Pkistn Journl of Nutrition 7 (3): 444-449, 2008 ISSN 1680-5194 Asin Network for Scientific Informtion, 2008 Potentils of Sweet Potto (Ipomoe tts) Lef Mel s Dietry Ingredient for Tilpi zilli Fingerlings M.A. Adewolu Deprtment of Fisheries, Lgos Stte University, Ojo, P.M.B. 001, LASU Post Office, Ojo, Lgos, Nigeri Astrct: An 8-week feeding tril ws conducted to evlute the potentil of sweet potto (Ipomoe tts) lef mel s dietry protein source in the diet of Tilpi zilli fingerlings. Five isonitrogenous diets of 30% crude protein were formulted to contin 0, 5, 10, 15 nd 20% sweet potto lef mel (Diets 1-5) to prtilly replce other protein ingredients in the tilpi diet. The diet contining 0% lef mel served s the control. Tilpi zilli fingerlings were rered in 50L circulr plstic tnks mintined in flow-through system. Ech dietry tretment ws tested in triplicte groups of 10 fingerlings per tnk. The results of the growth nd nutrient utiliztion responses show tht there were no significnt (p>0.05) differences mong the fish fed diets 1-4 (0-15% sweet potto lef mel) ut were significntly (p<0.05) different from fish fed on diet 5 (20% sweet potto lef mel) which hd lower growth nd feed utiliztion vlues. There were no significnt (p>0.05) differences in the crcss composition of Tilpi zilli fingerlings fed on experimentl diets. The present findings show tht sweet potto lef mel hs good potentil for use s one of the protein sources in Tilpi zilli diet up to 15% level without compromising growth. Key words: Sweet potto lef mel, plnt protein, feed utiliztion, growth, tilpi Introduction One of the prolems fcing the quculture industry tody is the high cost of fish feed. Nutritionist ll over the world re constntly serching for the dietry protein sources in which fish will mximize growth nd increse production within the shortest possile time nd t lowest cost. Lef mels re one of the chepest sources of proteins tht my reduce the high cost of fish feed. Mny studies hve een conducted using vrious sources of lef mel proteins (Ng nd Wee 1989, on cssv lef mel, Yousif et l., 1994 on Alflf, Reyes nd Fermin, 2003 on Cric ppy nd other lef mel, Birgi et l., 2004 on Leucen leucocephl). The sweet potto, Ipomoe tts L. (Lm) elongs to the morning-glory fmily Convolvulcee. It is cultivted in over 100 ntions nd rnks fifth mong the most importnt food crops in the tropicl res (An, 2004). The leves of this plnt hve een used in the tropics s chep protein sources in ruminnt feeds. Studies hve een conducted to determine the nutritive vlue of sweet potto lef mel. According to Woolfe leves, ccording to Oyenug (1968), re the invertse nd protese inhiitors. These sustnces cn e inctivted y vrious processing methods such s oven or sun-drying, oiling or steming nd grinding prior to inclusion in fish feeds. Although, vrious lef mels hve een tested s potentil fish feed ingredient to decrese diet cost, the use of sweet potto lef mel hs not een tested. It is ginst this ckground tht the present study ws designed, to evlute the potentils of incorporting sweet potto lef mel into the pelleted feed of Tilpi zilli, widely culturle fish species in Afric. The ojective of this work, therefore, ws to determine the growth performnce, feed utiliztion nd crcss composition of Tilpi zilli fingerlings fed on grded levels of sweet potto lef mel. Mterils nd Methods Collection nd preprtion of sweet potto lef mel: Fresh leves of sweet pottoes were collected from evergreen frms Idiroko rod, Ogun Stte, Nigeri. The (1992), Ali et l. (1999), Ishid et l. (2000), An (2004), collected smples were wshed thoroughly with tp Ekenyem nd Mduuike (2006), the lef mel hs wter to remove dirt nd deris, drined properly nd high protein content of etween 26 to 33%, with high lter sun dried to constnt weight. The dried leves mino cid score. It hs good minerl profile nd were milled using lortory miller, pcked in the vitmins such s A, B 2, C nd E. Aside from its nutritive freezer t-20 C until use. vlues, sweet potto leves cn e hrvested mny times throughout the yer (Hong et l., 2003) therey Diet formultion nd preprtion: Five isonitrogenous mking the lef mel to e undnt. One mjor fctor nd isocloric diets were formulted to contin 30% limiting the use of this lef mel in fish feed is the crude protein. The sweet potto lef mel ws presence of nti-nutritionl fctors (Tcon, 1993). The incorported into ech of these diets t 0, 5, 10, 15 nd ntinutritionl sustnces present in the sweet potto 20% to replce other protein ingredients in the diets. The 444
diet contining 0% lef mel serves s the control. Feed ingredients were weighed ccording to the gross composition tle in Tle 1. The ingredients were mixed together using kitchen mixer efore the ddition of vitmin premix. Oil ws lter dded to the dry ingredient nd mixed thoroughly. Wrm wter ws dded to the premixed ingredients nd homogenized until dough-like pste ws formed. The dough ws pssed through n improvised pelleting mchine. The moist pellets were oven dried t 60 C to constnt weight nd kept in ir tight continers. Experimentl design nd feeding trils: Fingerlings of Tilpi zilli were purchsed from Animshun fish frms, Bdgry, Lgos, Nigeri. The fish were llowed to cclimtize for 10dys, during this period, they were fed on commercil diet. Prior to the commencement of the experiment, ll fish were strved for 24 hours. This prctice ws to eliminte vrition in weight due to residue food in the gut nd lso to prepre the gstro intestinl trct for the experimentl diets, while t the sme time to increse the ppetite of the fish. The feeding tril ws conducted in flow-through plstic quri ech with 50L cpcity of wter. 150 fingerlings of initil men weight of 2.13±0.85g were rndomly llotted t the rte of 10 fingerlings per qurium into five dietry groups designted Diet 1, Diet 2, Diet 3, Diet 4 nd Diet 5 nd ech group ws fed on 0, 5, 10, 15 nd 20% sweet potto lef mel respectively. Fish were fed on llotted experimentl diets t 3% of their totl ody weight per dy. Feedings were generlly done in the mornings t 09:00 nd 16:00 h. Except on weighting dys when they were fed fter weighing. All fish were reweighed every fortnight nd feed weight ws djusted ccordingly to ccommodte for weight chnges. For sttisticl resons, ech of the dietry group ws triplicte. The experiment lsted for 56 dys. Digestiility study: The digestiility tril ws conducted seprtely in sttic quri. Removl of the uneten feed ws done y siphoning. Fecl smples were then collected from the three replictes of ech dietry tretment. The feces were esily detected nd immeditely removed from the wter with glss cnul nd dried to constnt weight in n oven t 60 C (Rmchndrn nd Ry, 2007). Apprent digestiility coefficient for protein (ADC P) ws clculted ccording to Zho et l. (2006). 100 - (100 % Cr2 O3 in diet % protein in diet % ADCp = ----------------------------------------------------------- %Cr2 O3 in feces % protein in feces. Adewolu: Potentils of Sweet Potto Moisture ws otined y drying the smple t 105 C in n oven until constnt weight ws chieved. Crude protein ws determined y using the microkjeldh digestion method (N 6.25). Crude lipid content ws done y soxhlet-extrction. Ash content ws done y comustion in muffle furnce to constnt weight t 550 C. Crude fier ws determined using the cid/se digestion process. Nitrogen Free Extrct (NFE) ws computed y tking the sum of vlues for crude protein, crude lipid, crude fier nd moisture nd sutrcting this from 100 (Mynrd et l., 1979). All nlyses followed the procedures of A.O.A.C (1990). Wter nlyses: Wter qulity ws monitored every week throughout the feeding trils. Temperture rnged etween 26-28 C, dissolved oxygen 5.0-6.5mg/l nd ph 6.5-7.3. These wter prmeters were within the recommended rnge for tilpi culture (Blrin nd Hlton, 1979). Evlution of growth nd nutrient utiliztion prmeters: Growth nd nutrient utiliztion prmeters were ssessed in terms of ody weight gin (WTG), Percentge Weight Gin (PWG), Specific Growth Rte (SGR), Food Conversion Rtio (FCR) Gross Food Conversion Efficiency (GFCE) nd Protein Efficiency Rtio (PER). The following formuls were used. WTG = Men finl ody weight-men initil ody weight Men weight gin PWG = --------------------------- 100 Men initil weight Log W - Log W e 2 e 1 SGR = -------------------------- 100 T -T 2 1 Where W 2 = Weight of fish t time T 2 in dys W 1 = Weight of fish t time T 1 in dys Log e = Nturl log to se e Weight of dry feed fed (g) FCR = ------------------------------------ Live weight gin of fish (g) Gin in weight of fish (g) PER = ------------------------------------- Protein consumed (g) Sttisticl nlysis of dt: All experimentl dt were sujected to the nlysis of vrince test (ANOVA) using Microsoft softwre STATISTICA followed y Duncn s multiple rnge test (Duncn, 1955). Results The result of the proximte nlysis of the sweet potto Chemicl nlyses: Smples of sweet potto lef mel, lef mel is presented in Tle 2. Sweet potto lef the experimentl diets, fecl smples nd mel hd crude protein level of 23.57% crude ft 3.07, experimentl fish t the eginning nd t the end of the feeding tril were sujected to proximte nlyses. crude fier 8.28%, totl sh, 11.01% nd 49.05% for nitrogen free extrct. 445
Adewolu: Potentils of Sweet Potto Tle 1: Gross composition of the experimentl diets (%) Diet 1 Diet 2 Diet 3 Diet 4 Diet 5 Ingredient 0%SPL 5%SPL 10%SPL 15%SPL 20%SPL Yellow Mize 31.85 25.18 19.15 13.73 8.82 Groundnut cke 30.20 28.56 27.07 25.75 24.15 Fish mel 12.08 11.44 10.84 10.30 9.82 Sweet potto lef mel - 9.99 18.97 27.30 34.37 Soyen mel 18.12 17.13 16.26 15.43 14.73 Corn oil 5.00 5.00 5.00 5.00 5.00 Bone mel 1.00 1.00 1.00 1.00 1.00 Chromic Oxide 1.00 1.00 1.00 1.00 1.00 Vitmin premix 0.50 0.50 0.50 0.50 0.50 Sodium chloride 0.25 0.25 0.25 0.25 0.25 SPL = Sweet potto lef mel Tle 2: Nutrient Proximte composition of sweet potto (Ipomoe tts) lef mel Percentge composition Moisture 4.02 Crude protein 23.57 Crude ft 3.07 Crude fier 8.28 Totl Ash 11.01 Nitrogen Free Extrct (NFE) 49.05 The growth performnce nd feed utiliztion efficiencies of Tilpi zilli fingerlings in terms of weight gin, specific growth rte feed conversion rtio nd protein efficiency rtio re presented in Tle 3. The men finl weight of the fish incresed from the initil vlue in ll the dietry tretments. Tilpi zilli fingerlings fed on Diet 1 hd the highest weight gin while Diet 5 hd the poorest weight gin. The generl trend ws tht decresing growth rte ws oserved with incresing inclusion level of sweet potto lef mel in the experimentl diets. However, there were no significnt differences (p>0.05) in the weight gin of fingerlings fed Diet 1 with those fed on Diets 2, 3 nd 4. Fingerlings fed on Diet 5 hd significntly (p<0.05) lower weight gin thn the other diets. The FCR ws lowest 1.53±0.20 in fish fed on Diet 1 nd highest 3.8±1.76 in fish fed on Diet 5, however, FCR vlues were not significntly (p>0.05) different in ll the diets except Diet 5 which ws significntly (p<0.05) different from other diets. The protein efficiency rtio were not significntly (p>0.05) different in Diets 1, 2, 3 nd 4 ut were ll significntly (p<0.05) different from Diet 5. The pprent protein digestiility of the experimentl diets y the tilpi fingerlings rnge from 75.39% in Diet 5 to 79.79% in Diet 1. The results of crcss composition of Tilpi zilli fingerlings efore the commencement of the feeding trils nd t the end of the experiment re presented in Tle 4. There were no significnt (p>0.05) differences in the crcss composition of Tilpi zilli fingerlings fed on diets contining different levels of sweet potto lef mel. However, the initil crcss composition of fish efore the feeding trils hd lower moisture, crude protein nd crude lipid content thn the finl ody composition of the fish. Discussion When lterntive sources of feedstuff such s plnt protein re used in fish diets, one of the common prolems is the cceptility y fish nd this hs to do with the pltility of the diet (Rodriguez et l., 1996). In the present investigtion, ll the experimentl diets were ccepted y Tilpi zilli fingerlings, indicting tht the levels of incorportion of sweet potto lef mel did not ffect the pltility of the diets. This might e due to the processing technique employed in this study. These drying nd the grinding techniques might hve reduced the ntinutrient in the sweet potto lef mel therey incresing its pltility in Tilpi Zilli. This oservtion is in support of the work of Siddhurju nd Becker (2003), Frncis et l. (2001) nd Fgenro (1999). These workers reported tht reduction in ntinutrient y different processing techniques resulted in etter pltility nd growth in fish. The potentils of feedstuff such s lef mel in fish diets cn e evluted on the sis of its proximte chemicl composition, which comprises the moisture content, crude protein, crude fire, crude lipid, totl sh nd nitrogen- free extrct. The proximte composition of sweet potto lef mel in the present investigtion reveled tht the crude protein content ws 23.57%, crude fire 8.2% nd sh 11.01%. These vlues were lower thn the vlues reported y Woolfe (1992) nd An (2004) for sweet potto lefmel. These differences might e due to different environmentl conditions such s soil type, hrvesting time, locl vrieties nd processing methods. On the protein digestiility, the overll efficiency of Tilpi zilli fingerlings to digest protein in the experimentl diets decresed s the level of sweet potto lefmel incresed in the diet. These vlues were in close rnge (75.39-79.79%) nd were not likely to e significnt. This decresing trend hve een reported in diets contining lck grm seedmel (Rmchndrn 446
Adewolu: Potentils of Sweet Potto Tle 3: Men growth nd nutrient utiliztion prmeters of Tilpi zilli fingerlings fed on experimentl diets Prmeters Diet 1 Diet 2 Diet 3 Diet 4 Diet 5 Initil weight (g) 2.34±0.28 2.23±0.31 2.09±0.18 2.17±0.33 2.14±0.29 Finl weight (g) 4.93±0.43 4.67±0.48 4.31±0.31 4.36±0.64 3.19±0.38 Weight gin (g) 2.58±0.29 2.45±0.46 2.22±0.19 2.19±0.34 1.05±0.29 Feed intke (g) 3.93±0.47 3.74±0.52 3.51±0.31 3.64±0.56 3.59±0.49 (SGR)% dy 1.69±0.19 1.56±0.37 1.42±0.15 1.38±0.27 0.01±0.57 FCR 1.53±0.20 1.60±0.47 1.58±0.15 1.67±0.15 3.80±1.76 PER 2.22±0.33 2.23±0.58 2.12±0.23 2.00±0.19 0.99±0.31 1 APD 79.79 77.62 77.02 75.63 75.34 1 Figures in the sme row hving similr superscript re not significntly different t p>0.05; Sttisticl nlysis not determined, s smples were pooled Tle 4: Proximte crcss composition of Tilpi zilli fingerlings t the strt nd end of the feeding trils Crcss composition% Initil fish Diet 1 Diet 2 Diet 3 Diet 4 Diet 5 Moisture 3.27±0.02 5.26±0.20 5.15±0.02 5.10±0.20 5.00±0.02 5.20±0.01 Crude protein 59.0±0.20 62.13±0.20 63.50±0.15 63.0±0.13 62.80±0.10 63.00±0.10 Crude lipid 5.13±0.15 8.50±0.50 8.45±0.50 8.10±0.05 8.00±0.40 7.85±0.20 Totl sh 11.14±0.60 11.28±0.40 11.50±0.50 10.85±0.40 11.00±1.30 11.20±0.25 Figures in the sme row hving similr superscript re not significntly (p>0.05) different nd Ry, 2007) diets with lef mel (Ry nd Ds, 1994; Birgi et l., 2004) nd diets with grss pe seed mel Rmchndrn nd Ry, 2004; Rmchndrn et l., 2005). The resons for this present oservtion might e due to high fire content of lefmel nd the presence of protese inhiitor in sweet potto lef mel (Oyenug, 1968); decresed in proteolytic enzyme ctivity (Flge et l., 1978; Euseio et l., 2004) nd nutrient sorption (Shiu, 1997; Oliver-Novo et l., 2002). Although the nutritionl qulity of sweet potto lef mel s determined y Tilpi ody weight gin, specific growth rte, food conversion rtio nd protein efficiency rtio ws higher in fish fed the control diet (0% lef mel) no significnt (p>0.05) differences were oserved in other experimentl diets contining lef mel up to 15% level. To dte, there is no pulished informtion on the incorportion of sweet potto lef mel in fish diets, ville informtion on other lef mels reveled tht 1pil-1pil, Leucem leucocephl lef mel in the diets of Oreochromis niloticus t 12.5% inclusion did not ffect growth, however, t high levels of inclusion, 25% or more, the growth of O. niloticus ws dversely ffected (Sntigo et l., 1988). In the present investigtion, inclusion of sweet potto lef mel t 20% level reduced the growth rte nd feed utiliztion of Tilpi zilli fingerlings. Fskin et l. (1999) reported tht 30% inclusion of duckweed, Spirodel polyrrhiz in the diet of O. niloticus supported growth. Ritcher el l. (2003) reported tht Moring oleifer lef mel could replce 10% fish mel sed dietry protein for Tilpi without cusing ny dverse effect on fish growth. However, Afung et l. (2003) reported tht solventextrcted moring lefmel could replce 30% of fish mel from O. niloticus diets. These vrious workers hve shown tht lef mel protein t low levels of inclusion (less thn 50%) in fish diets were le to support growth, therefore, supporting the results of this study. The proximte crcss composition dt of Tilpi zilli fingerlings showed insignificnt (p>0.05) differences in fish fed diets contining different levels of sweet potto lef mel, these mount however incresed more thn the initil vlues. This oservtion is in ccordnce with the report of Rmchndrn nd Ry (2004). The ody moisture nd crude protein content were similr in ll the experimentl groups, ut there were reductions in the ody lipid of fish fed on sweet potto lef mel. The reson here might e due to the reduction of the level of fishmel lipid s the level of sweet potto lefmel incresed in the diets. This is in greement with the results of Siddhurju nd Becker (2001) nd Afung et l. (2003) who oserved similr reductions in ody lipid of fish fed on diets contining plnt-sed proteins. In conclusion, the results of this study show tht sweet potto lef mel could e included up to 15% level in Tilpi zilli diets without ny negtive effects on the growth nd feed efficiency. Furthermore, sweet potto leves re loclly ville in the tropics nd cn e otined throughout the yer. Acknowledgements The uthor thnks Mr. R.G. Ajepe nd Mr. A. Fgohun for their technicl ssistnce. References A.O.A.C., 1990. Officil Methods of Anlysis. 15th Edn. Assocition of Officil Anlyticl Chemist. Arlington, VA, USA. Afung, W., P. Siddhurnju nd K. Becker, 2003. Comprtive nutritionl evlution of rw, methnol extrct residues nd methnol extrct of moring (Moring oleifer Lm.) leves on growth performnce nd feed utiliztion in Nile Tilpi. (Oreochromis niloticus L.). Aquculture Res., 34: 1147-1159. 447
Adewolu: Potentils of Sweet Potto Ali, M.A., T.H. Tgeldin nd E.M. Solimn, 1999. Effect Ishid, H., H. Suzuno, N. Sugiym, S. Immi, T. of sweet potto tops or roots in growing rit diets on growing performnce, digestiility, crcss trits nd economic efficiency. Egypt. J. Rit Sci., 9: 13-23. An, L.V., 2004. Sweet potto leves for growing pigs. Biomss yield, digestion nd nutritive vlue. Doctor s thesis, Swedish University of Agriculture Sciences, pp: 49. Birgi, A., K. Srkr Ghsh, S.K. Sen nd A.K. Ry, 2004. Evlution of the nutritive vlue of Leucen leucocephl lef mel, inoculted with fish Tdokoro nd A. Mekw, 2000. Nutritive vlue on chemicl components of leves, stlks nd stem of sweet potto (Ipomoe tts Poir), Food Chem., 68: 359-367. Mynrd, L., J. Loosli nd H. Hintz, 1979. Animl Nutrition. 7th edition McGrw Hill, New York. Ng, W.K. nd K.L. Wee, 1989. The nutritive vlue of cssv lef mel in pelleted feed for Nile Tilpi. Aquculture, 83: 45-58. Oliver-Novo, M.A., L. Oliver-Cstillo nd C.A. Mrtinez-Plcios, 2002. Sunflower seed mel s intestinl cteri Bcillus sutilis nd Bcillus protein source in diets for Tilpi rendlli circulns in formulted diets for rohu, Leo rohit (Hmilton) fingerlings. Aquculture Res., 35: 436-446. Blrin, J.D. nd J.P. Hlton, 1979. Tilpi: A guide to their iology nd culture in Afric. University of Stirling, Stirling, Scotlnd, UK. Duncn, D.B., 1955. Multiple rnge nd multiple F-tests. Biometrics, 11: 1-42. Ekenyem, B.U. nd F.N. Mduuike, 2006. An ssessment of Ipomoe srifioli lef mel s feed ingredient in roiler chick production. Pk. J. Nutr., 5: 46-50. Euseio, P.S., R.M. Coloso nd R.E. Mmug, 2004. Apprent digestiility of selected ingredients in diets (Boulenger, 1896) fingerlings. Aquculture Res., 33: 223-229. Oyenug, V.A., 1968. Nigeri s foods nd feeding-stuffs. Their Chemistry nd nutritive vlue. 3rd edition. The Cxton Press (West Afric) Ltd. Idn, 99p. Rmchndrn, S. nd A.K. Ry, 2004. Inclusion of extruded grss pe, Lthyrus stivus seed mel in compounded diets for rohu, Leo rohit (Hmilton, 1822) fingerlings. Act Ichthyol. Pisct., 34: 205-218. Rmchndrn, S. nd A.K. Ry, 2007. Nutritionl evlution of fermented lck grm (Phseolus mungo) seed mel in compound diets for rohu, Leo rohit (Hmilton), fingerlings. J. Appl. Ichthyol., 23: 74-79. for juvenile grouper, Epinephelus coioides Rmchndrn, S., A. Birgi nd A.K. Ry, 2005. (Hmilton). Aquculture Res., 35: 1261-1269. Improvement of nutritive vlue of grss pe Fgenro, O.A., 1999. Comprtive evlution of hetprocessed winged en (Psophocrpus (Lthyrus stivus) seed mel in the formulted diets for rohu, Leo rohit (Hmilton), fingerlings fter tetrgonolous) mels s prtil replcement for fermenttion with fish gut cterium. Bioresour fishmel in diets for Africn ctfish (Clris Technol., 96: 1465-1472. griepinus). Aquculture, 170: 297-305. Ry, A.K. nd L. Ds, 1994. Apprent digestiility of Flge, R., L. Schpnol nd K. Jurss, 1978. Amylse some qutic mcrophytes in rohu, Leo rohit esterse nd protese ctivity in the intestine (Hmilton), fingerlings. J. Aquculture Tropics, 9: content of rinow trout Slmon girdneri (Rich), 335-342. fter feeding with feed contining different mounts Reyes, O.S. nd A.C. Fermin, 2003. Terrestril lef mels or freshwter qutic fern s potentil feed of strch nd protein. J. Ichthyol., 18: 283-287. ingredients for frmed lone Hliotis sinine Frncis, G., H.P.S. Mkkr nd K. Becker, 2001. The (Linneus 1758). Aquculture Res., 34: 593-599. ntinutritionl fctors present in plnt-derived Ritcher, N., A. Siddhurju nd K. Becker, 2003. lternte fish feed ingredients nd their effects in Evlution of nutritionl qulity of moring (Moring fish. Aquculture, 119: 197-227. oleifer Lm.) leves s lterntive protein source Fskin, E.A., A.M. Blogun nd B.E. Fsuru, 1999. Use for Tilpi (Oreochromis niloticus L.). Aquculture, of duckweed, Spirodel polyrrhiz L. Schieiden, s 217: 599-611. protein feedstuff in prcticl diets for tilpi, Rodriguez, S.M., N.M.A. Olver nd O.C. Crmon, 1996. Oreochromics niloticus L. Aquculture Res., 30: Nutritionl vlue of niml y product mel in 313-318. prcticl diets for Nile Tilpi, Oreochromis niloticus Hong, N.T.T., M. Wnpt, C.K.P. Wchirpkorn nd P. (L) fry. Aquculture Res., 27: 67-73. Rowlinson, 2003. Effect of timing of initil cutting Sntigo, C.B., M.B. Ald, M.A. Lron nd O.S. Reyes, nd susequent cutting on yields nd chemicl 1988. Reproductive performnces nd growth of compositions of cssv hy nd its Nile Tilpi (Oreochromis niloticus) rood stock fed supplementtion on lctting diry cows. Asin- Austrlin J. Anim. Sci., 16: 1763-1769. diets contining Leucen leucocephl lef mel. Aquculture, 70: 53-61. 448
Adewolu: Potentils of Sweet Potto Shiu, S.Y., 1997. Utiliztion of crohydrtes in wrmwter fish-with prticulr reference to tilpi, Oreochromis niloticus nd O. ureus. Aquculture, 151: 79-96. Siddhurju, P. nd K. Becker, 2001. Preliminry nutritionl evlution of mucun seed mel (Mucun pruriens (L.) DC vr. utilis in common crp (Cyprinus crpio L.) n ssessment y growth performnce nd feed utiliztion. Aquculture, 196: 105-123. Siddhurju, P. nd K. Becker, 2003. Comprtive nutritionl evlution of differentilly processed mucun seeds (Mucun pruriens (L.) DC vr. utilis (Wll ex Wight) Bker ex Burck, on growth performnce, feed utiliztion nd ody composition in Nile Tilpi (Oreochromis niloticus L.), Aquculture, 34: 487-500. Tcon, A.G.J., 1993. Feed ingredients for wrmwter fish. And other processed feedstuffs. FAO Fisheries Circulr No. 856, FAO, Rome, pp: 64. Woolfe, J.A., 1992. Sweet potto n untpped food resource. Cmridge University press, Cmridge, pp: 643. Yousif, O.M., G.A. Alhdhrmi nd M. Pssrki, 1994. Evlution of dehydrted lflf nd Sltush Atriplex) leves in diets for Tilpi (Oreochromis ureus L.). Aquculture, 126: 341-347. Zho, M., S. Xie, X. Zhu, Y. Yng, L. Gn nd L. Song, 2006. Effect of inclusion of lue-green lge mel on growth nd ccumultion of microcystins in giel crp (Crssius urtus gielio). J. Appl. Ichthyol., 22: 72-78. 449