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1 Met Siene 81 (2009) Contents lists ville t SieneDiret Met Siene journl homepge: The effet of rtopmine hydrohloride (Pylen Ò ) on len rss yields nd pork qulity hrteristis of hevy pigs fed norml nd mino id fortified diets S.N. Crr, D.N. Hmilton, K.D. Miller, A.L. Shroeder, D. Fernández-Dueñs, J. Killefer, M. Ellis, F.K. MKeith, University of Illinois t Urn-Chmpign, Deprtment of Animl Sienes, 1503 S. Mrylnd Dr., 205 Met Siene L, Urn IL 61801, United Sttes Elno Animl Helth, A Division of Eli Lilly nd Compny, 2001 West Min Street, Greenfield, IN 46140, United Sttes Génétipor LLC, 606 3rd Avenue, W. Alexndri, MN 56308, United Sttes rtile info strt Artile history: Reeived 12 June 2008 Reeived in revised form 2 Septemer 2008 Aepted 5 Otoer 2008 Keywords: Swine Crss yield Rtopmine hydrohloride Hevy weight Pork qulity Effets of rtopmine hydrohloride (RAC) on rss prmeters in hevy weight ( ± 8.07 kg) finishing pigs (n = 278) given mino id fortified (AA) or 16% rude protein (CP) diets were evluted. A totl of seven experimentl diets were formulted; RAC ws dded t 0, 5 nd 20 ppm to the 16% CP diets (CP0, CP5 nd, respetively) nd t 0, 5, 10 nd 20 ppm to the AA fortified diets (AA0, AA5, AA10 nd AA20, respetively). Crss, tenderloin, nd hm weights were hevier (P < 0.05) for RAC AA diets vs. AA0. Loin weight ws hevier (P < 0.05) for AA20 vs. AA0 nd vs. CP0. No differenes (P > 0.05) were oserved for olor or firmness sores. Crss musle sore, hm weight nd protein% were greter (P < 0.05) for RAC diets. Moisture ws greter (P < 0.05) nd ft ws lower (P < 0.05) for AA5 nd AA20 vs. AA0 nd CP5 nd vs. CP0. Feeding RAC to lte finishing swine inreses rss yields nd protein% with lower ft% for pigs weighing up to 136 kg. Ó 2008 Elsevier Ltd. All rights reserved. 1. Introdution Rtopmine hydrohloride (RAC) is phenethnolmine with et-drenergi gonist properties nd hs een reported to inrese lenness nd redue the mount of ft in pork rsses s well s exhiit positive effets on growth performne trits in pigs. RAC effets on rss omposition nd pork qulity hve een reported in the literture (Anderson, Veenhuizen, Witt, Pxton, & Young, 1987; Crome et l., 1996; Prine, Huffmn, Brown, & Gillispie, 1987; Uttro et l., 1993). There hve een numerous prodution hnges tht hve trnspired in the United Sttes over the lst dede. Those hnges inlude genetis nd mngement prties, suh s seleting pigs to e muh lener; produing lener met produt for onsumers. A mngement hnge in swine prodution is the use of lower rude protein diets supplemented with the ddition of syntheti mino ids. This strtegy is intended to lower the mount of nitrogen exreted in the fees nd urine of the pig s the mount of nitrogen in the diet nd the pig nitrogen requirements re more losely lned (Shriver et l., 2003; Le, Arnink, Jongloed, vn der Peet Shwering, Ognik, & Verstegen, 2007). Another mngement ltertion is the weight t whih pigs re mrketed. Mrket weights hve grdully inresed over the pst dede in the United Sttes Corresponding uthor. Tel.: ; fx: E-mil ddress: mkeith@uiu.edu (F.K. MKeith). from pproximtely 109 kg to n verge mrket weight tody of pproximtely 125 kg with some pigs rehing n verge slughter weight of 140 kg. As pigs eome older nd hevier, the dditionl weight gin is often ompnied y n inrese in the mount of ft eing deposited t different ntomi positions of kft (Gu, Shinkel, & Mrtin, 1992; Shw, Bs, Stlder, & Mry, 2007). Crome et l. (1996) reported tht pigs fed RAC ould e mrketed t hevier weights (125 kg) while not deleteriously ffeting growth effiienies or rss hrteristis. Rtopmine hs een pproved for use in finishing swine weighing from 68 to 109 kg in the United Sttes sine Deemer of 1999 nd ws reently given pprovl y the Food Drug Administrtion (FDA) in My of 2006 to e fed t levels rnging from 5 to 10 ppm to finishing swine for the lst 20.4 to 40.8 kg of gin prior to hrvest. The ojetive of this experiment ws to hrterize the effet of different levels of RAC on rss prmeters in hevy weight finishing pigs (rered from pproximtely 99 kg to n pproximte trget finl weight of 136 kg) fed mino id (AA) fortified or 16% rude protein (CP) diets. 2. Mterils nd methods 2.1. Experimentl design, nimls nd diets One hundred thirty eight rrows nd one hundred forty gilts (PIC 337 sire PIC C22 dms) were used for this experiment. The /$ - see front mtter Ó 2008 Elsevier Ltd. All rights reserved. doi: /j.metsi

2 534 S.N. Crr et l. / Met Siene 81 (2009) study ws rried out s rndomized omplete lok design. Pigs were rered during two time periods (replition in time) with n initil weight of pproximtely 99 ± 5.4 kg. Eh rering period (replition in time) onsisted of two loks of rrows nd two loks of gilts, totlly four loks of eh gender. Bloks were rndomly ssigned to n environmentl lotion within the finishing fility. Animls were penned in groups of five pigs during the rering period (five pigs/pen) for totl of 56 oservtions (eight replites per tretment). The diets were formulted to meet or exeed NRC (1998) requirements for vitmins nd minerls. The lulted nutrient ontent of the diets for this tril is presented in Tle 1. Mjor feed ingredients used in formultion of the diets were orn nd soyen mel, long with pproprite ommeril soures of vitmin nd minerl premixes. Diets formulted to provide 16% CP were the sme for rrows nd gilts. At the onlusion of the live phse, two or three pigs in eh pen were designted for rss dissetion sed on finl verge weight. If less thn two pigs weighed within the weight window, pproximtely kg, pigs immeditely ove nd elow the window were seleted for dissetion. When more thn two pigs weighed within the weight window, the two pigs with the highest rss priority rnking were seleted. Crss priority rnking ws rndomly ssigned to eh pig within ll pens prior to onlusion of live phse. Amino id diets were formulted to meet the requirements of eh gender s well s len growth potentil of the niml. Estimted len growth rtes were then inresed 35% ompred to ontrol pigs (ording to previous reserh) to reflet the expeted inreses in len growth when 20 ppm RAC ws dded to the diet. The AA fortified diets hd lower levels of protein (Tle 1). Eh diet ws formulted from estimted len gin potentil nd feed intke to ontin the minimum CP ontent tht would result in n AA lned rtion for lysine, methionine, threonine, nd tryptophn. Amino id fortified diets were very similr in AA ontent onsidering len growth potentil nd feed intke levels. A totl of seven experimentl diets were formulted (1) 16% CP diet with no ddition of RAC (CP0); (2) s diet one, ut RAC dded t 5 ppm (CP5); (3) s diet one, ut RAC dded t 20 ppm (); (4) AA fortified diets with no ddition of RAC (AA0); (5) s diet four, ut RAC dded t 5 ppm (AA5); (6) s diet four, ut RAC dded t 10 ppm (AA10) nd (7) s diet four, ut RAC dded t 20 ppm (AA20) Crss, met evlution nd proximte nlysis Tle 1 Clulted nutrient profile of the experimentl diets. Diet onstituent 16% CP AA (rrows) AA (gilts) Crude protein (%) ME (kl/kg) Lysine (%) Methionine (%) Methionine nd ystine (%) Threonine (%) Tryptophn (%) Clium (%) Phosphorus, totl (%) Phosphorus, vil. (%) Sodium (%) Brrows nd gilts. Crss phse of the tril ws designed s n equl weight study. At the end of the equl time study period, individul pig weight y pen verged pproximtely 136 kg. Pens ontined t lest one nd preferly two pigs verging etween pproximtely 133 nd 139. These pigs were seleted nd slughtered for olletion of rss dt on n equl weight sis. At the end of the equl time study, pens not orresponding to the weight prerequisites for rss evlution were mintined on RAC treted feed until weights onurred with the defined weight requirements for rss evlution. One the weight prerequisites were met, pigs were trnsported to the University of Illinois, Met Siene Lortory for slughter the following morning. At the Met Siene Lortory, the pigs were kept overnight in two pens with similr numer of pigs for eh tretment represented in eh pen. Pigs were provided ess to wter, ut not ess to feed. At pproximtely 0700 in the morning fter delivery the pigs were hrvested in rndom order. The pigs were weighed immeditely prior to immoiliztion. After immoiliztion the pigs were exsnguinted, slded, dehired, depitted, eviserted, split nd pled immeditely into 4 C ooler. The pproximte time from stun to ooler ws 45 min. At pproximtely 24 h postmortem, the following rss dt were olleted: hilled whole rss weight, hilled right side rss weight, hilled left side rss weight, rss length, nd rss musling sore sed on sujetive five point sle (NPPC, 1991). Bkft mesurements were tken t the mid line nd perpendiulr to the skin, nd inluded the skin. All liner ft mesurements, whih inluded first ri, lst ri nd lst lumr verter were tken nd reorded for eh rss. The sides were ried y mking slie perpendiulr to the kone through the longissimus etween the 10th nd 11th ris. Tenth ri kft ws mesured t the 3=4 lotion over the longissimus musle of the 10th ri of the thori verter. The longissimus musle ws llowed to loom for pproximtely 5 15 min prior to evluting the musle for qulity vriles. After evluting the longissimus musle, vlue ws reorded for eh of the met qulity vriles: sujetive olor, mrling (NPPC, 1999) nd firmness (NPPC, 1991). Longissimus musle re ws tred on ette film for lter mesurement. The right side of eh rss ws frited for the determintion of ft-free len perentge (dt not presented) nd proximte nlysis determintion. Crss side ws seprted into soft tissues, one plus onnetive tissue nd skin. All three omponents were then weighed. Soft tissues were then ground t lest two times. The grinding proedure ws s follows: initil grind through grinder plte (>12.7 mm). After grinding, the soft tissue ws mixed thoroughly nd prepred for the seond grinding, whih ws through grinder plte (12.7 mm). The ground soft tissue ws mixed nd rndom smples were olleted to form omposite smple weighing pproximtely kg. The omposite smples were hnd-mixed nd prepred for the third homogeniztion, whih ws mde with owl hopper (Tls, model C40P, Spin). The hopping time ws longer thn 30 s on the highest speed possile. These su-smples where then gged in Whirlpk TM gs. Susequently, proximte nlysis ws onduted for moisture, ft, protein nd sh determintion. Duplite 5 g smples were oven dried (105 C, 24 h) to determine perent moisture. Perent ft ws determined on the smples extrted with 4:1 mixture of hloroform nd methnol (Novkofski, Prk, Behtel, & MKeith, 1989). Perent protein ws determined using duplite 3 g smples using the Kjeldhl method (AOAC, 1995). Perent sh ws determined (AOAC, 1995) using duplite 5 g smples ignited (550 C, 8 h) in muffle furne (Blue M Box Furne, model BF51794C). The side of the rss tht ws not used for determintion of ft-free len nd proximte nlysis ws then further proessed into wholesle uts (trimmed) nd oneless su-priml nd their respetive weights ptured. Trimmings were lso olleted nd weights ptured from eh rss.

3 f i j S.N. Crr et l. / Met Siene 81 (2009) Sttistil nlysis The PROC MIXED proedure of SAS (SAS, 2000) ws used to nlyze the dt with the pig eing used s the experimentl unit for the rss phse of the experiment. The model inluded the effets of level of RAC, gender, nd replition nested within lok s rndom effet nd ll intertions. Desired tretment omprisons ( AA5; AA10; AA20; CP5; CP0 vs. ; rrow vs. gilt) were tested for seleted single degree of freedom ontrsts. 3. Results nd disussion Finl weight, rss weights, kft, loin eye re, nd rss length mesurements re presented in Tle 2. Averge finl weight ws ± 8.07 kg. Hot nd old rss weights were greter (P < 0.05) with the ddition of RAC in the AA fortified diets. Crome et l. (1996) nd Crr et l. (2005) lso reported greter rss weights for pigs fed RAC when ompred to ontrol pigs. Crss weights did not differ (P > 0.05) mong pigs fed the CP diets. No differenes were oserved (P > 0.05) in rss lengths from pigs in ny of the CP diets. This is in greement with the findings of Stites et l. (1991) nd Crr et l. (2005). Pigs fed AA10 were shorter (P < 0.05) thn the AA0. For ll kft mesurements, rrows exhiited lrger (P < 0.05) mount of kft ompred to gilts (Dunshe, King, Cmpell, Sinz, & Kim, 1993). Differenes (P < 0.05) were oserved with treted pigs eing lener ompred to the CP0 pigs for lst lumr nd 10th ri. Tenth ri ft depths were lso lower (P < 0.05) for AA20 ompred to the AA0. Stites et l. (1991) nd Crr et l. (2005) reported no differenes (P > 0.05) in 10th ri kft thikness. Pigs from their trils were slughtered t live weight of pproximtely 104 nd 109 kg, respetively ompred to the trgeted verge ending live weight of pproximtely 136 kg from this study. With the remining kft mesurements, no differenes (P > 0.05) were oserved etween the ontrols nd the RAC supplemented pigs. Crenshw et l. (1987), Prine et l. (1987), Wtkins, Jones, Mowrey, Anderson, nd Veenhuizen (1990), Uttro et l. (1993) nd Crome et l. (1996) ll reported similr dereses (P < 0.05) in 10th ri ft s ompred to this experiment. Loin eye re ws inresed (P < 0.05) in pigs fed AA10 nd AA20 ompred to AA0. Pigs fed the lso yielded lrger (P < 0.05) loin eye re ompred to CP0. These results re in greement with the findings of Stites et l. (1991) nd Crr et l. (2005), whih oserved inresing loin eye res with inresing levels of RAC. For this experiment, the CP5 nd AA5 diets were not different (P > 0.05) ompred to their respetive ontrols. Sujetive loin qulity mesurements re presented in Tle 3. Gender ffeted (P < 0.05) olor nd firmness sores with the rrows eing drker nd firmer. In ontrst, Suzuki, Shit, Kdowki, Ae, nd Toyoshim (2003) reported no gender effet in olor sores. Pigs given RAC hd greter (P < 0.05) musle sores for ll levels of AA fortified diets ompred to AA0 nd oth levels of CP diets ompred to CP0. This is in greement with Crr et l. (2005), whih lso oserved n inrese in musling sore vlues y pigs supplemented with RAC. Sujetive olor sores were not hnged y the ddition of RAC to either the AA fortified diets or the CP diets. This is in greement with the findings of Stoller et l. (2002) nd Crr et l. (2005). Rtopmine fed pigs lso did not differ in firmness from the ontrols. Agin this is onsistent with the findings from Zimmermnn (1989), Stites et l. (1991), Herr et l. (2000), Stoller et l. (2002) nd Crr et l. (2005). Sujetive mrling sores were different (P < 0.05) etween genders with rrows exhiiting greter mrling sores thn gilts. Tle 2 Effet of rtopmine hydrohloride (Pylen Ò ) on rss weights, kft, loin eye re, nd rss length of hevy pigs fed norml nd mino id fortified diets. AA0 AA5 AA10 AA20 CP0 CP5 Averge B j G k Averge B j vs. G k AA5 AA10 AA20 CP5 LW kg HW kg CW kg FR d m LR e m LL f m TR g m LEA h m Len i m P < Live weight. Hot rss weight. Cold rss weight. First ri. Lst ri. Lst lumr. 10th ri. h Loin eye re. Length. d e g k

4 Tle 3 Effet of rtopmine hydrohloride (Pylen Ò ) on met qulity trits of hevy pigs fed norml nd mino id fortified diets. AA0 AA5 AA10 AA20 CP0 CP5 Averge B e G f Averge B e vs. G f AA5 AA10 AA20 CP5 Musling sore f 536 S.N. Crr et l. / Met Siene 81 (2009) Color sore Firmness sore Mrling sore d P < NPPC (1991) (in 0.5 inrements, where 1 = thin nd 3 = to thik). NPPC (1999) (where 1 = ple nd 6 = red). NPPC (1991) (where 1 = soft nd 5 = firm). NPPC (1999) estimted% lipid. d e This ws expeted s rrows rete ft t n erlier hronologil ge ompred to gilts (Hmilton, Ellis, Wolter, MKeith, & Wilson, 2003). The CP diet supplemented with 20 ppm of RAC hd greter (P < 0.05) mrling sore thn CP0. These results re inonsistent with those reported y Stites et l. (1991), Crome et l. (1996), Herr et l. (2000), Stoller et l. (2002) nd Crr et l. (2005) whih ll reported no differenes (P > 0.05). One possile explntion for this ould e tht ontemporry nimls fed 16% CP diet with RAC supplementtion re not meeting their mino id requirement for mximl len retion. With the ddition of RAC to the diet, the len growth potentil of the niml is inresed. Witte, Ellis, MKeith, nd Wilson (2000) oserved tht feeding pigs lysine defiient diet for five weeks prior to slughter resulted in n inrese in the intrmusulr ft ontent of the longissimus t the 10th ri. The mrling levels for this experiment were lower (P < 0.05) for the AA10 ompred to AA0. All trimmed wholesle nd oneless weights represent the weights of the respetive uts from single side of the rss. The numer preeding the ut desription is the Institutionl Met Purhse Speifition (IMPS, 1997) nd North Amerin Met Proessors Assoition (NAMP, 1997) numer of the ut most losely ssoited with the tul ut speifitions. Trimmed wholesle ut weights re presented in Tle 4. The hm (401) ollr off ws hevier (P < 0.05) for AA5, AA10 nd AA20 fed pigs ompred to the AA0 diet. This ut ws lso hevier (P < 0.05) for the CP5 nd diets ompred to the CP0 fed pigs. This inrese in 401 hm weight is onsistent to the findings of Stites et l. (1991); (RAC t 5, 10 nd 20 ppm), Uttro et l. (1993); (RAC t 20 ppm) nd Crome et l. (1996); (RAC t 10 nd 20 ppm). No differenes were oserved etween the AA0 nd AA diets supplemented with RAC or the CP0 nd CP diets supplemented with RAC for the pini (405) whih ws onsistent with results reported y Stites et l. (1991) nd Uttro et l. (1993). Pigs fed the AA5, AA20 nd diets were hevier (P < 0.05) for the Boston utt (406) nd loin (410) ompred to the AA0 nd CP0 ontrols, respetively, whih ws onsistent with results reported y Stites et l. (1991) nd Crome et l. (1996). No differenes (P > 0.05) were oserved etween AA0 nd AA10 s well s CP0 nd CP5 for the Boston utt (406) nd loin (410). The elly (409B skin on) ws hevier for the AA5 ompred to AA0 whih ws inonsistent with results reported y Stites et l. (1991) where elly ws not different when nimls were fed high RAC levels. No differenes (P > 0.05) were oserved etween the RAC supplemented diets nd their ontrols in either the CP or the AA fortified diets for side weight, or spreris (416). These results were inonsistent to those reported y Stites et l. (1991) nd Crome et l. (1996) where spreris were hevier when nimls were fed high RAC levels. In gender omprisons, gilts did hve hevier (P < 0.05) loin (410) ompred to the rrows. Belly (409B) weight hd sex y RAC intertion (P < 0.05) for AA10 nd AA20 s well s CP5 with weight. The ddition of RAC inresed elly (409B) weights more in rrows ompred to gilts. The oneless ut weights re presented in Tle 5. No differenes (P > 0.05) were oserved etween the RAC supplemented diets nd the ontrols in either the AA fortified diets or the CP diets for the hm (402F), hm knukle (402G), pini (405A), nd ushion (405B). The hm (402B), hm knukle (402G), tenderloin nd trimmings were ll hevier (P < 0.05) for the AA diets supplemented with RAC ompred to the AA0 diet. The loin (414) ws hevier (P < 0.05) for the fed pigs ompred to the CP0, s well s for the AA20 ompred to the AA0 fed pigs. Crome et l. (1996) oserved inresed hm weight, knukle, tenderloin nd loin t high RAC levels (10 nd 20 ppm). No differenes (P > 0.05) were oserved in the sirloin weight for the CP5 nd fed pigs ompred to the CP0, nor for AA10 ompred to the AA0 fed pigs.

5 Tle 4 Effet of rtopmine hydrohloride (Pylen Ò ) on trimmed wholesle ut weights of hevy pigs fed norml nd mino id fortified diets (kg). AA0 AA5 AA10 AA20 CP0 CP5 Averge B G Averge Side weight Hm ollr off 405 Pini Boston utt B Belly skin on 410 Loin Ris (P < 0.05). Aording to the Institutionl Met Purhse Speifition (IMPS, 1997). B vs. G AA5 AA10 AA20 CP5 Tle 5 Effets of rtopmine hydrohloride (Pylen Ò ) on oneless ut weights of hevy pigs fed norml nd mino id fortified diets (kg). AA0 AA5 AA10 AA20 CP0 CP5 Averge B G Averge 402B Hm F Hm G Outside hm 402G Knukle hm 414 Loin Sirloin Tenderloin A Pini B Cushion A Boston utt Trimmings P < Aording to the Institutionl Met Purhse Speifition (IMPS, 1997). B vs. G AA5 AA10 AA20 CP5 S.N. Crr et l. / Met Siene 81 (2009)

6 538 S.N. Crr et l. / Met Siene 81 (2009) Tle 6 Effets of rtopmine hydrohloride (Pylen Ò ) on proximte nlysis of whole side soft tissue of hevy pigs fed norml nd mino id fortified diets (%). AA0 AA5 AA10 AA20 CP0 CP5 Averge B G Averge B vs. G AA5 AA10 AA20 CP5 Ash Ft Moisture Protein P < The Boston utt (406A) ws hevier (P < 0.05) for ompred to the CP0 fed pigs, nd for AA20 nd AA10 ompred to the AA0 fed pigs. Crr et l. (2005) reported hevier (P < 0.05) Boston utt weights with inresing levels of RAC. Gilts exhiited hevier (P < 0.05) trimmings, tenderloin nd loin (414) ompred to rrows. Proximte nlysis vlues of the whole side soft tissue of pigs re presented in Tle 6. There ws gender differene (P < 0.05) for ll tretments s the rrows yielded soft tissue tht hd more ft, less sh, less moisture nd lower protein vlues ompred to gilts. These results were onsistent to those reported y Uttro et l. (1993) nd LTorre, Lzro, Gri, Nieto, nd Mteos (2003) where moisture nd protein were deresed wheres ft perentge ws inresed for rrows. In ompring tretments, no differenes (P > 0.05) were oserved in sh vlues for RAC supplemented diets ompred to AA0. Pigs fed the CP5 nd diets hd greter (P < 0.05) sh vlues ompred to CP0; this result ws onsistent with those sh vlues oserved y Dunshe, King, nd Cmpell (1993) when gilts were fed inresed levels of dietry rude protein nd RAC. For ft nd moisture vlues, RAC supplemented diets yielded soft tissue smples tht were lower (P < 0.05) in ft nd greter (P < 0.05) in moisture ompred to their ontrols with the exeption of AA10 whih ws only numerilly greter for moisture nd numerilly lower for ft. All pigs supplemented with RAC in their diets hd greter (P < 0.05) protein vlues ompred to their respetive ontrol. Moisture, ft nd protein results were onsistent to those reported y Uttro et l. (1993) when RAC ws fed t 20 ppm. Results from this study indite tht RAC hs dvntgeous effets on rss hrteristis nd rss utting yields when fed to hevy weight swine using oth CP nd AA fortified dietry regimes. Pigs n e mrketed t hevier weights (pproximtely 136 kg) without ffeting len rss hrteristis tht re desired y urrent mrket. Furthermore, results from this study onfirm previous reserh on lighter weight pigs tht RAC inreses rss ut yields with deresed perentges of ft nd inresed perentges of protein for pigs weighing up to 136 kg. In onlusion, these results lso indited tht RAC fed pigs n e mrketed up to pproximtely 136 kg with no dverse effets on rss liner trits, rss utting yields or rss qulity. Aknowledgement The uthors would like to thnk Lori Engel for her ssistne in dt olletion. Referenes Anderson, D. B., Veenhuizen, E. L., Witt, W. P., Pxton, R. E., & Young, S. S. (1987). The effet of dietry protein on nitrogen metolism, growth performne nd rss omposition of finishing pigs fed rtopmine. Federtion Proeedings, 46, AOAC (1995). Offiil methods of nlysis, method Wshington, DC: Assoition of Offiil Anlytil Chemists, In., AOAC. AOAC (1995). Offiil methods of nlysis, method Wshington, DC: Assoition of Offiil Anlytil Chemists, In., AOAC. Crr, S. N., Ivers, D. J., Anderson, D. B., Jones, D. J., Mowrey, D. H., Englnd, M. B., et l. (2005). The effet of rtopmine hydrohloride (Pylen Ò ) on growth performne nd rss hrteristis of lte finishing swine. Journl of Animl Siene, 83, Crenshw, J. D., Swntek, P. M., Mrhello, M. J., Hrrold, R. J., Zimprih, R. C., & Olson, R. D. (1987). Effets of phenethnolmine (rtopmine) on swine rss omposition [Astrt]. Journl of Animl Siene, 65(Suppl. 1), 308. Crome, P. K., MKeith, F. K., Crr, T. R., Jones, D. J., Mowrey, D. H., & Cnnon, J. E. (1996). Effet of rtopmine on growth performne, rss omposition, nd utting yields of pigs slughtered t 107 nd 125 kg. Journl of Animl Siene, 74, Dunshe, F. R., King, R. H., & Cmpell, R. G. (1993). Interreltionships etween dietry protein nd rtopmine on protein nd lipid deposition in finishing gilts. Journl of Animl Siene, 71,

7 S.N. Crr et l. / Met Siene 81 (2009) Dunshe, F. R., King, R. H., Cmpell, R. G., Sinz, R. D., & Kim, Y. S. (1993). Interreltionships etween sex nd rtopmine on protein nd lipid deposition in rpidly growing pigs. Journl of Animl Siene, 71, Gu, Y., Shinkel, A. P., & Mrtin, T. G. (1992). Growth, development, nd rss omposition in five genotypes of swine. Journl of Animl Siene, 70, Hmilton, D. N., Ellis, M., Wolter, B. F., MKeith, F. K., & Wilson, E. R. (2003). Crss nd met qulity hrteristis of the progeny of two swine sire lines rered under differing environmentl onditions. Met Siene, 63, Herr, C. T., Yke, W., Roson, C., Kendll, D. C., Shinkel, A. P., & Rihert, B. T. (2000). Effet of nutritionl level while feeding Pylen TM to lte finishing swine. Presented t Purdue University 2000 Swine Dy Report. IMPS (1997). Institutionl Met Purhse Speifition for Fresh Pork. Wshington, DC: Agriulturl Mrketing Servie, USDA. LTorre, M. A., Lzro, R., Gri, M. I., Nieto, M., & Mteos, G. G. (2003). Effet of sex nd terminl sire genotype on performne, rss hrteristis, nd met qulity of pigs slughtered t 117 kg ody weight. Met Siene, 65, Le, P. D., Arnink, A. J. A., Jongloed, A. W., vn der Peet Shwering, C. M. C., Ogink, N. W. M., & Verstegen, M. W. A. (2007). Effets of rystlline mino id supplementtion to the diet on odor from pig mnure. Journl of Animl Siene, 85, NAMP (1997). Met uyers guide. Reston, VA: North Amerin Met Proessors Assoition. Novkofski, J., Prk, S., Behtel, P. J., & MKeith, F. K. (1989). Composition of ooked pork hops: Effet of removing su-utneous ft efore ooking. Journl of Food Siene, 54, NPPC (1991). Proedures to evlute mrket hogs (3rd ed.). Des Moines, IA: Ntionl Pork Produers Counil. NPPC (1999). Pork qulity stndrds. Des Moines, IA: Ntionl Pork Produers Counil. NRC (1998). Nutrient requirements of swine (10th ed.). Wshington, DC: Ntionl Ademy Press. Prine, T. J., Huffmn, D. L., Brown, P. M., & Gillispie, J. R. (1987). Effets of rtopmine on growth nd rss omposition of finishing swine [Astrt]. Journl of Animl Siene, 65(Suppl. 1), 309. SAS User Guide, Version 8.1E (2000). SAS system. Cry, NC: SAS Institute In. Shw, C. R., Bs, T. J., Stlder, K. J., & Mry, J. W. (2007). Deposition rtes nd retion ptterns of intrmusulr ft, loin musle re, nd kft of Duro pigs sired y ors from two time periods. Journl of Animl Siene, 85, Shriver, J. A., Crter, S. D., Sutton, A. L., Rihert, B. T., Senne, B. W., & Pettey, L. A. (2003). Effets of dding fier soures to redued-rude protein, mino idsupplemented diets on nitrogen exretion, growth performne, nd rss trits of finishing pigs. Journl of Animl Siene, 81, Stites, C. R., MKeith, F. K., Singh, S. D., Behtel, P. J., Mowrey, D. H., & Jones, D. J. (1991). The effet of rtopmine hydrohloride on the rss utting yields of finishing swine. Journl of Animl Siene, 69, Stoller, G. M., Zery, H. N., Moeller, S. J., Bs, T. J., Johnson, C. D., & Wtkins, L. E. (2002). The effet of feeding rtopmine (Pylen TM ) on loin qulity nd sensory hrteristis in three geneti lines of swine [Astrt]. Journl of Animl Siene, 88(Suppl. 2), 79. Suzuki, K., Shit, T., Kdowki, H., Ae, H., & Toyoshim, T. (2003). Met qulity omprison of Berkshire, Duro nd rossred pigs sired y Berkshire nd Duro. Met Siene, 64, Uttro, B. E., Bll, R. O., Dik, P., Re, W., Vessie, G., & Jeremih, L. E. (1993). Effet of rtopmine nd sex on growth, rss hrteristis, proessing yield, nd met qulity hrteristis of rossred swine. Journl of Animl Siene, 71, Wtkins, L. E., Jones, D. J., Mowrey, D. H., Anderson, D. B., & Veenhuizen, E. L. (1990). The effet of vrious levels of rtopmine hydrohloride on the performne nd rss hrteristis of finishing swine. Journl of Animl Siene, 68, Witte, D. P., Ellis, M., MKeith, F. K., & Wilson, E. R. (2000). Effet of dietry lysine level nd environmentl temperture during the finishing phse on the intrmusulr ft ontent of pork. Journl of Animl Siene, 78, Zimmermnn, D. R. (1989). Effets of rtopmine on performne nd rsses of finishing pigs fed diets with vrious protein nd lysine onentrtions. In ISU Reserh Report 1989 (pp ). Iow Stte University, Ames, Iow