Dd Minh Vanh, Tran H o i n g Tuan, Tran Ngpc H i i w Quyen, Nguyen Thi Kim, Sano Masaa^' J"'* ^^f^
T r u o n g H o a n g Minh. 2016 Danh gii hieu q u i nudi Miziiho,2019 Current Situation of \ ;- ..M""^^''!"
tdm the chan trang t h i m eanh theo cac hinh thflc td in White Lea Shrimp (Litopen.h t i i f i ' n ' " " "
chflc d ddng bang song Cflu Long. Tqp chi Khoa hoc Intensive Farming: Focus on Dise.i^L -. .nirol i" 'he TrUdng Dai hgc Cdn Vid. quyen 2 (42): 50-57. Mekong Delta, Journal of Regional Fi^hcric<. ^'^ ^^f- C h a n r a t c h a k o o l , R, a n d Phillips M. J., 2002. Social and 146-156.
Economic bimpacts and Management of Shrimp Thuy, Nguyen Thi T h a n h , a n d Ford, A.-010, Learning Disease among Small-scale farmers in Thailand from the neighbors: economic and environmental and Vietnam. In Arthur J. R. Ed. Primary Aquatic impacts from intensive shrimp fanning m the Heahhcare in Rural, small-scale, aquaculture Mekong Delta of Vietnam Journal of Sustainability Development. FAO Fish: Technical Paper. No. 406: (2): 2144-2162. Online https://doi.org/10.3390/
177-189. SU2072144.
Comparison of production efficiency between white leg shrimp intensive VietGAP and non-GAP applied systems in Soc Trang province
Huynh Van Hien, Dang Thi Phuong, Nguyen I h i Kim Quyen, Le Nguyen Doan Khoi and Nobuyuki YAGl Abstract
The resuhs showed that the scale of VietGAP applied farms was smaller (8,189 m-) than non-GAP farms. Slocking density, production period and FCR ratio were not significantly different between the two systems. The yield in VietGAP model was 6.1 tons/ha/cycle, higher than non-VietGAP system (5.3 tons/ha/eycle). The production cost in VietGAP system (466 million VND/ha/cycIe) was also higher than n o n - G A P system (398 million VND/
ha/cycle), but higher profits (192 compared to 157 million VND/ha/cycIe, respectively) aUhough no significant difference and similar margin profit ratio (0.4 time). Consequently, shrimp culture according to VietGAP need to be encouraged and expanded because of good management of technical indicators and potential financial efficiency because of producing high quality products meeting the requirements for export and creating premise to benchmark international ecrtificitions such as ASC.
Keywords: White leg shrimp, production efficiency, VietGAP standard, Soc Trang province
Ngay n h a n bai: 25/12/2019 NgUdi p h a n bien: PGS.TS N g u y e n T h a n h L o n g Ngay phan bi?n: 02/01/2020 Ngay duyel d i n g : 13/01/2020
NGHIEN CCru UONG AU TRUNG TOM C A N G XANH THEO CONG NGHE BIOFLOC V6l CAC Ti LE C/N KHAC NHAU
Pham Minh Truyen', Lg Thanh Ngh!^
Chau Tai Tao', Nguyen Van H 6 a \ Tran Ngpc Hai' TOM TAT
Nghien cflu nham xae dinh ti le C/N thich hpp cho tang trUdng va ty le sdng cua au triing va hiiu au t r u n s tdm cang xanh (Macrobrachiiim rosenbergii) tot nhal bang cdng nghe biofloc. Nghien eflu gom 5 nghitrm thflc bd sung d u d n g eat vdi ti le C/N k h i c nhau lan lUOc la 12,5; 15; 17,5; 20 va nghiem thflc khdng bd sung kmi doi chflne moi nghiem thflc dupc lip lai 3 lan. Be Udng torn b i n g composite cd the tich 500 lit va nUdc Udng co dp man 12%o Au triing tdm dUdc Udng vpl m i l dp 60 eon/L va dddc cho an bang Artemia v i thflc an nhan tao Kel q u i nghien cflu cho thay sau 35 ng.n Udng, tdm d nghiem thflc ti le C/N bang 17.5 cho ket q u i tang trUdng chieu dai Pi,. ] 5 ^^^ ^ j ^ - ^ ( l l . S + 0,1 m m ) khac biet cd y nghia thdng ke d p < 0,05 so vdi nghiem thUc ddi chflng. Ty le si.r.^ '~-,f,g + j „ „ , . va nang hU.it (34.080 ± 1.111 con/m') tom PL-13 cao nhat d nghiem thflc ti le C/N b i n g 17,5 kh,., ^,„ , [,-'• '^.^
thdng ke (p > 0.05) so vdi cie nghiem thUc cdn lai. V) vay cd the ket luin r i n g , li le C/N b i n g 17 •, „-,, nf,|. r Udng au trung tdm cang xanh bang cdng nghe biofloc-
Tfl khda: Au trung tdm cang xanh, biofloc, tj le C/N
'Nghien cflu sinh Nuoi trdng thuy sin Khda 201", Hoc vien cao hpc khda 25 ' Khoa Thuy san - Dai hoc Can Thd
:ap chi Khoa -"cc Cong --jne \
-z^iepVie'.Nan:
I.DATVANDE
Tdm cing xanh li ddi tflpng cd gia tri kinh te cao va dflpc nudi pho bien hien nay Tuy nhien, trd ngai Idn nhat ddi vdi nghe nudi tdm cang xanh hien nay la thitfu tdm gidng va chat lupng gidng khdng dam bao.
De tim giai phap cho nghe san xuat gidng tdm cang xanh theo hUdng an toan sinh hoc thi viec flng dung cdng nghe biofloc Irong Udng au trimg tdm cang xanh de tao ra con gidng chat luong cao phuc \ai cho nghe nudi la rat can thiet. Biofloc cd tac dung nhu li che phi'm sinh hpc va cd nhieu vai trd quan trpng trong viec dn dinh mdi trUdng nUdc, an loan sinh hpc. ngin ngfla mam benh, lim thflc an trflc tiep cho tom, ting cfldng dudng chal tU nhien, giam d nhiem moi trUdng (Mcintosh el ai, 2000). Hien nay cd cac cdng trinh UPng gidng tdm cang xanh theo cdng nghe biofloc (Chau Tai Tao va ctv., 2016; DUdng Thien Kieu, 2018). Tran Ngoc Hii va cdng tdc vien (2018) cd nghien cflu bo sung ngudn carbon bing bdt gao vi ri dudng trong fldng au trung tdm cang xanh bang cdng nghe biofldc cho ket qua tdt. Ben canh dd, de ning cao ty le sdng va tang trfldng cua au trung va hau au trflng Idm cing xanh thi viec xdc dinh dfldc ti 1^ C/N ihich hdp de Udng au trung tdm cing xanh trong he thdng biofloc la rat quan trpng va can dupc thflc hien nhim gdp phan hoan thien quy trinh Uong nudi tdm cang xanh dat hieu qua cao.
IL VAT LIEU VA PHUONG PHAP NGHIEN CtfU 2.1. Vat lieu nghien cflu
Vat lieu nghien cflu: Be composite cd the tich 0,5 m\ be xfl ly nfldc 10 m'.mdybdm nfldc, xd nhfla, vpl, khuc xa ke, kinh hien vi, cin dien tfl, miy thoi khi, da bpt, binh ndn imhoff.
2.2. PhUPng phap nghien cflu 2.2.1. Nguon nUdc thi nghiem
Ngudn nfldc thi nghiem dflpc lay tfl ngudn nfldc ngpt (nfldc may thanh phd) pha vdi nfldc dt (dp man tfl 80 - 100%o dfldc lay tfl rudng mudi d huyen \'inh
Chau, tinh Sdc Trang), de tao thinh nfldc cd dp man 12%o sau dd duoc xfl ly bing chlorine vdi ndng dp 50 ppm, sue kbi manh cho het Ifldng chlorine trong nfldc, tiep theo diing Bicarbonate Natri nang dp kiem len 100 mg CaCO,/L va cudi eung bdm qua dng vi lpc 1 pm trfldc khi sfl dung.
2.2.2. Nguon au triing tom cdng xanh
Chpn tdm cing xanh me mang trflng miu xim den, chat lflpng tdt, khde manh, kich cd lfl 50 - 80 g/cdn, miu sic tfldi sang cho vao be ap nd cd the tich 500 lit. dp man 12%o. Sau khi trflng nd thinh au triing, chon au trung cd tinh hfldng quang manh de bd tri thi nghiem.
2.2.3. Tao biofloc
Cich tao bidfloc: Biofloc dfldc tao bing ngudn carbon tfl dfldng cdt (Bien Hda Pure) vdi cac ty le C/N khae nhau, dudng cat cd 55,54% C dUpc phan tich d Trung lim ky thuat tieu chui'n do Ifldng chat lUdng Can Thd, Dfldng cat dUpc pha bang nfldc am 60"C, vdi ty le 1 : 3 (1 dudng: 3 nUdc thed khdi Ifldng), khuay deu, va u trong 48 gid trUdc khi chd vid be fldng tdm. Phfldng thflc bo sung dudng cat dfla theo lupng thflc an nhin tao sfl dung la Lansy PL cd 48%
protein, dudng cat dfldc bo sung 3 ngay mdt lan dfla tren Ifldng thflc an cho tdm trong 3 ngay. Lflpng dfldng cat can bo sung vao be de tao biofloc dfldc tinh dfla theo cdng ihflc cua Avnimelech (2015).
Dudng cat dupe bo sung khi be fldng cd au trung xuat hien giai doan 4,
2.2.4. Bo tri thi nghiem
Nghien cflu gdm 5 nghiem thflc bd sung dfldng cat vdi ti le C/N khic nhau lan Ifldt la 12,5; 15; 17,5.
20 va nghiem thflc khdng bd sung lam ddi chflng.
mdi nghiem thflc dfldc lap lai 3 lan each bd tri hoin toan ngau nhien, be fldng bang composite 500 lit, the tich nfldc 400 lit, dd man 12 %o, mat do au trung 60 con/L, thdi gian thi nghiem la 35 ngiy 2.2.5. Chdm soc vd qudn ly du triing tom cdng xanh Bang 1. Cong thflc thflc an che bien cho au trflng tdm cang xanh
Giai doan au trung Giai doan 1 Giai doan 2 - 3 Giai doan 4 - 5
Giaidoan9-PL15
Loai thuc an Au trung (AT) artemia Thflc an Lansy PL Au trung artemia ThUc an Lansy PL A.U triing artemia Thflc an Lansy PL Au trimg artemia
Lupng thflc an Khdng cho an 1 AT arlemia/mL nUdc Udng 1 g/m'/lan
3 AT arlemia/mL nUde Udng 1,5 g/m'/lan
3 AT artemia/m\ nUde Udng 2 g/mVlan
4 AT ar(emifl/ml nUdc Udng
So lan cho an
2 lan/ngay (vio luc 7h vi 17h)
3lan/ngay (8h. I l h v i 14h)
1 lan/ngay (17h)
3 ian/ngay (8h, llhva 14h)
1 lan/ngay (17h)
3 lan/ngay (8h, ilhva 14h)
1 lan/ngay(17h) _
e:\j'^-Sd h ' 'J' 2020 Hang ngay theo ddi hoat ddng bdi ldi cua au trung \ j lupng thdc an cho iu trung an. Au trimg tdm cang xanh dUdc chim soc va eho in theo bing 1.
Trong thdi gian Udng khdng tha) nUdc, sue khi lien tuc de dam bao sU Id Iflng cua hat biofloc.
2.2.6. Cdc chi tieu theo ddi vd thu mdu phdn tich
- Chi lieu mdi trddng nfldc: Nhiet dd do bing nhiel ke, pH do bing may do pH, cac chi tieu nay do 2 lan/ngay (vao luc 8h vi I4h). Dp kiem, T.-\N va NO, dinh ky thu mau 7 nga\/lan. Ddi vdi dd kiem dfldc phan tich bing phfldng phdp chuan dd acid, T.AN dflpc phan tich bing pbUdng phdp Phenale va NO, dupc phan lich bang phupng phap Diazonium (APHA,2005).
- Cic ehi tieu theo ddi tdm: Chi sd bien thai cua au trflng (LSI) dupc xac dinh 3 ngay/1 lan, mdi lan thu ngau nhien 10 au trung/be, chi sd bien thai cfla au trung tdm cang xanh theo ddi den ngay thfl 21.
Chieu dai au trung va hiu au trung dUpc do d cac giai ddan 1, 5, 11, PL-I vi PI -15, mdi lan do 30 con/be. Ty le sdng va sinh khdi cua PL-15 dUdc tinh bing phfldng phap dinh lUpng khdi lUpng tdm, tfl dd xic dinh dfldc sd tdm trong be.
- Chi tieu VI sinh: Vi khui'n tdng sd va vi khuan Vibrio trong nfldc, dfldc xae dinh 15 ngay/lan. Vi khuan tdng sd vi vi khuan Vibrio trong tdm dfldc xac dinh cudi thi nghiem. Xae dinh mat dp vi khuan theo phUdng phap cua Huys (2002),
- Chi lieu biofloc: The tich biofloc (FV) dUdc xac dinh khi be Udng cd tdm d giai doan PL-5, PL-10 va PL-15 bing binh imboff, xae dinh kich cd hat biofloc bang each do chieu dai va chieu rdng ngau nhien 10 hat biofloc dUdi kinh hien vi cd trie vi thi kinh.
2.2.7. PhUcfng phdp xu' ly so lieu
Cac sd li^u thu thip dupe tinh todn cdc gia tri trung binh. dp lech chuan bang phan mem Microsoft Excel 2013, so sdnh sU khac biel gifla eac nghiem
thflc theo phUdng phap phin tich ANO\A m*-' nhin td voi phep thfl Duncan bing pb.in • em thong ke SPSS 22.0 d mflc y nghia (p < 0.051
2.3. Thdi gian vi dia diem nghien cflu Nghien cflu dUpc ihflc hien tfl thang 3 dei -'^^"S 4 nam 2019 tai Trai thflc nghiem niiOc Id, Khoa thuy san, Trudng Dai hpc Can Thd.
III. KET QUA VA THAO LL.\N
3.1. Cac yeu to mdi trfldng trong be uong au trung Trong qui trinh Udng au trung idm cang xanh cac yeu td mdi trudng dfldc the hi^n trdng bing 2. Cac gia tri nhiet dp, pH gifla cdc nghiem thflc chenh lech nhau khdng ding ke. Nhiet dp trung binh trong cic be flong cua thi nghiem dao dpng tu 29,4 - 31,2''C.
Rao vi Tripathy (1993) cho ring nhiet dd thich hpp cho sU phat trien cua au trung tdm cang xanh dao ddng trong khoang 26 - 31"C.
pH trung binh budi sang vi chieu cua thi nghiem dao dpng khdng Idn tfl 8,14 - 8,31. Nguyen Thanh PhUdng va cdng tic vien (2003) cho ring pH tfl 7 - 8,5 la thich hdp cho Udng au trung tdm cang xanh.
Bang 2 cho thay ham lfldng NO, d cac nghiem thflc dao dpng tfl 0,57 - 1,07 mg/L vi ham Ifldng TAN dad ddng tfl 0,8 - 1,76 mg/L. Theo Sandifer vi Smith (1985), nfldc Udng au triing tdm cang xanh thi ham Ifldng TAN phii dudi 1,5 mg/L va ham Iflpng NO^
khdng nen vfldt qua 1,8 mg/L. Qua ket qua phin lich chd thay dp kiem trong nfldc fldng au trung dad dpng trong khoang 111,9 - 116,4 mg CaCO^/L, Theo Chiu Tai Tao va Tran Minh Phu (2015) thi dd kiem thich hpp cho au trung va hau au trung tdm cang xanh tfl 100 - 120 mg CaCO IL.
Nhfl vay cdc yeu td mdi trfldng nhiet dp, pH.
TAN, NOjVa dp kiem cfla thi nghiem deu nam trong khding thich hdp cho Pong au trflng tdm cing xanh.
g 2. Cac ehi lieu moi trddng trong be Udng au trung tdm eanh xanh Nghiem thflc ty le C/N
Nhu -ldp(-C) pH NO. (mg/L) T A N l m g . n E)p luem (mg
Sang Chieu Sang Chieu
CaCO,;L)
Doi chdng 30.1 ± 0 , 3 31.0 ± 0 , 2 8.16 ±0.02 S,31 ±0.02 1.07 ± 0 . 2 5 1.76 + 0.36 114.9 ± 2 , 6
12,5 29.4 ± 0,6 30.7 ± 0,5 8,14 ± 0 . 0 3 8.29 ± 0.04 0.57 ± 0.06 0 93 ± 0,67 116,4 ± 4 , 5
15 30,0 ± 0,7 31,2 ± 0 , 5 8.14 ± 0 , 0 2 8,31 ± 0 . 0 1 0.87 ± 0,06 0.92 ± 0,29 114,9 ± 2 . 6
J 7,5 30,0 ± 1.0 31,0 ± 0 . 7 8,14 ± 0 , 0 4 8,28 ± 0.03 0.87 ± 0.40 1.17 ± 0 , 5 2 1 1 1 , 9 1 4 . 5
20
29,7 ± o.r
3(1,9 ± 0 . 1
^ ' I 5 ± 0 . 0 1 ' M ± 0.03 '•''5±0.-,3 ' " « ' ± ' J I 6 ' • ' • ^ i : : i ,
Ghi chu Cdc gid tri trong cimg mot hdng co k-i ru khac nhau thi khdc biel co y nghia thong ke (p
TapchiK^o^nocC i ''gheD^ie! Nam - 3.2. ("ie chi t i e u vi s i n h
3.2.J. Vikhud'ntong
Bang 3 c h o thay m a t d p vi k h u a n t d n g t r o n g nUdc d cac n g h i e m thflc cua thi n g h i e m d a o d d n g tfl 1,05 - ^?,3 « 10* C F U / m L khac biet cd y n g h i a t h d n g ke (p < 0,05) gifla c i c n g h i e m thflc. T r o n g dd, n g h i e m thflc lv le C/N 12,5 la c a o n h a t d hai lan t h u m a u , k h i c biet cd y nghia t h d n g ke (p < 0,05) so vdi cdc nghi?m thflc c d n lai. N g h i e m thflc ty le C / N 20
m a t d p vi k h u a n t d n g t r o n g nUdc t h a p n h i t , nhflng k h i c biet k h d n g cd y n g h i a t h d n g ke (p > 0,05) so vdi n g h i e m thflc t i l e C / N 15 v i 17,5.
Ben each dd, ket q u a p h i n tich m a u t d m c h d thay m a t d d vi k h u a n t d n g d a o d d n g 111,9 x 10* - 369,2 "
10' C F U / g . C a o n h a t d n g h i e m thflc ti le C/N = 20 vdi m a t dp vi k h u a n tdng 369,2 » 10' C F U / g va k h i c biet cd y n g h i a t h d n g ke (p < 0,05) so vdi cac n g h i e m thflc c d n lai.
B i n g 3. M i l dp ^ Chi ti£u Lan t h u Vi khuan 1 trong nUdc 2
\'i khuan trong tom
khuan tong trong mau nddc ( 1 0 ' C F U / m L ) va trong tdm (IO'CFU/g) N g h i e m thflc ty Ie C/N
Ddi chdng 12,5 15 17,5 20 3,53 ± 0 , 8 9 ^ 4,4 ± 1 , 8 ' 1,95 + 0,18^ 2 . 4 ± 1 , 0 " ' 1,05 ±0.17^
27,5 + 1'" 35,3 ± 15,2-= 28,0 ± 21,9^ 14,3 ± 7,P'' 10,7 + 0,8' 218,6 ± 34,7'' 111,9 ± 36,9" 167,2 ± 29,5^^ 112,7 ± 26- 369,2 ± 46' G/i( chu: Cdc gid tri trong cimg mgt hdng co ky tU khdc nhau thl khdc biet co y nghia thong ke (p < 0,05).
3.2.2. Vi khuan Vibrio
Mat dp vi k h u a n Vibrio t r o n g nfldc fldng t d m trung binh trong 2 lan t h u m a u d cdc n g h i e m thflc bien d p n g tfl 1,3 x 10" d e n 70,2 x 10- C F U / m L (Bang 4). Phan tich m a u lan I cho thay n g h i e m thflc doi chflng m a t dp vi k h u a n Vibrio cao n h a t k h a c biet cd y nghia t h d n g ke (p < 0,05) so vdi cac n g h i e m thflc cdn lai, mat dp Vibrio t h a p n h a t d n g h i e m thflc ti le C/N 15. 6 lan t h u m a u khi ket thiic thi nghiem, n g h i e m thflc ti le C / N 17,5 v i 20 cd m i t do VI khuan Vibrio cao n h a t lan lUdt la 70,2 x 10^
va 67,3 X 10- C F U / m L k h a c biet cd y nghia t h d n g
ke sd vdi c i c n g h i e m thflc c d n lai, n g h i e m thflc cd m a t dp Vibrio t h a p n h a t d n g h i e m thflc cd ti 1$ C/N b a n g 12,5, nhflng k h a c biet k h d n g cd y nghia t h d n g ke so vdi n g h i e m thflc cd ti le C / N b i n g 15. M i l dp VI k h u a n Vibrio t r o n g t d m cua n g h i e m thflc ty le C / N - 12,5 v i n g h i e m thflc 17,5 k h d n g cd vi khui'n Vibirio va k h a c biet cd y nghia t h d n g ke (p < 0,05) so vdi cdc n g h i e m thflc eon lai. Trong n g h i e n cflu ciia Tran Ngpc Hai va cdng t i e vien (2018), fldng au trung torn c a n g x a n h t r o n g h e t h o n g biofloc vdi cdc n g u d n c a r b o n k h a c n h a u m a t d o Vibrio len d e n 15,8 ± 1,05 X 10' C F U / m L chUa thay a n h hUdng den au t r u n g . B i n g 4. Mat dp vi khuan Vibrio trong mau nUdc (10^ CFU/mL) va trong tom (10^ CFU/g) u Lan thu
20 1
N g h i e m thflc ty le C/N
Ddi chUng 12^ 15 17,5 6.4 ± 1,2^ 4,3 ± 0,9'' 1,3 ± 0,3' 4,6 + 1,2'' 1,5 ± 0,5' 45,7 ±10,8'' 12,3 ± 2 , 4 ' 21,0 ± 4 , 1 ' 70,2 ± 6,3' 67,3 ± 11,2'
4.5 ± 7,8'^ 0,0 ± 0.0' 5.4 ± 9,4^ 0,0 ± 0,0= 7,8 ± 6,8'' Ghi chd: Cdc gid tri Irong ciing mgt hdng co ky IU khdc nhau Ihi khdc biet co y nghia thong ke (p < 0,05).
3.3. C a c chi t i e u biofloc 3.3.1. The tich vd kich cd hat biofloc
Thi lich va kich cd biofldc d n g h i e m thflc ddi chflng k h d n g cd n e n k h d n g dUdc p h a n tic. Ci lan thu mau thfl I the tich biofloc c a o n h a t d n g h i e m thflc ti le C/N b a n g 17,5 (0.37 ± 0,38 m i / L ) , k h a c biet k h d n g cd y nghia t h d n g ke so vdi cac n g h i e m thflc cdn lai. Thu m a u lan tiep theo, cho t h a y t h e tich biofloc cao n h a t d n g h i e m thflc ti le C / N b a n g 20
(0,70 ± 0,26 m l / L ) , khdc biet k h d n g cd y nghia t h d n g k e so v d i tat ca cac n g h i e m thflc. Lan thu m a u cuoi, t h e tich biofloc t a n g n h a n h va cao nhat d n g h i e m thflc ti le C / N b a n g 17,5 (2,10 ± 0,46 ml/L). Thed DUdng T h i e n BCieu (2018), fldng gidng t d m cang x a n h d eac d p m a n khdc n h a u t h e o c d n g n g h e biofloc cho thay t h e tich biofloc d a o d d n g tfl 0,21 den 2,29 ml/L la thich h d p . N h u vay, t h e tich biofloc d cac n g h i e m thflc thich h p p c h o sfl p h a t trien cua au t r i m g .
Chieu dil bat biotloc trung bmh cua cic nghiem thflc sau thdi gian Udng dao ddng lfl 0,16 mm den 0,2 mm. chieu rdng dao dpng tfl 0.15 - 0,2 mm.
Chieu dai dat gii trj Idn nhjlt d nghiem thflc cd ti le C/\ bang 15 \a I7,5deabalan thumau. Chieu rdng hat biofloc eua lan thu mau thfl 2 va 3 tang hdn so vdi thu d lan thfl nhat, nghiem thflc ti le C/N bang 15 va 17,5 cd chieu rdng Idn d ed ba lan thu mau va khae biet cd y nghia thdng ke (p < 0,05) so vdi
eae nghiem thUc con I41. Nhin ehuii; "t- mpt nghiem thflc. bien dpng kich ibu> >** '"'^
tflong ddi thip. Ngoai ra. kuh thiuK hat :>ioMd'- >-' xu hudng ting theo thdi gian uone; Njlhie'" *•
trUdc nhin dinh ring, biofloc eo vai ii>' •.UACA\ Ihi','' mdi trudng nUdc, ddng thdi lam thflc an bo >nng <• o tdm (Avnimelech, 2012). Nhd \ ay the tich vi kieh ^o hat biofloc cua cic nghiem thflc nam irong klioang thich hdp trong Udngiu trung idtn i-.inc ^ni'^
chi tieu
Tlie tich (mL/L)
] Chieu dai (mm)
Chieu rpng 1 (mm)
1
l i n 1 Lan 2 Lan 3 L a n l Liin2 Lan 3 Lan 1 Lan 2 Lan 3
Bang 5. The tich
12.5 0.10 ± 0.00*
0.30 ± 0.20"
1,33 ± 0 . 2 9 ' 0,16 ± 0 . 0 1 ' 0,18 ± 0 , 0 1 * 0,17 ± 0 , 0 1 "
0,16 ± 0.01- 0,17 ±0,02- 0,17 ±0,01*
va kich cd hat biofloc Nghiem i 5 0,23 ± 0 , 1 5 ' 0.27 ± 0.06' 1.40 ± 0 , 6 6 ' 0.17 ± 0.01'- 0.19 ± 0 . 0 1 ' ' 0.19 ± 0 , 0 1 ' 0,17 ± 0 , 0 1 ' ' 0,19 ± 0 , 0 1 "
0,19 ± 0 , 0 1 '
thiic tv- le C/N 17.5 0,37 ± 0,38' 0,57 ± 0,21 • 2,10 ± 0 , 4 6 ' 0,17 ± 0 . 0 0 ' 0,20 ± 0,0 r 0,19 ± 0 , 0 1 ' 0,17 ± 0 , 0 1 ' 0.20 ± 0 , 0 1 ' 0,19 ± 0 . 0 1 '
20 0.17 ± 0 , 1 2 ' 0.70 ± 0.26*
1.70 ±0,46*
0.16 ± 0 , 0 1 ' 0,17 ± 0 , 0 1 "
0,17 ± 0,01"
0.15 ± 0,01*
0,17 ±0,01*
0,17 ± 0 , 0 1 "
Ghi I till ('ill _i,'/ii tl I trong ciuig mot hdng ca ky tu khdc nhau tlii khdc biet co y nghia thong ke (p < 0,05).
3.4. Chi sd bien thii (LSI) cua au trung tdm cing xanh
Ket qua LSI eua au triing trong qua trinh thi nghiem dupc the hien d bang 6, cho thay LSI trung binh cua cac nghiem thUe Udng tfl ngay 3 den ngay 21 dad dpng lfl 3.17 - 10,73. Trong dd, nghiem thflc ti l^ C/N bing 20 cd chi sd bien thai cao nhat la 10,73
± 0,06, thip nhat d nghiem thflc ti le C/N bing 12,5
vdi ehi so bien thii la 10,40 ± 0,26. Nhflng gifla cac nghiem thflc thi khac biet khdng cd y nghia thdng ke (p > 0,05) trong qua trinh thi nghiem. Nghien cflu cua Tran Ngpc Hai va cpng tac vien (2018) ve fldng au trung tdm cang xanh bang cdng nghe biofloc vdi cac ngudn carbon khac nhau cho thay chi sd bien thai cua au trung tdm cang xanh dao dpng tfl 10,6 den 11,5.
Bing 6. Chi so bien thai (LSI) au trimg tom cang xanh
LSI3 ngay 6 ngiy 9 ngay 12 ng,i%
15 ngay IS ngay 21 ngay
Ddi chung 3,20 ± 0.30*
5,27 + 0,12"
5,80 ± 0,30' 6.70 ± 0,35*
8,40 ± 0,30*
S , 9 3 ± 0 . 1 2 ' 10.57 ± 0.47-
i2,5 -3,17 ±0,06*
5.30 ± 0 , 1 7 ' 5,90 ± 0.26*
6.57 + 0.21*
8.67 ± 0,06' 9.63 ± 0.59' 10.40 + 0.26
Ngh em thiic ty le C/N 15 3.20 ± 0 . 1 0 ' 5.27 ± 0 , 1 5 ' 5.77 ± 0 . 1 5 ' 5,73 ± 1,10*
8.50 ± 0 . 1 7 ' 9 , 1 7 ± 0 , 3 1 ' 10,63 ± 0 , 1 5 '
17,5 3,27 ± 0,12' 5,37 ± 0 , 1 5 ' 5,73 ± 0,12*
6,67 ± 0 , 3 1 ' 8,50 ± 0,20' 9.00 ± 0.79' 10,57 ± 0 , 2 1 '
20 3.27 ± 0 , 1 5 5,23 ± 0.23
^,93 1 0.40
" • ' / i l i . B . 5 0 t | ) , i ,
" • " 1 0 , 1 3 ' " ^ 3 i O j 6
Ghi chu: Cdc gid tri trong ciing mot hdng co ky tu kliai. nliau thi khdc biet c6 y nghia thong ke(p im^y
Tap chi Khoa he -..:•'jng-^e \dng nghiep Viei Nam - So W '0' 202C
3.5. Chieu dii au trung va hau au trung tdm cang xanh
Kel qui theo ddi chieu dai cua au trung va hiu au trung tdm cang xanh dfldc the hien qua bang 7 O giai doan I. chieu dai trung binh cua au trung tdm cing xanh d cac nghiem thflc li 2,0 mm, khdng cd sfl chenh lech gifla cac nghiem thflc. O giai doan 5, nghi?m thflc ti le C/N bing 17,5 tdm cd chieu dii Idn nhat (4,0 ± 0,2 mm) va nghiem thflc ti ie C/N bing 12,5 cd chieu dii thap nhal la 3,7 ± 01 mm, nhflng khac biet khdng cd y nghia thdng ke (p > 0,05) dcic nghiem thflc. (3 giai doan 11, chieu dai iu trung dao dpng tfl 7,4 den 7,8 va khac biet khdng cd y nghia thdng ke (p > 0,05) gifla cic nghiem thflc
Theo Uno vi Soo (1969), chieu dii cua au trflng giai doan 5 va 11 lan lUdt la 2,80 \a 7,73 mm. Chieu dii cua PL-1: nghiem thUc ti le C/N bing 12,5 cd chieu dai thap nhit 8,4 ± 0,3, khic biet cd y nghia thdng ke (p < 0,05) so vdi cac nghiem thflc cdn lai. Chieu dai cua PL-15 d nghiem thflc ed ti le C/N bang 17,5 lot nhat la 11,8 ± 0,1 mm va khac biet cd y nghia thdng ke (p < 0,05) so vdi nghiem thflc ddi chflng cd chieu dii thap nhat (9,5 ± 1,0), nhflng khac biet khdng cd y nghia thdng ke (p < 0,05) so vdi cdc nghiem thflc cdn lai. Thed Chiu Tai Tao va cdng tic vien (2014). chieu dai trung binh au trung tdm cang xanh giai doan 5, 11, PL-15 lan lUdt la 2,81 ±0,15 mm;
6,69 ± 0,25 mm; chieu dii PL-15 la 9.06 ± 0.23 mm.
Bing 7. Chieu dai (mm) au trung va hau au trung tdm cang xanh Nghiem thflc ty Ie C/N
2,0 ± 0.0^
3.8 ± 0,2' 7,4 + 0,0"
8.9 ± 0,2'' __ 11,7 ±0,9"
Ghi chii: Cdc gid tri trong cung mot hdng co ky IU khdc nhau thi khdc biet co y nghia thong ke(p< 0,05).
Giai doan Giai doan 1 Giai doan 5 Giai doan 11 Postlarvae-1 Posllarvae-15
Ddi chdng 2,0 ± 0,0"
3.9 ± 0.2' 7,5 ± 0,3' 8,9 ± 0,2' 9,5 ± 1,0'
12,5 2,0 ± 0,0"
3,7 ± 0 , 1 ' 7,8 ± 0,0' 8,4 ± 0,3' 11,0 ± 0 , 4 '
17,5 2,0 ± 0,0' 4,0 ± 0.2' 7,6 ± 0,4*
9,1 ± 0 , 1 ' 11,8 ± 0 , 1 '
20 2,0 ± 0,0' 3,8 ± 0 , 1 ' 7,5 ± 0 , 1 ' 9,0 ± 0,4' 10,9 ± 0 , 8
3.6. T^ 1| sdng vi sinh khoi tdm PL-15 Ty 1? sdng cua PL-15 gifla cac nghiem thflc dao dpng tfl 48,7 - 56,8% va sinh khdi PL-15 cua cdc nghiem thflc dao ddng tfl 29.200 - 34.080 con/m\
Trong dd d nghiem thflc ti le C/N bing 17,5 cd ti I? sdng (56,8 ± 1,9 %) vi sinh klidi (34.080 ± 1.111 con/m') cao nhat khac biel cd y nghia thdng ke (p < 0,05) so vdi cdc nghiem thflc cdn lai. Theo nghien cflu cua Nguyen Thanh PhUPng va cpng tac
vien (2003) sinh khdi tdm PL-15 la 27.800 con/m';
cdn theo Tran Ngpc Hai va cpng tie vien (2018), fldng au trung tdm cang xanh trong he thdng biofloc vdi bo sung cac ngudn carbon khac nhau tfl giai doan 4 cho nang suat PL-15 dao dpng lfl 18.411 den 24.569 con/m' vi ty le sdng dat lfl 30,7 den 40,9%. Qua dd cho thay ty le sdng va sinh khdi PL-15 d nghiem thflc li ie C/N bang 17,5 la tdt nhat.
1. Ty le sdng va sinh khoi cua PL-15
Chi tieuTyle song (%) Sinh Idioi (con/m')
Ddi chdng 48,7 ± 1,3' 29.200 ± 760'
N g h i e m thijfc ty le C/N
12.5 ( 5 17,5 49,3 ± 1 , 9 ' 50,4 ± 1 , 4 '
29.580 ± 1.149* 30.240 ± 8 3 1 *
56,8 ± 1 , 9 ' 34.080± 1.111'
20 51,5 ± 1.2*
30.880 ±716*
Ghi chii: Cdc gid trj Irong cung mgt hdng co ky tii khdc nhau thi khdc biet co y nghia thong ke(p < 0,05) W. KET LUAN VA DE NGHI
4.1. Ket luan
Ket qua nghien cflu cho thay cic yeu td dam NO, vi TAN d nghiem thflc cd bd sung dUdng cit thap hpn so vdi nghiem thflc ddi chflng.
Chieu dil eiia tdm PL15 d cac nghiem thflc cd bo sung dfldng cat dao dpng tfl 10,9 ± 0,8 mm den 11,8
± 0,1 mm, khdc biet cd y nghia thong ke (p < 0,05) so vdi nghiem thfl'c ddi chflng.
Ti le song (56,8 ± 1,9 %) va sinh khdi (34.080 ±
1.1 II con/m-) eua PL15 cao nhat d nghiem thflc bd
sung dfldng cat vdi ti le C/N bang 17,5 khdc biet cd
y nghia thdng ke (p < 0,05) so vdi eac nghiem thflc
cdn lai.
4.2. D e n g h i
U n g d u n g bd sung d u d n g eat \ d i ti le C / N ^ 17.5 t r o n g u o n g au trimg tdm c i n g x a n h d e flng d u n g v a o thflc te san xuat.
L d l C . \ . M O N
D e t i i n i y dflpc tai t r p b d i Dfl a n N i n g c i p Trfldng Dai h p c C a n ThP \ N 1 4 - P 6 b i n g n g u d n v d n vay O D A tfl c h i n h phu Nhat Ban
TAILIEUTHAMKHAO
Chau Tai Tao, Tran Minh Nhut v i Tran Ngpc Hai.
2014. D i n h g i i chal luong au trung va hau au trung ciia mpi so nguon lorn cing xanh {Macrobrachium rosenbergii) d cac tinh phia nam. Tqp chi Khoa hgc, Dai lioc Cdn Thd. (34) 64-69.
Chau Tai T i o , Tran Minh Phu. 2015. Anh hUdng cua dp kiem len tang trUdng \ J I\ le song cua au trung v i h i u au triing tdm cang xanh (Macrobrachium rosenbergii). Tap chi Nong nghiep vd Phdt trien nong thon, (3+4): 93-99.
C h a u Tai Tao, Tran Ngpc Hai v i Pham Chi Nguyen, 2016. Anh hudngciia mat dp len langtrudngva tyle song cua Udng gidng tom cing xanh (Macrobrachium rosenbergii) theo cdng ngh? biofloc. Tap chi Khoa hoc Cong nghe Nong nghiep Viet Nam. (09): 60-64.
DUdng Thien Kieu, 2018. Nghien ciiu dnh hUdngcua do mdn vii cildng do dnh sdng trong Udnggiong torn cdng xanh (Miicrobrachium rosenbergii) bang cong nghe biofloc. Luin van tot nghi?p Cao hpc nginh nudi trdng thuy sin. Dai hpc Can Tho,
Nguyen Thanh PhUdng, Tran Ngoc H i i , Tran Thi Thanh Hien v i Marc\ N Wilder, 2003. Nguyen ly vd ky thudt sdn xudt giong torn cdng xanh (Macrobrachium rosenbergii). Nha xuat b i n Nong nghiep TP. Hd Chi Minh. 127 trang.
Train Ngpc H i i , Pham V i n Day va Chau Tai Tao. 2018.
Nghien eflu Udng i u trung tdm cang xanh bang
A.^soeMl'on , -1 159p , uiiion. '^''"'''"
,rd Methods cdng ngh? biofloc voi cac ngudn cacbi' Tup chi Khoa hgc Cong nghe Nong ny' quyen 95 (10): 125-129.
AOAC, 2000. OJficial .Methods oj Ana.
of Official Analytical Chemists Arln' A P H A , 2 0 0 5 . A » i . ' n c a n \ \ ; i i t r U ' o r f c s A "
Pollution Control Association. Sl.ir for the Examination of Water and Wasiewater, 2 1 " edition. American Public Health Association, Washington, DC, USA
Avnimelech, Y., 2012. Biofloc Technology A Practical Guide Book, 2"'' ed. The World Aquaculture Society, Baton Rouge, Louisiana, EUA. 272p
Avnimelech, Y., 2015. Biofloc Technolo\:v A Practical Guide Book, 3"^ Edition. The Woitd Aquaculture Society, Baton Rouge, Louisiana United States.
182 pages.
Huys, G., 2002. Preservation of bacteria using commercial cry preservation systems. Standard Operation Procedure, Asia resist. 35p,
Mcintosh, B. J.; S a m o c h a , T. M.; Jones, E. R.;
Lawrence, A. L.; McKee, D . A.; H o r o w i t z , S. and H o r o w i t z , A., 2000. T h e effect of a bacterial supplement on the high-density culturing of Litopenaeus vannamei with low-protein diet on o u t d o o r tank system a n d n o water exchange.
Aquacultural Engineering, 21: 215-227.
Rao, K.|. a n d S.D. Tripathy, 1993. A manual of giant freshwater prawn hatchery. CIFA Manual Series 2.
50 pages.
Sandifer P.A. a n d Smith T.I.J, 1985. Freshwater Prawns.
In Hunner, ). and E.E. Brown (Ed.), Crustacean and Mollusk Aquaculture in the United State. Van Noslrand Rienhold, Newyork, p p 63- 125.
Uno, Y. a n d K.C. Soo., 1969. Larval development of Macrobrachium rosenbergii reared in the laboratory /. Tokyo Univ Fish., 55 (2): 79-90.
Rearing larvae of freshwater prawn by biofloc technology with different C/N ratio
Pham Mmh Truyen, Le U a n h Nghi, Chau Tai Tao, Nguyen Van Hoa, Tran Ngoc Hai Abstract
This research aimed lo investigate die appropnate C/N ratio for the best growth and survival rate of freshwater prawn (Macrobrachium rosenbergii) lariae and postlarvae (PL) using biofloc technology. There were hve treatments of granulated sugar supplement with different C/N ratios as (i) no sugar addition (control) (n) C/N = 1 2 ^ i (HI) C/N = 15 : 1. (iv) C/N = 17.5 : 1 and (v) C/N = 20 : I, with three replications. Composite tanks of 500 litter and water salinity of 12%o were used Larvae were stocked al 60 inds/L and fed with Artemia and artificial f d Alter 35 days of rearing, die results of the experiment showed that C/N ratio of 17,5 : 1 was recorded the hiehect T h in length of PL-15 (11.8 ± 0.1 m m ) and the ditferenee was statistically significant at p < 0,05 compared to c T l treatment. Sur\ival rate (56.8 ± 1.9%) and producti\it)-(34,080 ± 1,111 prawn/m^) of PL-15 pravsn m the tr ? with C/N ratio of 17.5 were the best sigmficant difference at p> 0.05 compared to other treaUnents 11;, roforc T u^
concluded dial die C/N ratio of 17.5 : 1 was best for la^^•ae rearing of giant freshwater prawn using biolUjc tech ^T
Ke>'words: Biofloc, freshwater prawn lar\'ae, C N raiio °'' N"ga\ n h a n bai: 15/12/2019
Ngj> p h i n bien: 6/01 •:020
NgUdi p h i n bien: T S . N g u y e n Van I N g i y duygt d a n g : 13/01/2020
