w^ KHOA HOC-KY THUAT
TSVN 19(194) THUTU 1.10.2014
Nghien ciiu nuoi ca chien trong ao nu^ofc chay va long tren song
Ca chien la doi tuong thuy dgc son quy hiem co gid tri kinh te cao, dupc nuoi theo hinh thuc trong ao nuoc chdy vd long fren song. Viec nghien ciiu cdc hinh thdc nudi ndy giup ngudi dan cd nhung hieu biet vd kinh nghiem sdn xuat, tgo hieu qud nudi trdng cao.
1. Sir can thiet
Cd chidn {Bagarius rutilus - Ng va Kottelat, 2000) Id loai ban dja quy biem, cd sdng trong moi trudng nudc chay, phan bd tii An Dp qua Myanmar, Thai Lan, Bdc Vidt Nam, Indonesia. O nudc ta, ca thudng xuat hidn trong cac sdng sudi d vimg trung va thupng luu sdng Ld, Gdm, sdng Hdng, sdng Da, cd co kich thudc Idn, thit ngon va dupc xudt khdu sang thj trudng Trung Qudc.
Hidn nay ngudn loi ca chidn bi khai thdc qua miic vd cd nguy co bjydt chiing, theo Sdch Dd Vi^t Nam xdp cd chidn d miic nguy cap biic 2 (Bp Khoa bpc - Cdng nghd vd Mdi tnrdng, 2000). Nhidu ngudi dan khu vuc Ha Giang, Tuydn Quang, Yen Bdi dd nudi cd trong long bdi nghe sdng nudc lau ddi da giiip ho cd nhieu kinh nghiem chdm sdc ca nudi. Ngudn cd gidng cd nuoi dupc ddnh bdt tir tu nhidn nen lai cdng Iam cho ngudn gidng cd tu nhidn can kiet
Vide nghidn cuu "Ky thudt nudi thuong pham ca chien trong ao nudc chdy vd ldng trdn sdng" se gdp phan hoan thien ve nghien ciru vdng ddi ciia cd chidn va xay dung quy trinh nudi cd mdt cdch bdi ban.
2. Phircfng phap nghien cuti BA tuang n^iSn cuu Thi nghiem dupc thuc hien tren cd chien gidng. Ca gidng dupc san xuat tai Trung tam Qudc gia Gidng thliy san nudc ngpt mien Bgc (Thach Khdi, TP Hdi Duong) trong khudn khd de tdi: "Khai thdc va phdt trien ngudn gen cd chien Bagarius rutilus - Ng & Kottelat, 2000".
Phuang phdp hdtri M n^iim - Nudi cd chien trong ao nu&c chdy vdi mat do khdc nhau
Thi nghiem bd hi trong 3 ao, mdi ao didn tich 900 rn-', dimg luoi chia deu mdi ao thdnh 3 ngdn. Thi
nghiem mat dp nudi dupc bd tri ngdu nhidn hoan toan vdi 3 lan 1^. Dimg 2.400 con cd chien gidng lon co' 30 - 50 g/con de bd tri thi nghiem.
- Cdng thuc thi nghiem:
+ Cdng thiic 1: 0,7 con/m' (210 con/ngdn)
+ Cdng thirc 2: 0,9 con/m' (270 con/ngdn)
+ Cdng thiic 3: 1 con/m' (300 con/ngdn)
- Chd dp chdm sdc vd quan ly: Cac ao nudi dp dung chung che dp cham sdc.
- Thirc dn: Dimg cd me hoac cd tap bdm nhd vira mieng ca.
Cd CO 50 - 150 g/con, cho an 2 lan/ngdy, thiic an chidm 5 - 7% khdi luong thdn.
Khi ca > 150 g/con, cho an 1 lan/
ngay vdo buoi chieu. thirc dn chiem 3 - 4% khdi luong than. Hang ngay kiem tra sang dn, hang thang Idem U-a tang h-png cd de dieu chinh dnic an, bd tri mdy phun mua cung cap dxy. Vd sinh sang dn va ngan ludi.
- Nudi cd chiin trong ldng tren sdng vdi mdt dd khdc nhau
Thi nghidm tai Phil Thp vd Hai Duong, mdi noi sir dung 3 mat do ngdu nhidn vdi 3 Idn lap. Sd cd su dung 3.460 con (30 - 50 g/con).
+/ Cdng thuc mat do:
Phu Thp: Ldng 20 m' - Cdng dure 1: 7 con/m' (140 con/long)
- Cdng thuc 2; 9 con/m= (180 con/long)
- Cdng Uiirc 3: 10 con/m' (200 con/long)
Hai Duong: Ldng 25 m^
- Cdng dure 1: 7 con/m' (175 con/long)
- Cdng diuc 2: 9 con/m= (225 con/long)
- Cdng thiic 3: 10 con/m' (200 con/long)
+/ Chidd chdm sdc: Nhu nhau.
- Thiic an: cd tuoi bam nhd phii hop vdi cd
i/ Ca 50 - 150 g/con cho dn 2 lan/ngdy vdi khau phan bdng 5 - 7%
khdi lupng than,
ii/ Cd > 150 g/con cho an 1 lan/
ngay. Khau phan dn 3 - 4% khdi lupng thdn. Hang ngdy, hdng thang
• kiem tra sang an va tdng trpng cd de dieu chinh luong thirc dn phii hpp, vd sinh sang an va long nudi.
Chi Uiu theo doi:
- Khdi luong cd tdng thdm WG (weight gain)
WG(gam)-W2-Wl (W2 va Wl la khdi luong cd sau vd tnrdc khi tha)
- Chieu ddi cd tdng thdm LG (length gain)
LG = L2 - Ll
(L2 va Ll la chieu dai cd sau vd trudc khi tha)
- Tdc dp tang trudng binh qudn ngdy ADG (average daily growth)
ADG (gam/con/ngdy) = (W2 - Wl)/Sd ngdy nudi
- Ty le sdng TLS (%) = Sd cd cdn lai khi thu hoach/sd cd khi thd.
- Nang sudt ca nudi
ui(kg)-KL^Lilhn(kg|
2.3. Phuang phdp x&lU^li^
Sd lieu dupc x^ ly bang phan mem Excel, phdn tich Anova 1 nhan td, xac dinh su sai khdc gifia cdc cdng thiic thi nghiem.
3. Ket qua nghien ciifu va thao luan
3.1. Nudi cd chiin trong ldng trinsdtig
Kit qud nudi cd chien trong long tai Phu Thg.
Sau 18 thang thi nghiem nudi thuong pham cd chidn trong long trdn sdng da cho ket qud khd quan, sd lieu dupc tdng hpp cu thd qua Bang 3. L
Kdt qua bdng 3.1 cho thdy chidu dai vd trpng lupng cd gidm ddn khi
mat dp nudi tdng. Khdi lupng cd thu hoach trung binh thap nhat b mat dp 3 la 1,36 kg/con, cao nhat d mat dp 1 la 1,48 kg/con vd hep den la mdt dp 2 dat 1,38 kg/con. Nhu vdy, nudi cd chidn trong long trdn sdng b mat do khdc nhau cd su khdc bi^t vd trpng lupng ca cuoi chu k^ nudi, tuy nhidn su khdc biet nay khdng c6 y nghia thdng kd ^ > 0,05). T^ 1^
sdng cd sau 18 thdng nudi b mat dp 1 cho kdt qua cao nhat (85%) vd th^p nhat d mat dp 3 (73%).
K^ qud nudi cd chien ling tgi Hdi
Ca chien dupc thi nghidm nudi thirong pham trong long trdn sdng tai Hai Duong vdi cb tha 17,4 cm/con, trpng lupng 40 - 43 g/con.
Kdt qua nudi dupc the hidn qua Bang 3.2.
Sau 14 thang nudi qua Bang 3.2 cho thay mat dp nudi tang thi tang tnrong chidu dai vd trpng lupng cd giam. Trpng lupng cd thu ho^ch trung binh cao nhat d cdng thiic 1 Id 1,04 kg/con, cong tiiitc 2 d^t 0,97 kg/con va cdng thiic 3 Id 0,93 kg/con. Ty Id sdng d cdng thiic 1 ao nhdt dat 81,0% va thap nhdt b cdng tiuic 3 la 72,5%.
- Ndng sudt vd hi0u qud kinh ti Kit qud Bdng 3.3 cho th^y, nudi cd chidn cho hieu qua kinh td cao. (f Phii Thp, sau 18 thdng nudi cho hidu qua kmh te cao nhat d mat dd 1 (iai 29,8 trieu/ldng 20 m^). Khi dd, sau 14 thdng nuoi cho ket qua cao nhat d mat d p i Oai 23,13 trieu/ldng 25 m^.
Khi so sanh voi Oidi didm thdng nudi 14 tai Phii Thp, nudi ca chidn frong ldng trdn sdng tai Hai Duong cho kdt qud t h ^ hon. Didu nay cd thd 1? gidi rang do cdchienla loai cd bdn dia ndn viec thich nghi voi mdi trudng smh didi, cdc ydu td thiiy \^ hda tdt hon so vdi mdi hndng nudi mdi '
Ket qua nudi cd chien trone ao nuac chdy tgi Hd Giang
Trpng lupng ca khi thu hopch
KHOA HOC - KY THUAT
TSVN 19<194) THUTU 1 10.2014
Bdng 3.1. Chiau dai vd liong lunng ca chi&i sau 18 thang nu6i (Mgt d 5 1 ; 2 , 3 \ha lupt la 7; 9; 10 ma/ts^
^ ^ J
Chieu dai Trong lirong Clueu dai Trona laaas song (cm) ' (g) i£El (kg) ^ Co)
Matd62 17.55±0.44= 4 2 . 6 7 ± 1 . 2 2 ' .^7.19±0,57^ 1..^8±0,04= 76.6 MItdo? 17.24±0.40= 41.92±1,15" 37.52 ± 0.67" 1..^6±0.04^ 73,0 39,?2 ± 0.64' L48 ± 0.05= 85.0
Ghi chli: Trong moi cot, cdc chu cm khdc nhau thi CO su chenh lech giUDchuiigkhoiigcDy nghia lli6ngke(p>0.05)
. Bang 3.Z Oiikt d i i vd tiong lugng cd chien qua 14 Ihdng nu5i (Ugt do I ; 7; 3 Ion luot Id 7; 9; 10 con^m^
T h o n g
C h i e u d a i T r o n g tiitrng 17.43
0.39=
17,55 0,44"
Matd63 17.24 ± 41.92±1,15" 30,98
0.40' 0,82'' Chieu dai Trong iirong
(cm) I (kg) '"
31.07 0.74"
L04± 0.025= 81.0 0.97 ± 0.0 W'' 75.3
0.93 = 0.019" 72.5
Ghi chl). Tiong moi tot, cdc chD cdi l;hdc nhau thi cd su chenh lech giQo chung khdng cd y nghTa Ihdng ke (p>0,05)
Bfing 3.3. Odnh^id hitu qua kinh te dio C hi - T h u
Clli pill coil s m i i a C l i i p l u l l u r c a i i Chl cona lao clous Chl phi t h u o c , h o a ehat Chl phi kliau iiao l o u a Tong chi p h i Tong t h u Lfn nil II an TB
md hinh nuoi cd chi^ trong l^ng toi Phd Thg vd Hdi Dugng lan vi. Tri^ dong • - P h u T h o
M D 1 4 . 2 0 0 1 7 . 5 3 4 1 4 . 0 0 0 0 . 5 0 0 5.000 4 1 . 2 3 4 7 1 , 0 4 0 2 9 , 8 0 6
MD2 5 . 4 0 0 20 0 6 0 14 0 0 0 3 0 0 0 5 0 0 0 4 7 - 4 6 0 7 6 . 1 7 6 2 8 . 7 1 6
M D 3 6 . 0 0 0 2 1 7 6 4 14 0 0 0 4 0 0 0 5 . 0 0 0 5 0 . 7 6 4
BM D u c m g MDI 5 . 2 5 0 1 4 . 3 6 0 10.8S9 0 . 5 0 0 5 , 0 0 0 3 5 9 9 9 7 9 . 4 2 4 • 59 1 2 9 2 8 , 6 6 0 1 2 3 , 1 3 0 2 9 . 0 6 ] 1
M D 2 6 . ' ' 5 0 16.460 1 0 . 8 8 9 0 . 7 0 0 5 . 0 0 0 39."^99 6 2 2 9 4 2 2 . 4 9 5 2 0 . 1 2 6
M D 3 6 . 0 0 0 1 3 . 6 0 0 1 0 . 8 8 9 1,000 5 . 0 0 0 3 6 . 4 8 9 5 1 . 2 4 3 1 4 , 7 5 4
^ ^ P o n p l . Tong tmflng cd chien nudi trgig go nudc chdy (Mat do 1; 2; 3 lan lugt; 0,7; 0,9, i con/m').
Thong
Mat do 1 Mat do 2 Mat do 3
Liic biit diiu thil Chieu dai
(cm) 15,87 + 0.33=
15.83 = 0.34^
16.05 ± 0 . 3 4 = T r o n g liroiig
(e) 34.91 ± 0,78' 35.25 ±0.84' 35.39 ± 0 76'
Kbi thu hoiich Chieu dai
(cm) 35,21=0.76' 33.94 = 0.70' 32,78 ±0.57^
Trone I110112 (?) 1.29 = 0.039' 1.15=0.034^
1.08=0.026' Tvle
(%)•
83,3 79,5 77,0 Ghi ctiu: Trong m5i cpt, cdc chu cdi khdc nhau Ihl cd su chenh leth giua chung khdng c6 y nghio thdng ke (p>0,05)
^ ^ F Biing 3.5. Hieu qvJr idnh te ciJo mo liinh nuoi cd chien oo nudc chdy (Oon vi; Tiiiu dcIng]
C h i so Chi phi con a i o n s Chl phi thirc an Chl C0112 lao dciua Chi phi thuoc, hoa chat Chi phi thue ao ToQo chi p h i Tong thu Lgi nhuan
C o n g t h i i c 1 6.300 21 966 14.000 1,000 5,000 48.266 85.785 37,519
C o n g thitc 2 8.100 24.604 14.000 2.500 5.000 54.204 86.538 3 2 , 3 3 4
CoDo t h i t c 3 9.000 25.200 14.000 3,500 5,000 56,700 87.318 3 0 , 6 1 8 tnmg binh tti^ nhat a m^t dd 3 la
1,08 kg/con vh cao nhat a mat d^ 1 U 1^9 kg/con (Bang 3.4). Tf 1§
s6ng cua cd nu6i b mat do 1 cao nhat voi 83,3% va thSip nhat 77%. b mSt dp
3. Nguyen nhan do nuoi ca chien trong long trin song loai ca nay co vay nguc cung, rSng sic, khi nuoi mat dp cao neu thiic an khong du hoac khong rai deu trong ao thi ca
se tranh gianh thuc an, cp sat, cm lln nhau gay thuong tich, tao di^u kien dich benh phat trien lam ty le sdng thap- Mac dii nam 2013 - 2014 miia dPng lanh, nhiet dp bien dong, anh huong den tang truang ca nhung so voi mot sd loai ca nudi khac thi ca chien chiu lanh t6t hon.
- Ndng sudi vd hiiu qud kinh ticda nudi cd chien trong ao nu&c chdy.
Sau 18 thang nudi, sa bp danh gia hieu qua kinh te 6' ca 3 mat dp nudi de xac dinh mat dp nuoi phu hpp n h ^ Ket qua the hien cu the qua Bang 3.5.
Ao 300 m^ cho loi nhuan cao nhat d-mat dd 1 la 37,5 W^u ddng/ao, ti^p theo la mat do 2 va 3 lan lupt la 32,3 va 30,6 trieu/ao. Vay, co the khkig dinh rang ca chien phat tri^n tdt trong ao nudc chay, nudi mat do 0,7 con/m^ la phit hpp va cd kha nang phat tri^n nhan rpng.
3.2. Binh cd vd cdch phdng tri Ket qua phan tich cho thay ca chi6n nuoi 0 ck ao va long chu y^u bi nhiem ky sinh trimg nhu: trimg qua dua, trimg banh xe, benh do vi khuan Pseudomonas, Aeromonas va Steptococcus, trong dd ty le ca nhidm trung qua dua cao (}in din 47,8% khi ca nhd), chua phat hien nam hay vi khuan gay benh ca nudi thuong phdm.
Cdch phong tri
Tri bdnh trimg qua dua bang for- malin (7-12ppm); tam 10-15 phiit, tSm lidn tuc trong 5 ngay. Ca bi lb loet b gdc vay va quanh mieng cd thd dung khang sinh frifampicih trdn vao thiic an (450 mg/kg ca moi), cho an 7 ngay lien tuc. Tri tning banh xe, diing CuS04 hoac Formalin (3 - 5 ppm) tam ca 10 -15 phut/lan/2 ngay hoac phun xudng ao vdi lieu lupng 0,5 - 0,7 g/m^ nudc.
4. Ket luan va de xuat
4.1. Kit ludn
- Ca chien tang trudng trung binh sau 18 thang nudi trong long tren song d" mat dp 7 -10 con/m\ trpng luong > 1 kg/con, trpng lupng ca dat cao nhat khi nudi tai Phii Tho mat dp 7 con/m^ la 1,48 kg/con.
- Ca nudi ao dat tang tnrong tdt nhat (1,29 kg) d- mat dp 0,7 con/m^ khi tang mat dp thi tang tnrong giam.
- Nudi ca chien long tren sdng cho nang suat va hidu qua kinh te cao han nuoi ao nudc chay.
- Ca chien khi nhd dd bi benh ky sinh tning (tning qua dua), khi lon
thi bi benh Id' loet do vi khuan. Cd the chua ky sinh tning bang formar lin va vi khuan bang rifampicin.
VO VAN BINH, NGUYEN MAI HUONG, DANG V A N HOAN, MAI V A N NGUYEN, NGUYEN ANH HIEU
NBC, Vien Nghien cuu Nudi trdng Thdy sdn 1
\ Tai lieu tham khao j l.Piovdinl-F-, 1973 Hudng dan nghien cuu cd.
I NXB Khoa hoc vd Ky Ihudt Hd Noi (Tran Thi Mmh : Giong. dich),
2 Phgm Bdu vd CIV, ZOOD Bieu tro nghien cdu : hien trang vd hien phdp bdo ve, phuc hoi mot so lodi cd hoong do qu^ hiim cd nguy to fuyel chung tren he thdng sdng Hdng: Cd anh vu Se[iiiloheo nolnbilis (Peleis, 1880); Cd bong Spiiiiborbus[iei)ticutDtus(ci5himD,1926), Cd Idng chdm Hemibagmsguttolus (Locepede, 1803); Cd chien Bagoiius yorrelh (Sykes, 1841). Vidn Nghren ciiu Nuoi tidng Thuy sdn I 3. Nguyin Duong Dung, Nguyen Ode Tudn vd CIV, 2001 Luu giu nguon gen vd giong thuy sdn nudc ngot. Bdo cda de Idi. Vien Nghien cdu Nudi trong Thuy sdn I.
4 Nguyen Vdn Hdo, 1993 Ngu logi hoc tap 2 Nhd xunt hdn Nong nghiep 5 Iron Anh Tudn, 2010. Bdo cdo tong ket ik tdi
"Nghien cuu guy trinh sdn xudt giSng cd chi§n trong dieu krdn nhdn too". Vien Nghien cdu Nuoi . Irdng Ihuy sdn I
I 6. Nguyen Eldc Tudn, 200S. Bdo cdo tong Vk de I tdi: "Nghien cdu sinh son nhdu too cd ldng chdm Hemibagrus guttulus (Locepede, 1803) trong dieu l<ien nuoi", Vien Nghien cdu Nufii trong Thuy son I.
7. Woi Dinh Yen, 1978. Oinh loai cd nudt ngot cdc tinh phio Bac Viet Norn. Nhd xuot bdn Khoa hoc Ky thudt, Hd NDI
B Mai Dinh Yen, 1983 Cdc lodi cd kinh t l mien Bdc Viet Nom NXB Khoo hoc vd Ky thudl. Hd Ndi- 9. B5 Khoo hoc - Cong nghe vo Moi trudng, 2000, Sdch fid Viet Nom Nhd xuot bdn Khoa hoc vd Ky thudt, Hd Ndi.
10 DuvidE H. 1990-Methodkrhshbiology.
Ameiicon Fishery society, Bethesda Mory load, USA. Niall R, Bromoge and Ronold J, Roberts Bloodstock monogement ond egg ond lonrai qual- ity pp 2 6 7 - 2 7 0
11 Roberts Tyson R, 1983 Revision of the South ond Southeosi Asion Sisorid Cotfrsh Genus Bogorius, vjitli Descriptron of 0 New Species from tiie Mekong, Copeio 1983 (2): 4 3 5 - 4 4 5 , 12. ShenPeirong, 1989. "Biology of Mojo Freshwoter - Cultivofed fish in Cbino", Integrnled hsh forming in China, Network of Aquoculture Center in Asm ond the Pocific, Bangkok, Thailand, pp. 1 - 32
