975) cmpared amylglucsidase susceptibilities f steam flaked, recnstituted, micrnized and dry rlled srghum. Starch frm steam flaked srghum was mre (P<.05) susceptible t enzymatic attack than starch frm recnstituted, micrnized r dry rlled srghum. Enzymatic susceptibility was greater (P<.05) fr micrnized than recnstituted and dry rlled, with n differences (P<.05) between recnstituted and dry rlled srghum. The respnse f recnstituted grain srghum t amylglucsidase attack is nt cnsistent with starch digestin trials which shw recnstituting t imprve starch digestin ver dry rlling. Hibberd et al^. (1985), using yeast Instead f rumen micrbes, reprted higher (P<.05) in

26 19 vitr gas prductin values after 12 hurs f incubatin fr recnstituted than dry rlled grain srghum. Results als shwed that diets cntaining recnstituted srghum had higher (P<.05) gas prductin values after 6 and 12 hurs f incubatin than diets cntaining dry rlled srghum. Several methds f prcessing have shwn imprvement in energy utilizatin. Hwever, lesser detailed attentin has been given t the results f these prcessing methds n the utilizatin f grain srghum prtein. Grain srghum has been shwn t have a lwer prtein digestibility than ther grains (ranging frm 33 t 71%) f cereal grains cmmnly fed t cattle (Keating et al^., 1965; and Hale et al. 1966). It is als generally recgnized that the amin acid cmpsitin f grain srghum prtein is decidedly pr relative t essential amin acid requirements fr mammalian tissue prtein synthesis, cntaining lw levels f lysine and high levels f leucine (Bressani and Ris, 1962). Therefre, ruminal cnversin f grain srghum prtein int micrbial prtein is necessary fr maximum tissue utilizatin f Ingested grain prtein. In a digestin study Ptter et al. (1971) used steers fitted with permanent abmasal cannulas t cmpare amin acid patterns in abmasal cntents f steers fed grain srghum prcessed by different methds and t relate these amin acid patterns t the extent f ruminal cnversin f feed prtein t bacterial prtein and subsequent prtein utilizatin in the lwer digestive tract.

27 20 Prcessing methds evaluated were steam flaking, recnstituting, micrnizing and grinding. Results shwed that ttal nitrgen reaching the abmasum and pst-abmasal true nitrgen digestin were nt different (P <.05) fr prcessing methd. Hwever, abmasal prteins frm steers fed recnstituted srghum cntained less (P<.05) feed prtein and mre (P <.05) micrbial prtein than thse steers fed micrnized and grund srghum. Feed prteins as a percent f abmasal prtein was nt different (P<.05) fr steers fed recnstituted r steam flaked srghum. Recvered essential amin acid patterns f abmasal prteins shwed significant differences in mlar percentages f lysine and leucine. Abmasal prteins frm steers fed recnstituted and cntained mre (P<.05) lysine and less leucine (P<.05) than steers fed micrnized r grund srghum. Abmasal prteins frm steers fed steam flaked srghum were higher (P<.05) in lysine and lwer (P<.05) in leucine than steers fed micrnized srghum. Amin acid patterns f abmasal prteins were nt different (P<.05) fr steam flaked and recnstituted srghum. These findings suggest that benefits frm recnstituting and steam flaking, and the pssible detrimental effects f micrnizatin, are nt bserved in ttal digestin but in the cnversin f pr quality grain prtein t higher quality micrbial prtein. This cnclusin is supprted by the wrk f Rahnema et al. (1987). In cmparing prtein digestibilities f cattle fed steam flaked srghum t steers fed dry rlled srghum, results shwed n differences (P<.05) in ruminal degradatin f feed

28 21 prtein; hwever, steers fed steam flaked srghum needed t have great pst-ruminal and ttal digestibilities f prtein. These tendencies were cncluded t be the prduct f a numerical increase (P<.05) in the amunt and percent f bacterial prtein in the abmasal digesta and a marked increase (P<.05) in the percent f bacterial prtein digested pst-ruminally in cattle fed steam flaked srghum. Similarly, in situ wrk by Walker and Lichtenwalner (1977) shwed n differences (P<.05) in apparent ruminal prtein digestibilities f grain srghum prcessed by either recnstituting r dry grinding. The Effects f Prcessing n the Physi-chemical Structure f Starch Hale (1973) and Wald (1973) reviewed the literature and agreed that raw srghum starch is mre resistant t ruminal digestin than ther cereal starches. Hwever, digestin studies have shwn that prcessing grain srghum, by any ne f several prcessing methds, results in an increase in ruminal and ttal-tract starch digestin. This suggests that prcessing alters the native starch granule and/r alters the assciatin f the starch granule t the surrunding prtein. Birefringence techniques and electrn micrscpy have been used t detect and measure differences in the physical state f prcessed starch granules. McNeill et al. (1975) bserved under plane plarized light that starch granules f steam flaked and micrnized srghum were cmpletely gelatinized (i.e. lss f birefringence) and

29 22 extensively swelled. Recnstituted and dry rlled srghum were similar, in that n lss f birefringence was bserved. Using electrn micrscpy, Harbers (1975) studied the effects f prcessing grain srghum n starch granule structure and subsequent susceptibility t micrbial and enzymatic attack. Steam flaking altered starch granules in such manner that they were either left intact, with indented surfaces, r disassciated int shapeless cnglmerates. Micrnizatin ppped mst f the sft endsperm, but granules near the surface resembled thse prcessed by steam flaking. Ppping changed the starch granules int thin lattices f intercnnecting sheets. Prtein bdies f the prcessed srghum was bserved t be intact, but the prtein surrunding individual starch granules was disrupted. The pattern f attack was similar fr rumen micrbes and alpha-amylase. Amyllysis f the altered starch was bserved t be Initiated n gelatinized starch and at indented sites n damaged granules. The uter edges f the damaged granules were mre resistant t attack than the indentatins, but were less resistant than raw starch granules. Labratry methds utilizing in vitr systems have shwn that the alteratin f starch granules and subsequent increase in availability frm mist-heat treatment f srghum is the result f an interactin between misture, pressure and heat. Liang et al. (1969) and Frederick et al. (1973) reprted that pressure cking srghum with wet steam increased enzymatic 2 degradatin as pressure increased (1.8 t 6.0 kg/cm and 1.4 t

30 2 7.0 kg/cm, respectively) ver untreated srghum. These results are 23 Incnsistent with the findings f Osman et al^. (1966) and Trei. et al. (1970) which shwed that pressure cking belw 4.2 kg/cm was detrimental t starch availability. A similar decrease in starch availability has been reprted fr steam prcessed srghum (Osman et al., 1966; Trei et al., 1970; Frederick et al., 1973). The additin f mechanical pressure (i.e., flaking r rlling) t steam prcessed r pressure cked srghum has shwn t significantly Increase enzymatic degradatin ver untreated srghum (Osman et al., 1966; Trei et al., 1970; Frederick et al., 1973). These data shw that as flake thickness decreases enzymatic degradatin f steam prcessed srghum increases; with srghum cked at higher pressures receiving less benefit frm higher degrees f flaking than srghum cked at lwer pressures. These studies indicate a psitive relatinship between mist-heat treatment and pressure. Frederick et al. (1973), studying the effects f varying pressure with unheated and heated plates n in vitr starch digestibility, fund a significant (P<.05) interactin between misture level, pressure and temperature. Results shwed that starch digestin was lwer (P<.05) fr steamed srghum (20% misture cntent) nt flaked by direct pressure than dry grain while water saked srghum exhibited an Increase (P<.05) in starch digestin. The additin f pressure resulted in a misture x pressure interactin (P<.01). Starch digestin was higher

31 24 (p<.01) fr steamed and saked srghum than dry srghum. The critical pressure required fr imprvement in starch digestin was 2 140kg/cm fr all three treatments. When the pressure plates were heated all interactins between pressure, temperature and misture were significant (P<.01). Critical pressure required t imprve starch digestin was decreased (P<.01) t 35 kg/cm^ fr steamed and saked srghum. Maximum starch digestin fr saked srghum was Imprved (P<.01) by heating the plates; whereas maximum starch digestin fr steamed and dry srghum was nt altered (P<.01) by plate temperature. Unlike mist-heat treatment starch granules, recnstituted starch granules exhibit n lss f birefringence (McNeill et al. 1975). Therefre, increases in starch digestin resulting frm recnstitutin can nt be attributed t alteratins in starch granule structure. Sullins et al. (1971) under high magnificatin fund that recnstitutin had a majr effect n the structure f the kernel at the subcellular level. Recnstituted srghum shwed & distinct lack f rganizatin and a general disruptin f the endsperm as cmpared t a high degree f rder fr untreated srghum. Higher magnificatins f the endsperm cell shwed starch granules were disrupted, causing a release f free starch granules and prtein bdies. Sullins and Rney hypthesized that the degree f disrganizatin is the result f enzymatic hydrlysis f prtein, starch and ther carbhydrates. The release f free starch granules and prtein bdies cmbined with

32 25 the effects f rlling r grinding is the prbable reasn fr increased starch utilizatin. Effects f Chemical Cnditining Grain Srghum The chemical cnditining f grain has been incrprated int many wet prcessing techniques. Researchers have hypthesized that the additin f chemical cnditining agents, prir t prcessing, reduces the resistance f the aluerne and peripheral endsperm layers t misture and alters the swelling prperties f starch granules, thereby increasing the efficiency and verall effectiveness f prcessing. Water enters the srghum kernal at the pedicel near the hilum and at the stylar area, diffusing int the endsperm thrugh the germ. The aleurne layer has thick cell walls that effectively prevent rapid water mvement int the endsperm. Althugh the peripheral endsperm is near the kernal surface, it becmes hydrated last, after water has penetrated the germ, flury and crneus endsperm layers. The water uptake f grains is determined by the macr-and micrstructure, cnditin and chemical cmpsitin f the grain, the temperature, physical-state and slute cntent f water and the relative amunt f distributin f the water ver the grain surface (Rney and Pflugfelder, 1986). The uptake f water plays an imprtant rle in the mist-heat treatment f grains. Cllisin and Chiltn (1974) and Dnvan (1979) fund that critical amunts f water are required t initiate and cmpletely gelatinize starch. Lund (1984) in review f the influence

33 f misture n gelatinizatin, prpsed that starch gelatinizatin in 26 the Intact grain is limited by water diffusin. This limiatatin was cntributed t the fact that during the cking prcess, at temperatures abve thse required t initiate gelatinizatin, starch gelatinizes and hlds mre water; this increase in water capacity reduces the diffusin cefficient acrss the gelatinized layer. This indicates that increasing the misture f the grain prir t prcessing culd imprve the effectiveness f mist-heat treatment. Chemical grain cnditiners are liquids cntaining a cmbinatin f surfactants and rganic and inrganic acids. Chemical cnditiners are designed t facilitate water absrptin by altering the wetting prperties f water and reducing the tensin at the slid-liquid interface. Studies carried ut at Kansas State University (Arnett, 1972) have shwn ecnmic advantages frm the use f chemical cnditining. Results shwed that when E-Z Flake, a cmmercial cnditining agent, was applied t srghum and held fr 1 t 3 hurs prir t flaking increased (P <.025) prductin per hur ver uncditined srghum. The amperage required t flake E-Z Flake treatment srghum was less (P <.001) than untreated srghum. There als was a tendency tward slightly thinner flakes with treated srghum, hwever, gelatinizatin values indicated little difference. Mercier (1971) reprted that crn treated with a cmmercial cnditining agent (Temper) befre flaking increased the damage f starch and in vitr digestibility. Owsley (1982) cnducted

34 27 several labratry experiments and a digestin trial t determine the effects f cmmercial cnditiners n steam flaked and cld rlled grains. Results shwed that srghum treated with chemical cnditiners had higher (P <.05) percentage f sluble starch than untreated srghum. In vitr digestibilities f dry matter and starch were nt affected by cnditining. Results f the digestin trial shwed n differences (P<.05) in apparent digestibilities f dry matter, crude prtein and starch fr sheep fed either untreated steam flaked srghum, r treated cld rlled srghum. Similar results have been reprted fr cattle feeding experiments (Arnett, 1972) in that cattle fed uncnditined steam flaked srghum perfrmed equally t cattle fed cnditined steam flaked srghum.

35 CHAPTER III LABORATORY EVALUATION OF PROCESSED GRAIN SORGHUM AND CORN Abstract A series f labratry experiments were cnducted t determine the effects f prcessing methd n the utilizatin f grain srghum and crn. Prcessing methds fr grain srghum included: dry rlling (DRM), steam flaking (SFM), recnstituting (RWM) and recnstituting then steam flaking (RSFM). Prcessing methds fr crn were dry rlling (DRC) and steam flaking (SFC). One-stage in vitr dry matter digestibility (1-IVDMD) was nt different (P<.05) fr prcessing methd r grain type. Tw-stage in vitr dry matter (2-IVDMD) and rganic matter (2-IVDMD) digestibilities were higher (P<.05) fr SFM, RWM and RSFM than DRM with n differences (P<.05) amng SFM, RWM and RSFM. Tw-stage IVDMD and IVOMD were lwer (P<.05) fr SFC than +DRC. Cmparisns between grain types shwed that 2-IVDMD was similar between prcessed srghum and DRC while 2-IVOMO was higher (P<.05) fr RWM than DRC. Prtein slubilities fr RWM and RSFM were greater (P<.05) than SFM and DRM with DRM being greater (P<.05) than DFM. different (P<.05) than DRC. Prtein slubility fr SFC was nt Prtein slubilities fr RWM ard RSFM were higher (P<.05) than DRC and SFC. In vitr gas prductin (IVGP) after 2, 4 and 8h was greater (P<.05) fr RWM and RSFM than 28

36 29 SFM and DRM with n differences (P<.05) between RWM and RSFM. In vitr gas prductin after 2 and 4 h was greater (P<.05) fr SFM than DRM. In vitr gas prductin after 2 and 4h was nt different fr SFC than DRC, hwever 8h IVGP was higher (P<.05) fr SFC than DRC. Cmparisns between grain type shwed that IVGP after 2, 4 and 8h were greater (P<.05) fr RWM and RSFM than DRC while SFC was similar t RWM and RSFM. These data Indicate that the utilizatin f grain srghum is increased by prcessing with recnstitutin being equal r superir t steam flaking srghum, hwever prcessing had little r n effect n the utilizatin f crn. Cmparisns between grain types Indicate that prcessed srghum is equal t prcessed crn. Intrductin Grain srghum and crn are the primary energy feedstuffs fr grwing-finishing cattle. Many factrs, increased csts, imprved technlgy, and lw ecnmic returns have prvided the ecnmics incentive needed t btain maximum efficiency in prcessing grains accmpanied by maximum utilizatin by cattle. Hydrthermal prcessing (steam flaking) is the mst widely used methd fr prcessing grains fr mdern suthwest feedlts. A number f structural changes ccur in the starch and prtein cmpnents f grain during hydrthermal prcessing that imprve verall digestibility and in additin alter the site f starch digestin (McNeill et al. 1971). Feeding recnstituted and early harvested

37 30 grains have given similar values t that f steam flaked grains in feed efficiency and daily gains in beef cattle finishing trials (Hale, 1980). Hwever, recnstituting time and strage capacity have prevented many cattle feeders frm using recnstituted and early harvested grains. Mrever, a marked increase in energy cst required t steam flake culd prvide the ecnmic incentive t warrant further investigatin int recnstituted and early harvested grains by cattle feeder. It was the bjective f these labratry studies t determine the fllwing: dry matter and rganic matter digestibility; starch availability; and prtein slubility f steam flaked srghum, recnstituted whle srghum, recnstituted steam flaked mil and dry rlled srghum as cmpared t steam flaked crn and dry rlled crn. Experimental Prcedures Prcessed grain samples were btained frm varius feedlts during the same time f year. There were differences in the number f samples btained frm each lcatin and the number f lcatins sampled. Therefre, differences in grain variety and agrnmic practices cannt be accunted fr. Chemical analysis. Prcessed grain samples were reduced t a particle size f 1mm prir t all labratry determinatins. Dry matter cntent was determined by placing a sample (2-g} int an air-drying ven fr 12h at 100 C. Prtein cntent was determined by Kjeldahl nitrgen prcedure (AOAC, 1980). Chemical analyses are presented in Table 1.

38 31 crn. Table 1. Chemical cmpsitin f prcessed grain srghum and a Grain type Dry matter Crude prtein Grain srghum Dry rlled Steam flaked Recnstituted Recnstituted, steam flaked Crn Dry rlled Steam flaked ^Dry matter basis.

39 32 Experiments 1 and 2. One-stage (1-IVDMD) and tw-stage (2-IVDMD) in vitr dry matter digestibility was determined by the Mre mdificatin f the tw stage Til ley-terry prcedure (Harris, 1970) which was further mdified by using 2.0-g samples and 100 ml rumen fluid: buffer slutin inculum in 250-ml centrifuge bttles (Sherrd and Summers, 1974). One-stage IVDMD was determined by terminating fermentatin prir t the additin f HCL and pepsin. After incubatin, residue samples were ashed in a muffle furnace t determine ash cntent fr calculatin f rganic matter digestibility. Experiment 3. Prtein slubility was determined by incubating grain samples (2.0g) in McDugal's buffer slutin (withut urea) at 39 C fr 2h. The residue frm each sample was then filtered thrugh Whatman 54 filter paper and analyzed fr nitrgen cntent. Results are presented as a percent f ttal prtein. Experiment 4. An in vitr gas prductin (IVGP) prcedure was used t determine starch availability f prcessed grains (Hibbered et il., 1982). Grain samples (.4g) were placed in 50-ml Erlenmeyer flask and inculated with a slutin f amylglucsidase (.1% w/v) and cmmercial baker's yeast (.25g/Flask) and maintained in a water bath at 39 C. Gas prduced was cllected in water (COp saturated) filled inverted cylinders. Gas measurements were recrded after 2, 4 and 8h f incubatin. Results are presented as ml f gas/g f grain dry matter.

40 33 Statistical analysis. Because there were differences in the number f samples btained frm each lcatin end in the number f lcatins sampled, statistical analyses were first cnducted t determine if there were differences due t lcatin within prcessing methd and grain type. N differences (P<.05) were fund fr lcatin acrss all prcessing methds and grain type. Therefre, data were pled and analyzed using a cmplete randm design with unequal cell size fr analysis f variance. Tukey's mean separatin test was implemented t detect differences amng least-squares means (Steel and Trrie, 1980). Results and Discussin Experiment 1. One-stage in vitr dry matter digestibility (1-IVDMD) is presented in Table 2. One-stage IVDMD was nt different (P<.05) between prcessing methd r grain type, hwever numerical values tended t be higher fr steam flaked (SFM), recnstituted (RWM) and recnstituted than steam flaked (RSFM) than dry rlled srghum (DRM). Dry matter digestibility f crn tended t be higher fr steam flaked (SFC) than dry rlled (DRC). Experiment 2. Tw-stage in vitr dry matter (2-IVDMD) and rganic matter (2-IVOMD) digestibilities are presented in Table 2. Dry matter and rganic matter digestibilities were higher (P<.05) fr SFM, RWM, and RSFM than DRM. N differences (P<.05) were bserved between SFM, RWM and RSFM fr IVDMD and IVOMD. Similar differences in in vitr digestibilities have been reprted. Hinman and Jhnsn (1974a) reprted that in vitr dry matter

41 34 Table 2. In vitr dry matter and rganic matter digestibility f prcessed srghum and crn. One stage In vitr digestibilities Tw stage Dry matter Dry matter % Organic matter Grain type Grain srghum Dry rlled 76.8^ 90.9^ 91.8^ Steam flaked 81.5^ 94.9^ 95.8^ Recnstituted 83.5^ 96.6^ 97.7^ Recnstituted, steam flaked 78.5^ 95.3^ 96.3^^ Crn Dry rlled 81.1^ 92.8^^ 93.2^^ Steam flaked 82.8^ 85.6^ 86.5^ SE" ± 2.72 ±.74 ±.73 1 Data represent least-squares means. Standard errr f the mean. a,b,c,d ^ggp5 ^-p ^i^g sajne clumn with different superscripts differ (P <.05).

42 35 digestibility was greater fr steam flaked srghum than dry rlled srghum. McNeill et al. (1970) reprted that in vitr digestibility f insluble dry matter was higher fr steam flaked and recnstituted srghum than grund srghum. Dry matter and rganic matter in vitr digestibilities were lwer (P<.05) fr SFC than DRC. These data are incnsistent with findings f Galyean et al. (1981) wh reprted that in vitr dry matter digestibility was higher fr steam flaked crn than grund crn. Hwever, similar decreases in in vitr dry matter digestibilities have been reprted by Ramirez et al. (1985). The lwer digestibilities in this study fr SFC may be the result f grain surce rather than prcessing effect. The lwer prtein cntent fr SFC (Table 3) wuld indicate a lwer quality grain surce fr SFC than DRC. Cmparisns between grain srghum and crn shwed that IVDMD was nt different between dry rlled crn and prcessed srghum. Steam flaked crn was bserved t be inferir in IVDMD than srghum. Experiment 3. Prtein Slubility is presented in Table 3. Slubility f prtein was higher (P <.05) fr RWM and RSFM than SFM r DRM. Prtein slubility fr steam flaked srghum was lwer (P <.05) than DRM. These data are in accrdance with the finding f Hibberd et al. (1981) which reprted that the cncentratin f highly sluble albumin and glbulin prteins were increased while the cncentratin f prlamines were decreased during recnstitutin. Hamaker et al. (1986) fund that cking grain srghum r crn