RESEARCH OPINIONS IN ANIMAL & VETERINARY SCIENCES

www.rovs.com EISSN: 2223-0343 RESEARCH OPINIONS IN ANIMAL & VETERINARY SCIENCES Protected methionine nd dry ft for improving performnce of growing Awssi lmbs Mutssim Mohmed Abdelrhmn King Sud University, College of Food nd Agriculture Sciences, Deprtment of Animl Production, Riydh 11451- Sudi Arbi Abstrct This study ws crried out to evlute the effect of high dietry energy s dry ft nd protected methionine on growth efficcy, feed intke nd efficiency nd crcss prmeters of Awssi lmbs during finishing stge. Twenty four Awssi lmbs (3-4 months old) were distributed eqully into four tretments groups s follow: Control (NRC requirements); T1 (High energy 3.0 Mcl ME/kg); T2 (high energy 3.0 Mcl ME/kg nd 2.5 g protected methionine/hed/dy) nd T3 (high energy 3.0 Mcl ME/kg nd 5 g protected methionine/hed/dy methionine). Feeding Awssi lmbs with high energy lone or with protected methionine cused significnt (P<0.05) increse in weight gin during second, third nd overll gin when compred with the control group. Tretments did not cuse ny significnt effect on feed intke, feed conversion, verge nd reltive growth rte, dressing nd tissues percentges except for spleen, hert nd lungs. Moreover, bck ft thickness, omentl ft percentge nd blood serum cholesterol significntly decresed (P<0.05) with feeding protected methionine (T2 nd T3) when compred with lmbs fed dry ft (T1). In conclusion, incresing dietry energy by using dry ft with or without protected methionine of Awssi lmbs during the finishing period improved the totl weight gin. This indicted tht the requirements of energy by growing Awssi lmbs might be higher thn reported by NRC. Keywords: Energy; protected methionine; Awssi; crcss; NRC To cite this rticle: Abdelrhmn MM, 2012. Protected methionine nd dry ft for improving performnce of growing Awssi lmbs. Res. Opin. Anim. Vet. Sci., 2(4), 249-255. Introduction Awssi sheep is the most numerous nd indigenous breed in the Middle Est. This is multipurpose breed used for met, milk nd wool production hving high dptbility to hrsh environmentl nd feeding conditions. The full potentil of Awssi sheep is not utilized becuse of undernutrtion nd lck of scientific reserch regrding the nutrients requirements under their rising conditions. Fttening of Awssi lmb hs gret potentil to mke significnt contribution to red met production nd reducing the imported mounts of red mets in Middle Est. The dily nutrients requirements of ruminnt niml depend on the breeds (genetic potentil), ge nd physiologicl sttus. The most importnt requirements re energy nd protein. The blnce between protein, mino cids nd energy for mintennce nd production is very importnt for the livestock. The requirements of ruminnt nimls of energy cn esily be covered by feeding cerels such s corn, brley, whet etc. Sometimes dry ft nd oil cn be used for frm niml rtion s substitution of cerels s n energy source. Animl ft is mtter of concern for humn being due to some helth issues. The sop stock of the vegetble oil ft is new products introduced to the mrket for frm nimls. Sop stock is by- product of the vegetble oil refining procedure nd rich in polyunsturted ftty cids (PUFA) nd clcium in some cses. Sop stock cn esily be used to substitute the oil in frm nimls rtions s source of energy becuse oil is expensive nd compete with humn feeding. Corresponding uthor: Mutssim Mohmed Abdelrhmn, King Sud University, College of food nd Agriculture Sciences, Deprtment of Animl Production, P.O.Box 2460, Riydh 11451- Sudi Arbi 249

On the other hnd, covering their needs from protein is very complicted becuse of the ruminl degrdtion of protein nd the high demnd for specific mino cids. The first gol of ruminnt protein nutrition is to optimize the efficiency of the niml s use of dietry protein for growth nd production. This implies tht protein supplementtion for ruminnts should be done on the bsis of mino cids in ddition to crude protein. By providing individul mino cids to the smll intestine, the inclusion of undegrdble protein cn be reduced. This permits more spce for other ingredients needed to support ruminl microbil protein synthesis (Clrk et l., 1992). Methionine is considered to be one of the most limiting mino cid for protein synthesis of growing ruminnts nd consequently increse growth rte of beef cttle (Merchen nd Titgemeyer, 1992) nd lmbs (Lynch et l., 1991). This suggests tht dditionl methionine my be required postruminlly to optimized growth, prticulrly for growing ruminnt nimls (Loerch nd Oke, 1989). Smrtmine TM M (Adisseo, Inc., Antony Frnce) is new product of lipid/ph sensitive polymer protected methionine, recently introduced to the Jordnin mrket s postruminl methionine. Ntionl Reserch Council (NRC, 1985) identified only the quntities of crude protein for growing lmbs for interntionl breeds t different ges, but not the quntities of the essentil nd most limiting mino cids such s methionine nd lysine. Moreover, the expression of mino cids requirements s rtio to energy did not exist which my be prticulrly useful for ruminnts, becuse microbil protein production is relted to the intke of fermentble energy (Roher et l., 1986; Sniffen nd Robinson, 1987; Clrk et l., 1992). Unfortuntely, no dt is vilble regrding the mino cids nd energy requirements for our locl Awssi breed nd most of vilble scientific dt is bsed on studies of temperte breeds. This study ws crried out to evlute the effect of high dietry energy s dry ft nd protected methionine on the growth, feed intke nd efficiency, verge nd reltive growth rte of growing Awssi lmbs. Moreover, crcss prmeters nd blood serum metbolites were lso evluted. Mterils nd Methods Feeding tril nd smpling Twenty four growing Awssi lmbs, 3-4 months old, were used in this experiment. Animls were individully housed t University Reserch Sttion nd were vccinted ginst enterotoxemi. During the experiment, lmbs were divided eqully into four groups nd ech ws housed in n individul pen (0.8x 1.4 m) with seprte feeder nd drinker. The dietry tretments for ech group were s follow: Control (NRC requirements; 2.8 Mcl ME/kg); T1 (High energy 3 Mcl ME / kg); T2 (high energy 3 Mcl ME /kg nd 2.5 g methionine/ hed/dy) nd T3 (high energy 3 Mcl ME/kg nd 5 g/hed/dy methionine). The concentrte diets were formulted ccording to NRC (1985) nd the energy levels were incresed by using dry ft (Mgnpc). Mgnpc is usully use for incresing the energy contents of concentrte diets. The nutritive vlue of Mgnpc (Norel-Misr, Egypt): crude ft%= 84; Moisture%= 3.5; Ash%= 16; cid insoluble sh%= 0.5 nd C%=9. Moreover, lmbs were fed the ssigned diets which for 12 weeks (Tble 1). All lmbs were bled t the beginning of the experiment nd every 4 weeks vi the jugulr vein. Blood smples were centrifuged t 3000 rpm for 15 minutes nd serum ws seprted. Serum smples were stored t 20ºC until nlysis. Feed intke ws recorded dily nd body weight every 4 weeks. At the end of experiment, ll lmbs were slughtered nd tissues were collected (liver, hert, kidney, spleen, testicles, lungs nd met) nd omentl fts were weighed nd smples were tken for further nlysis. After slughtering, weights of hot crcss were tken for ll slughtered lmbs nd recorded to determine dressing percentge. Moreover, cross section of the crcss ribs (12 nd 13) were removed to mesure the bck ft thickness (cm). Cre nd mngement of lmbs during the tril ws followed ccording to the regultion of the university, Den of Acdemic Reserch. Blood serum smples were prepred nd nlyzed for glucose, totl protein nd cholesterol using vilble commercil kits (BIOLABO SA, Mizy, Frnce) by spectrophotometer. Tble 1: Ingredients composition of diets (Dry mtter bsis) Ingredient (%) Diet 1 1 Diet 2 2 Brley 64.38 64.10 Soyben mel 4.26 5.50 Whet brn 14.19 10.10 Alflf hy 15.37 15.32 Dry ft (Mgnpc) 0.00 3.18 CCO 3 1.20 1.20 Slt 0.50 0.50 Minerl & vitmins premix 3 0.10 0.10 Chemicl composition : Crude protein (g/ Kg DM) 159.54 158.33 Metbolizble energy (Mcl/kg DM) 2.80 3.00 Clcium (g/ kg DM) 8.11 9.72 Phosphorus (g/ kg DM) 5.3 4.8 1 Formulted ccording to NRC (1985) to cover nutrients requirements; 2 Incresing metbolizble energy by dding dry ft (Mgnpc); 3 Minivit-Forte, VAPCo, ech 1 kg contins: Cu sulphte= 9.417 mg, Fe sulphte= 85 mg, Mg sulphste= 535 mg, Mn sulphte= 41.25 mg, Zn sulphte= 77.2 mg, Di- C phosphte = 145 mg. Vit A= 6250 I.U, vit D3= 1510 I,U, vit E= 4.375 I.U., Coblt chloride= 1.933 mg, K iodide= 6.367 mg nd N selenite= 0.274 mg. 250

Sttisticl Anlysis Dt were nlyzed by using SPSS TM version (16.0) s complete rndomized design (CRD). The protected lest significnt differences test (LSD) ws used to determine differences mong tretments mens for significnt dietry effect (Steel nd Torrie, 1980). The P<0.05 ws considered sttisticlly significnt unless otherwise noted. Results nd Discussion Live weight gin, feed intke nd efficiency The dt on Tble 2 shows the effect of feeding high energy nd protected methionine (Smrtmine) on monthly nd overll weight gin of Awssi lmbs fed finishing diets. There were no significnt differences (P>0.05) in weight gin in the first month s result of tretments, even though the control showed higher vlues compred with lmbs from the other groups. A significnt increse (P<0.05) of weight gin were detected on the second nd third months. For the second month, tretments cused significnt higher weight gin for lmbs in T1 nd T3 compred with the lmbs in the control nd T2. In third month, lmbs in T3 showed significntly higher (P<0.05) weight gin compred with other treted groups. For the totl weight gin during the whole feeding period, lmbs fed high energy (T1) nd high energy with the two levels of the protected methionine (T2 nd T3) gve significntly higher weight gin compre with the control group Tble 2). Jindl et l. (1980) reported tht high dietry energy cuses deposition of ft in tissues nd increse weight gin. Moreover, Khinizy et l. (2004) found tht feeding high levels of energy to wened lmbs incresed the verge dily gin nd improved feed efficiency, but no effect of high protein intke on their generl performnce ws observed. Kioumrsi et l. (2008) found tht feeding Tleshi lmbs high energy improved verge dily gin by producing more metbolizble energy nd fermentble products for microorgnisms to increse synthesis of microbil protein s supply of mino cids to the smll intestinl trct nd consequently improve growth performnce (Erly et l., 2001). Hence, the energy intke of lmbs from T1 cn be considered s n cceptble limit to cover the energy requirements without negtive effect on the performnce in term of weight gin nd feed intke. On the other hnd, lmbs from T2 nd T3 groups which were fed high energy nd protected methionine showed similr totl weigh gin when compred with lmbs in T1, but significntly higher when compred to the control. This give n evidence tht feeding protected methionine to growing lmbs do not ffect the growth performnce since dietry protein is high (16% CP). This result greed with the recommendtion of Titi et l. (2000) nd Hddd et l. (2001) who identified the optimum level of dietry crude protein for growing Awssi lmbs in Jordn. Furthermore, Wiese et l. (2003) reported tht incresing the dietry level of methionine s Smrtmine to merino lmbs did not led to n increse in growth rte, dily feed intke, feed conversion or finl body weight. In ddition, Wright (1971) found tht feeding methionine with niml fed low protein (8% CP) incresed rte of gin nd feed efficiency, but hd no effect on those fed 12% crude protein diet. This men feeding protected methionine to sheep my cuse very little effect on some trits nd their effect reduced significntly with high dietry percentge of crude protein which might supply lmbs with their needs of essentil mino cids, such s methionine. Tretment didn't cuse ny significnt effect on totl nd monthly feed intke nd totl feed conversion in term of concentrte nd lflf hy (Tble 3 nd 4.). This finding is in disgreement with the finding of Lu nd Potchoib (1990) who reported tht dry mtter intke ws influenced by dietry energy in curviliner fshion which is considered the dominnt fctor. But our results re consistent with the findings of Wiese et l. (2003), Bldwin et l. (1993), Wright nd Loerch (1987) nd Deswysen et l. (1991) in which protected methionine filed to increse feed intke, verge dily gin nd nitrogen retention in lmbs. Furthermore, tretment did not cuse ny significnt effect on verge nd reltive growth (AGR nd RGR) except for the first nd second months for the AGR (Tble 5). Crcss yield nd tissues weights The dressing percentges nd different tissues percentges (clculted of hot crcss weight) of lmbs in different experimentl groups re given in Tble 6. Tretment did not cuse ny significnt effect on the dressing percentges between treted groups (T1, T2 nd T3) compred with the control. Wiese et l. (2003) reported tht feeding lmbs protected methionine s Smrtmine did not improve hot crcss weight, dressing percentge which greed with our findings. Furthermore, no significnt differences between ll groups in term of tissues percentges except for the spleen (P<0.001), hert (P<0.05) nd lungs (P<0.05) with higher vlues for lmbs fed high energy nd protected methionine (T3) were observed. On the other hnd, omentl ft percentges were significntly higher for lmbs from T1 group compred with the lmbs from the control, T2 nd T3, but the differences between the previous three groups were not significnt (Tble 6.). Ebrhimi et l. (2007) reported trend of incresing ft deposition in the crcss nd noncrcss prts of Mehrbn lmbs with feeding high dietry energy density which greed with our findings. Moreover, the sme trend ws found for the bck ft thickness (BFT), 251

Tble 2: The effect of tretment on monthly nd totl weight gin (Kg) of growing Awssi lmbs Tretments M1 WG 4 M2 WG M3 WG Totl WG Control 9.10 5.08 4.46 18.25 T1 1 8.82 7.16 b 4.07 19.95 b T2 2 7.97 5.59 3.85 b 18.72 b T3 3 7.63 6.43 b 5.30 c 19.15 b SEM 0.481 0.64 0.39 1.21 NS * * * 2.5 g/d/hed smrtmine; 3 High energy+5.0g/d/hed; smrtmine; 4 MWG= Monthly weight gin; SEM= stndrd error of mens; NS = not significnt; * P <0.05. Tble 3: The effect of tretments on the monthly, totl feed intke (kg) nd feed conversion of growing Awssi lmbs Tretments M1 FI 4 M2 FI M3 FI Totl FI TFC Control 47.19 50.63 38.24 139.6 7.73 T1 1 48.05 50.1 44.92 140.17 6.45 T2 2 50.86 45.23 41.05 137.15 8.51 T3 3 46.58 47.37 41.06 136.76 7.53 SEM 1.01 1.37 1.60 1.81 0.46 NS NS NS NS NS Control: NRC requirements; 1 High energy diet; 2 high energy + 2.5 g/d/hed smrtmine; 3 High energy+5.0g/d/hed smrtmine; 4 M FI= Monthly feed intke; TFC= Totl feed conversion; SEM= stndrd error of mens; NS = not significnt. Tble 4: Totl concentrte nd lflf hy consumption (kg) by growing Awssi lmbs Mesure. Control T1 1 T2 2 T3 3 SEM Sign. Concentrte 126.4 126.5 122.5 119.03 1.9 NS Alflf hy 16.34 16.58 14.65 15.97 0.39 NS 2.5g/d/hed smrtmine; 3 High energy+5.0g/d/hed smrtmine; SEM= stndrd error of mens; NS = not significnt. Tble 5: Averge (AGR) nd reltive growth rte (RGR) of Awssi lmbs during the experiment Mesurements Month 1 Month 2 Month 3 Overll AGR: Control 0.17 0.14 0.13 0.1 T1 1 0.19 0.13 0.14 0.13 T2 2 0.15 0.14 0.15 0.12 T3 3 0.14 0.12 0.12 0.12 SEM 0.01 0.01 0.02 0.01 NS NS NS NS RGR * Control 0.221 0.114 0.067 0.383 T1 1 0.239 0.130 0.075 0.588 T2 2 0.195 0.085 0.049 0.313 T3 3 0.200 0.132 0.085 0.496 SEM 0.0166 0.0119 0.009 0.044 NS NS NS NS 2.5g/d/hed smrtmine; 3 High energy+5.0g/d/hed smrtmine; SEM= stndrd error of mens; NS = not significnt;* RGR= Finl weight t the end of ech month initil weight t the beginning of the month/ initil weight t the beginning of the month. Tble 6: Crcss prmeters nd tissues percentges of slughtered Awssi lmbs Mesurements. Control T1 1 T2 2 T3 3 SEM Sign. Dressing (%) 51.67 52.10 52.6 52.82 0.50 NS Liver (%) 2.57 2.38 2.34 2.66 0.07 NS Kidney (%) 0.37 0.45 0.39 0.45 0.01 NS Spleen (%) 0.23 2.60 0.21 0.48 b 0.04 *** Hert (%) 0.92 0.94 0.89 1.11 b 0.04 * Lungs (%) 2.64 2.4 2.10 2.01 b 0.11 * Testicls (%) 0.87 1.15 0.99 1.07 0.09 NS Omentl ft (%) 2.15 3.52 b 2.77 2.64 0.27 * Bck ft thickness (cm) 0.41 0.59 b 0.42 0.49 0.03 *,b different superscripts in row differ significntly P<0.05 2.5g protected methionine/d/hed; 3 High energy+5.0g protected methionine/d/hed; SEM= stndrd error of mens; NS = not significnt; * P<0.05; *** P<0.001. Tble 7: Cholesterol levels (mg/dl) in serum of Awssi lmbs during fttening Tretment Cholesterol Cholesterol Cholesterol Cholesterol 1 2 3 4 Control 40.43 128.5 185.50 77.85 T1 1 b 26.20 150.06 188.26 b 98.83 T2 2 33.69 142.77 177.52 82.01 T3 3 b 25.87 133.74 152.21 34.34 SEM 2.10 16.96 11.69 5.51 P vlue 0.05 0.1 0.7 0.05,b different superscripts in column differ significntly P<0.05; * Cholesterol 1= for the initil blood smples; cholesterol 2= for blood fter first 4 week; cholesterol 3= blood smples fter 8 weeks; cholesterol 4= fter 12 weeks t slughtering; Control: NRC requirements; 1 High energy diet; 2 high energy+ 2.5g/d/hed smrtmine; 3 High energy+ 5.0g/d/hed smrtmine; SEM= stndrd error of mens. Tble 8: Glucose levels* (mg/dl) in blood serum of Awssi lmbs during fttening Tretment Glucose Glucose Glucose Glucose 1 2 3 4 Control 43.78 48.23 32.75 61.69 T1 1 46.53 59.29 47.03 69.45 T2 2 45.17 56.02 31.48 64.85 T3 3 42.30 38.55 43.32 70.38 SEM 2.61 3.72 3.13 4.23 P vlue 0.15 0.21 0.21 0.15 * Glucose 1= for the initil blood smples; glucose 2= for blood fter first 4 week; glucose 3= blood smples fter 8 weeks; glucose 4= fter 12 weeks t slughtering; Control: NRC requirements; 1 High energy diet; 2 high energy+ 2.5g/d/hed smrtmine; 3 High energy + 5.0g/d/hed smrtmine; SEM= stndrd error of mens. but dding protected methionine led to decrese the BFT when compred with the lmbs from T1 which fed only dry ft. This finding greed with Wiese et l. (2003) who reported reduction in bck ft thickness with feeding protected methionine s Smrtmine. Brry (1981) reported reduction in lmb's ft crcss 252

s result of bomsl infusion of csein nd methionine which lso supported our findings. This mens feeding by-pss methionine s sulfur mino cid cn cuse gret effect on ft metbolism in term of BFT nd omentl ft contents. For comprison, this finding ws lso reported by other reserchers for other species such s young chicks (Boomgrdt nd Bker, 1973) nd growing broiler (Tkhshi et l., 1994; Bunchsk et l., 1998; Wllis, 1999). Tble 9: Protein levels* (mg/dl) in blood serum of Awssi lmbs during fttening Tretment Protein 1 Protein 2 Protein 3 Protein 4 Control 5.49 5.61 4.66 4.09 T1 1 5.64 5.63 5.23b b 4.89 T2 2 6.15 5.70 5.34b c 5.29 T3 3 5.59 5.98 4.99b c 5.47 SEM 0.21 0.15 0.57 0.32 P vlue 0.47 0.85 0.05 0.04 * Protein 1= for the initil blood smples; protein 2= for blood fter first 4 week; protein 3= blood smples fter 8 weeks; protein 4= fter 12 weeks t slughtering; Control: NRC requirements; 1 High energy diet; 2 high energy + 2.5g/d/hed smrtmine; 3 High energy +5.0g/d/hed Smrtmine; SEM= stndrd error of mens Blood Prmeters The blood serum cholesterol profile ws significntly ffected by tretments. At the end of experiment, for lmbs from the T3 group compred with other group with generl trend of higher levels for ll groups tht fed high energy nd protected methionine (Tble 7). This trend greed with number of previous studies which reported tht feeding of ft supplements to ruminnts rised the cholesterol concentrtion in blood serum but not in the tissues nd milk (Bohmn et l., 1962; Bitmn et l., 1973; Nestel et l., 1973). Nestel et l. (1978) studied the effect of ft supplementtion on cholesterol metbolism in sheep nd gots. They reported hypercholesterolemi tht ws primrily due to n increse of the intestinl biosynthesis of cholesterol nd prtly due to decrese cholesterol excretion of bile duct. Furthermore, tretment did not cuse significnt (P>0.05) effect on glucose level in blood serum during the whole experiment (Tble 8), even though, the glucose levels t the end of experiment for the lmbs from treted groups were numericlly higher compred with the control group. Kholif et l. (2006) reported significnt increse in glucose concentrtion in serum s result of feeding protected methionine nd lysine which prtly greed with our findings trend. The explntion of the trend of incresing the level of glucose in the blood serum my be due to incresing the production of voltile ftty cids (VFA's) especilly propionic cid, precursor of gluconeogenesis, s result of feeding dry ft (Demeterov et l., 2002). The sme trend ws found in blood serum protein levels during the whole experimentl period (Tble 9). The higher levels of protein t the end of experiment greed with the experiment conducted by Kholif et l. (2006) who reported significnt increse in serum protein levels s result of feeding protected methionine nd lysine. The increses of blood serum protein my be due to the high efficiency of methionine bsorption from the smll intestines s result of their protection from rumen digestion. Moreover, our finding lso greed with Blum et l. (1999) who reported tht rumen protected mino cids supplementtion incresed plsm mino cid concentrtions. Incresing dietry energy by using dry ft with or without protected methionine of Awssi lmbs during the finishing period improve the overll weight gin. Feeding protected methionine my ply n importnt role in ft metbolism by reducing crcss ft ccumultion nd blood cholesterol. In generl, the requirements of energy by Awssi lmbs might be higher thn reported in NRC, but 16% crude protein in diet cn considered being dequte for growing Awssi lmbs. Acknowledgments This Project ws supported by King Sud University, Denship of Scientific Reserch, College of food nd Agriculture Sciences, Reserch Center. Apprecition goes to the stff of the niml production frm for providing proper cre nd mngement for this tril. References AOAC. 1990. Officil Methods for Anlysis, 15 th edn. Assocition of Officil Anlyticl Chemists. Wshington, DC, pp. 88. Bldwin, J.A, Horton, G.M.J., Wholt, J.E., Pltini, D.D. nd Emnuele, S.M. 1993. Rumen protected methionine for lcttion, wool nd growth in sheep. Smll Ruminnt Reserch, 12:125-132. Brry, T.N. 1981. Protein metbolism in growing lmbs fed on fresh ryegrss (Lolium perenne)-clover (Trifolium repens) psture d lib of csein nd methionine. British Journl of Nutrition, 46: 521-532. Bitmn, J., Dryden, L.P., Goering, H.K, Wrenn, TR, Yonciskie, R.A., Edmondson, L.F. 1973. Efficiency of trnsfer of polyunsturted fts into milk. Journl of the Americn Oil Chemists Society, 50: 93-98. Blum, J.W., Bruckmier, R.M. nd Jns F. 1999. Rumen-protected methionine fed to diry cows: Biovilbility nd effects on plsm mino cid pttern nd plsm metbolic nd insulin concentrtions. Journl of Diry Science, 82: 1991-1998. 253

Bohmn, V.R., Wde, M.A. nd Torell, C.R. 1962. Effect of dietry ft nd grded levels of lflf on growth nd tissue lipids of bovine. Journl of Animl Science, 21:241-247. Boomgrdt, J. nd Bker, D.H. 1973. Effect of dietry energy concentrtion on sulfur mino cid requirements nd body composition of young chicks. Journl of Animl Science, 36: 307-311. Bunchsk, C., Tnk, K. nd Ohtni, S. 1998. Effect of supplementing nonessentil mino cid on growth performnce nd ft ccumultion in broiler chicks fed diet supplemented with Met+Cys. Jpnese poultry science journl, 35: 182-188. Clrk, J.H, Klusmeyer, T.H. nd Cmeron, M.R. 1992. Microbil Protein Synthesis nd flows of nitrogen frction to the duodenum of diry cows. Journl of Diry Science, 75:2304-2323. Demeterov, M., Vdio, V., Pstierik, P. nd Koteles, A. 2002. The effect of protected ft nd protein supplements on rumen metbolism on some prmeters of intermediry metbolism, nd on the qulity nd production of milk in diry cows. Foli Veterinri, 46:20-26. Deswysen, A.G, Bruyer, D.C., Nveu, C., De Mol, J. nd Ellis, W.C. 1991. Effect of methionine hydroxy nlog on voluntry intke, digestibility,nitrogen blnce nd chewing behvior in sheep fed grss silge. Journl of Animl Science, 69:3798-3806. Erly, R.J., Mhgoub, O. nd Lu, C.D. 2001. Energy nd protein utiliztion for mintennce nd growth in Omni rm lmbs in hot climtes. П. Composition of tissue growth nd nitrogen metbolism. Journl of Agriculturl Science, 136(4): 461-470. Ebrhimi, R., Ahmdi, H.R., Zmiri, M.J. nd Rowghni, E. 2007. Effect of energy nd protein levels on feedlot performnce nd crcss chrcteristics of Mehrbn rm lmbs. Pkist`n Journl of Biologicl Science, 10 (10):1679-1684. Hddd, S.G., Nsr, R.E. nd Muwll, M.M. 2001. Optimum dietry crude protein level for finishing Awssi lmbs. Smll Ruminnt Reserch, 39(1): 41-46. Jindl, S.K., Meth, A.K. nd Ro, M.V.N. 1980. Influence of dietry energy on the body composition nd feed conversion during growth in gots. Indin Journl of Nutrition nd Dietetics, 17: 95-100. Khinizy, A.M., Sddick, I.M. Kndil, A.B., Ahmed, B.M. nd Shhin, F.M. 2004. Effect of energy level Steel, R.G.D. nd Torrie, D.A. 1980. Principles nd Procedures of Sttistics. McGrw-Hill, NY, pp. 377-444. nd protein source on sheep performnce of the wened lmbs. Egyptin Journl of Nutrition nd Feeds, 7(1): 55-67. Kholif, A.M., El-Ashry, M.A., El-Syed, H.M., El- Almy, H.A. nd Aly, T.A. 2006. Effect of rumenprotected methionine nd/or lysine supplementtion to the rtions on productive performnce of lctting buffloes. Egyptin Journl of Nutrition nd Feeds, 9 (1):1-13. Kioumrsi, H., Khorshidi, K.J., Zhedifr, M. nd Seidv, A.R. 2008. The effect of dietry energy nd protein level on performnce efficiency nd crcss chrcteristics of Tleshi lmbs. Asin Journl of Animl nd Veterinry Advnces, 3(5): 307-313. Loerch, S.C. nd Oke, B.O. 1989. Rumen protected mino cids in ruminnt nutrition. Pges (187-200) in Absorption nd Utiliztion of Amino Acids. Vol. 3. M. Friedmn, ed. CRC Press, Inc., Boc Rton, Florid. Lu, C.D. nd Potchoib, M.T. 1990. Feed intke nd weight gin of growing gots fed diets of vrious energy nd protein levels. Journl of Animl Science, 68: 1751-1759. Lynch, G.P., Jckson, Jr C., Elsser, T.H., Rumsey, T.S. nd Cmp, M.J. 1991. Nitrogen metbolism of lctting ewes fed rumen-protected methionine nd lysine. Journl of Diry Science, 74:2268-2276. Merchen, N.R. nd Titgemger E.C. 1992. Mnipultion of mino cid supply to the growing ruminnt. Journl of Animl Science, 70 (10):3238-3247. Nestel, P.J., Hvenstein, N., Whyte, H.M., Scott, T.W. nd Cook, L.J. 1973. Lowering of plsm cholesterol nd enhnced sterol excretion with the consumption of polyunsturted ruminnt fts. The New Englnd Journl of Medicine, 288:279-282. Nestel, P.J., Poyser, A., Hood, R.L., Mills, S.C., Willis, M.R., Cook, L.J., nd Scott, T.W. 1978. The effect of dietry ft supplements on cholesterol metbolism in ruminnts. Journl of Lipid Reserch, 19: 899-909. NRC. 1985. Nutrients Requirements of sheep. Ntionl Acdemy Press. Wshington, DC. Rohr, K.P., Lebzien, P., Schfft, H. nd Schulz, E. 1986. Prediction of doudenl flow of non-mmoni nitrogen nd mino cid nitrogen in diry cows. Livestock Production Science, 14:29-40. Sniffen, C.J. nd Robinson, P.H. 1987. Protein nd fiber digestion pssge nd utiliztion in lctting cows. Microbil growth s influenced by dietry mnipultions. Journl of Diry Science, 70:425-441. Tkhshi, K., Konshi, S., Akib, Y. nd Horiguchi, M. 1994. The effects of dietry methionine nd dispensble mino cid supplementtion on 254

bdominl ft deposition in mle broilers. Animl Science nd Technology, 65:244-250. Titi, H.H., Tbb, M.J., Amsheh, M.G., Brkeh, F. nd Dqmseh, B. 2000. Comprtive performnce of Awssi lmbs nd blck got kids on different crude protein levels in Jordn. Smll Ruminnt Reserch, 37(1-2): 131-135. Wllis, I.R. 1999. Dietry supplement of methionine increse brest met yield nd decrese bdominl ft in growing broiler chicken. Austrlin Journl of Experimentl Agriculture, 39:131-141. Wiese, S.C., White, C.L., Mster, D.G. nd Milton J. B. 2003. The growth performnce nd crcss ttributes of Merino nd Poll Doreset x Merino lmbs fed rumen-protected methionine (Smrt mine TM -M). Austrlin Journl of Agriculturl Reserch, 5 (5):507-513. Wright, P.L. 1971. Body weight gin nd wool growth response to formldehyde treted csein nd sulphur mino cids. Journl of Animl Science, 33:137-141. Wright, M.D. nd Loerch, S.C. 1987. Effect of rumenprotected methionine (RPMet) on lmb N blnce, steer performnce nd plsm mino cid concentrtions. Journl of Animl Science, 65 (Suppl. 1):155. 255