Veterinry World, EISSN: 2231-0916 Aville t www.veterinryworld.org/vol.7/april-2014/14.pdf RESEARCH ARTICLE Open Access The evlution of metolizle protein content of some indigenous feedstuffs used in ruminnt nutrition 1 2 3 2 Lltendu Keshry Ds, S. S. Kundu, Dinesh Kumr nd Chnder Dtt 1. Veterinry Dispensry, Klmpur, Klhndi, Odish, Indi; 2. Division of Diry Cttle Nutrition, Ntionl Diry Reserch Institute, Krnl, Hryn, Indi; 3. Division of Animl Nutrition, Indin Veterinry Reserch Institute, Iztngr, Uttr Prdesh, Indi. Corresponding uthor: Lltendu Keshry Ds, emil: drlltendu27@gmil.com Received: 01-02-2014, Revised: 20-03-2014, Accepted: 25-03-2014, Pulished online: 21-04-2014 doi: 10.14202/vetworld.2014.257-261 How to cite this rticle: Ds LK, Kundu SS, Kumr D nd Dtt C (2014) The evlution of metolizle protein content of some indigenous feedstuffs used in ruminnt nutrition, Veterinry World 7(4): 257-261. Astrct Aim: To determine the metolizle protein (MP) content of common indigenous feedstuffs used in ruminnt nutrition using in situ method. Mterils nd Methods: Nine ruminnt feeds such s mize grin (MG), groundnut cke (GNC), mustrd oilcke (MOC), cottonseed cke (CSC), deoiled rice rn (DORB), whet rn (WB), erseem fodder (BF), mize fodder (MF) nd sorghum fodder (SF) were included in this study. Ech test feed ws dried, ground nd chemiclly nlysed for proximte principles (DM, CP, EE, OM, Totl sh), fier frctions (NDF, ADF, cellulose, hemicellulose, lignin), NDICP nd ADICP. Two dult fistulted ulls were used for evluting the protein degrdtion chrcteristics of ech test feed using the nylon g method. Metolizle energy (ME) content of the test feeds were predicted from their chemicl composition dt using summtive pproch of NRC (2001) model. The equtions of AFRC (1992) were used to predict the rumen degrdle protein (RDP), digestile microil protein (DMP), digestile undegrded feed protein (DUP) nd MP content of test feeds. Results: The MP content of MG, GNC, MOC, CSC, DORB, WB, BF, MF nd SF ws found to e 95.26, 156.41, 135.21, 125.06, 101.68, 107.11, 136.81, 72.01 nd 76.65 g/kg DM, respectively. The corresponding ME (MJ/kg DM) content of the test feeds ws 13.66, 13.12, 13.65, 10.68, 9.08, 11.56, 9.64, 8.33 nd 8.03, respectively. Among the test feeds, GNC contined the highest nd MF contined the lowest MP per kg DM. Conclusion: It ws concluded tht the degrdility of crude protein (CP) of the test feeds cn e used in MP determintion nd diet formultion. Feed CP content is not ville s such t intestinl level in ruminnts s definite prt of it undergoes extensive microil degrdtion in rumen. The pttern nd extent of such degrdtion do influence the mount of protein presented to lower digestive trct (MP) for sorption nd utiliztion in ruminnts. It ws lso found tht the MP content of feed is not constnt s tht of its CP content s it entirely depends on the degrdtion chrcteristics in given niml. Keywords: in situ method, metolizle energy, metolizle protein, microil protein, ruminnt nutrition. Introduction estimtes of ville microil nd dietry escpe In ruminnts, rtion lncing sed on CP protein [1, 2] nd re potentilly more ccurte thn the content of feedstuffs hs een considered s osolete CP systems re. due to the ctivities of ruminl microorgnisms such s The CP degrdility cn e mesured y in vivo degrdtion of feed protein, synthesis of microil nd in vitro methods. In vitro methods re quicker for protein nd pssge of oth undegrded feed protein screening of lrge numer of feeds ut do not give nd microil protein to lower intestine. Therefore protein degrdility in solute terms. In situ method protein evlution system in ruminnts is now sed on of Agriculturl Reserch Council (ARC) using nylon RDP nd RUP. Mere clssifiction of feed protein into g is widely ccepted to mesure the degrdility, which is nlysed y computer model developed y RDP nd RUP lso could not solve the purpose of Orskov nd McDonld [3]. Severl ttempts were lncing ruminnt diets for dequte protein s it did mde to estimte the MP content of niml feeds y not provide ny informtion regrding the protein vrious methods. Islm et l. [4] evluted MP content ville to the nimls in the lower intestinl trct for of whole crop rice silge t different stges of hrvest, productive purposes. In such sitution, the concept of which is usully not common ruminnt feed under MP content of ruminnt feeds seems more logicl nd Indin conditions. Similrly MP content of Wolffi scientific s it represents the ctul quntity of true mel ws evluted y Pooponpn et l. [5] in roilers. protein or mino cids tht gets sored y the niml Rhrpour et l. [6] used the nylon g (in situ) [1]. MP systems define the niml's requirement using technique to determine the MP vlue of tomto pomce. However MP vlues of typicl ruminnts feeds re lcking. It is importnt to note tht, MP content of feeds is etter indictor of niml performnces, (prticulrly diry niml production) thn the corresponding CP Copyright: The uthors. This rticle is n open ccess rticle licensed under the terms of the Cretive Commons Attriution License (http://cretivecommons.org/licenses/y/2.0) which permits unrestricted use, distriution nd reproduction in ny medium, provided the work is properly cited. Veterinry World, EISSN: 2231-0916 257
Tle-1: The chemicl composition of feedstuffs (% DM) Aville t www.veterinryworld.org/vol.7/april-2014/14.pdf Feedstuffs DM CP EE TA NFC NDF ADF ADL NDICP ADICP MG 92.73 10.28 5.39 2.30 59.38 24.62 7.04 2.07 1.97 0.45 GNC 93.05 40.66 7.59 6.13 24.62 23.67 18.30 4.19 2.68 0.86 MOC 90.80 38.24 7.87 4.78 30.11 22.16 18.46 3.37 3.16 2.02 CSC 92.13 26.00 8.00 4.58 12.76 50.91 37.34 8.50 2.26 1.23 DORB 91.10 13.47 1.66 9.47 33.72 47.93 17.64 6.39 6.30 2.53 WB 88.62 15.68 2.92 5.48 40.17 39.86 11.48 2.84 4.11 0.68 BF 14.70 18.18 2.91 9.06 33.84 41.10 21.23 6.49 5.09 1.60 MF 14.94 9.77 1.55 9.25 17.22 65.36 35.36 4.58 3.16 1.52 SF 18.01 9.89 1.61 10.05 12.96 68.99 40.19 4.61 3.51 1.47 DM: Dry Mtter, CP: Crude Protein, EE: Ether Extrct, TA: Totl Ash, NFC: Non Firous Crohydrte, NDF: Neutrl Detergent Fier, ADF: Acid Detergent Fier, ADL: Acid Detergent Lignin, NDICP: Neutrl Detergent Insolule Crude Protein, ADICP: Acid Detergent Insolule Crude Protein vlues s evidenced y severl reserch works. [7-10]. This study is, therefore, imed t evluting the ME nd MP content of test feeds so tht dtse regrding the MP vlues of common indigenous ruminnt feeds could e developed. Mterils nd Methods cme out of the gs. The gs were then dried in hot 0 ir oven t 80 C to constnt weight for 48 h to hve properly dried feed smples fter their exposure to ruminl degrdtion process. The residul dry mtter (DM) t different incution periods ws tken nd nlyzed for CP disppernce. Chemicl nlysis: DM, orgnic mtter (OM), CP, Ethicl pprovl: The experimentl design nd pln of the present study ws duly pproved y the Institution ether extrct (EE) nd totl sh in test feed smples Animl Ethics Committee of Ntionl Diry Reserch were determined s per methods prescried y AOAC Institute (NDRI), Krnl, Hryn. [11]. The frctions of cell wll constituents neutrl detergent fier (NDF), cid detergent fier (ADF) nd Smple collection: The smples of feeds nd fodders cid detergent lignin (ADL) were determined s per were collected from forge section of NDRI, Krnl methods of Vn Soest et l. [12]. Neutrl detergent nd from locl mrket of Krnl. Fodder smples were insolule crude protein (NDICP) nd cid detergent collected from t lest five different res within ech insolule crude protein (ADICP) were estimted s per field. They were thoroughly mixed nd composite Licitr et l. [13]. Totl digestile nutrients (TDN) nd smple of out 100 g ws used. Similrly the concen- ME content of feeds were predicted from their trte feeds were collected from t lest five different chemicl composition vlues s per NRC [14]. DM nd loclities. The smples were dried in hot ir oven t CP degrdtion kinetics were evluted y the model 0 60 C for dys till constnt weight ws ttined to of Orskov nd McDonld [3]. MP content of the test ensure proper nd complete drying of smples. The feeds were estimted using the equtions of AFRC dried smples were ground through 1mm sieve using [15]. The ruminl outflow rte of feed DM nd CP were electriclly operted willey mill. The ground smples ssumed to e 5%/h s per Rmirez et l. [16]. The were stored in ottles of 200 ml cpcity, leled fctor 'y' for clculting the microil yield ws tken properly nd stored for further nlysis. s 10 for growing niml s per AFRC. Selection nd feeding of fistulted nimls: Two dult Sttisticl nlysis: The results otined were fistulted ulls were selected from institute herd nlyzed using softwre pckge SPSS version 16.0 (NDRI). They were fed diet contining 40% concen- [17]. Mens were compred using one wy nlysis of trte, 40% green erseem nd 20% whet strw. The vrince (ANOVA) test t 5% level of significnce. feed ws offered in equl proportion for every 8 h to mintin reltively constnt rumen microil environment. Results nd Discussion Chemicl composition: The chemicl composition of test feeds is presented in Tle-1. As expected, the oil In situ rumen incution of feeds: Smples of totl dry ckes i.e. GNC, MOC nd CSC contined higher CP, mtter, pproximting 5 g were plced into nylon gs while mong green fodders, erseem hd highest CP (length 150x90 mm, 44 µm pore dimeter nd 350 ecuse of its leguminous nture. CSC, DORB nd WB mesh size) seprtely. Roughges were plced into contined higher NDF nd ADF mong concentrte nylon gs in 7 replictes nd concentrtes plced in 6 feeds, while MF nd SF recorded higher NDF nd ADF replictes. The gs were tied with nylon threds. Ech mong green fodders. The otined chemicl composmple ws tken in qudripultes nd experiment ws sitions of test feeds re different compred to reports of repeted twice. The gs were tied to n iron chin nd NRC [14] nd AFRC [15]. These differences my e then suspended in the rumen of fistulted nimls. relted to vrince in environmentl conditions, vriety Then the gs were tken out t 0, 2, 4, 8, 16, 24, 48 nd of feeds, mturity during time of cut, oil extrct ssy 72 h intervl for roughges nd 0, 2, 4, 8, 16, 24 nd 48 nd other processing fctors. h intervl for concentrtes. The gs were then wshed thoroughly under running tp wter until cler wter TDN, ME nd fermentle ME (FME) content: The Veterinry World, EISSN: 2231-0916 258
Tle-2: TDN, ME nd FME content of feedstuffs Aville t www.veterinryworld.org/vol.7/april-2014/14.pdf Feedstuffs td NFC td CP td FA td NDF TDN DE ME FME (% DM) (% DM) (% DM) (% DM) (% DM) (MJ/kg) (MJ/kg) (MJ/kg) MG 58.19 10.10 4.39 12.30 83.48 15.38 13.66 11.77 GNC 24.13 40.31 6.59 8.30 80.57 14.85 13.12 10.46 MOC 29.51 37.43 6.87 8.02 83.42 15.37 13.65 10.90 CSC 12.51 25.51 7.00 20.71 67.48 12.44 10.68 7.88 DORB 33.11 12.45 0.66 18.85 58.91 10.86 9.08 8.50 WB 39.36 15.41 1.92 20.13 72.23 13.31 11.56 10.54 BF 33.16 16.36 1.91 15.08 61.90 11.41 9.64 8.62 MF 16.87 8.11 0.55 35.64 54.85 10.11 8.33 7.79 SF 12.70 8.27 0.61 37.89 53.24 9.81 8.03 7.47 td: Truly Digestile, FA: Ftty Acid, TDN: Totl Digestile Nutrient, DE:Digestile Energy, ME: Metolizle Energy, FME: Fermentle Metolizle Energy. Tle-3: In situ DM disppernce (%) of feedstuffs Feeds Period of incution (h) 0 2 4 8 16 24 48 72 MG 35.20 42.24 46.58 54.82 68.43 75.49 83.78 - GNC 62.44 71.81 76.01 78.77 83.02 85.77 88.64 - MOC 59.51 74.60 82.16 83.47 85.74 90.26 92.19 - CSC 32.06 41.46 49.01 54.43 61.09 63.48 d 66.11 - DORB 30.98 51.08 53.82 58.76 61.93 68.47 c 74.20 - WB 38.78 53.13 55.83 62.12 67.46 69.43 c 73.33 - BF 33.76 44.62 46.70 51.30 55.21 70.54 77.06 78.60 MF 13.08 18.92 21.35 28.92 43.43 48.08 57.43 60.88 SF 17.27 25.87 28.58 33.17 38.04 46.50 48.71 59.15 Mens ering different superscripts in the sme column differs significntly (P < 0.05). 48 h DM degrdility of concentrte feeds nd 72 h DM degrdility of green fodders hve een compred. Tle-4: In situ CP disppernce (%) of feedstuffs Feeds Period of incution (h) 0 2 4 8 16 24 48 72 MG 42.14 48.53 62.99 71.25 78.74 82.20 88.46 - GNC 35.97 40.33 50.89 66.44 83.06 89.33 92.07 - MOC 28.23 57.56 71.66 76.36 80.51 82.14 84.02 - CSC 32.19 39.39 43.12 58.56 62.56 73.14 89.74 - DORB 17.19 21.25 28.63 33.78 39.72 55.08 62.93 - WB 38.46 51.45 54.54 61.10 67.56 77.70 85.56 - BF 7.09 9.83 17.64 26.73 42.62 62.38 69.24 73.88 MF 22.22 29.24 41.26 61.23 64.44 69.40 71.66 76.73 SF 11.74 21.59 36.85 53.81 57.61 63.53 66.44 68.70 Mens ering different superscripts in the sme column differs significntly (P < 0.05). 48 h CP degrdility of concentrte feeds nd 72 h CP degrdility of green fodders hve een compred. vlues for TDN, ME nd FME content of test feeds environmentl conditions nd soil sttus in which they long with their digestile nutrients re presented in were grown. Tle-2. MG, GNC nd MOC contined higher TDN In situ DM nd CP disppernce: The disppernces nd ME vlues mong concentrte feeds, while mong of DM nd CP t different time of incution re shown green fodders erseem hd higher TDN nd ME in Tle-3 nd 4. Among concentrte feeds, GNC hd content. Similr trend ws oserved in FME content of highest (62.44%) zero h DM degrdility followed y feedstuffs. Nutrient composition of feeds s enlisted in MOC (59.51%). Among forges, erseem fodder hd NRC [14] nd feed lirry of CNCPS [18] reported higher (33.76%) zero h DM degrdility. MOC similr TDN nd ME vlues. However, NRC [14] recorded highest (92.19%) 48 h DM degrdility, reported less TDN vlue for MOC thn the present while CSC recorded lowest (66.11%) mong concentrte findings. CNCPS [18] reported higher vlue of TDN feeds. Berseem green recorded highest (78.60%) 72 h for CSC. Both NRC [14] nd CNCPS [18] reported DM degrdility. The results for concentrte feeds re slightly higher TDN vlues for green fodders thn the in ccordnce to the findings of Singh nd Kundu [19]. present results. Such differences in feed chemicl Smpth et l. [20] reported similr vlues of mize composition gin cn e ttriuted to the vritions in fodder. Among concentrte feeds, mize grins hd Veterinry World, EISSN: 2231-0916 259
Tle-5: CP degrdtion kinetics of feedstuffs Aville t www.veterinryworld.org/vol.7/april-2014/14.pdf Feeds c RDP RUP RDP RUP ERDP (% CP) (% CP) (% DM) (% DM) (g/kg DM) MG 41.66 44.59 0.129 73.79 26.21 7.59 2.69 67.30 GNC 32.83 61.44 0.097 73.37 26.63 29.83 10.83 271.63 MOC 28.40 53.22 0.393 75.61 24.39 28.91 9.33 267.42 CSC 33.89 62.08 0.045 63.30 36.70 16.46 9.54 146.95 DORB 17.75 51.89 0.044 42.04 57.96 5.66 7.81 51.84 WB 42.50 44.30 0.064 67.37 32.63 10.56 5.12 92.31 BF 4.18 71.90 0.053 41.18 58.82 7.49 10.69 73.34 MF 20.23 53.04 0.136 59.01 40.99 5.77 4.00 53.70 SF 10.44 55.89 0.152 52.50 47.50 5.19 4.70 49.85 : quickly degrdle frction, : slowly degrdle frction, c: degrdtion rte of frction, RDP: Rumen degrdle protein, RUP: Rumen undegrdle protein, ERDP: Effective rumen degrdle protein Tle-6: Metolizle protein content of feedstuffs Feeds MCP (g/kg DM) DMP (g/kg DM) DUP (g/kg DM) MP(g/kg DM) MG 117.74 75.06 20.20 95.26 GNC 104.64 66.70 89.71 156.41 MOC 108.96 69.46 65.75 135.21 CSC 78.80 50.24 74.82 125.06 DORB 84.99 54.18 47.50 101.68 WB 105.38 67.18 39.93 107.11 BF 86.22 54.96 81.85 136.81 MF 77.88 49.65 22.36 72.01 SF 74.67 47.60 29.05 76.65 MCP: Microil crude protein, DMP: Digestile microil protein, DUP: Digestile undegrded feed protein, MP: Metolizle protein highest (42.14%) zero h CP degrdility followed y my e due to their lower DUP content. whet rn (38.46%). Among forges, mize fodder hd higher (22.22%) zero h CP degrdility. 48 h CP Conclusion degrdility ws highest (92.07%) in GNC nd lowest It is concluded tht feed protein frctions vry (62.93%) in DORB mong concentrte feeds. Among considerly from ech other with respect to their forges, oth erseem nd mize fodder recorded degrdtion kinetics in rumen; therefore only CP higher (73.88 nd 76.73%) 72 h CP degrdility. content of feed cn not represent its true feeding vlue in ruminnts. CP vlue of feed is lwys constnt s it CP degrdtion kinetics: CP degrdtion prmeters (, nd c) long with RDP, RUP nd effective RDP is chemicl composition vlue nd thus will e sme (ERDP) content of test feeds re presented in Tle-5. for ll clss of nimls whether ruminnts or non The RDP content ws highest (75.61%) in MOC nd ruminnts. But the degrdtion kinetics of feed CP lowest (42.04%) in DORB mong concentrte feeds. content will e different from niml to niml in cse Among forges, mize fodder hd highest (59.01%) of ruminnts s result the MP content of given feed RDP vlue, while erseem hd the lowest (41.18%) will e different in different nimls. However s MP vlue. CP degrdtion rte ws highest (0.393) for vlue represents the true protein mount ville to MOC nd lowest (0.044) for DORB mong ruminnts for ody utiliztion, it cn e used in diet concentrte feeds. Among forges, oth mize nd formultion for ruminnts nd thus is more relile in sorghum fodder hd higher (0.136 nd 0.152) CP predicting the feeding vlue. degrdtion rtes. Wdhw et l. [21] nd Singh nd Authors contriutions Kundu [19] reported similr CP degrdtion kinetics of concentrte feeds. GNC nd MOC recorded higher SSK nd CD designed the experiments. LKD nd DK ERDP content, while DORB contined lower ERDP. crried out the experimentl work. LKD wrote the mnuscript nd did the dt nlysis. All uthors red MP content: MP content of test feeds long with their nd pproved the finl mnuscript. DMP nd DUP content re presented in Tle-6. There were differences etween otined results for DUP nd Acknowledgements MP of test feeds compred to AFRC [15]. The differences The uthors re thnkful to the Director, NDRI, re possily due to vritions in microil yield, type, Krnl, Hryn for providing finncil support to vriety nd processing of feedstuffs, solule nd crrying out this study. The corresponding uthor is insolule protein content etc. GNC showed high MP indeted to NDRI nd ICAR for providing him compred to other feeds tht cn e resulted from high institutionl scholrship during his M.V.Sc progrmme DUP content resulting supply of high mino cids for t NDRI (2010-12). ruminnts. High MP content of erseem s compred Competing interests to other fodders cn e ttriuted to the sme fctor s tht of GNC. Lower MP vlues of MG, MF nd SF The uthors declre tht they hve no competing interests. Veterinry World, EISSN: 2231-0916 260
Aville t www.veterinryworld.org/vol.7/april-2014/14.pdf References Effect of metolizle protein supply nd mino cid supplementtion on nitrogen utiliztion, milk production, 1. Burroughs, W., Trenkle, A. nd Vetter, R.L. (1974) A system nd mmoni emission from mnure in dirycows. J. Diry of protein evlution for cttle nd sheep involving Sci., 95(9): 5253-5268. metolizle protein (mino cids) nd ure fermenttion 11. AOAC. (2005). Officil Methods of Anlysis, Assocition of potentil of feedstuffs. Vet. Med. Sm. Anim. Clin. 69: 713. th Officil Anlyticl Chemists. 18 ed. Virgini, USA. 2. ARC. (1984) The nutrient requirements of ruminnt 12. Vn Soest, P.J., Roertson, J.B. nd Lewis, B.A. (1991) livestock. Suppl. 1. Commonwelth Agriculturl Bureux, Symposium: crohydrte methodology, metolism nd Slough, UK. nutritionl implictions. In diry cttle. Methods for dietry 3. Orskov, E. R. nd McDonld, I. (1979) The estimtion of fier, neutrl detergent fier nd non strch polyscchrides protein degrdility in the rumen from incution in reltion to niml nutrition. J. Diry Sci., 74: 3583-3597. mesurements weighed ccording to rte of pssge. J. Agr. 13. Licitr. G., Hrnndez, T.M. nd Vn Soest, P.J. (1996). Sci. (Cmridge). 92: 499-505. Stndrdiztions of procedures for nitrogen frctiontion of 4. Islm, M.R., Ishid, M., Ando, S., Nishid, T. nd Yoshid, ruminnt feeds. Anim. Feed Sci. Tech., 57: 347-358. N. (2011) Whole crop rice silge: Prediction of yield nd 14. NRC. (2001) Nutrient Requirements of Diry Cttle. 7th content of metolizle energy, metolizle protein nd Revised Edition. Ntionl Acdemy Press, Wshington, DC. other nutrients for diry cows from crop mturity nd 15. AFRC. (1992) Nutritive requirements of ruminnt niml: otnicl frctions t hrvest. Anim. Feed Sci. Tech., 163: Protein Nutrition Astrcts nd Reviews. CAB Int. Wlling 222-230. Ford. Oxon, 62: 787-835. 5. Pooponpn, P., Chinrsri, O., Senthweesuk, S. nd 16. Rmirez, R.G., Gonzlez-Rodriguez, H., Morles- Chntirtikul, A. (2011) Evlution of metolizle protein Rodriguez, R., Cerrillo-Soto, A., Jurez-Reyes, A., Grcind metolizle energy vlues of Wolffi mel [Wolffi Dessommes, G.J. nd Guerrero-Cervntes, M. (2009) gloos (L). Wimm.] in roilers. Int J Poult Sci, 10(5): 401- Chemicl composition nd dry mtter digestion of some 403. ntive nd cultivted grsses in Mexico. Czech J. Anim. Sci., 6. Rhrpour, A., Plngi, V., Eivgi, P. nd Jlili, M. (2012) 54: 150 162. Clcultion of metolizle protein nd energy of tomto 17. Sttisticl pckges for socil sciences 16.0. (2010). SPSS th pomce y nylon gs nd gs production dts. Eur. J. Inc., 233, South wlker Drive, 11 floor, Chicgo, USA. II. Exp. Bio., 2(3): 822-825. 60606. 7. Weiss, W.P., St-Pierre, N.R. nd Willett, L.B. (2009) Vrying 18. CNCP. (2003) The net crohydrte nd protein system for type of forge, concentrtion of metolizle protein, nd evluting herd nutrition nd nutrient excretion. CNCPS source of crohydrte ffects nutrient digestiility nd Version 5.0., Cornell University. 130 Morrison Hll, Ethc, production y diry cows. J. Diry Sci., 92(11): 5595-5606. New York. 8. Rius, A.G., Mcgillird, M.L., Umerger, C.A. nd Hnign, 19. Singh, R. nd Kundu, S.S. (2008) Estimtes of energy nd M.D. (2010) Interctions of energy nd predicted protein frctions of concentrte ingredients used in Indi. metolizle protein in determining nitrogen efficiency in Indin J. Anim. Nutr., 25 (4): 302-312. the lctting diry cows. J. Diry Sci., 93(5): 2034-2043. 20. Smpth, K.T., Ro, A.S. nd Smpth, S.R. (1989) 9. Aoozr, M. (2012) Impcts of dietry metolizle Ruminl protein degrdility of certin feedstuffs y nylon protein on performnce nd ruminl prmeters of Holstein g technique. Indin J. Anim. Sci., 59 (10): 1304-1307. cows t erly lcttion. Res. Opin. Anim. Vet. Sci., 2(2): 102-21. Wdhw, M., Mkkr, G.S. nd Ichhponni, J.S. (1993) In 108. scco degrdility of protein supplements used in ruminnt 10. Lee, C., Hristov, A. N., Heyler, K. S. nd Cssidy, T. W. (2012) rtion. Indin J. Anim. Sci., 63 (6): 684-686. ******** Veterinry World, EISSN: 2231-0916 261