KHOA HOC CONG NGHfi
v/l\lGHIEIV CUU AIVH HUOIXIG CUA H A M LUOIXIG EIXIZYM KHAC IXIHAU TROIXIG THUC AIXI TOIXIG H O P LEIXI SIIXIH
TRUOIXIG, TY LE SOMG, HE S O TIEU H O A C U A CA CHilXIH H O A {AnguiUa marmarat^ GIAI DOAIXI GIOIXIG
T r ^ Thi Thu H i ^ ^ Hoang Vdn DudtS Nguy&n Thanh DQng^
T6MTAT
Bai bao trinh bay su anh hudng cua thiic an tdng bop co bd sung enzym d^n tdc d6 tang trudng, ty le sdng vd h$ sd thiic an cua ca chinh hoa {Anguiha marmorata) giai doan gidng. Sii dung thuc an tdng hgp voi ham lirpng protein 52%, hpit 9,0%, tinh b6t 9,6% cd bd sung enzym vdi 3 ham luong khac nhau la: Nghi&m thitc 1:
1.000 Ul/kg; nghi&m tiuic 2 :1.500 UI/1^ va nghiem tiiiic 3 : 2.000 Ul/kg; 16 ddi chiing la tiiiic an tdng hpp khdng bo sung enzym. Sau 90 ngay uong, co su khac biet ve tdc do tang tnrdng va h$ sd thuc an giira thiic an CO bd sung enzym va ddi chimg. Neu su dung thiic an co bd sung enzym tdc d6 tang tnrdng trung binh 0,514 ± 0,0063 g/ngay, he sd thiic an trung binh 2,75 ± 0,052. Neu sii dung thiic an ddi chiing tdc do tang truoTig 0,449 ± 0,002 g/ngay, he sd thiic an 3,01 ± 0,035. NghiSm tiiuc 2 co tdc d6 tang trudng ldn nhfit 0,527
± 0,0027 g/ngay, b§ sd tbiic an thap nhat 2,64 ± 0,042. KhOng cd su khac biet vd ty le sdng giua cdc nghi&m thiic vol 16 ddi chiing.
Ttt khda: Ca chinh hoa, bd sung enzym, thdc in ca cbinh.
I.BATVANBi
Cd chinh Id lodi cd gid tri kinh te rat cao, thit thom ngon, gidu dinh dudng va rat dupc thi trudng ua chupng. Nghe nudi cd chinh bat dau d Nhat tir nam 1879, tidp ttieo Id d Y, Phap (Matsui, 1979) va sau dd d Ddi Loan (1952), Trung Qudc (1973) (Xu et al, 1992). Hai loai dupc nudi pbd bidn d cac nudc tidn la ca chinh chdu Au {Anguiha anguihi) vd cd chinh Nhdt {Anguiha japonici).
O Viet Njun ca chinh dupc nudi ldn dau tidn vdo nam 2000 d Bmh Dinh vd Phii Ydn, sau dd nhanh chdng duoc phdt tridn d cac tinh phia Nam nhu TP.
Hd Chi Minh, Dong Nai, Tien Giang, An Giang, Cd Mau, Bac Udu. Nhin ehung nudi ca chmh dem lai hieu qua kinh td cao va cd trien vpng phdt trien ff nhidu noi tidn khdp ca nirdc. Tidm ndng phat trien nghd nudi cd chmh a nudc ta rdt Ion nhd cd ngudn gidng tu nhidn phong phu tir cdc tinh mien Tnmg, didu kidn khi hdu tiidi tiet thudn lpi, phu hop cho phat tri^n cua ca chinh, didn tieh mat nudc rdng ldn, ndng Cd Mau da cd hon 1000 ha ed the nudi cd chinh. Nhung nghe nudi cd chinh a nudc ta hidn nay dang edn lae hdu vd kem hidu qud vdi hinh thirc nudi chu yeu la quang canh, su dung fhiic an Id cd tap nen ndng suat va hidu qua thap. Nudi ca chu yeu dua vdo ngudn tfiirc dn cd tap gdy ra d nhidra mdi trudng, khdng quan ly dupc mdm bdnh ed tiong thuc dn ca tap. De thiie day nghd nudi cd chinh phat trien theo
Vien Nghien ciiu Nudi Udng Thuy san III
hirdng cdng nghiep, can cd ttnic an tdng hop dat chat lupng cao.
Enizym la rapt chat xiic tdc smh hpc gdp phan quan trong tiong cdc phan ung hda hpe eua co thd.
Nhieu cdng trinh nghidn ciiu khoa hpc vd enzyme trong thiec an vdi mue dich nang cao hidu qua sit dung fhuc an, nit ngan thdi gian nudi va giam d nhidm tir ede chat thai ra tiong ehan nudi.
Hien nay enzym dang dupc nghidn cim su dung tiong nhidu linh vue nhu thue pham, chdn nudi (Nguyen Chi Thudn, 1991,1996), ndng nghidp va dae bidt la nghien euu sir dung enzym tiong lmh vuc nudi tidng thuy san (Nguydn Chi Thuan, 2001; Nguydn Tien Luc, 2003). Nhm chung, su dung enzym tiong san xudt thiic an nudi thuy san dem Iai nhung lpi ich nhu cung cap cac enzym tidu hda cdn thidu hut lam tang kha nang tidu hda va hdp thu protem, tinh hot, chdt beo tir thiic dn. Nhd do, giiip vdt nudi tang tiudng nhanh va nit ngdn thdi gian nudi, giam hd sd thuc an va tang hieu qua su dung thue an. Gidm lupng thiec dn vd cac chat thai htiu co ddo thai qua con dudng phdn, Iam giam thidu d nhilm mdi trudng va dich bdnh.
Tuy nhien, cho den nay ehua cd nghidn euu ung dung enzym ttiuong mai vao san xuat tiiifc dn nudi ca ehinh. Vide san xuat duoc thiic an tdng hpp cd iing dung enzym cung cap cho nghd nudi ca ehinh la budc dot phd tiong vide ung dung, phat tiien ngdnh san xuat thuc an nudi thuy san.
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 1/2015 95
Ung dung enzym de san xuat thiec dn tong hpp eho ca chinh tiianh cdng se chii ddng dupc tinic an cdng nghidp thay thd ngudn ihirc dn truydn thdng Id ca tap, han che tdi da su d nhidm mdi trudng vd nguy Cff mat an toan thue pham.
Dd ehu ddng san xudt vd ndng cao hidu qua kinh td eho nghe nudi ca chmh tai Viet Nam, Bd Cdng thuong da giao eho Vien Nghidn cuu Nudi trdng Thuy san III chu tri thuc bien de tai "Nghien cuu cdng nghd san xuit thdc in nudi ci chmh tir enzym vi mdt sd loai nguyen heu sin cd a Vidt Nam". Tuoi gian thue hidn ttidng 1/2012 - 06/2014, den nay de tdi dd kdt thuc. Bdi hao nay trinh bdy mdt phan ket qua eua de tdi.
2. VAT UEU VA PHUDNG PHAP NGHIBV CUU 2.1. V$t Iidu
- Ca thi nghidm la gidng ca chmh hoa (Anguilla marmorati), cd ca trung binh 25 g/eon.
Bdng 1: Thdnh phan dinh dudng vd
-Thtic an sudung Id tiiirc an cachinh gidng dang bdt min, hdm Urpng protein: 52%, hpit 9%, tinh bdt 10%. Trong dd nguydn hdu gdm: bdt ca Kidn Giang;
28%, bdt huydt 14%, bdt tiim que: 7,3%, bpt nam men 5%, bdt gluten: 18%, bdt khoai mi; 6%, hot bdp 11%, dau ddu ndnh 0,2%, ddu ed: 0,5%, vitamin C: 0,5%, prenux;
0,5%, chdt ket dinh: 5%, chat phu gia: 4%, bo sung enzym feed eua Cdng ty Nanogen cd dang bpt mau tiang sira, tiidnh phan; (tidn 1 k ^ >100.000 UI ciia mdl loai enzym: Proteaza, phytaza, amylaza. Ham lupng enzym dupe bo sung vdo thue an nhu sau:
Nghidm thuc 1 (NTl): ham lucmg enzyra 1000 Ul/kg.
Nghidm tinic 2 (NT2); hdra luong enzym 1500 Ul/kg.
Nghidm tinic 3 (NT3); ham lupng enzym 2000 Ul/kg.
Ddi ehiing CDC): khdng bd sung enzym.
hdm lupng engym cua thiic dn thi nghidm Chi tieu
Bo am (%) Protein {%) Lipit (%)
Tro (%) Xo (%) Ca (mg/kg)
P (mgftg) Proteaza (Ul/kg) Amylaza (Ul/kg) Pliytaza (Ul/kg)
NTl 11,96+1,12
51.67+1,29 9,77+0,36 12,69+1,12 2,30+0,20 52,43+1,51
14,46+0,50 1.002,67+15,14 1.032,67+46,52 1.018,67+44,56
NT2 12,49+0,36 51,63±0,52 9,73+0,28 14,05+0,94 2,21+0,08 49,97+2,05 13,09+0,54 1.501+27,22 1.459+32,91 1.483,00+39,84
NT3 ia,63±0,26 51,63±0,78 9,73+0,30 15,12±0,41
1,81±0,05 54,15+1,81 13,21+0,27 2.017,67+14,64 2.020,67+36,12 1.985,00+33,18
DC 12,27±1,06 51,64±1,18 9,76±0,38 10,87+4,48 2,06+0,25 50,53+2,47 13,53+0,95
0 0 0 2.2. Bd til tili nghidm
- Thdi gian thit nghidm Id 03 ttiang.
- Ca dupc bd tii tiong be compozit kich tbudc 1,2x1,8 xl m.
-Matdd; 100 con/ml
- Thi nghiem duoc bd tri theo so do khdi ngdu
nhidn (Hmh 1).
- Chuan hi bd uong: bd duoc rua s^ch bang p.
phdng, ngara clo ndng dp 100 ppm ti-ong 24 gid, sau do nia sach tnrdc khi cap nudc. Nudc ngpt dupc siic khi tiong 24 gid, sau dd cap vdo be uong va lap dat hd thdng sue khi.
Bd tri thi nghidm anh hudng eua ham lupng enzym khdc nhau tiong thiie dn ldn ed chinh gidng
Ddi chiing
DC
"T:
Thuc an ed bo simg enzym
X
X X
Danh gia cac chi tieu ky thuat: he sd thiic an, tdc do tang truong, ty le s NTS
Hinh 1: So d6 khdi phuong ph4p nghita ciiru
KHOA HOC CONG N G H |
- Thirc dn; su dung thirc dn dang hot rain do de tai san xuat, ca dn thtic an dudi dang bdt nhao, pha tidn ti Id 1/1 (thiic dn khd/nudc).
- Cho an: ngay 2 ldn, vao 5 gid vd 17 gid, khoang 2-5% khdi lupng tinic an khd/khdi luong thdn/ngdy.
Lupng cho dn duoc dieu ehinh theo kha nang bat mdi cua ca.
- Thay nudc ngay 1 lln, vd sinh day loai bd chat thai, kiem sodt
- Vdt thiic an du thira ra bdng vpt ludi mdm, sau khi cho dn khoang 20 phut. Cdn luong tinic an thua d^ tinh lupng tinic dn cd sic dung va didu chinh Iupng thiic an eho ldn tidp theo.
- Sue khi hdn tue, duy tri hdm lupng oxy > 5 ppm.
2.3. Theo ddi cdc y^u t6 m6i trudrng - Do nhidt dd bdng nhidt kd bach phdn (dp chinh xde 1"C), vdo Itic 7-8 gid vd 15-16 gid.
- Do bang may pH raetter \ "mgapore san xudt, dp chmh xae 0,1), 1 lan/ngdy.
- Xdc dinh DO bang Oxygen Metier: LT Lution DO-5511,1 lan/ ngdy.
- NH3 7 ngdy/lan bang phuong phap so mdu vdi bp hda chat test kit cua Cdng ty SERA - Diic.
2.4. Theo doi tdng trudng, h§ sd thirc dn vd t^ Id sdng cda cd
- Djnh ky 30 ngay tidn hanh can, kiem tia tdc dp tang trudng cua ca.
- Sd mdu bat ngdu nhien; n = 10 - 30 con/ mdu.
- Cdn cd bdng cdn didn tit Precisa: XT do Tliuy S? sdn xuat cd dp chinh xdc 0,01 g.
- Tde dp tdng trudng khdi Iupng binh qudn tidn ngdy: ^Wt-Wo TBTTig/ngay)
- Hp sd chuy&n ddi thiec an (FCR) tinh bdng edng thiie: ,_,^, ,
PQ^ _ Wtasd Wg
Ti Id sdng tinh theo edng thiec;
y
TLS(.%) = ^!^x\m%
Ghi chu: W,: Khdi lugng ca khi kdt thiic thi nghiem (g); W„: Khdi luong ca khi bat dau thi nghiem (g); t thdi diem ket thiic thi nghiem (ngay);
tf,: thdi didm bdt dau thi nghidm (ngay); '^t^^. Khdi lugng thiic an sti dung (kg), dugc tinh b dang hot khd tnidc khi pha trdn vdi nudc; Wgi Khdi Iugng ca
Zr„.
tdng trudng 0kg); TLS: Ty Id sdng
y
sd ca thu boach; •^-''
:Tdng : Sd cd tha ban dau.
2.5. Xii I^ sdlidu
Sd hdu dupc luu tru vd xii ly trong phan mem Microsoft excel 2003; sir dung phan mdm SPSS Version 16.0 tiong phdn tich so sanh phuong sai 1 yeutd (One Way ANOVA) d miie ^ nghia P<0,05,
3. KFT QUA VA THAO L U A N
Sd hdu mdt so yeu td radi trudng nudc d cae nghidra thifc dupc the hidn o bang 2. Cae ydu td mdi trudng tiong phara vi thich hpp cho sir phat tridn ciia cd chmh gidng.
Theo Zhong Lin (1991) nhiet dd thich hop eho su phdt trien cua cd chinh dao ddng 26,3 - 30,5°C.
Theo Asuishi (1991) dd dat kich cd thuang phdm, ea ehinh dupe nudi radt 1,5 ndm o Dai Loan nhung phai mat dd'n 4 ndm b Anh, dudi khoang 12''C ca chinh Anguiha japonica, A anguilla va A rostrata khdng an vd khdng tang trudng ve mat khdi Iuang. Nhu vdy, nhidt dd nudc ddng vai tid quan tipng tiong sir phat trien cua cd chmh, didu kidn nhidt dp tiong qud trinh uong thi nghidm tuong ddi phu hpp cho ca ehinh phat trien.
pH 7,1 - 7,3 vd NH3 duy tii d mirc 0,003 - 0,005 mg/I tiong ngudng thieh hpp khdng anh hudng den hoat ddng sdng cua cd chuih.
Oxy 5,0 - 5,3 mg/l ndm tiong khoang thieh hpp.
Ham Iupng oxy tdi uu cho su phat tridn cua ed ehinh la 5-10 mg/l (Tomaka va Shin-ichi, 1999). Hdm lupng oxy hod tan trong nudc cho ca chinh ydu cau trdn 2 mg/l. Khi oxy hda tan xudng qud ratic chiu dimg (<2 mg/l) se anh hudng true tiep den cudng dp bdt mdi, tde do sinh trudng.
Khdng cd su khac biet ve ehi sd chat Iupng mdi trudng giua cac nghiem thue.
B ^ Loai thiic an
NTl
g 2: C ^ ydu td mdi tnidng nudc ugng c^ chinh gidng tgi c ^ b^ thi nghi&m Nhidt do ("O
26,5-30,5'"
28,2+0,7 p,
pH 7,3 ± 0,2
DO (mg/l) 5 - 5 , 3 5,1 ±0,1
NH,(mg/l) 0,003 ± 0,001
N O N G NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 1/2015 97
NT2
NT3
DC
2 6 , 7 - 3 0 , 4 28,2 ± 0 , 7 26,6-30,1 28,0 ±0,6 26,3-30,1 28,0 ±0,6
7,2 ± 0,2
7,1 ± 0,2
7,3 ± 0,1
5 - 5 , 3 5,1±0,1
5 - 5 , 3 5,1 ±0,1
5-5,3 5,i±ai
0,003 ± 0,001
0,004 ± 0,002
0,005 ± 0,002 Ghi chu: ^'h khoang dao ddng; ^^^: gla tn trung binh va dd ldch chuan.
Ket qua su dung thitc an khdc nhau vdi ham the hidn qua bang 3.
Iuong enzym khae nhau sau 90 ngdy thi nghiem dupc
Bdng 3: Tdc dd tdng tnrdng CIBTT), hd sd tiiiic dn (FCIO vd t^ Id sdng (Tl^) oia cd chinh gidng sir dung thiic an cd bo sung enzym sau 90 ngdy uong
Loai thtrc an NTl NT2 NT 3 DC
Khdi luong ca Ban dau 25,2 + 0,46 26,1 + 0,75 25,3 + 0,17 25,3+ 0,29
Thu hoach 69,5 ± 0,23 73,6 + 0,52 72,5+ 0,43 65,6± 0,43
TDTT(g/ngay) 0,492 ±0,0062°
0,527 ± 0,0027=
0,525 + 0,0069°
0,449 ± 0,0020"
FCR 2,94 + 0,020°
2,64 + 0,060"
2,66 ± 0,015"
3,01+0,035°
TLS (%) 93,0 ±0,58 93,7 ± 0,33 93,3 ±0,88 93,0 ±0,58 Ghi chd: Cic ehd eai khae chu cai a, b, c, d ghi tren cac gia tii trung binh trong cung mgt cdt khdng gidng nhau thi khac nhau ed y nghia (p<0,05). Cae gia tri thi hidn tren bang li gia tri trung bmh va sai sd chuan
Ty Id sdng khoang 93%, khdng cd su khdc nhau giua cac nghidm tiuic, cho thay thiec dn cd bd sung enzym khdng anh hudng ddn ty Id sdng eua ca ehinh giong.
Thiic dn ed anh hudng Idn qud trinh sinh trudng ciia ed chinh gidng thdng qua ddnh gid cdc chi sd hd sd fhiic an, tdc dp tang tnrdng.
Tdc dp tdng trudng giua cac nghidm tiiicc sit dung thiic an khdc nhau cd su sai khdc cd y nghia ve mat thdng kd ^<0,05) vd khdng ed su sai khde nhau (p>0,05) giua nghidm thuc sic dung thue dn nghidm thuc 2 va thuc an nghidm thiic 3. Tdc dp tang tnrdng eua cd sir dung thiic dn nghidm thiic 2 ed tde dd cao nhat (0,527 g/ngay) vd Idn hon sii dung thitc an ddi ehiing Odidng su dung enzyra).
He sd thuc an cd su sai khdc cd y nghia vd mat
thdng kd (p<0,05) giiia ede nghidra ttnic cd su dung cdc loai thiic an khac nhau, thap nhat ff nghiem thiic su dung tinic dn nghidra thuc 2 (2,64) vd nhd hon su dung thuc an ddi chung (3,01).
Trong dd tdi ndy khi thue dn thu nghiem cd ho sung enzym (nghiem tinic 2) ca tdng trudng 25 - 72,3 g/con, 0,527 g/ngay trong vdng 90 ngdy nudi, h i ^ qua tdt hon so vdi sit dung thiic an ehd bien khdng su dung enzym ed tdng budng 0,49 g/ngay (Chu Van Cdng va Nguydn Thi Hodn, 2007) vd theo kdt qua cua Nguydn Minh Phat (2008), thu nghidm ti-dn ed chinh hoa cd tang tiirdng 0 - 6 5 gr/con tiong 90 ngdy nuoi diing thiic an chd bien khdng su dung enzym.
Mdt sd chi tidu danh gia hidu qua cua vide sit dung cac Ioai thuc dn thu nghidm dupc tdm tdt qua bang 4.
Bang 4; Hidu qui su dung ctta cac loai thiic an thii nghidm
STT 1 CHi TIEU N T l 1 NT2 1 NT3 DC
I. CAC CHi T E U BAN B A U VA KET THUC 1
2 3 4 5 6 7 8
The tich be ugng (m^) Mat do ugng (con/m^
Sd be tha (be) Sd luong ca ban dau (con) Khdi lugng ca tha (g/con) Tv le sdng (%) Khdi luong ca thu (g/con) He sd thiic an (FCR)
2 100
3 300 25,2 93,0%
69.5 2,94
2 100
3 300 26,1 93,7%
73,6 2,64
2 100
3 300 25,3 93,3%
72,5 2,66
2 100
3 300 25,3 93,0%
65,6 3,01
KHOA HOC CONG N G H i
9 10
Tdng khdi luong ca tang (kg) Lugng thiic an sii dung (kg)
11,83 34,78
12,86 33,95
12,70 33,79
10,71 32,24 n. CHI PHI (Bvt: 1000 VND)
1 2 3 4 5 6 7 8 9
Gidng Thiic an Thudc hda chat Dung cu vat tu Dien Nhan cdng Chi khac Khau hao
Chi phi tidu thu san pham
16.800,0 1.492,1 600 300 1.896,8
3.300 500 1.666,7
796,7
16.800,0 1.466,5 600 300 1.896,8
3.300 500 1.666,7
795,9
16.800 1.469,8 600 300 1.896,8
3.300 500 1.666,7
796,0
16.800 1.363,9 600 300 1.896,8
3.300 500 1.666,7
792,8 in. HACH TOAN HIEU QUA
1 2 3 4 5 6 7 8 9 10
San luong thu hcach (Q) (con) Kich CO thu hgach (g/cgn) Gia ban san phjm P (1000 VND) /con Tdng thu nhap/dgt TR - P*Q Tdng chi phi/dot (TC^ (VND) Diem hda vdn theo san lucng = TC/P Tdng W nhuan/dgt LN - TR-TC Hidu qua chi phi - TR/TC Ty suat lgi nhuan - LN/TC (%) Thgl gian hoan vdn dau tu =Tdng vdn d^u tu/ (Lgi nhuan + KH)
279 25,2 105 29.295,0 27.352,3 260,5 1.942,7
1,07 7,1%
7,6
281 26,1 110 30.921,0 27.325,9 248,4 3.595.1
1,13 13,2%
5,2
280 25,3
no
30.789,0 27.329,3 248,4 3.459,7
1,13 12,7%
5,3 279 25,3 100 27.900,0 27.220,3 272,2 679,7 1,02 2,5%
11,6 Bang 4 eho ta thay su khde biet giira tinic an ed
stt dung enzym vd tiiiie dn ddi chung khdng su dung enzym. Vide bo sung enzym Idm gidm he sd thiie an, tdc dp tang trudng tang thdng qua cd thu hoach cd ldn hon so vdi ddi chiing, qua dd raang Iai hidu qua kmh te. Cac nghidm fhuc cd su dung enzym cho thay nghidm tiuic 2 va nghidm thue 3 khdng cd su khae bidt ve hidu qua kinh te so vdi nghidm thue 1. Tuy nhidn, d nghidm thiie 2 ehi phi thap hon so vdi nghidm thiic 3 do chi phi thiic an gid thanh a nghidm thiic 3 eao hon nghidm thiic 2. Neu dp dung d dieu kidn quy md sdn xuat thi su dung thiie an d nghiem tinic 2 tdt ban so vdi thiec dn cua nghidra tinic 3,
Nhiing nghidn ciiu ve enzym cho thay sit dung enzym tiong san xuat thiic dn nudi thuy san dem Iai nhiing Ipi ieh nhu; cung cap cdc enzyra tieu hda cdn thidu hut Idm tdng kha nang tidu hda va hap thu protein, tinh bpt, chat beo tir ttnic an. Nhd dd, giiip vdt nudi tdng trudng nhanh va nit ngdn thdi gian nudi, giara hd so thiic dn va tang hidu qua sii dung thitc dn. Kdt qua nghidn eiiu tidn ed hdi cua Gorskova vd Yu-Dvinen (1984) va cua Carter et al.
(1994) eho thay nhirng eai thidn dang kd ve tdc dd
tdng trudng cua ed khi hd sung enzym. Enzym Id nhirng chat xiic tde smh hpc cd nhiing tmh chat uu vidt hon so vdi edc chat xiic tac vd co nhu: ehi edn mdt lupng nhd enzym cung cd kha ndng xiic tdc ehuyen hda rapt lupng Idn ca chat.
Nhung ket qua tidn cho thay vide sit dung thuc dn cd bd sung enzym mang lai hidu qud tdt hon so vdi thuc an khdng bd sung enzym. Cd tac dung tdt tdi tdc dp tang tnrdng, he sd thue an eiia ca chinh qua dd cd the nit ngan thdi gian nudi.
4 . KET LUAN VA BE XUAT 4.L Kgt Iudn
Cac ydu td mdi trudng nudi tiong cdc nghidra thue ndm trong khoang thieh hpp eho su phdt trien cua ea chinh.
Thue an tdng hpp cd bd sung ham Iupng enzym 1.500 Ul/kg tdt nhat cho su tang tiTrdng (0,527 g/ngay) va he sd thiic an (FCR 2,64) eua ed chinh.
Tyle sdng dat 93,7%.
4.2. Dixudt
Can phai nghidn eiiu sau hon thiic an tong hpp ve cac yeu to nhu: dp ndi, dd kdt dinh (tang dp ben N O N G NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 1/2015 99
trong nudc)... mdi cd the dam bao hieu qua sii dung cac cdng trinh nghidn ciiu nghien ciiu kho.. lioc cdng ciia thiic an. nghd (2005-2009), tr. 604.
4. Nguydn Chi Tiiuan, NguySn Hoang Uydn vi IJIUHJ THAM KHAO Nguydn Tai Lugng, 1996. Sii dung enzym hong cdng 1. Atsuishi Usui, 1991. Eel culhu-e. Fishing News nghe san xuat thiic an nudi tdm. Ky ydu 1995. NXB books, Oxford. 27,64 p. KH va KT, tt. 212-221.
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THE EFFECT OF DIFFERENT SUPPLEMENTAL ENZYME LEVELS ON SYNTHETIC FEED ON GROWTH RATE, SURVIVAL RATE AND FEED CONVERSION RATIO OF JUVENILE EEL
(Anguilla warmoratii
Tian Thi Thu Hien, Hoang Van Duat, Nguyen TTianh Dung Summary
The report presents the effect of a synthetic feed supplemented with enzyme on specific growth rate, -i^
survival rate and feed conversion ratio of juvenile eel (Anguilla marmorata). The synthetic feed containing 52% protein, 996 hpid, 9,696 amyloid was used for the experiment. The experiment involved four treatments equivalent to four supplemental levels of enzyme including 1,000 Ul/kg, 1,500 Ul/kg, 2,000 Ul/kg and 0 Ul/kg (control). After 90 days, the result showed that grovrth rate and feed conversion ratio of fish had significant difference among U-eatments. Growth rate and feed conversion ratio of fish fed feed supplemented with enzyme were 0.514 + 0,0063 g/day and 2.75 + 0.052, respecUvely. In comparison, fish fed conhol feed obtained growtti rate of 0.449 + 0.002 g/day and feed conversion raUo of 3.01 + 0.035. The highest growth rate of 0.527 + 0.0027 g/day and die lowest feed conversion ratio of 2.64 + 0.042 were achieved in the treatment 2. The survival rate offish had no significant difference among treatments.
Kisy words: Anguilla marmorata, supplemental enzyme, eel synthetic feed.
Ngudi nh4n xdt PGS.TS. Ld Thanh Htog Ng4ynMnhM: 10/10/2014
NgJy thdng qua phan bidn: 10/11/2014 Ngiy duydt dang: 17/11/2014
