KHOA HOC C O N G NGHfi
SO SAIMH K H i A CAIMH K Y T H U A T V A T A I CHilMH EilLTA CAC HilMH THIJC SAIXI X U A T T O M SLI {Penaeus manadaiii
T H A M I:AI\IH O TiixiH BEIM T R E
Pham Cdng Kmh^ Trin Nggc HaiS Truong Hoing Minh'
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Nhim so sanh khia canh ky thuat va tai chinh ctia cac hinh thiic san xuat trong nuoi torn sii tham canh a huydn Thgnh Phii, tinh B^n Tre, nghien ciiu nay da dupc thuc hidn thong qua viec bd tri 3 ao tlii nghidm (TN) ddng tiidi tiieo doi 3 ao d m6i hd tiidng san xuat (HTSJQ gdm ho nong din (ND), to hgp tac ^TWV) va cdng ty (Cty). Kdt qui cho thay dien tich ao nudi oTHT (0,62 ha/ao) Ion hon so voi TN (0,32), ND (0,55) va Cty (0,54). Tdm giong tiia nuoi (PL12) da dupc xet nghidm PCR 100% oTN va cac HTSX. Thdi gian nuoi ciia TTI va TUT ngin hon so voi ND va Cty, nhimg co tdm thu hoach khdng khac biet (21,8-26,7 g/con).
Hd s6 tidu tdn tinic an (FCR) d TN (1,23) tiiip hon so voi cic HTSX cdn lai (1,41-1,59). Ti Id sdng (75,1- 86,7%) vi nSng su^t tdm nudi (5,9-7,73 tin/ha/vu) khOng khic bidt giua TN va cac HTSX. Cic y^u td moi tiudng fliich hpp cho tdm tang frirdng (3,924,7096/ngay va 0,17^,23 g/ngay). Tdng chi phi ttr 635-800 ti.d/ha/vu. Gii fhanh san xuat cua TN la 91,6 nghin dong/kg thap hon 20,4-37,4 nghin ddngAg, nhung gia ban (122 nghin ddng/kg) cao bon 3-21 nghin dongAg so vdi cac HTSX con lai. Do dd lpi nhuan va ty suat lgi nhugn ciia TN cao ban so voi cac HTSX khac. Ngoai ra, nhiing thuan Ipi va kho khan tiong cic HTSX cflng duoc phan tich trong nghien ciiu nay.
lixV^dz: H^ thing san xuit, ky thu$t, Penaeus monodon, tai chinh, torn sii.
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Nginh nudi tdm nudc Ig l i mdt trong nhiing nginh kinh td mui nhgn cua nudc ta. Nim 2012 didn tich nudi tdm nudc Ig Ii 657.523 ha, didn tich nudi tdm sii chidm 94%, sin Iuong dgt 476.424 tan vai 63%
sin Itrgng tdm sti (Hidp hpi Chd bidn v i Xuit khau Thiiy sin ViOt Nam-VASEP, 2012). Tinh Bdn Tre Ii mdt tiong nhiing tinh cd dien tich nudi tdm rat phit tiidn oDBSCL Nim 2012 toin tinh cd 31.880 ha didn tich nudi tdm, ting 2,87% so vdi nam 2011, trong dd, didn tich nudi tdm sii cdng nghiep Ii 3.120 ha (Chi cyc Nudi trdng Thuy sin tinh Ben Tre, 2012). Trong nim 2012, dich bdnh xiy ra trdn didn rgng, giy thidt hgi 500 ha, bdn canh dd chi phi sin xuat gia ting, tiong khi gii bin giim Iim thidt hgi kmh te ning ne cho ngudi nudi. Hidn tai tinh Bdn Tre tdn tgi nhieu hinh thiic nudi tdm sii cdng nghidp khic nhau nhin ho ndng din (ND), td hgp tic CIHT) va cdng ty (Cty), tiiy nhidn khi nang quin Iy ky thuit cung nhu tii chinh nhu thd nio dd ung phd vdi thuc trgng khd khan trdn thi chua dtroc dinh gii cu thd. Xuat phit tir nhiing vin dd thgc td trdn nghidn ciiu " i o sinh khia c^h kp thuit vi tii chinh gida cic hinh thuc san
xuit tdm sii thim canh a huydn Thanh Phti, tinh Bdn Trd' da dugc thuc hidn.
2. PHUONG PHilP N N H CUU 2.L M d t i nghidn Clhl
Nghien ciiu niy dugc thuc hidn tir thing 5 den tiling 9/2012 tai 2 x i An Nhon v i An Didn, huydn Thanh Phu, tinh Bdn Tre ti-dn 12 ao nudi (3 ao/HTSX) vdi cic HTSX gdm ao TN, ND. THT v i Cty. TN dtroc theo ddi tai trgi nudi tdm Iflnh-TTianb;
cic ao cua ND vi THT dtrpc chpn d cic hd nudi khic nhau v i 3 ao nudi ciia Cty (Lim-Thiiy sin Bdn Tre) d i dugc chpn dd theo ddi. Mit dp tdm nudi Ii 30 con/m^ d tat ca cic HTSX.
2.2. Phuong phip thu v i phin tich miu Cic thdng sd ky thuit (didn tich mit nuac ao nudi, do siu, ngudn gidng, kich ca gidng tha nudi, FCR CO- tdm thu hogch, thdi gian nudi, ti I§ sdng v i ning suit nudO vi hidu qui tii chinh (tdng chi phi, tdng doanh thu, gii bin, lgi nhuin v i ti suat Igi nhuin thu dugc tir cic HTSJQ dtrpc ghi nhin tir thoi diem tha gidng den khi thu hoach.
Cic chi tieu mdi trudng. dp trong, dp min, dp kidm v i NH3 dugc do hing ngiy vio mdi budi sing (6 h), cic chi tidu nhi^t dp va pH dupc do 2 lan tiong ' Khoa Thuy san, Dgi hpc Can Tho
NdNG NGHllP VA PHAT TRIEN NdNG THdN - KY 2 - THANG 8/2014 65
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ngay (6 h va 15 h) trong sudt chu ky nudi, cic phuong phap phan tich v i chu ky thu miu dugc the hidn dbang 1.
Bang 1. Cic chi tieu mdi tnrdng v i phtrong phip phan tich Chi tieu
Dd trong Dd man Nhidt dd pH Dd ki^m NH3
Phuong phip phan
tich Dia secchi Khiic xa ke Nhiet ke Test sera Test sera Test sera
Chu ky thu mau 1 lin/ngav(7 ngay/lin) 1 lin/ngay (7 ngay/lin) 2 lin/ngiy (hang ngay) 2 lan/ngay (hang ngiy) 1 lan/ngav (7 ngiy/lan) 1 lan/ngay (7 ngay/lin) Tdc do tang trudng tuyet ddi (g/ngay) vi tdc do tang tmong 6.ac bidt (%/ngay) ciia cac ao nghien ctiu cung dugc thu dinh ky 10 ngay/lin tir khi tha gidng de thu hoach. Mdi lin thu 30 con/HTSX (10 con/ao), d kich CO- torn dudi 30 ngay tuoi mdi lin cin 10 con/lin (chia ra lay gia tn trung binh cho mdi con) va tir 30 ngay tudi trd' ldn mdi lan can 1 con/lin. Tdc dp tang truong va ty le sdng tdm duoc tinh toan theo cdng thu'c sau:
Tang tru'dng ngay tuyet ddi: DWG (g/ngay) - (W,-WO / (trt,)
Tang tiardng dac biet: SGR (%/ngay) = [Ln(W^- Ln(W,) / (t.rt,)] *100
Trong do:
W,: Khdi Iugng tdm tai thdi diem tj W2: Khdi Iugng tdm tai thoi didm t2 Ti le sdng (%) = (Sd lugng tdm thu hoach / Sd luong tdm gidng tha) * 100
Sd lieu sau khi dugc thu thap su dung phin mem Microsoft Excel va SPSS for Window de tinh toan va phan tich thdng ke. Cac gii tri trung binh, dd lech chuan duac tinh toan va so sanh su khac biet theo phuong phip kiem dmh (ANOVA), d mirc y nghia a-0.05.
3. KET QUA VA THAO LUAN S.L Khia canh ky tiiuit
Dien tich mat nudc ao nudi ciia cac HTSX bien dpng 0,32-0.62 ha {P<0.03} (Bang 2), tirong img vai ke't qua nghien ciiu cua Nguydn Thanh Phuong va ctv. (2008) va Barg (1992) lan lugt 0,455 ha va 0,48- 0.56 ha. Vi d dien tich nay thuan lgi cho viec chim
sdc va quin ly. Khi didn tich ao nudi nhd mdi tiirdng bidn ddng ldn theo ngay ddm v i theo miia gay anh hudng bat Igi den tdm nudi, nguoc lai khi didn tich ao nuoi ldn vide chim sdc v i quin ly gap nhieu kho khan.
Do sau ao nudi cd vai trd quan trgng trong viec dn dinh nhiet dp nudc theo ngiy dem, ddng tiidi d^
ngin nudc trin bd khi lu ve. Trong nghidn ciiu do sau cua cac ao Ii 1,80 m vi muc nudc ao nudi 1,3 m (Bang 2), nim h-ong khoang nghien cuu ciia Nguy&i Thanh Long va ctv. (2010) Ii 1-1,4 m. Theo Barg (1992) dp sau ao nudi tdm thich hgp 1,&-1,8 m, con theo Boyd (2010) Ii dudi 2 m. Nhu viy, dO siu va muc nudc ao nudi trong nghien ciru tao dieu Id^n thuan Igl cho tdm tang tnrdng va phat trien.
Chit luong gidng la mpt trong nhiing yeu to j quyet dinh ddn thinh cdng trong nuoi tom sii tham j canh. Ngudn gidng duoc cic HTSX su dung ro:
nguon gdc tu Ninh Thuin vdi ca gidng PL 12 va dime;
xet nghidm PCR trudc khi tha nudi. Theo ket qui:
didu tra cua Nguydn Thanh Phuong va ctv. (2008) co I gidng duoc cac hd nudi d tinh Sdc Trang su dung R!
10-17. Trong do, PL12 dugc chon de tha nudi nhi^ | nhit vi d cd gidng nay tdm it bi sdc vdi didu kidn moi | truong thay ddi va cd kich cd ddng ddu. j
Ca tom thu hoach phu thudc vao nhieu y^u to!
quan trong nhu: thdi gian nudi, didu kien mdi tnrong, | cham sdc va quan ly;... Trong cic HTSX tdm dirot | nudi vol thdi gian bien ddng dang ke 114-140 nga; j {P<0, OS) (Bang 2). Tuy nhidn, ca tdm thu hogch khai' i biet khdng dang ke (21,8-26,7 g/con), oTNvaCtyc* j thdi gian nudi ngin vi ca tdm thu hoach Idn hon the j hien ro trinh do ky thuat va kinh nghidm nudi cao j hon so vol ND va THT. O nghien cuu nay, ca tdm tbu j hoach ldn hon so vol nghien cuu trudc diy cua j Nguydn Thanh Phuong va ctv. (2008) vdi cd tdm ihi::
hoach la 24,4 g/con sau 150 ngay nudi. ; Ti le sdng cua tdm nudi bidn ddng Ion giiia cac j HTSX 75,1-86,7% (Bang 2). Ket qua dat dugc tmi \ ling vol nghien cuu cua Nguydn Thanh Long vi eH j (2010) la 80,1% vi cao hon so vdi ket qua khao sal:
cua Nguydn Thanh Phuang va ctv. (2008) la 59%,*:
mat dd tha nudi 17 con/m-. FCR cao hay thip phi):
thudc rat Ion vao ti Id sdng, do do a TN va THT tflm I cd ti Id sdng cao tucmg iing vn- •QR thap (1,23-1.41) | Ket qui ciia nghidn cuu tuoii mcr vol nghidncuii|
Nguydn Thanh Long vi ctv. {2<,; ( 1, 147 ^^ jjguyfc i
Thanh Phuang va ctv. (2008) l i 1 .:< \ 66
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Nitjg suit tdm nudi phu thuOc rit Idn vio trinh do ky thuit v i kinh nghidm nudi. Trong nghidn cuu ning suit dat tuong ddi cao, bidn dgng 5,90-7,73 tin/ha/vu (Bang 2) v i cao hon nhidu so vdi kdt qua
nghidn ciiu cua Ngitydn Thanh Long v i Vo TTianh Toin (2008) b mat dO 27 con/m^ la 4,95 tin/ha/vu vi d mat do 35 con/m^ l i 4,84 tin/ha/vu.
BanK 2. C4c y6i ri kf fliuSt chinh cua cac HTSX ( I B J B L Q D i ^ g i a i
Di§n tich ao nudi (ha/ao) DO sau ao (m) Muc nuDC ao (m) NRu6n Kiong Phuong phap xet nghidm CoKi6ngtha(PL) Loai thiic an (TA) Cof tdm thu hoach (g/con) Thoi gian nuoi (ngay) Tile sdng (%) Nang suat ( t ^ / h a ) FCR
HTSX TN
0,32±0,(E' l.SOtO.OO 1,30±0,00 Ninh Thuan PCR 12 UP 26,5±2,89 114+0,00"
84,at4,99 6,95+0,73 l,23+0,06»
ND 0,55±0,14"i'
1,80+0,00 1,30+0,00 Ninh Thuan PCR 12 UP 24,4+3,74 140±0,00i' 78,4±8,34 7,73+1,82 1,57+0,12">
THT 0,62+0,06''
1,80+0,00 1,30+0,00 Ninh Thuan PCR 12 UP 21,8+3,11 112+8,66' 86,7+4,35 5,90+1,25 1,41±0,16''
Cty 0,53±0,11*
1,80+0,00 1,30+0,00 Ninh Thuan PCR 12 UP 26,7+0,50 140+4,24'' 75,1+2,19 6,80+0,31 1,59+0,01'' Ghi chd- Cac gii tri trdn cimg 1 hanged chu cai khic nhau thi khic bidt cd y nghia thdng ke (P<0,05) 3.2. Bidn dOng mdi trudng nudc trong ao nuoi b
cic HTSX
Do trong it bidn ddng trong qui tiinh nudi giira cic HTSX, bidn ddng 41,8-45,8 cm O^ang 3), do vide quin Iy cic chi tidu dmh dudng tiong ao nudi chit chd (quan ly^ thiic i n cung nhu theo doi eic chi tidu bidn ddng mdi tiudng nudc tiong sudt qui trinh nudi). Theo Truang Qudc Phii vi Vu Nggc Ut (2006) do trong thich hgp cho nudi tdm 3045 cm, vi d gidi hgn niy ao nudi cd miic dinh dtrdng phii hgp, hgn chd svr phit trien qui miic ciia tio (him lupng DO vi gii trj pH it bi bidn dOng theo ngiy ddm). Ddng thai khdng giy cin tid hoat ddng ciia tom trong nudi.
Dd m$n ti-ong TN (13,8%o) tiiap hon va khac bi§t cd y nglua thdng kd so voi cic HTSX (16,4- 18,2%o) cdn Igi. TN cd dp min thap Ii do tiong qui trinh nudi hgn chd thay nudc, ndn dO min trong ao giim dan vio cudi vu (do inh hudng cua nudc mira).
DO m$n giim theo thdi gian nudi (ddi vdi TN) nhung chua giy inh hudng den dieu kidn sdng cung nhu tdc do ting trudng ciia tdm, do tdm sii cd kha ning thich nghi vdi dO man bidn ddng Idn trong chu ky nudi Ii 10-35 %o (Barg, 1992). Tuy nhidn, cung can dam bao dO min thich hgp nhat dd tdi uu tdc dp tang tru6ng cua tdm nudi.
Nhiit dg la ydu td quan trgng nhat inh hudng ddn nudi trdng thuy sin (Ld Vin Cit vi ctv. 2006).
Vio budi sing nhidt dd bidn ddng 28,6-29, PC vi budi
chidu 29,8-30,7*'C (Bing 3), nhiet dO it hi bidn ddng giua cic tiidi didm trong ngiy b cic HTSX Ii do hg thdng quat nudc trong ao nudi ngoii cung cip oxy hda tan cdn cd vai trd quan trgng dn dinh nhidt dO trong ao. Trong nghidn ciiu niy nhidt dO it bi bien ddng han so vdi kdt qua nghidn ciiu d tinh Sdc Trang cua Nguydn Thanh Long va Vo Thinh Toin (2008) vio budi sing nhidt dd 26,9-31,5*'C vi chidu 27,9- 34,2''C. Nhidt dp trong nghidn ciiu niy nim trong khoang nhidt dp thich hop cho tdm sinh trudng tdt, 22-3PC (Barg, 1992).
Gii tri pH trong ngiy bidn ddng cao hay thap phu thudc vao mit dO tio, dO man vi dO kidm trong ao (Nguydn Thanh Long vi Vo Thinh Toin, 2008).
Gii tri pH trong cic ao vio budi sing bidn dOng 7,41- 7,99, thap hon so vdi budi chidu 7,78-8,26 (Bang 3).
Nguydn nhin l i do qui trinh quang hgp ciia tio (nhidt dp vi inh sing cing cao miic dd quang hgp cua tio didn ra cinh manh), Iim giam ndng dO H*
trong ntrde. Gii tri pH trong nghidn ciiu niy nim trong khoang thich hgp (7,5-8,9) cho tdm ting tiirdng (Barg, 1992) vi tiieo Boyd, 2001 Ii 7-9.
Do kiem cd vai trd quan trgng trong vi?c dn dinh pH bidn dOng theo ngiy vi ddm. Trong ao khi dO kidm <40 mg/L thi vide didu chinb gii tri pH gap nhidu khd khin (Nguydn Thanh Long vi Vd Thanh Toin, 2008). Trong nghidn ciiu niy, dO kidm bidn dOng 44,4-86,4 m g / L Trong dd dO kidm d TN thip nhat (44,4 mg/L) va khic biOt cd y nghia thdng ke so NdNG NGHllP VA PHAT TRIEN NdNG THdN - KY 2 - THANG 8/2014 67
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voi cic HTSX khic {P<0,03} (Bang 3). Nguydn nhin cd the do dd man d cac ao TN (13,8 %o) thap hon ding ke so vol cic HTSX khac. Mat khac, do nghien Cliu nay dupc thuc hien trong miia mua (thing 5-9) vi khdng thay nudc dugc i p dung trong TT^. Ke't qua nghien ciru niy thap hon rat nhidu so vdi gidi han thich hgp cho tang trudng cua tdm sii 80-120 mg/L (Boyd, 2007). Trong cic ao cd do kidm thip cd the gay didu kidn bat Igi cho tang trudng cua tdm nudi, tdm cham lot vd va de gay nen hien tugng tdm hi bdnh mem vd (benh da thiet). Do dd, cac HTSX cin tang ndng do kidm trong cac ao nudi (dac biet vio cudi vg), vi dp kiem thuong giam vao cudi vu.
Amoniac(NH3) ti'ong ao nudi cao sd giy dgc cho tdm, ti-ong khi NHj* cd Igi cho thuc vat tiiuy sinh phit trien. Trong nudc NH3 v i NH4* chuyfii hda qua lai phu thudc v i o nhidt dO v i pH cua ninSc (Boyd, 2001). Trong ao khi nhidt dO va pH cao lam cho h i m Itrgng NH3 ting cao. Trong c i c HTSX ham Iugng NH3 bidn dgng thap 1,33-1,41 m g / L (Bang 3), do cd didu kien nhidt dO (29,8-30,7''C) v i pH (7,78- 8,26) thich hap. Theo Boyd (2001b) ham Iuong TAN thich hgp cho tdm su 1 4 mg/L. Kdt qua nghien ciiu cho thay h i m Iugng NH3 chtra gay dgc cho tdm nudi.
Bang 3. K^t qua bi^n ddng chat luong nuoc trong cac Chi tieu
Do trong (cm) Do man (%o) Nhiet do («C)
Gia tri pH Dd ki6m (mg/L) NH,(mg/L)
Thdi diem thu mau Sang Sang Sang Chieu Sang Chl^u Sang Sang
HTSX (TB + DLC) HTSX
TN 42,3±0,46 13,8+0,98"
28,7±0,01 29,8±0,12 7,41+0,05"
7,78+0,10' 44,4±9,1"
1,35+0,01"' ND 41,8+4,94 18,1+0,12'- 28,7+0,01 29,8+0,12 7,89+0,01' 8,04+0,06'' 86,4+4,88' 1,33+0,01"
THT 45,8±1,84 16,4±0,20'' 28,6±0,01 29,8+0,05 7,99+0,03'- 8,26±0,09' 65,3+4,16'' 1,37+0,02"
Cty 45,2±1,60 18,2+0,36' 29,1+0,64 30,7±1,32 7,93+0,08'' 8,15±0,07'' 75,0+3,33"
1,41+0,02' Chi chu: Cic gii tri tien cung 1 hanged chu cai khac nhau thi khic biet cd y nghia thdng ke (P<0,05)
hinh thiic nay (ND) cung thap hon (tdm chim Ion ban) so vdi cac HTSX con lai. Trong nghidn ciiu n^y tdm cd tdc do tang trudng tuydt ddi Idn hon so vdi nghien ciru ciia Nguydn Thanh Long va Vd Thanh Toan (2008), nghia la 0,15 g/ngay (d mgt dp 27 con/m^ va 0,17 g/ngay (d mat do 35 con/m^. Tuy nhien, thip hon rat nhieu so vdi nghidn ciiu tien nuoi tdm be compozit cua Nguydn Trudng An (2011) la 0,73-0,75 g/ngay d mat dp 15 c o n / m l
3.3 .Tdc dp ting tnrdng cua tdm b cic HTSX Tdc do tang tnrdng dac biet cua tdm nudi b TN cao hon cd y nghia thdng ke so vol cac HTSX cdn lai (Bang 4) va ldn hon r i t nhieu so vdi nghien ciiu ciia Nguydn Trudng An (2011) khi nudi tdm tren be voi mat dp 15 con/m^ b giai doan tdm 10 g/con la 0,43
%/ngiy. Ciing thdi gian nudi 120 ngay thi khdi luong tdm d' ND nhd hon so vdi cac HTSX cdn lai CTN ldn nhat). Do dd, tdc do tang trudng tuyet ddi cua tdm b
Bang 4. Tdc dd Dien giai
Tang trudng dac biet (%/ngay) Tang trudng tuyet ddi (g/ngay)
tang truong va nang suat cua tdm (TB + DLC) HTSX TN
4,70+0,03'' 0,23+0,01'
ND 3,92+0,05' 0,17±0,02"
THT 4,48+0,01' 0,18+0,01''
Cty 3,99+0,01' 0,19+0,02' Ghi chii: Cacgia tii tren cung 1 hanged cha cai khac nhau tiii khic biet cd y nghia thdng ke (P<0,05) Kich CO tdm thu hoach 6- cac HTSX dao ddng
21,5-26,6 g/con, tuy nhien TN va THT cd thai gian nudi ngin ban so vdi ND v i Cty (Hinh 1). 6 ciing thai gian nudi 120 ngay thi khdi luong tdm nuoi a T N la ldn nhat (28,2 g/con) va ND nho nhat (13.7 g/con) {P<0.0S}, THT va Cty lin lugt la 21.5 va 15,6 g/con.
Tdm nudi 6- TN co tdc dd tang trudng nhanh han cac HTSX cdn lai (dac biet l i ND) li do didu kidn ao nu6i (he thdng ao hoan chinh). kha nang quan Iy (it thay nudc, sir dung vi sinh cii thien mdi tnrdng), kinh nghiem va trinh dO chuyen mdn cao han so vdi cac HTSX cdn lai.
68 NONG NGHIEP VA PHAT TRIEN NONG THdN - KY 2 - TH/. G 8/2014
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- • - T N - • - N D - * TKT - • - D y
Hinh 1. Tdc dO ting tnrdng ci!ia tom theo thdi gian 3.4. Hidu q u i tii chinh
Kdt q u i phin tich cic ydu td Hdn quan ddn tii chinh cho thay trong thuc trgng hidn nay nghd nuoi tdm sii tdn chi phi diu tu cao, 635-800 tr.d/ha/vu {P>0,03i, nhung chi d' hinh thiic TN v i Cty cd Igi nhuin lin Itrgt l i 214 v i 47,6 tr.d/ha/vu, thap hon so vdi nghidn cuu trudc diy cua Nguydn Thanh Long v i ctir. (2010) l i 231 ti-.d/ha/vu. O hinh tiuic THT v i ND cd miic 16 lan lugt l i 67,8 v i 102 ti-.d/ha/vu.
Thdm vig dd ti Id Id vdn a THT v i Cty l i 67% va ND ti 100%, cao hon so vdi nghidn euu cua Nguydn Bing 5. Ca ciu chi phi, doanh thu v i
Thanh Phuong v i ctv. (2008) chi vol 7,5% sd hO nudi hi Id. Cty, THT v i ND co miic thua Id cao hon TN la do gii ttianh sin xuit cao hon lan lugt 112-129 so vdi 91,6 n£^iin ddng/kg va cao hon rat nhidu so vdi gii thinh sin xuat nim 2008 chi vdi 51,25 nghin ddng/kg (Nguydn Thanh Phuong va ctv., 2008), ddng Ihdi tdm cd kich cdr thu hogch nho (37,5-46,5 con/kg) v i gii bin hap (thdi diem nghidn ciiu) da lam ting ti Id rui ro. O TN c i c khoan chi phi dau vao dugc idem soit chat chd hon (dgc bidt chi phi TA, thudc v i hda chat), ddng thdi ban chd thay ntroc trong q u i trinh nudi v i tang lupng men vi smh dtrge sir dung dd kidm soit mdi truong, do dd Iim giim chi phi sin xuat v i tdm c6 tdc dp ting tnidng tdt hon so vdi cic ILTSX cdn lai. Bdn cgnh dd cic bidn ddng mdi trudng trong ao nudi dugc theo ddi mdi budi sing v i chidu de cd nhiing giii phip khic phuc kip thai khi cd nhiing bidn dOng mdi trudng bit Igi ddn tdm nudi.
Do cd Igi nhuin mang Igi thip ndn ti suit Igi nhuin mang Igi chi 0,0&O,33 lin CTN v i Cty) va i m 0,10-0,13 lanCTHTviND).
Igi nhujn cua cic HTSX CIB + DLC) Hang muc
Chi phi cd dinh - Khau hao cdng trinh - Thud dit Chi phi bi^n d6i - TA
Con gidng C^i tao ao Nhien lidu Nhan cdng Thudc va hda chat Lai suat ngan hang Chi phi khac Tdng chi phi Gi4ban(1.000/lgr) Gii thanh SX(1.000/kg) Tdng thu (tr.d/ha/vv) Lcri nhuin (tr.d/ha/vu) Til$aol6(%) Tisu^tl«inhuiln(LN/rC) Hi«u qua chi phi (TT/TC)
HTSX(Dvt b-.d/ha/vu) TN
38,1±1,78' 15,9±0,75' 22,2+1,05' 597+42,2 290+25,3 39,3+0,61' 59,1+4,66' 32,8+3,32"
71,4+3,31' 65,7+6,67' 23,7+1,42 15,0+1,21' 635+43,9 122+1,97'' 91,6+3,41' 849+104 214±60,3' 0"
0,33+0,07' 1,33+0,07'
ND 29,9±8,88'' 12,3+3,68"
17,6+5,23"
770+67,9 398+33,7 27,6+0,42' 55,1+15,8' 73,7+21,7'' 45,2+15,8"
122+18,2"
29,0+2,76 20,3+2,82' 800+76,8 114±6,36"
129+4,31' 701+83,2 -102+10,0"
IOC -0,13+0,02' 0,88+0,02"
THT 27,6+2,87' Il,4±l,16' 16,3+1,68"
639+126,5 294+81,5 23,8+1,41"
29,8+4,62"
43,7+7,32"
66,3+10,4' 64,4+29,0"
24,1+4,67 93,3+19,1'' 667+129 101+6,52"
114+13,6"
599+160 -67,8+97,6'
67' -0,10+0,15"
0,90+0,15"
Cty 36,2+1,09"
14,9+0,42*
21,3+0,64"
727+139,4 338+126 27,2+0,07' 45,3+0,35"
76,9+1,55' 51,9+1,56"
139+4,24' 27,6+5,09 21,8+0,49"
763+141 119+0,35' 112+15,6"
811+39,9 47,6+101'' 67' 0,08+0,15"
1,08+0,15"
Ghi chu: Cac gid tri tr&n cung 1 hang co chd cai Idjac nhau thi Idiac bi$t co y nghia thdng lie (P<0,05);
LN: lgi nhuin: TC: ting chi va TT: t6ng thu
NdNG NGHllP VA PHAT TRIEN N 6 N G THON - KY 2 - THANG 8/2014
KHOA HQC CONG NGHE Co cau chi phi bien ddi chiem phin ldn trong
tdng chi phi nuoi tdm 94-96%, cao hon so vdi nghien Cliu ciia Nguyen Thanh Phuang va ctv. (2008) d miic 93,5%. Trong dd, chi chi TA cao nhat 43-50% va khdng cd su khac biet ldn giUa cac HTSX. Chi phi thudc va hda chat d Cty (18%) va ND (15%) cao hon so voi TN va THT a miic 10%. Sii dung lugng thudc va hda chat Idn trong qua trinh nudi se gay ndn nhiing tic dpng tieu cue den moi trudng sinh thai (6 nhidm mdi trudng), tang gia thanh san xuit va khdng dam bao an toan ve smh thyc pham cho ngudi tieu dung (tiem an nguy ca ngd dgc thuc pham va khd vuot qua rao cang ky thuat khi xuat khau). Do do, viec giam lugng thudc va hoa chat sit dung la can thiet ddi vdi hinh thtic Cty va ND. Ngoai ra chi phi sir dung nhien lieu de thay nudc, cdng lao ddng, lai vay ngan hang binh quan 5-10% d mdi HTSX.
cdng lien ic ucmz Hinh 2. Co cau chi phi bien ddi CIT^
Tiiudc KH Lii>m CP
•feHCihue cong 4''^ kJiac 15% dat trinb >'-.
cone lie^j ^,^, 6% i,% -,.
Con sions
Time KH dk com ^^^ >'-H -ft-j.-i.^^ 2"^v tnnh -"-=
V HC
Hinh 4. Ca ciu chi phi bidn ddi (THT) Time ^ ^ LSiNH ^ cong ^5,- khac trinh ' 3%
Hmh 3: Co cau chi phi bien ddi (ND)
Nhau Nhien Cm mo -^Coii cdng lieu ao gidng
7% W.'n 6% ''^%' Hinh 5: Co cau chi phi bien ddi (Cty) 3.5. Thuan lgi v i khd khan cua cac HTSX
Thuan loi: Nhd- cd didu kien tu nhien thuin lgi, nim trong vimg qui hoach nudi tom tham canh ciia tinh nen thudng xuyen duac hd trg ky thuat cua cac nha khoa hoc. Hon niia, ngudi nudi cd nhieu kinh nghiem nudi torn. Hinh thu'c Cty cd ngudn vdn ldn, chi phi ti-ung gian thap (hen kdt vdi Cty cung cap thiic an, thudc va cung cap san pham true tiep cho nha may che bien), ngudn thdng tin thi trudng tdt va ngudn nhan luc cd trinh do ky thuat cao. 6 hinh thuc THT, ngudn vdn duoc hd tro giira cac thanh vidn trong td hgp tic, ngudn thdng tin cung nhu cac vii de ky thuat thudng xuyen dugc chia se vol nhau. 0 hinh thiic ND, cd so ao nudi nho ndn vide cham soc va quan ly dugc chat che hon. Q hinh thiic TN, chii dpng dugc ngudn vdn cung nhu trinh do chuyen mdn cao nen vide quan ly tro- ndn chat che hon.
Khd khan:Trong nhimg nam gan diy benh hoai tir gan tuy (EMS) ngiy cing tid' nen nguy hiem hon.
Nhidu hd nudi bi thiet hai ldn ve nang suit vi thu nhap (nam 2012). Ben canh dd, chi phi diu tu cao trong khi gii tdm thuang pham bidn dgng ldn v^
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 8/2014
KHOA HOC C O H G N G H t
thudng t h ^ . Trong khi dd vide tidp can ngudn vdn ngin hing it dugc quan tim lim thidu vdn s i n xuat Ddi vdi ND, trinh dd din tri thap nen vide i p dvmg thanh tuu khoa hoc vio trong sin xuat cdn nhidu hgn chd; b THT, fliudng xuat hidn nhung m i u thuin tiong nOi bO. giy mit doin kdt, cd nhidu y kidn trii ngugc nhau ndn lim han chd su phit tridn; d TN, dipn tich ao nudi nhd nen vide kidm soit mdi trudng khd khin hon; d Cty, ed qui md sin xuat ldn ndn khi dich benh xiy ra dd liy Ian trdn dien rdng giy thiet hgi nang vd kinh t^. Ngoii ra, cdn tdn tgi rihieu miu thuan tiong nOi bd ciia cic cdng nhin ndn vide quan Iy cdn nhidu bat cap.
4.KETLU0NVABEXIMT 4.1. Kdt luin
Didn tich ao nudi ciia TN nhd ban so vol cie HTSX cdn Igi. DO s i u muc nudc ao nudi, ca gidng thi, phuong phip xet nghiOm v i logi TA duge su dung gidng nhau df cic HTSX. Thdi gian nudi cua TN vi THT ngin hon so vdi ND v i Cty, tuy nhidn TN v i Cty tdm cd tdc do ting tnrdng nhanh ndn kich ca thu hogch ldn ban so vdi ND viTHT. FCR a T N dugc su dung hidu qua ban cic HTSX cdn Iai, tuy nhidn ti Id sdng vi nang suit nudi (5,90 - 7,73 tan/ha/vu) khdng khac bidt ldn giila cic HTSX.
DO trong v i nhidt dO (sing, chidu) giira cic HTSX khdng cd sg khic biet ldn. DO min v i dp ki^m b TN tiiip hon cic HTSX cdn lgi. Gii tii pH (sing, chidu) v i NH3 cd su khic biet giira cic HTSX, nhung ddu nim trong khoing thich hop cho ting trudng cua tdm sti.
Tdng chi phi dau tir cho md hinh Ii k h i cao 635- 800 tr.d/ha/vu. Tuy nhien, TN mang Igi Igi nhuin cao nhit; Cty cd Igi nhugn thap; THT v i ND Id vdn lin lugt Ii 67,8 v i 102 ti-.d/ha/vu. Ti Id Id vdn Ii k h i cao (67-100%) 6 hinh tiuic ND, THT v i Cty. Ti suit Igi nhugn chi -0,1^,33 lan 6 cic HTSX.
4.2. Dd xuit
Ky thuit dd ning cao hon niia vd mat ky thuat trong md hinh nudi tdm su thim canh g tinh Bdn Tre nhiing giai phip sau day dugc dd xuat (1)0 TH didn tich ao nudi torn ndn tang ldn 0,4-0,6 ha/ao dd tidn loi cho vide quin ly v i k h i ning diu tii; (2) ND vi Cty cin chgn TA cd chit lupng v i ning cao ky tiiuit quan IJ TA dd giam FCR tit)ng sin xuat v i (3) ND v i THT ti-ao ddi tfldng tin ky thuit v i bidn dgng tiii tiirdng nhi^u hon.
Tai chinh: de giim riii ro cho nghe nudi tdm sii thim canh b cic HTSX thi (1) Cty can giam chi phi su dung TA; ( ^ ND v i Cty can giim chi phi su dung thudc & hda chat v i nhidn hdu dd thay nuoc; (3) THT can chpn ra ngudi cd ning luc dd quan Iy chung, trinh mat doin kdt giira cic thinh vidn.
Tiii UEU THAM nUO
1. Barg V. C , 1992. GuideUnes for tiie Promotion of Environmental Management of Coastal Aquaeulture Development EAO Fisheries Technical Paper No. 328. EAO, Rome.
2. Cao Thanh Trung, Nguydn Van Hao v i Ld Hdng Phudc, 2011. Tliuc trgng sii dung thudc, hda chat v i chd pham sinh hpc trong ao nudi thim canh, vin dd bdnh trdn didn rdng d cic md hinh trang trai d My Thanh, Sdc Trang. Vidn Nghidn cuu NTTS 2.
3. Chi cue Nudi trdng Thuy s i n tinh Ben Tre, 2012. Bio cio tdng kdt tinh hinh thuc hien nhiem vu cua nam 2012 v i giii phip thuc hidn nhi^m vu nim 2013 cua Chi cue Nudi trdng Thiiy sin tinh Bdn Tre.
4. Claude E. Boyd, 2001a. Water quahty standards: pH. Sustainable aquaeulture practices. Pp.
4244.
5. Claude E. Boyd, 2001b. Water quality standards: Total ammonia rutrogen. Sustainable aquaeulture practices. Pp. 84-85.
6. Claude E. Boyd, 2007. Total alkalmity, ti)tal hardness. Sustainable aquaeulture practices. V^. 64- 66.
7. Claude E. Boyd, 2010. Water temperature in aquactdture. Sustainable aquaculttue practices. Pp.
28-30.
8. Ld Vin Cit, Dd Thi Hdng Nhung v i Ngd Ngpc C i t 2006. Sich Nudc nudi thiiy sin chat lugng vi giai phip cii thidn chat Iugng. Sd 136- 2006/CXB/16OO6/KHKT. NXB Khoa hpc Ky tiiuit - H i Ndi.
9. Nguydn Thanh Long v i Vo Thinh Toin, 2008. Dinh gii muc dd tich liiy dgm, lin tiong md hinh nudi tdm su {Penaeus monodon) tham canh.
Tgp chi Khoa hpc. Trudng Dgi hpc Can Tha. Trang 44-52.
10. Nguydn Thanh Long, Duong Vinh Hao va Ld Xuin Stiih, 2010. Phin tich cic khia cgnh kmh td vi ky thuit ciia md hinh nudi tdm sii {Penaeus monodon) thim canh d tinh Sdc Tring. Tgp chi Khoa hpc. Trudng Dgi hge Can Tho. Trang 119-127.
N C N G NGHllP VA PHAT TRIEN NONG THON - KY 2 - THANG 8/2014
KHOA HOC CONG NGHE
11. Nguydn Thanh Phuong, Vo Nam Son v i Vo nudi trdng thiiy san. Khoa Thiiy sin Dai hoc Can Van Be, 2008. Phin tich cic khia canh ky thuit v i Tha.
kinh td mo hinh nudi tdm su {Penaeus monodoh} 13. Truong Qudc Phu v i Vu Ngoc Ut, 2000. Giao tham canh rai vu d Sdc Trang. Tap chi Khoa hpc. trinh: Quan ly chat luong nuoc trong nudi ti6ng Trudng Dai hge Can Tha. Trang 157467. Thiiy sin. Khoa thuy san - Dai hge Can Tha.
12. Nguydn Trudng An, 2011. Nghien cuu su 14. VASEP, 2012. Bio cao tdng kdt nginh tdm dung ciy nan tuong de cai thien mdi trudng ao nudi Vidt Nam nam 2012 v i xu hudng nam 2013.
tdm sii {Penaeus monodon). Luin van cao hge nginh
COMPARISON OF TECHNICAL AND FINANCIAL ASPECTS IN DIFFERENT INTENSIVE SHRIMP {Penaeus monodon) PRODUCTION SYSTEMS IN THANH PHU DISTRICT, BENTREPROVINCE
Pham Cong Kmh, Tran Ngoc Hai, Truong Hoang Minh Stunmaiy
In order to compare the technical and economic status in different intensive shrimp (Penaeus monodon) farms in Thanh Phu district, Ben Tre province, this study was earned out in three expenmental ponds (Exp) and in other three ponds m each shrimp produchon system (PS) which consists of farmers ponds (Far), coorperative farmers' ponds (Cop) and company" ponds (Com). Results showed that ponds area of Cop (0.62 ha/pond) was larger than tiiat in Exp (0.315), Far (0.553) and Com (5.43). 100% of stocked postparvae (PL12) were tested by PCR method ui Exp and the PS. Culture penods of Exp and Cop were shorter than that in Far and Com but harvest sizes were not different (21.8 - 26.7 g/pieces). Feed conversion rate (FCR) in Exp (1.23) was lowest than that in the other PS (1.41-1.59). The survival rate (75.1-86.7%) and yield m Exp were not different from the other PS. Environmental parameter variations were suitable for shrimps growth (3.92 4.70%/day and 0.17 - 0.23 g/day). Total cost was ranged from is VND 635-800 miihon/Oia/crop. Cost price in Exp 91.6 thousand VND/kg was lower from 20.4 to 37.4 thousand VND/kg, but farm gate price (122 thousand VND/kg) was higher than from 3 to 21 thousand VND/kg in the other PS. Therefore, profit and benefit per cost in Exp were higher than that in the other PS. In addihon, advantages and disadvantages in all PS were identified in this study.
Keyword: Shrimp. Penaeus monodon. production system, technique, f nance.
Ngudi phin bidn: TS. Nguyen Thanh Timg Ngiy nhin bii: 9/5/2014
Ngiy thdng qua phin hien: 9/6/2014 Ngiy duydt ding: 16/6/2014
72 NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 8/2014
