Tgp chi Khoa hgc vS Ph^ttrien 2012T9P 10, s6 3:411-416 www.hua.edu.vn
THU NGHIEM mOT SO LOAI THOC AN VIEN OUNG NUOI THUDNG PHAM CA LANG VANG [Mystusitemum TRONG LONG TREN HO C H U A TAI YEN THANH-NGHE AN
Nguyen Quang Huy'*, Nguyen Thj Hong T h a m \ Tran Minh Hieu^
Nguyen Du-ong Dire', Phan Gia Thanh', Tong Hoai Nam^
'Phan vi^n Nghien ciru Nuoi trong Thuy san Bac Trung Bo;
^Vi^n Nghien cim Nuoi irong Thuy san 1; ^Dai hgc Vinh 'Email: nguyen.huy(^rial.org
Ngay gtri bai: 28.03.2012 Ngay chSp nhan: 25.05.2012
T 6 M TAT
Bon loai thdc an vien c6 co nang lup'ng tuong ti,F nhau (2,93-3,10 kcal/g) nhung khac nhau ve ham lugng protein va lipid la Dl {35% Pr, 10% L), D2 (42% Pr, 10% L), D3 (42% Pr. 5% L) va D4 {35% Pr, 5%
L) dugc su' dyng de thi> nghigm nudi thuong pham ca lang vang (Myslus nemurus) trong Idng tren hd chua d huyen Yen Thdnh. Nghe An. Ca thi nghigm cd cd ban dau 47,0 ± 1.2 g/con dug-c cho an ngay 2 lan den no trong 85 ngay nudi. Ca sd dyng thuc an thi>c an D2 cd ham lugng protein va lipid cao nhit tang trudng nhanh nhat, hg sd chuyen ddi thuc an thap nhat (P < 0,05). Ca an thuc an D4 cd toe dg tang trudng chgm nhat, higu qua si> dyng protein thap nhat va h? sd chuyen ddi thuc an cao nhat. Ca an thdc an D3 cd toe do tang trudng, hieu qua si> dyng protein tu'O'ng ti/ nhu' ca an thuc an Dl (p>0,05) nhung cd he so chuyen ddi thdc an thap hon (P <0,05). Ti Ig song cua ca an cac logi thdc an thi nghigm deu cao (93,3-94,0%) va khdng cd st^ khac biet giua cac nghigm thuc thdc an. Dya vao ket qua tren, thuc an D2 cd ham lug'ng protein 42% va lipid 10% la thuc an phu hg^p nhat cho nudi thuang pham loai ca nay trong so 4 logi thuc an nghien ci>u.
Ti> khda Ca lang vSng, Mystus nemurus. thuc an
Using Formulated Diets for Growth-Out Trial of Bragid Catfish {Mystus nemurus) in Cages in Reservoir at Yen Thanfi District, Nghe An Province
ABSTRACT
Four isoenergic feed pellets of different protein and lipid levels, namely Dl (35% Pr, 10% L). D2 (42%
Pr, 10% L), D3 {42% Pr, 5% L) and D4 (35% Pr, 5% L), were used to investigate the growth of bagrid catfish Mystus nemurus in cages breed in water resen/oir in Yen Thanh, Nghe An. Experimental fish of initial size of 47.0 ± 1.2 g were fed twice a day to satiation in 85 days. Fish fed on diet D2 which contained the highest protein and lipid levels showed the best growth rate and the lowest feed conversion ratio (P
<0.05). Fish fed on D4 diet with the lowest in protein and lipid content yielded the lowest growth rate and protein efficiency ratio and the highest feed conversion ratio (P <0.05). Fish fed on diet D3 gave similar growth rate protein efficiency ratio to those fed on diet Dl but had a lower feed conversion ratio {P <0.05).
Survival rates of fish from all feed troatments were high {93.0-96.0%) and no significant difference was found among treatments. Based on these results, diet D2 (42 % protein and 10 % lipid) was recomended for maximizing growth rate and feed utilization of Mystus nemurus.
Keywords: Bagrid catfish, mystus nemurus. feed
Thd nghigm mpt so loai thuc an vien diJng nudi thuong pham ca lang,..
l.DATVANDK
Ca lang vang, Mystus nemurus (ten dong nghia Hemibagrus nemurus), la Ioai ca nhiet ddi phan bd' d vung Ddng Nam A (Ng va cs., 2000 a) va la mgt trong gan mudi loai ca lang (Mystus sp.) phan bd' d Viet Nam {Nguyen Chung, 2008). 6 Viet Nam ca sinh sd'ng chu yeu trong cac thijy viic nildc nggt hoac nUdc Ig nhe gan vung ciia song, ndi co do man dildi 6%o thugc luu viic cac song d mien Ddng va ddng bang sdng Ciiu Long (Nguyin Chung, 2008). Ca lang vang la mdt trong nhiing loai ca dac san nirdc nggt c6 thit thdm ngon va bd difdng va gia tri thifdng mai cao. Hien nay, cung nhu cae loai ca ban dia eiing hg nhu ca lang cham (Hemibagrus guttatus), lang ham (M filamentus), ca lang vang ngay cang bi khai thac nghiem trgng nen san lifdng ca t a nhien ngay mot giam tha'p.
Mac du ca lang vang tang trindng chdm hon so vdi mgt sd loai ca lang khac nhu lang nha (M. wyckiioides), lang ham, nhung trong thap ki qua da cd nhieu no lUc trong nghien cdu de phat trien nudi loai ea tiem nang nay. Nghien ciiu sinh san nhan tao ca lang vang da thanh cong til nam 2003 (Nguyin Chung, 2008). Hien nay, loai ca nay dang dUdc nudi trong long tren sdng hoac trong ao dat vdi quy md nhd, san lUdng nudi cdn han che, Thiic an nudi ca lang vang dang phu thugc chii yeu vao ngudn ea tap. Ngudn thiic an nay thUdng khong on dinh ve so' iKdng, chat lUdng va Cd nguy cd gay d nhilm mdi trudng nuoi, lan truyen dich benh cao. Su le thugc vao ngudn thdc an ca tap la mgt trong nhiSng nguyen nhan can trd phat trien nghe nudi loai ca nay, dac biet la phat trien nudi trong long d hd chda mien nui, ndi tiep can vdi ngudn thiic an ca tap khd hdn nhieu so vdi vung ddng b^ng
duyen hai. Vi vay phat trien thiic an vien cdng nghiep nh&m thay the ca tap de nuoi loai ca nay la rat can thiet.
Protein va lipid la hai yeu td dinh difdng chinh trong thiic an anh hifdng Idn tdi tang trudng va hieu qua sd dung thiic an cua ca. Thiic an cd ham iKdng protein va lipid phii hdp se giup ca tang tritdng nhanh va hieu qua sd dung thiic an cao (he so chuyen dd'i thdc an thap). Tuy nhien hieu biet ve nhu cau dinh dudng cua ca lang vang de phat trien thiie an vien con rat han che. Cac nghien ciiu tren the' gidi mdi chi tap trung vao vao nhu cau protein h giai doan ea gid'ng (Khan va cs., 1993; Ng va cs., 2000b). De nhanh chdng xac dinh difdc cdng thdc thiic an vien phii hdp cho ca lang vang, phuc vu san xua't thiic an cdng nghiep cua loai ca nay, nghien ciiu nay tie'n hanh thii nghiem nudi thUdng pham ca vdi mgt so' loai thiie an vien cd ham lifdng protein vk lipid khac nhau.
2. VAT LIEU VA P H U O N G PHAP 2.1. Vat lieu n g h i e n ciiu
Phan mem WUFF-DA 2008 dUdc sil dung de thiet ke bdn loai thiic an vien thi nghiem cd nang liTdng tUdng tii nhau (2,93 - 3,10 kcal/g thtic an) nhUng khac nhau ve ham lifdng protein va lipid, gdm: D l : 35%
Pr, 10% L (protein thap va lipid cao); D2:
42% Pr, 10% L (protein cao va lipid cao);
D3: 42% Pr, 5% L (protein eao va lipid thap) va D4: 35% Pr, 5% L (protein thap va lipid tha'p). Nguyen lieu dung che bie'n thiic an thi nghiem bao gom: bdt ca, hot thit va xifdng, eac hdn hdp khoang va vitamin premix ciia hang Nutriway, chat ket di'nh global binder ciia hang Glocal, enzyme phytase va cac nguyen lieu can thiet khac.
Thanh phan phdi trgn cac nguyen lieu va ket qua phan tich dinh duSng cac loai thdc
N g u y e n Q u a n g H u y . N g u y e n T h j H d n g T h l m , T r a n M i n h H i e u , N g u y e n D u o - n g D d c , P h a n G i a T h a n h , T o n g H o a i N a m
an the hien b Bang 1. Ket qua phan tich cho thay ham liTdng protein, lipid va nang litdng trong thiic an gan vdi miic thiet ke.
Thiic an thi nghiem difdc che bie'n tai xudng san xuat thiic an thuy san cua Vien Nghien ciiu Nudi trdng Thuy san 1.
Ca lang vang ciing mdt dan difdc mua tii mien Nam va nuoi thuan dUdng 01 thang trong long tren hd chiia Quan Hai, huyen Yen Thanh, Nghe An. Trong thdi gian nudi thuan difdng ca difdc cho an ket hdp giiia ca tap va thiic an cong nghiep
(42% protein) nhdm luyen cho ca sii dung hoan thoan thiic an cdng nghiep trifde khi tien hanh thi nghiem.
Bo' tri thi nghiem: Ca thi nghiem cd cd trung binh 47,0 ± 1,2 g/con dUdc bd tri vao 12 long nuoi the tich 5,0 m^' (1,5 xl,5 x 2,2 m), moi long 100 con (mat do 20 con/m^).
Liia chgn ngdu nhien ba Idng nudi cho moi loai thiic an thi nghiem. Cho ca an de'n no 2 Un/ngay vao bud'i sang va chieu. Thi nghiem ditde tien hanh trong 85 ngay nudi.
Bang 1. Cong thufc va thanh phan dinh difdfng cua thiic an thi nghiem
Ty 1$ nguyen heu (%)
D1 18,2 13,0 14,0
Thuc Sn Ihl nghipm D2
26,2 16,0 18,0
D3 25,2 16,0 18,0
D4 18,2 13,0 12,0 Bgt ca (60% Pr)
B^t th|t va xuo'ng Kh6 do An Dp (44% Pr) Gluten ngo Men bia kho Bpt mi C i m ggo Dau ca Choline Chloride Dicalcium Phophate Chat ket dinh Premix Vtm va khoSng L-Lysine HCl Feimen Phytase
16,4 12,4 1.0
16,4 27,2 1.5
0.2 1,0
0.1 0,1
0.2 1,0
Th^nh ph4n dinh du&ng va nSng lug'ng cac logi thijc an v a t chat kho (%)
PfOfein tho (%) Lipid kha (%) NSng lugng (kcal/g)' P / E '
35,7 10,3 2,99 119,4
91,6 42,1
3.16 133,2
91,0 41,6
3,10 134.2
2.93 118,1 ' Nang lUdng tong so ditdc ti'nb toan tit ham ]nang cac chat dinh di/dng trong thiit
^ Protein/Nang lupng (P/E) = mg protein/kcal
Thd nghigm mgt so logi thdc an vien dung nudi thuong pham ca lang....
2.2. Thu va xijf li m d u
Dinh ky hang thang do mau nglu nhien 30 con/long nudi va do toan bg toan bg ca khi ket thiic thi nghiem. Tang trildng va hieu qua sii dung thdc an cua ca b cac nghiem thiic ditdc xac dinh qua cac chi so':
khdi lifdng ca trung binh khi ket thuc thi nghiem, to'c do tang trKdng khdi lifdng tifdng dd'i (SGRw %/ngay), hieu qua sii dung protein trong thiic an (PER = khd'i litdng ca tang/khd'i lUdng protein sii dung) va he so' sii dung thiic an (FCR = khdi lifdng ca tang/khdi lUdng thiic an sii dung).
Nhiet do, ham lifdng oxy hda tan va pH dUdc do hang ngay bdng may do chuyen dung cua hang MILWAUKEE vao buoi sang (7-8 h) va buoi chieu (16-17 h). Ham lUdng NH3 dUdc do hang tuan vao buoi sang (7-8 h) bang bg Kit so mau.
Vat chi't khd, protein thd va lipid thd trong thiic an dKdc xac dinh theo cac tieu chuan Viet Nam (TCVN) tKdng iing la TCVN 4326:2001, TCVN 4328:2001 va TCVN 433 1:2001. Nang lUdng thd difdc tinh theo I;^
thuyet dua vao phan mem may tinh.
2.3.Xijflisolieu
So' lieu trong nghien ciiu nay dUdc the hien la gia tri trung binh (TB) ± do lech chuan (SD). Ket qua nghien ciiu dKdc so sanh bang each phan tich phUdng sai mdt nhan to (one-way ANOVA) va s^ dung phep kiem dinh Duncan de xac dinh sii khac biet giiia cac nghiem thdc thdc an vdi do tin cay 95%. So' lieu difde xii ly bang phan mem thdng ke SPSS 16.0.
3. KET QUA v A THAO LUAN Bie'n ddng nhiet do nirdc trung binh thang trong thdi gian thi nghiem tang tif 22,1 ± 1,7''C d thang nudi dau den 30,5 ± 0,6°C d thang nudi cud'i. Gia tri pH nam trong khoang 6,6-7,9. Ham iKdng d xy hda tan bie'n dgng d miic 5,1 de'n 6,8 mg/L. Ham lifdng NH3 trong nildc nhd hdn 0,01 mg/L.
Cae thong so' mdi trildng tren nhin chung la phii hdp cho tang triidng cua ca lang vang, ngoai tril nhiet do nUdc trong hd d thang nudi dau chiia ndm trong khoang nhiet do td'i iru cho loai ca nhiet ddi nay.
Tang trifdng ve khdi liTdng hang thang cua ca sii dung cac loai thiic an thi nghiem khac nhau the hien d Hinh 1.
0 30 50 85 Ngay niioi
Hinh 1. Tang trv^ofng khoi Iittfng ca theo thdi gian nuoi
Nguyen Quang Huy, Nguyen Thj Hong Tham.Tran Mmh Hieu, Nguyen Duo'ng Ddc, Phan Gia Thanh, Tong Hoai Nam
Khdi liidng trung binh ca an thiic an D2 cd xu hudng Idn hdn ca sil dung cac loai thiic an cdn lai txi thang thii nhat trd di.
Tuy nhien sii khac biet ve khd'i lUdng ca d cac nghiem thiic chi the hien cd y nghia thd'ng ke (P < 0,05) tai thdi diem ket thuc thi nghiem, sau 85 ngay nudi. Tai thdi diem nay, khd'i lUdng trung binh ciia ca an thUc an D2 la Idn nhat (92,1 ± 2,2 g/con). Khdi lUdng trung binh cua ca an thiic an Dl (85,1 ± 3,9 g/con) va D3 (86,1 ± 0,8 g/con) khdng khac biet nhau (P > 0,05) va Idn hdn ca sd dung thiic an D4 (72,6 ± 2,4 g/con), la loai thiic an cd ham lUdng protein va lipid tha'p nha't.
Su khac biet ve to'c do tang trudng tUdng ddi ngay cua ca cl cac nghiem thUc thiic an ciing the hien tUdng tU nhU sii khac biet ve khd'i lUdng cua ca tai thdi diem ket thuc thi nghiem vdi sil vUdt trgi ciia ca sd dung thUc an D2 (Bang 2). Ti le sd'ng ciia ca d tat ea eac nghiem thiic deu eao (93,3 - 94,0%) va khdng cd sii khac biet cd y nghia thd'ng ke (P > 0,05).
FCR cua ca sii dung thiic an D2 (2,1) khdng khac biet vdi ea an thiic an D3 (2,3 ) va tha'p hdn cd y nghia thd'ng ke (P < 0,05) so
vdi ca an thUc an Dl (2,6) va D4 (3,4). Ca an thiic an D4 cd FCR cao nha't (P < O.O'S). Hieu qua sii dung protein (PER) eiia ca an thiic an D2 cao hdn ca sii dung cac loai thUc an cdn lai nhUng khdng khac biet cd y nghia thd'ng ke doi vdi ca an thiic an Dl va D3 (P >
0,05). Ca an thUe an D4 cd hieu qua sii dung protein tha'p nhd't (P < 0,05; Bang 2).
Ket qua thi nghiem nay cho tha'y vdi cung mdc nang lUdng trong thUe an, ca sii dung thiic an D2 va D3 cd ham lUdng protein cao, cung the hien qua ti le P/E cao (Bang 1), cho tdc dd tang trUdng, hieu qua sd dung thde an cao hOn ca an hai loai thiic an cd ham lUdng protein thap la Dl va D4.
Ddng thdi, khi sd sanh theo cac cap nghiem thdc thdc an ciing ti le P/E la: Dl va D4, D2 va D3, cho thay ca sii dung thUc an cd ham lUdng lipid cao hdn deu cho td'c do tang trUdng, hieu qua sii dung thiic an va protein eao hdn (Bang 2).
Ket qua nay gdi y rang ca lang vang giai doan nudi thUdng pham ed nhu cdu cao ca ve protein (> 35%) va lipid (> 5%). Dieu nay ciing phii hdp vdi ket qua nghien citu ciia Khan va cs (1993) khi thi nghiem nudi ca lang vang trong ao da't vdi cd ca gid'ng 25,9 g/con.
Bang 2. Tang trifcfng, ti le so'ng, he so' c h u y e n doi thiic an va hieu qua svif dung protein cua ca suf dung cac loai thOfc an khac nhau
Chi lieu
W CUOI (g) SGRwl. (%/ngay) TF le s6ng (%) FCR PER
D l 85,1 ± 3 , 9 ' ' 0,71 ± 0,04"
93,3 ± 1,7 2,6 ± 0,2'' 1,22 ± 0 , 1 4 '
Cong D2 92,1 ± 2,2*
0.62 ± 0 , 0 2 ' 93,7 ± 0 , 8 2,1 ± 0 . 2 ' 1.26 ± 0 , 0 8 "
thuc thirc an D3 86,1 ± 0,8'' 0,73 ± 0 , 0 1 "
93,7 ± 0,6 2,3 ± 0 . 1 ' 1.13 ± 0 , 0 4 '
D4 72,6 ± 2.4' 0,51 ± 0,04'
94,0 ± 2,0 3,4 ± 0,2' 0.93 ± 0,07"
a tri r S i SD. So'lieu ciing hang vdi ki hieu inO khac nhau la khac nhau coy nghia thong ke (P <0,05)
ThCr nghiem mgt s6 loaithCK Sn vi§n dung nuoi thuv/ng pham cd l^ng..
Tac gia nay da xac dinh dUdc ham lUdng protein toi au trong thiic an cho tang trudng la 42%. Tuy nhien b giai doan ca nhd hdn (7- 18 g/con) ham lUdng protein protein toi Uu trong thUc an dUdc xac dinh trong nghien ciiu Ng va cs. (2000b) la 44 %, cao hdn trong nghien ciiu cua Khan va cs. (1993).
Protein, lipid va carbohydrate la nhiing thanh phan dinh dudng chinh cua thiic an. Ham lUdng protein va lipid trong thiic an phu hdp cd y nghia quan trgng cho tang trudng ciia ca. Neu ham lUdng lipid thap, protein cd the bi sii dung de cung ci'p nang lUdng ehd ea (Garling va cs., 1976).
Khi ham lUdng lipid dap iing nhu cau nang lUdng, protein trong thiic an cd the danh cho qua trinh ddng hda, giiip ea tang trUdng (Satpathy va cs., 2003). Dieu nay cd the K giai vi sao ca an thiic an D4 cd eiing ham lUdng protein (35 %) nhiing cd ham lUdng hpid (5%) thap hdn thiic an Dl (10%) cd hieu qua scf dung protein tha'p hdn va dan den td'c dg tang trUdng cham hdn ca sii dung thUe an Dl (P < 0,05) mac du nSng lUdng thd ciia cac loai thiic an nhU nhau.
Nghien ciiu ve thdc an nudi thUdng pham phu hdp cho ca lang cham, la loai ca ciing gid'ng vdi ca lang vang, da xac dinh dUdc ham lUdng protein va hpid trong thdc an thich hdp nha't cho tang trudng tiidng iing la 45% va 10 % (Nguyin DUc Tuan, 2008). Ket qua nghien ciiu ciia chiing tdi va ciia cac tac gia trudc (Khan va cs., 1993; Ng va cs., 2000b;
Nguyen DUc Tuan, 2008) cho thay ca lang vang va lang cham cd nhu cau protein va lipid trong thiic an kha gidng nhau.
4. KET LUAN VA DE X U A T 4.1. Ket luan
Day la nghien citu dau tien ve thiic an vien diing nudi thUdng pham ca lang vang.
Dua vao to'c do tang trudng, hieu qua sii dung thiic an va hieu qua sii dung protein cua ca lang vang, thiic an cd ham lUdng prdtein 42% va lipid 10% (D2) la thiic an
thich hdp nha't cho nudi thUdng ph^m loai ca nay trong so' 4 loai thUc an nghien ciiu.
4.2. De xua't
Ket qua nghien ciiu budc d^u cho thSfy cdng thUc thUc an thiie nghiem D2 cd the sii dung de san xuat thdc an vien nudi thUdng pham ca lang vang. Tuy nhien, can cd them cac nghien cdu de tiep tuc cai tien chat ludng thdc an (vi du giam FCR, tang td'c do tang trudng ciia ca) ddng thdi lam rd hieu qua kinh te ciia loai thUc an nay, vi du so sanh vdi viec sii dung mgt so' loai thiic vien cdng nghiep khac hien cd tren thi trudng nhu thiic an nudi ca loc.
TAI LIEU THAM KHAO Garhng Jr. D.L., R.P. Wiison (1976). The
optimum protein-to-energy ratio for channel catfish, Iclalurus punctatus. J. Nutr., 106, p.
1368-1375.
Khan M.S., K.J. Ang, M.A. Ambak, CR. Saad (1993). Optimum dietary protein requirement of a Malaysian fresh water catfish, Mystus nemurus. Aquaculture 112, p. 227-235.
Ng, W.K, K.S. Lu, R. Hashim, A. Ali (2000a). Effects of feeding rate on growth, feed utilization and body composition of a tropical bagrid catfish.
Aquaculture International 8, p. 19-29 Ng, W.K., S.C. Soon, R. Hashim (2010b), The
dietary protein requirement of a bagrid catfish, Mystus nemums (Cuvier &
Valenciennes), determined using semipurified diets of varying protein level. Aquaculture NuU-ition7, p. 45-51.
Nguyen Chung (2008). KT thuat san xuit gidng va nudi ca lang nha, lang vang. Nha xuat ban Ndng Nghiep, tr. 1-95.
Nguyen Diic Tuan (2008). Bao eao tdng ket kiioa hgc va ky thuat de tai Nghien cuu cdng nghe nudi thuong pham Ca Lang cham Hemibagrus guttatus (Lacepede 1803). Vien Nghien ciiu Nudi trdng Thiiy san 1.
Satpathy B.B., D. Mukherjee, A.K. Ray (2003).
Effects of dietary protein and lipid levelson growth, feed conversion and body composition in rohu, Labeo rohita (Hamilton), fingerlings.
Aquae. Nutr. 9, p. 17-24.
