Effect of Amino Acids on Non-Protein Nitrogen Utilization by G-F Swine

Transcription

1 University f Nebraska - Lincln DigitalCmmns@University f Nebraska - Lincln Faculty Papers and Publicatins in Animal Science Animal Science Department 1973 Effect f Amin Acids n Nn-Prtein Nitrgen Utilizatin by G-F Swine P. D. Platter University f Nebraska-Lincln E. R. Pe, Jr. University f Nebraska-Lincln P. E. Vipperman University f Flrida P. J. Cunningham University f Nebraska-Lincln Fllw this and additinal wrks at: Part f the Animal Sciences Cmmns Platter, P. D.; Pe, Jr., E. R.; Vipperman, P. E.; and Cunningham, P. J., "Effect f Amin Acids n Nn-Prtein Nitrgen Utilizatin by G-F Swine" (1973). Faculty Papers and Publicatins in Animal Science This Article is brught t yu fr free and pen access by the Animal Science Department at DigitalCmmns@University f Nebraska - Lincln. It has been accepted fr inclusin in Faculty Papers and Publicatins in Animal Science by an authrized administratr f DigitalCmmns@University f Nebraska - Lincln.

2 Jurnal f Animal Science 37 (1973), pp Cpyright 1973 American Sciety f Animal Science. Used by permissin. EFFECT OF AMINO ACIDS ON NON-PROTEIN NITROGEN UTILIATION BY G-F SWINE 1 P. D. Platter, E. R. Pe, Jr., P. E. Vipperman 2 and P. ]. Cunningham Nebraska Agricultural Experiment Statin, Lincln Summary WO metablism and ne feeding experi- T ment were cnducted with a ttal f 118 crssbred pigs t determine the effect f amin acids n nn-prtein nitrgen (NPN) utilizatin by G-F swine. In the first tw experiments, 3.1% f a 14% prtein crn-sybean meal diet was prvided frm a mixture f 66% mnsdium glutamate and 28% glycine. Maximum nitrgen retentin ccurred when the diet cntained the Natinal Research Cuncil's recmmended levels fr lysine, methinine, tryptphan and threnine. When amin acid levels exceeded the Natinal Research Cuncil's recmmended levels nitrgen retentin decreased. The phsphrus and calcium retentin pattern was nt cnsistent acrss the tw experiments. Hwever, increased calcium retentin was nticed when pigs were fed diets cntaining.6% DL-methinine as cmpared t pigs fed diets cntaining.45%. Als, phsphrus retentin increased in pigs fed diets cntaining.56% DL-threnine cmpared t thse fed.42%. Packed cell vlume, bld serum prtein and bld serum albumin were nt significantly affected in either experiment by level f amin acids r by NPN. Hwever, pigs fed diets with high levels f lysine and threnine shwed less bld serum urea nitrgen than pigs fed diets lw in lysine and threnine. In experiment 3, tw levels f prtein, 12% and 15% were fed. In additin cmparisns were made in which mn-ammnium phsphate supplied 1.5% prtein-equlvalent t the diet and amin acids were added t prvide % lysine,.6% methinine;.2% tryptphan and.56% threnine. The additin f amin acids t the 12% prtein diets 1 Published with the apprval f the Directr as Paper N. 3487, Jurnal Series Nebr. A~gr. Exp. Sta. ~Present address: University f Flrida, Agricultural Research Center, Marianna, Flrida. a Department f Animal Science. Acknwledgement is made t Fred Krieger in caring fr the experimental animals and t Jhn Welch fr assistance in labratry analyses and t Dawes Labratries, Inc., Chicag, fr prviding the vitamin mixtures used in these studies. 514 increased gain as cmpared t the gain f pigs fed the unsupplemented diets. This effect was nt bserved in pigs fed the 15% prtein diets. Gain, feed cnsumptin and backfat thickness f pigs were nt significantly affected by the additin f amin acids r NPN t either prtein level. Pigs fed the 12% prtein diets gained significantly (P<.1) less than pigs fed the 15% prtein diets. Als, pigs fed the 12% prtein diets cntaining amin acids plus NPN gained significantly (P<.5) less than pigs fed the 12% prtein diets plus amin acids. Carcass length, carcass backfat, and percent ham and lin were nt significantly affected by prtein level, supplementatin f amin acids r by NPN. Breaking strength f the metatarsal bnes indicates that mnammnium phsphate is an acceptable surce f phsphrus fr G-F swine. Intrductin The quantitative and qualitative relatinship between essential and nn-essential amin acids in the animal bdy is nt full understd. It is recgnized that level f essential amin acid nitrgen required by animals changes as ttal dietary nitrgen changes (Almquist, 1952), but little is knwn abut nn-essential nitrgen requirement. The nnessential prtin f dietary nitrgen can be added inexpensively t swine diets. Hwever, results frm the additin f nn-prtein nitrgen (NPN) have been variable. Several wrkers have reprted that the additin f NPN alne depresses grwth, feed cnversin and ften feed intake (Hays et al., 1957; Cmbs et al., 1969). Cnversely, Krnegay (1969) did nt bserve any depressin in average daily gain r feed cnversin in pigs fed diets cntaining 2 % NPN frm urea. T, the additin f lysine and methinine in cmbinatin with NPN may result in imprved nitrgen retentin in G-F swine (Hays et al., 1957; Wehrbein, 1969; Werman, 197). JOURNAL OF ANIMAL SCIENCE, vl. 37, n. 2, 1973

3 USE OF NON-PROTEIN BY G-F SWINE 515 The purpses f the research presented in this paper were t: a) determine if a prtin f the prtein N in swine diets can be supplied with NPN withut critically affecting perfrmance; b) determine the level f lysine, methinine, tryptphan and threnine which wuld increase NPN utilizatin by swine and c) determine the value f ammnium phsphate as nitrgen and phsphrus surces fr G-F swine. Animals. In experiment 1, 1 Hampshire x Yrkshirex Durc barrws averaging 23. kg were randmly assigned by weight, within litter t five dietary treatments. The experiment was divided int tw perids. Each perid cnsisted f 8 days---3 days fr pigs t adjust t their respective diets (deemed lng enugh by the authrs frm previus unpublished research) and 5 days fr the metablism study. Twelve Hampshire x Yrkshire barrws averaging 28.3 kg were randmly assigned by weight, within litter t six dietary treatments fr experiment 2. This experiment was divided int three perids. Each perid was the same as described in experiment 1. In bth experiments, the pigs were maintained in the experimental unit fr a 2-week envirnmental adjustment perid. In experiment 3, 96 Hampshire x Yrkshire x Durc pigs were randmly assigned t six dietary treatments, and blcked by weight grups. The light blck averaged 16.1 kg, whereas the heavy blck averaged 22.6 kilgrams. The experiment was cnducted fr 98 days during the winter mnths. Husing. The pigs in experiments 1 and 2 were hused in a ttally envirnmental cntrlled facility in which the relative humidity was maintained at 55%, the ambient temperature averaged 22.5 C and light was prvided 24 hr. per day. In experiment 3, the pigs were hused in a ttally enclsed structure with frced air ventilatin, supplemental heat and artificial lighting. The flrs in this facility were cncrete and 66% f the flr area was slatted. Diets. The cmpsitin and calculated analysis f the diets used in experiments 1 and 2 are shwn in table 1, and in table 2 fr experiment 3. In experiment 1 and 2, a 1.9% prtein paque-2 crn-sybean meal diet supplemented with 3.1% prtein frm NPN was used as a basal t which varius levels f amin acids were added. NPN was supplied frm a mixture f 66% diammnium citrate, 6% mnsdium glutamate and 28% glycine. L-lysine, DL-methinine, DL-tryptphan and DL-threnine were used t furnish the selected amin acid levels. These diets were cmpared t a 14% prtein crn-sybean meal diet withut supplemental amin acids. In experiment 1, lysine and methinine levels were varied while tryptphan and threnine levels were held cnstant. The levels f lysine used wer.e.6% and %, whereas, Diet 2 Ingredients Yellw crn Opaque-2 crn Sybean meal (48.5%) 6.3 Dicalcium phsphate (18.5%) 1,79 Calcium carbnate.5 Salt (I).5 Trace mineral b,5 Vitamln-antibitic premlx e 1, Starch O, 45 Nitrgen mix a 3,6 Chline chlride.6 L-lysine (5%) DL-Methinine (99%) 137 DL-Tryptphan.1 DL-Threnine... Calculated analysis Prtein 14.1 Calcium O. 59 Phsphrus Lysine.6 Methinine.6 Tryptphan.15 Threnlne.42 TABLE 1. COMPOSITION OF EXPERIMENTAL Experiment 1 a DIETS Experiment 2 a 3 4 land8 5and i. 1. O. 42 O. 6 O i.22 b~bi O.Ol O.Ol , , ~6~ , , , , *Diets I, 2, 3, 4. 5 fed in experiment 1; diets 7, 8, 9, I, II, 12 in experiment 2. b Cmpsitin (%): Mn, I.; Fe, IO.; Cu, 1.; C,.1; I,.3; n, I.; Calcium Carbnate Cmpany, Quincy, Illinis. e Cntributes the fllwing vi#amlns per kilgram diet: Vit A, 264 IU; Vit Ds 396 IU; Ribflavin, 1.76 rag; Pantthenic acid, 6.6 rag: Niacin, 21.7 rag; Chline chlride, 12. rag; Vit B~, 11. mcg: and 1.1 g auremycin., a Cmpsitin (%): Mnsdium glutamate, 6.; Diammnium citrate, 66.; glycine, 28..

4 516 PLATTER ET AL. TABLE 2. COMPOSITION OF EXPERIMENTAL DIETS Experiment 3 Diet Ingredients Yellw crn Sybean meal (48.5%) Dicaldum phsphate (18.5 %) Calcium carbnate Salt (I) Trace mineral a O. 5 O. 5 O. 5 O. 5 Vitamin premixb Amin acid premix ~ Mn-ammnium phsphate Calculated analysis Prtein Calcium O Phsphrus O O O. 85 Lysine.46 O. 7 O. 7 Methinine Tryptphan.13.2 O O. 2.2 Threnine O a See table 1, ftnte b fr cmpsitin. b Cntributed the fllwing vitamins per kg diet: Vit A, 264 IU; Vit D2, 396 IU; Ribflavin, 1.76 mg; Pantthenic acid, 6.6 nag; Niacin, 17.6 mg; Chline chlride, 185 rag; Vit B~, 11. micrgrams. e Lysine, methinlne, tryptphan and threnine were added t diets 2, 3, 5 and 6 t attain levels f %,.6%,.2% and.56% fr the respective amin acids. the methinine levels were.45% and.6%. The level f tryptphan and threnine was held at.15% and.42%, respectively. In experiment 2, tryptphan and threnine levels were varied while lysine and methinine were held cnstant. The levels f tryptphan were.15% and.2%, whereas, the level f threnine was.42% and.56%. Lysine and methinine levels were % and.6%, respectively. In experiments 1 and 2, the amunt f feed prvided was.9 x bdy wt ~ grams per day. Half this amunt was mixed with a small amunt f water t reduce wastage and fed twice daily. Water was partially restricted t keep daily urinary vlumes under 3, ml t simplify sampling prcedures. In experiment 3, tw prtein levels were used, 12 and 15%. Each prtein level was fed unsupplemented, supplemented with amin acids r supplemented with amin acids plus NPN. A level f % lysine,.6% methinine,.2% tryptphan and.56% threnine was prvided in all diets cntaining supplemental amin acids. The frm f amin acids was the same as that used in experiment 1 and 2 except fr methinine. In this experiment, methinine hydrxy analgue was used. NPN was prvided by mn-ammnium phsphate and cntributed 1.5% prtein (Nx6.25) t the diets. The diets were self-fed and water was prvided by autmatic waterers. Management. Prir t each perid in the metablism studies (experiment 1 and 2) the animals were weighed and assigned t dietary treatments. Circular metablism crates cnstructed f expanded metal sides with heavy mesh flrs were used. The diameter f the crates were adjusted t equal the length f each pig t frce dunging arund the utside and urinatin tward the middle f the crates. Drpping pans were used under the crates t cllect the feces. A large screen-cvered metal funnel lined with glass wl filtered the urine befre it was cllected in glass strage bttles. General cllectin prcedures used in experiment 1 and 2 were similar t thse described by Luce, Pe and Hudman (1966). Ttal daily cllectins f urine and feces were made fr five days after the dietary adjustment perid. Urine was standardized t 3, with distilled water and a ne-percent sample was taken and immediately frzen in sealed plastic bttles until analyzed. Daily fecal cllectins were bagged separately and frzen immediately in plastic bags. After the 5-day cllectin perid, the samples were pled per pig, ven-dried fr 48 hr. at 1 C and allwed t air-stabilize fr 24 hr. prir t analyzing. Bld samples were taken befre and after each perid t mnitr bld changes. Apprximately 15 ml f bld were cllected frm the brachial vein regin by use f heparinized Bectn-Dickinsn (B-D) vacutainer bleeding tubes. At apprximately 91 kg, all pigs in experi-

5 ment 3 were prbed fr backfat and all measurements were adjusted t a cnstant bdy weight f 9.9 kilgrams. All barrws were slaughtered at the Gerge A. Hrmel packing plant in Fremnt, Nebraska. Carcass weight, length, backfat and ham and lin weights were btained. The right-hand leg was als cllected and breaking strength (BKS) f the third and furth metatarsals was used as a criterin fr evaluating the effect f amin acids, NPN and phsphrus surce n bne frmatin. The metatarsal bnes were brken accrding t prcedure utlined by Libal et al. (1969). In these experiments nitrgen determinatins were made by Kjeldahl methds utlined in A.O.A.C. (196). All calcium determinatins were made by atmic absrptin accrding t Perkins (1968). Phsphrus was determined accrding t Summers (1944). In experiments 1 and 2, bld samples were analyzed as fllws: packed cell vlume (PCV) was determined by micrcentrifuge technique described by Merck (1966); bld serum prtein (BSP) was determined by the biuret technique described by Cnway (1957); bld serum urea nitrgen (BSUN) was determined by the methd described by Hffman (1954); bld serum amin acid nitrgen (BSAA) was analyzed by the prcedure set frth by Frame (1943) and bld serum albumin (BSA) was determined by the flurmetric prcedure as described by Turner (1968). The data were statistically analyzed by analyses f variance methds as utlined by Steel and Trrie (196). Carcass data b- USE OF NON-PROTEIN BY G-F SWINE 517 tained in experiment 3 were analyzed by the least squares methd described in Snedecr and Cchran (1967). Results Experiment 1. A summary f the effects f NPN, lysine and methinine level n nitrgen, phsphrus and calcium retentin fr experiment 1 are shwn in table 3. The verall treatment effect fr percent nitrgen and phsprus retained was significant (P<.1). Pigs fed diets cntaining NPN retained significantly (P<.1) mre phsphrus than pigs fed the cntrl diet, but nitrgen and calcium retentin was nt affected' significantly. The pigs fed diets cntaining the high level f lysine (Diets 1 and 3) retained significantly (P<.1) mre nitrgen than pigs fed diets with the lw level f lysine. Calcium and phsphrus retentin was nt affected by lysine level. Pigs fed diets cntaining the high level f methinine retained significantly (P<.5) mre calcium than pigs fed the lw methinine diets. Nitrgen and phsphrus retentin was nt influenced by the methinine level. The lysine x methinine interactin fr nitrgen and phsphrus retentin was significant (P<.1). Maximum nitrgen retentin was fund in pigs fed high lysine, lw methinine diets, whereas maximum phsphrus retentin ccurred in pigs fed high lysine, high methinine diets. The results" f the bld data frm experiment 1 are shwn in table 4. Packed cell vlume (PCV), bld serum prtein (BSP), and bld serum albumin (BSA) were nt TABLE 3. EFFECT OF NPN AND LEVEL OF LYSINE AND METHIONINE ON NITROGEN, PHOSPHORUS AND CALCIUM RETENTION (Experiment 1) 9 Treatments a NPN b N NPN Criteria Cmparisns Mean value Level f Sig NPN vs. Cntrl 42.8 vs % N Ret 45, Lw vs. High Lys Lw vs. High Met 38.3 vs vs Lys x Met e 4,2 vs NPN" vs. Cntrl 32.4 vs % P Ret Lw vs. High Lys Lw vs. High Met 3.2 vs vs Lys x Met e 38.7 vs NPN vs. Cntrl 61.9 vs. 6.6 % CaRet Lw vs. High Lys Lw vs. High Met 66.4 vs vs Lys x Met e 64.6 vs. $8.8 9 Trt 1---% Lys,.6% Methinine. " 2--.6% Lys,.6% Methinine. " 3---% Lys,.45% Methinine. " % Lys,.45% Methinine. " 5--14% crn-sybean meal cntrl b NPN--prvided 3.13% prtein-equivalent. e High lys-high met, lw lys-lw met vs. lw lys-high met, high lys-iw met.

6 518 PLATTER ET AL. TABLE 4. EFFECT OF NPN AND LEVEL OF LYSINE AND METHIONINE ON PACKED CELL VOLUME, BLOOD SERUM PROTEIN, BLOOD SERUM AMINO ACID NITROGEN AND BLOOD SERUM ALBUMIN (Experiment 1) Treatments* NPN b N NFN Level Criteria Cmparisns Mean value f Sig NPN vs. Cntrl 4.6 vs. 4.8 ' Lw vs. High Lys 4,2 vs. 41. PCV, %a Lw vs. High Met Lysx Met c 4.1 vs vs. 3.9 NPN vs. Cntrl 6. vs. 6.2 BSP, %d Lw vs. High Lys 6.vs. 6. (N x 6.25) Lw vs. High Met 6,vs. 6.1 Lys x Mete 6.1vs. 6. BSUNfl NPN vs. Cntrl Lw vs. High Lys 14.8 vs vs O.1 mg]1 ml Lw vs. High Met Lys x Met c 15.1 vs vs BSAA. d NPN vs. Cntrl Lw vs. High Lys 1.2 vs vs. 9.9 rag/1 ml Lwvs. HighMet Lysx Met c 1.4 vs vs. 1.2 BSA. d NPN vs. Cntrl 2.2 vs. 2. Lw vs. High Lys 2.2 vs. 2.2 g/1 ml Lw vs. High Met 2.3vs. 2.2 Lys x Met e 2.2vs , b, e See table 3 fr descriptin. d PVC=Packed cell vlume; BSP:Bld serum prtein; BSUN:BId serum urea nitrgen; BSAA=Bld serum amin acid nitrgen and BSA=BId serum albumin. affected by any f the dietary treatments. Bld serum urea nitrgen (BSUN) was significantly (P<.1) reduced in pigs fed the high level lysine diets as cmpared t pigs fed the lw level lysine diets. Bld serum amin acid nitrgen (BSAA) was significantly (P<.5) higher in pigs fed the cntrl diets as cmpared t pigs fed the diets cntaining NPN. Experiment 2. The results f NPN, tryptphan, and threnine level n nitrgen, phsphrus and calcium retentin in experiment 2 is shwn in table 5. There was n verall significant treatment effect n nitrgen, phsphrus r calcium retentin. Pigs fed the cntrl diets (7 and 12) retained significantly (P<.5) mre phsphrus and calcium than pigs fed diets cntaining NPN. Nitrgen re- TABLE 5. EFFECT OF NPN AND LEVEL OF TRYPTOPHAN AND THREONINE ON NITROGEN, PHOSPHORUS AND CALCIUM RETENTION (Experiment 2) Treatments a N NPN NPN b N NPN Levi Criteria Cmparisns Mean value f Sig % N Ret % PRet % CaRet Trt 7--14% Crn-sybean meal cntrl (Ps.). Trt % Try;.42% Thr. Trt % Try;.42% Thr, Trt % Try;.56% Thr Trt % Try;.56% Thr, % Try;.56% Thr cntrl (Neg). b NPN---prvided 3.13%prtein equivalent. 9 High Try-High Thr, Lw Try-Lw Thr vs. High Try-Lw Thr, Lw Try-High Thr. NPN vs. Cntrl 43,6 vs. 46. Lw vs. High Try Lw vs. High Thr 44,4 vs , vs Thr x Trlr e 44,8 vs Ps vs. Neg 47,1 vs NPN vs. Cntrl Lw vs. High Try 3.9 vs ,3 vs Lw vs. High Thr 24.9 vs Thr x Tryr 28.9 vs N~ Ps vs. Neg 38.6 vs NPN vs. Cntrl Lw vs. High Try 38.4 vs vs Lw vs. High Thr Thr x Try c 33.1 vs ,6 vs Ps vs. Neg 51.8 vs. 45.7

7 tentin was nt significantly affected by any f the dietary treatments. Pigs fed diets cntaining the high level f threnine retained significantly (P<.5) mre phsphrus than pigs fed the lw level f threnine. Nitrgen and calcium retentin were unaffected by the level f threnine. Neither the tryptphan level, nr the trytphan x threnine interactin had any significant affect n nitrgen, phsphrus r calcium retentin. Bld cmpnents were mnitred as in experiment 1. The results f the bld cmpnents fr experiment 2 are shwn in table 6. PCV, BSP and BSA were nt affected by any f the dietary treatments. As might be expected, BSUN was significantly (P<.5) higher in pigs fed diets cntaining NPN as cmpared t pigs fed the cntrl diets. Pigs fed diets cntaining the high level f threnine had significantly (P<.5) less BSUN than pigs fed the lw threnine diets. BSUN was significantly (P<.5) lwer in pigs fed the negative cntrl diet as cmpared t pigs fed the psitive cntrl. Similarly significantly (P<.1) mre bld serum amin acid nitrgen (BSAA) ccurred in pigs fed the negative cntrl diet. Experiment 3. The results frm experiment 3 are shwn in table 7. Pigs fed the 15% pr- USE OF NON-PROTEIN BY G-F SWINE 519 tein diets gained significantly faster (P<.5) and with better feed cnservatin (P<.1) than pigs fed the 12% prtein diets with supplemental amin acids. The gain/feed rati was significantly lwered (P<.5) in pigs fed the 12% prtein diet with amin acids and NPN as cmpared t thse fed the same diet withut NPN. Feed cnsumptin and backfat thickness were nt significantly affected by any f the dietary treatments. The carcass data btained frm the barrws in experiment 3 are als shwn in table 7. The carcass backfat, percent ham and lin, and bne breaking strength were nt affected by any f the dietary treatments. Discussin Experiment 1. Pigs fed a 1.9% prtein crn-sybean meal diet, cnsidered adequate in lysine, methinine, tryptphan and threnine, plus sufficient NPN t bring the ttal crude prtein t 14%, retained slightly mre nitrgen than pigs fed a 14% prtein crn-sybean meal diet. Pigs fed diets cntaining the high level f lysine retained a greater percentage f ingested nitrgen than pigs fed the lw level lysine diets. N differences were nted in nitrgen retentin amng pigs fed the high r lw TABLE 6. EFFECT OF NPN AND LEVEL OF TRYPTOPHAN AND THREONINE ON PACKED CELL VOLUME, BLOOD SERUM PROTEIN, BLOOD SERUM UREA NITROGEN, BLOOD SERUM AMINO ACID NITROGEN AND BLOOD SERUM ALBUMIN (Experiment 2) Treatmentsa N NPN NPN b N NPN Level Criteria Cmparisns Mean value f Sig PCV, a % BSPA % (N'x 6.25) BSUN, a mg/1 ml ]3SAA, d mg/1 ml BSA, a gm/1 ml a, b, e See table 5, ftntes a, b and e fr descriptin. a See table 4, ftnte d fr descriptin. NPN vs. Cntrl Lw vs. High Try 35. vs vs Lw vs. High Thr 37.1 vs Thr x Try ~ 36.5 vs Ps vs. Neg 34.8 vs NPN vs. Cntrl 5.9 vs. 5.9 Lw vs. High Try 5.9 vs. 5.9 Lw vs. High Thr 5.8vs. 5.9 Thr x Try 5.9vs. 5.8 Ps vs. Neg 5.9 vs. 5.9 NPN vs. Cntrl 17.6 vs Lw vs. High Try 17.7 vs Lw vs. High Thr 18.9 vs Thr x Try 17.6 vs Ps vs. Neg 17.6 vs NPN vs. Cntrl 13.5 vs. 13. Lw vs. High Try 13.8 vs Lw vs. High Thr 13.5 vs Thr x Try 13.6 vs Ps vs. Neg 11.6 vs NPN vs. Cntrl 2.1 vs. 2. Lw vs. High Try 2.1 vs. 2. Lw vs. High Thr 2. vs. 2.1 Thr x Try 2. vs. 2.1 Psvs. Neg 2.3 vs. 2.

8 52 PLATTER ET AL. i~ 5~D ~2~ IF25 ~ O[2D 9 6c~~ ~S66~'!s OOOO ~ ~ ~ j ~ ~ 4 4 '[4 4 ~ ~ Q ~, ~, ~, ~, ~ q ~ q ~, ~ ~ O O O O O ~~ ~ ~ z z gl ;>. < < < < = + + N~g~g ~+.+. < <I < < " ++l= + + ~+.+ [~+.+. < < = + + ~+~ + + ~ = + + ~+.+. ~.M ~+~+ e,i 1~ ~+~+. < 4< ~ - ~+~+ ~.<.< 9 ~+~+ gg~gg ggggg ~+~+ ggggg < ~ z~ + + P-. e,~ O O e~ O c~ E "4 ~ m,m O + 6 e~ O,d- ~.~ +. e~ O ~ 6 e~ O.d"..,.M M v S..= v eq

9 level f methinine. These findings indicate that lysine was prbably the first limiting amin acid. Werman (197) reprted similar trends in nitrgen retentin when lysine and methinine were added t diets cntaining NPN. The greatest percentage f retained nitrgen ccurred with pigs fed a diet cntaining % lysine,.45~' methinine,.15% tryptphan and.42% threnine. This diet cntained the Natinal Research Cuncil's recmmended level fr each f the amin acids mentined fr pigs weighing 22. t 44. kilgrams. Meade (1956) fund that maximum nitrgen retentin ccurred in pigs fed their required level fr a particular amin acid. Diets cntaining higher than required levels f amin acid depressed nitrgen retentin. This may partially explain the lysine X methinine interactin bserved in experiment 1. Pigs fed diets cntaining NPN retained mre phsphrus than pigs fed a 14% crnsybean meal diet. This bservatin is in cntrast t that bserved by Wehrbein (1969) wh fund a depressin in phsphrus retentin when NPN was added t the diet and that a further depressin ccurred when lysine, methinine and tryptphan were added t the NPN diets. Werman (197) reprted a linear decrease in phsphrus retentin with increased levels f supplemental methinine. The lysine X methinine interactin bserved in experiment 1 fr phsphrus retentin is unexplained at this time. Calcium retentin was nt affected by the additin f NPN r by level f lysine. Pigs fed the diets with the high level f methinine retained mre calcium than pigs fed lw methinine diets. Wehrbein (1969) reprted that the additin f NPN and amin acids t swine diets decreased calcium retentin. Resuits frm this experiment are nt cnsistent with his findings. The reasn fr the variatin in calcium retentin is als unexplained. Bld analysis revealed n differences in PCV, BSP and BSA due t the additin f NPN r level f amin acids prvided. Werman (197) reprted lwered BSA and increased BSP when NPN was added t swine diets fr shrt perids f time. Wehrbein et al. (197) reprted that PCV and BSP were nt affected by the additin f NPN r amin acids, hwever, BSUN was decreased when NPN was added and the cncentratin was lwered further when amin acids were cmbined with 'the NPN. Results frm this experiment agree with the findings f Wehr- USE OF NON-PROTEIN BY G-F SWINE 521 bein. Pigs fed diets cntaining the high level f lysine had less BSUN than pigs fed the lw level lysine diets. Lysine culd have been the limiting factr in prtein synthesis, resulting in lwered utilizatin f NPN fr the synthesis f nn-essential amin acids. The lwered utilizatin f NPN culd result in higher cncentratins f BSUN. The lwered BSAA cncentratin f pigs fed the NPN diets as cmpared t pigs fed the 14% prtein crnsybean meal diet is uncertain but prbably caused by a lwer cncentratin f amin acids in the diet r a failure f the system t synthesize nn-essential amin acids frm NPN. Experiment 2. Pigs fed 1.9% prtein crnsybean meal diets cntaining adequate lysine, methinine, tryptphan and threnine plus enugh NPN t bring the ttal crude prtein level t 14%, retained apprximately the same amunt f nitrgen as pigs fed the 14% prtein crn-sybean meal diet. Prviding tryptphan and threnine alne r in cmbinatin, abve their required levels failed t increase the retentin f NPN by G-F swine. Hwever, maximum nitrgen retentin ccurred in pigs fed the diet cntaining % lysine,.6% methinine,.15% tryptphan and.42% threnine. This suggests that maximum utilizatin f NPN ccurs when the required levels f lysine, methinine, tryptphan and threnine are prvided. Pigs fed diets cntaining NPN retained less phsphrus and calcium than pigs fed the cntrl diets. This is in direct cntrast with experiment 1. Pigs fed the high level threnine diets retained mre phsphrus than pigs fed the lw level threnine diets. PCV, BSP and BSA were nt affected by NPN r level f amin acids. BSUN was lwer in pigs fed the cntrl diets as cmpared t thse fed diets cntaining NPN. Als, pigs fed the high level threnine diets prduced less BSUN than pigs fed the lw level f threnine, suggesting lwered utilizatin f NPN by pigs fed diets lw in threnine. Pigs fed the negative cntrl diet had higher cncentratins f BSUN cmpared t pigs fed the same diet with NPN. This suggests that the level f BSUN may nt be related directly t the utilizatin f NPN. Experiment 3. The benefits frm the additin f amin acids and NPN t G-F swine diets appear t be few. The greatest benefit frm amin acid supplementatin ccurred when pigs were fed the 12% prtein diets. The Natinal Research Cuncil recmmends

10 522 PLATTER ET AL. a 16% prtein diet fr the weight pig used in these studies. The stress placed n the pigs at the start f the experiment was partially vercme by the additin f amin acids t the diet. The additin f amin acids t the 15% prtein diet did nt prduce any significant effect n perfrmance. Meade et al. (1965) fund they culd add lysine and methinine t a sub-ptimal prtein diet and prduce perfrmance equal t a diet cntaining 2% mre prtein. Their finding agrees with the trend nticed in this experiment. The additin f NPN t either prtein level prduced n effect in gain, feed cnsumptin r backfat thickness. Hwever, gain per unit feed was reduced in pigs fed a 12% prtein diet with NPN plus amin acids as cmpared t the pigs fed the 12% prtein diet plus amin acids. Cmbs (1969), Wehrbein (1969) and Werman (197), all reprted decreased grwth with the additin f NPN t G-F swine diets. Werman (197) als nticed decreased feed cnsumptin with the additin f NPN. Cmbs (1969) indicated that 2% prtein-equivalent frm NPN is the maximum amunt a pig can utilize. Krnegay (1969) reprted the additin f urea t 11% and 14% prtein swine diets did nt affect gain r feed efficiency. Analysis f carcass data btained frm the barrws revealed n significant effect f prtein level, r the additin f NPN r amin acids n percent ham and lin, carcass length r carcass backfat. Jurgens et al. (1967) reprted that lysine supplementatin increased the percent ham and lin f pigs fed either 12% r 16% prtein diets. This was nt apparent in experiment 3. Breaking strength f the metatarsal bne was nt significantly affected by prtein level r by the additin f amin acids r NPN. The data suggested that mn-ammnium phsphate is a readily available phsphrus surce fr swine. Similarly, Wehrbein (1969) and Werman (197) have reprted that the bilgical availability f phsphrus frm diammnium phsphate fr G-F swine is excellent. Literature Cited Almquist, H. J Amin acid requirement fr chickens and turkeys (a review). Pul. Sci. 31:966. A.O.A.C Official Methds f Analysis (9th Ed.) Assciatin f Official Agricultural Chemistry, Washingtn, D.C. Cmbs, G. E Recent Flrida swine nutritin research. Feedstuffs, July 19. Vl. 41, N. 29, p. 28. Cnway, E. J Micrdiffusin Analysis and Vlumetric Errr (4th Ed.). Crsby Lckwd, Lndn. Frame, R. J Methd fr determining amin acid nitrgen. J. Bil. Chem. 149:255. Hay, V. W., G. C. Ashtn, C. H. Liu, V. C. Speer and D. V. Catrn Studies n the utilizatin f urea by grwing swine. J. Anita. Sci. 16:44. Hffman, W. S. Bichemistry f Clinical Medicine Yearbk Publishers, Chicag, Illinis. Jurgens, M. H., D. B. Hudman, C. H. Adams and E. R. Pe, Jr Influence f a dietary supplement f lysine fed at tw levels f prtein in grwth, feed efficiency and carcass characteristics f swine. J. Anim. Sci. 26:323. Krnegay, E. T Prtein levels, lysine and supplementatin and urea substitutin. J. Anita. Sci. 29:138. (Abstr.). Libal, G. W., E. R. Pe, Jr., R. P. Andrews and P. E. Vipperman, Jr Levels f calcium and phsphrus fr grwing-finishing swine. J. Anita. Sci. 28:3. Luce, W. G., E. R. Pe, Jr. and D. B. Hudman The availability f niacin in wheat fr swine. J. Nutr. 88:39. Meade, R. J The influence f tryptphan, methinine and lysine supplementatin f a crnsybean il meal diet n nitrgen balance f grwing swine. J. Anita. Sci. 15:288. Meade, R. J., J. T. Typp, M. E. Tumblesen, J. H. Gihl and Helmut vnder Mehden Effects f prtein surce and level, and lysine and methinine supplementatin n rate and efficiency [ gain f pigs weaned at an early age. J. Anim. Sci. 24:626. Merck Manual (llth Ed.) The Merck Manual f Diagnsis and Therapy, Merck Divisin f Research. Perkins, E. J Analytical Methds fr Atmic Absrptin Spectrphtmetric, Perkins-Elmer C. Snedecr, G. W. and W. G. Cchran Statistical Methds, (6th Ed.). The Iwa State University Press, Ames. Steel, R. G. D. and J. H. Trrie Principles and Prcedures fr Statistics. McGraw-Hill Bk C., New Yrk. Summer, J. B A methd fr the clrimetric determinatin f phsphrus. Science 1:413, Turner, G. K Manual f Flurmetric Clinical Prcedure. Wehrbein, G. F Diammnium citrate and diammnium phsphrus as a surce f dietary nitrgen fr grwing-finishing swine. M.S. Thesis, University f Nebraska, LincIn. Wehrbein, G. F., P. E. Vipperman, Jr., E. R. Pe, Jr. and P. J. Cunningham Diammnium citrate and diammnium phsphate as surces f dietary nitrgen fr grwing-finishing swine. J. Anita. Sci. 31:2. Werman, R. L Effect f NPN surce and amin acid supplementatin n NPN utilizatin by swine. M.S. Thesis, University f Nebraska, Lincln.