^ap chi Khaa hoc Tmdng Dpi hpc Cdn Tha Phdn B: Ndng nghiep, Thiiy sdn vd Cdng nghe Sinh hpc: 34 (2014): 64-69
Tap chl Khoa hoc Tru'dng Oai hpc Can Thd
website: sj.ctu.edu.vn
1
DANH GIA C H A T LlTgfNG AU TRtlNG VA HAU AU TRtlNG
CtlA MOT S 6 N G U 6 N TOM GANG XANH (MACROBRACHIUM ROSENBERGII) d CAC TINH PHIA NAM
Chau Tai Tao', Trin Minh Nhut^ va Trin Ngoc Hai' ' Khoa Thuy sdn, Trudng Dgi hgc Cdn Tha Thdng tin chung:
Ngdy nhdn: 28/05/2014 Ngdy chdp nhdn: 30/10/2014 Title:
Evaluation of the quality of freshwater prawn
(Macrobrachium rosenbergii) larvae and post-larvae produced from different broodstock sources in the South of Vietnam Tirkhda:
Tdm cdng xanh, ngudn tom bd m^, chdt lugng du trimg Rewards:
Freshwater prawn, broodstock sources, larval quality
ABSTRACT
This study was conducted to evaluate the quality of freshwater prawn (Macrobrachium rosenbergii) larvae and post-larvae produced fi-om different broodstock sources. Prawn larvae produced from broodstock which were collected from Ca Mau, Can Tho, Long An, and Dong Nai provinces and were reared in the modified static green water system.
Results showed that Dong Nai prawn had the fastest growth and the longest length at stage I (1.88 ± 0.04mm), stage 5 (2.95 ± 0.28 mm), stage II (6.9 ± 0.35 mm), and PLjs (9.5 ±0.42 mm) and was significantly different from the other sources. Survival rate at PLis of Dong Nai prawn (46.9 ± 17.07 %) was significantly higher than that of Long An (37.8%) but not significantly different from those of Can Tho (56 ± 13.5 %) and Ca Mau prawn (49.2 ± 11.8%). Survival rates of all PL/s sources after being shocked by formalin (150 ppm in 30 minutes) and ammonia (IOO ppm in 30 minutes) were ranged 98.1 to 99.1%, respectively (Can Tho prawn) to 100% (Dong Nai and Long An prawn). No parasite or Macrobrachium nodavirus diseases were found in four sources of postlarvae. It was suggested that Dong Nai broodstock produced the best quality of freshwater prawn postlarvae.
TOM TAT
Nghiin cuu-rih^Mddnli^^g^^£lugng'du triing vd hdu du triing cua mdt s6 ngudn tdm cdng xanh (Macrobrachium rosenbergii). Au triing tdm cdng xanh dugc sinh sdn tu bdn nguon tdm bd me a Cd Mau, Cdn Tha, Long An vd Ddng Nai dtrgc uang din giai dogn PLis trong hi thdng nude xanh cdi tiin. Kit qud nghien cuu cho thdy ngudn tdm Ddng Nai tdng trudng ve chiiu ddi a giai dogn I (1.88 ± 0,04 mm), giai dogn 5 (2,95 ± 0.28 mm), giai dogn II (6,9 ± 0,35 mm) vd PLis (9,5 ± 0,42 mm) tdt nhdt, khdc biet cd y nghTa thdng ke (p<0,05) so vdi 3 ngudn tdm cdn lgi. Ty li sdng PLis cda ngudn tdm Ddng Nai (46,9 ± 77,07 %) cao han cd y nghia (p<0,05) so vai ngudn tdm Long An (37,8 ± 14.24 %) vd khong khdc (p>0,05) so vdi ngudn tdm Cdn Tha (56 ± 13,5 %) vd Cd Mau (49,2 ± 11.8%). Ty U sdng cua PLjs khi gdy sdc bdng formol (150 ppm trong 30 phut) vd ammonium (100 ppm trong 30 phut) cua cdc ngudn tdm diu cao, tirang ung tie 98,1 vd 99,1%
(tdm Cdn Tha) din 100% (tdm Ddng Nai vd Long An). PLis cua 4 ngudn tdm khdng cd binh ki sinh trimg vd virut due thdn (Macrobrachium nodavirus). Kit qud nghiin cdu cho thdy nguon tdm bd me a Ddng Nai cho chdt lugng PLis tdt nhdt
Tpp chi Khoa hpc Trucmg Dpi fiQC Cdn Tha 1 GIOI THIEU
Phan B: Ndng nghiep, Thiiy sdn vd Cdng nghi Sinh hgc: 34 (2014): 64-69
Tdm cang xanh (^Macrobrachium rosenbergii) Id loai cd kich thudc to nhdt trong cac lodi tdm nude ngpt, thit thom ngon, gid tri kinh te cao nen dupe xem Id mdt trong nhimg ddi tuong giap xac quan Upng dupe nudi phd biin d cac nude nhu Viet Nam, Trung Qudc, Thai Lan, Malaysia vd An Dp. Tuy nhiin, nghi nudi ldm thucmg pham vd sdn xudt giong dii da phat trien kha lau nhung cho den nay ngudn tdm cdng xanh bd me van dua chii yeu vdo khai thdc tir tu nhiin. Qua ihuc li cho thay d nhiiu nude nhu Thai Lan, Tmng Qudc do sir dung tdm nudi thit lam tdm bd me anh hucmg din tang trudng cda torn con chdm (FAO, 2002). CJ Viet Nam, tdm cang xanh nudi hiin nay dang cd nhieu diu hi$u suy thodi vi mdt di truyin nhu di nhiem b?nh, ty Ip sdng thdp, tdng trudng chara, su phan dan Idn, ^ I? tdm cai cao hem tdm due, ty Ii phan CO it di (Dinh Hung vd ctv. 2011). Trong khi do, gdn ddy cdc chuang trinh gia hda va chpn Ipc de nang cao chdt lupng tdm bd me dd duac dp dyng dii vdi tdm sii, tdm the chan trdng cho thay nhiing kit qua khd quan. Tuy nhiin, ddi vdi ldm cdng xanh ket qua nghien ciiu su thay doi chat lupng tora bi me sau nhiiu thi hi gia hda vdn cdn kha h^n che. Do dd, vi?c danh gid chat lupng au trimg va h^u 4u trimg cda mdt sd ngudn tdm cdng xanh d cdc tinh phia Nam dang la mpt van de rat can thiit di ldm CO sd cho chuang Uinh gia hda va chpn lgc ndng cao ch^t lupng tdm bd me di phuc vy cho sdn xuat giong va nudi thit.
2 PHU'CTNG PHAP NGHIEN CUtJ 2.1 Nguon tdm bi m^ v^ nuoi vo.
Ngudn tdra bd rae dupe chpn mua lir 4 noi ITcK&^au Id tdm d luu vyc sdng Ddng Nai (Ddng Nai), luu vyc sdng Vdm Cd (Long An) luu vuc sdng Trem (Ca Mau) va luu vuc sdng Hau (Cdn Tho). Tdm dupe thu mua tir cac ghe cdo cua ngu dan, mdi n^uon tdm chpn 30 cdp (tdm due vd tdm cdi) cd khdi lupng dao ddng tii 6,7-10,3 g/con, khde mgnh, khdng thuong tich hay ddu hiiu binh, phy bp day du, mau sac tuai sdng, mdi cap tdra dupe nudi rieng Uong giai ludi cd kich co (1 x 1 x 1,5 m), trong dieu kien chdm sdc va qudn Iy gidng nhau, cdc giai ludi dupe dat Uong 1 ao cd dien tich 3.000 m^ dupe cai tao tdt tnrdc khi tha tdra, thay nude ao nudi mdi thdng 2 Idn. Thai gian nudi vd tdm cdng xanh Id 3 thang, tdm bd me nudi vd dupe cho dn bdng thiic dn viin ciia cdng ty CP, cd ham lupng d^m Id 40%. Cho an ngdy 2 ldn sang va chiiu (8h va 16h), moi Idn cho dn tii 2-5% khdi lupng than. Bd sung thjl cd biin tuoi 2 ngay/mSn
vdi ty Ii 10-15% khdi lugng thdn. Moi tuan theo ddi tdm me mang trdng, bd tri tdm me mang tning Ien bi cham soc cho deal khi tdm nd di thu au trimg ttmg ca thi cua tiing ngudn tdm di bd tri thf nghiem uong an trung.
Hinh 1: Nudi vd 4 nguon tdm c^ng xanh b6 m$
2.2 iJoDg au triing tdm cdng xanh Au triing cua timg tdm me cua mSi ngu6n tdm se duoc uong riing trong 1 xd nh\ra cd thi tfch 120 lit. Tdm dupe bi fri uong d dd radn 12%o, m|t dp uang 60 con/L, uong theo qui trinh nude xanh cdi tien cd bd sung che phdm sinh hpc Deocare vd Zimovac. Artemia bung dii dupe cho dn m5i ngdy 2 ldn vao Idc 6 gid sang va 18 gia chiiu bdt dau tir ngay thii 2 den ngay thii 5. Lupng cho dn 1- 2 con/mL. Artemia mdi nd cho dn tir ngdy thii 6, lupng cho an td 2-4 con/mL. Thiic dn chi biin (Bdng 1) cho an tir ngay thii 6 trd di, cho iu tning an ngay 3 Idn Iuc 8h sang, 12h trua vd 16h chieu, tiiy vdo su phat triin ciia du triing ma cho an thirc an chi biin vdi mdt ludi thich hap (300 (im d GD 4-5,500 ^im d GD 6-8 va 700 fini d GD 9 ~ PLis).
Bang 1: Cdng thirc (hire an cho i\x triing t6m cang xanh (Nguyin Thanh Phuong va ctv., 2003)
Thanh phan Tning ga Siia bdt giau can-xi Diu muc Lecithin Vitamin C
Litons 1 tnhig 10 g 3.0%
1.5%
100-500 mg/kg 2.3 Cac chi tiiu theo ddi
Cac chi lieu mdi trudng nude dupe theo dOi gdm nhiet dp, oxy, pH do 2 ldn/ngay (sdng va chiiu), TAN va NO2" do 3 ngay/ldn.
- Cac chi tieu theo doi tdm gdm: Chi so biin thai cua du trung (LSI) 3 ngay quan sdt I liin, moi lan quan sdt 30 du triing. Do chiiu dai iu triing vd
Tgp chi Khoa hgc Trucmg Dgi hpc Cdn Tha Phdn B: Ndng nghiip. Thuy sdn vd Cong nghi Sinh hpc: 34 (2014): 64-69 tdm PL d cac giai d o ^ 1, 5, 11 vd PLis, mSi ldn do
30 con^e. Ddnh gid su tang trudng cda du trung d giai doan tdm PLis bdng each can khdi lupng tdm PLis vd do chiiu dai timg con (30 con/Idn). Ty le soi^ va nang sudt is giai doan tdm PL|s
Gay sdc bdng formol 150 mL/m^ ti-ong 30 phut, va sdc ammonium vdi ndng dp 100 rag/lit h-ong 30 phiit (Cavalli, 2000) d tdm PLis.
2.4 Phuang phap xu ly sd lieu
Cac sd liiu thu thdp dupe se tmh todn gia tri trung binh, dd lech chuan, ti li phdn tram, so sdnh su khac biit giiia cac nghiem thiirc ap dyng phuong p h ^ ANOVA bdng phep tiui DUCAN ip< 0,05) sii dyng phdn mira Excel cua Office 2010 vd SPSS phien ban 13.0.
3 KET QUA NGHIEN CUtJ 3.1 Cac yiu to mdi trudng
Trong qua trinh uong i^x trimg cac yiu td mdi ti-udng dupe tiii hiin qua Bdng 2. Cdc sd do mdi trudng nude uong cd chinh lich giiia budi sang va budi chiiu giiia cdc ngudn tdm, nhung su chenh lech nay khdng nhiiu. Nhiit dp tnmg binh nude uong ciia thi nghiem dao ddng lir 27,6 - 30,7''C. Gia tri pH sdng vd chieu ciia thi nghiim giao ddng khing Idn tir 7,6 - 8,3. Oxy dao dpng tii 5,8 - 7,3 mg/Iit Hdm lupng TAN tiimg binh cua tbi nghiim cd khuynh hudng tang ddn vi cudi chu ky uong dao ddng tii 0,10 - 0,93 mg/L. Tuong tu ham lupng NOj" ciia thi nghiem nay dao ddng lir 0,14-0,56 mg/L.
Bang 2: Bien dpng cua cdc yiu t i moi trudug trong qua trinh uong tim cang xanh
-•«5^SBi
Hinh 2: Khu vuc uong du triing torn cdng Danh gid chdt lupng ciia hiu au triing tdm cdng xanh
Benh k^ sinh trimg va binh virut due thdn (Macrobrachium nodavirus) cda tdm PLis (Phuong phap PCR d phdrig thi nghiim Khoa Thiiy san - Trudng Dai hpc Can Tha).
Nhiit dd(°C)?.f?f ' Chieu pH
f.^f
^ Chieu Oxy(mg/L) ^ ^ f „ TAN (mg/L) 0,10 ±0,04' N02-(mg/L) 0,14 ±0,02"
CIMau 28,5 ±0,44' 30,7 ±0,17' 8,0 ±0,10' 8,2 ± 0,07"
6,4 ±0,08' 7,1 ±0,13'' 0,14±0,01"
0,13 ±0,02-
Nguon tdm CSn Tho 29,3 ± 0,04=
30,6 ±0,11' 7,6 ± 0,02' 8,2 ± 0,04"
6,5 ± 0,03=
7,3 ± 0,03' 0,93 ±0,10' 0,56 ±0,10'
Long An 27,6 ± 0,04"
29,9 ±0,17"
8,2 ±0,06' 8,3 ± 0,06"
5,8 ±0,07"
6,0 ±0,06"
0,76 ±0,05' 0,4 ±0,03'
Bdng Nai 27,6 ± 0,03"
30 ±0,08"
8,2± 0,06' 8,3 ±0,06' 5,8±_0,031„
5,9 ± 6,02".=
Cdc gid tri trin cUng 1 ddng cd chQ'cdi khdc nhau thi khdc biit cd y nghTa Ihdng liS (p<0.05) Nhiet dp mdi trudng nude cdc bi uong du triing
cua ngudn tdm Cd Mau vd Can Tho cao hon ngudn tdm Ddng Nai, Long An vd khdc nhau cd y nghia thdng ki (p<0,05). Sy khac biit nay Id do du tiling tir ngudn tdm Ddng Nai, Long An dupe uang vdo thdng 2 vd 3 khdc vdi du tiling tir ngudn tdm Cd Mau, Cdn Tho dupe uong chii yiu tdp trung vdo tiiang 3 va 4. Theo New va Singholka (1985) cho ring nhiit dd thich hpp cbo su phdt triin ciia du Uiing tdm cdng xanh la 26-31 "C, trong khodng nhiit dd thich hpp niu nhi?t dO cang cao tiii du Uung phdt triin cdng nhanh. Nhi§t dd ldi uu cho su
phat trien ciia au triing tdra cdng xanh dao ddng tir 28-30''C (Nguyin Thanh Phuang vd ctv., 2003).
Theo Nguyin Thi Thanh Thuy (2000) cho rdng khoang pH thich hpp cho uong du trimg tdm cang xanh la 7,4-8,0, Nguyin Thanh Phuong va ctv.
(2003) di nghi gidi han pH tCr 7 - 8,5 Id tiu'ch hpp.
TAN vd NO2" cao nhdl d ngudn tdm Long An va kbac biit cd y nghia thing ki (p<0,05) so vdi cac ngudn tdra cdn Iai, Ang (1985) thi cho rdng Uong radi Irudng uong du tiimg tdm cdng xanh nude xanh ham lupng TAN vupt qua miic 2,5 mg/L nhung vdn chua anh hudng din du triing. Rao vd Troipathi (1993) nude uong nudi du Uung ldm
Tpp chi Khoa hpc Truong Dgi hpc Cdn Tha Phan B: Nong nghiip, Thuy sdn vd Cong nghi Sinh hoc: 34 (2014) • 64-69 cang xanh thi hdm lupng TAN phdi dudi 1,5 rag/L,
va ham lupng nitrite khdng nen vupt qua 1,8 mg/I.
Theo ghi nhan cua Margarete Mallasen et al.
(2006) thi ty le sdng, tdng tiirdng vd chi sd biin thai khdng cd su khdc biit khi au triing tdm cang xanh dupe uang d miic NO2' tir 0 va 2 mg/L. Nhin chung, cdc yiu td mdi irudng tdt vd phu hpp au triing tdm cdng xanh phat trien tdt.
3.2 Tang trudng ciia au triing va hdu au triing Kit qud tang trudng ciia cac giai doan du triing lim cang xanh cda bdn ngudn tdm dupe the hiin qua Bang 3. Au trimg giai do^n 1 ciia ngudn tdm Can Tho cd kich thudc trung binh ldn nhat 1,92 ± 0,07 mm tuy nhiin khdng khac biit vdi au trung giai d o ^ 1 cda ngudn tdm Dong Nai vd Cd Mau (p>0,05) nhung khdc biil cd y nghia thdng ki so vdi ngudn tdra Long An (p<0,05). Tii giai doan 5 cho thdy du triing cua nguin tdm Ddng Nai vd Bang 3: Tang tnrdng cua cdc giai do^n an triing va
Long An phdt triin tdt nhdt. An trimg giai d o ^ 11 ciia ngudn tdm Ddng Nai cd kich thudc ldn nhdt (6,9 ± 0,35 mm) khdc biit cd y nghia thdng ki (p<0,05) so vdi cac ngudn ^ m cdn lai, giai doan PLis ciia ngudn tdm Ddng Nai va Long An khong khac (p>0,05), nhung khac biet cd y nghTa thing ke (p<0,05) so vdi giai doan PLis cua nguon tdm Cdn Tho vd Ca Mau. Khdi lupng PLis ciia bon nguin tdm gdn nhu tuong duong nhau khdng cd sy khac biit. Kit qua cua nghiin ciiu nay do uong trong miia ndng cd nhiit do thich hop nin qud trinh tdng trudng cda 4 ngudn tdm diu tdt. Theo Uno vd Soo (1969), kich thudc cua au trung giai d o ^ 1, 5 vd 11 Idn lupt la 1,92, 2,80 vd 7,73 mm. Theo Nguyin Thanh Phuang vo ctv. (2006) thl kich cd cda torn PL|5 tir bo m? dupe nudi vd dao ddng trong khodng 7,88 - 8,90 mm. Theo New (2002), tdm PL sau 20 ngay. uong si cd khdi lupng 0,02 g. Cdc kit qua nay phii hpp so vdi nghien ciiu tren.
h^u au trdng tdm cdng xanh
Chi tiiu Ngudn tdm
Ca Mau Long An Pong Nai
Chiiu dai du ti-ung d giai dogn 1 (mm) 1,87 ± O.OS*" 1,92 ± 0,07'=
Chiiu dai du Uiing d giai doan 5 (ram) 2,71 ± 0,09^ 2,81 ± OtlS'""
Chiiu dai du trung d giai dogn 11 (mm) 6,64±0,14'' 6,69±0,25^
Chieu dai cua PLis (mm) 9,14 ± 0,15^ 9,06 ± 0,23'
1,81 ±0,05* 1,88 ±0,04**
2,95 ± 0,27" 2,95 ± 0,28'' 6,66 ±0,1" 6,9*0,35"
9,46 ±0,41'' 9,5 ± 0,42"
Khdi lupng cua PLis (g) 0,015 ± 0,002" 0,014 ± 0,002° 0,015 ± 0,003^ 0,015 ± 0.004' Cdc gid trj trin citng J dong co chU cdi khdc nhau Ihi khdc biit cdy nghia ihdng ki (p<0,05)
3.3 Chi so biin thdi
Chi sd LSI the hien sy bien thai va raiic dp ddng diu ciia du trimg ldm cdng xanh Uong bi uang. Sy phat triin ciia du triing tdm cang xanh dupe quan sdt ihdng q^ua chu ki lot xdc vd biin thai.
Au triing trai qua 11 Idn Ipi xdc vd biin thai di hinh,_
thdnh h|iu au triing (Nguyen Tiianh Phuong va^tvF-'*
2003). Tuy nhiin, tiidi gian Idt xdc mdi giai doan liiy tiiudc vdo dieu kien mdi trudng, dinh duong, gidi tinh, radt dd uang vd dieu ki?n sinh Iy ciia chiing. Qua kit qua Bang 4 cho thay chi si bien Bdog 4: Su bien thai ciia au triing tdm cang xanh
thai trung binh (LSI) tir ngay thii 1 den thii 24 ciia 2 ngudn tdm Cd Mau va Cdn Tha cao hon 2 nguon tdm Ddng Nai vd Long An va sir khac biit nay cd ^ nghia thing ki (p<0,05). Vi 2 ngudn tdm Ding Nai va Long An khi uong cd nhiit dd thdp 27,6^ nin qud trinh biin tiiai chdm. Theo Nhan et al (2009)
^''sd^biin tiidi ngay thii 10 va 15 ciia du triing t6m cang xanh ciia ngudn bd me dupe danh bit tgi Bin Tre thudc ha luu sdng Mekdng duac nu6i vS lan luat Id 6,4 ± 1,0 va 7,2 ± 1,1. Cdc kit qud ndy khdng khdc bi?t nhiiu so vdi nghiin ciiu trin.
Chi so biin thdi (LSI) LSI -ngay 3 LSI - ngdy 6 LSI - ngdy 9 LSI - ngay 12 LSI - ngdy 15 LSI-ngdy 18 LSI - ngdy 21 LSI - ngay 24
CaMau
Nguon tdm
CanTho Long An Bong Nai
2,8 ±0,13=
4,7 ±0,12' 5.6 ± 0,16*=
6.7 ±0,12'' 8,2 ± 0,2"
9,5 ± 0,43"
10,4 ± 0,45"
11,1 ±0,44'^
2,8 ± 0,05"^
4,8 ± 0,06"=
5.7 ±0,05^
6.8 ± 0,08"
8,3 ± 0,05"
9,3 ± 0,09"
10,3 ±0,1"
11,1 ±0.34'^
2,2 ± 0,22"
3.5 ± 0,52"
5,0 ± 0,83"
6,4 ±1,15"
7.6 ±1,27"
8.7 ±1,26"
9,7 ±1,24"
10,5 ±1,16""
1,9 ± 0,08' 2,9 ± 0,34»
3,9 ± 0,5' 5,2 ± 0,75' 6,5 ±0,71' 7,8 ± 0,8' 9,0*0,74"
10,1 ±0,59' Cdc gid Iri trin cimg 1 dong cd chU cai khdc nhau ihi khdc biit cd y nghia Ihdng ki (p<0.05)
Tpp chi Khoa hgc Trucmg Dgi hpc Cdn Tha Phdn B: Ndng nghiip, Thity sdn vd Cong nghi Smh hpc: 34 (2014): 64-69 3.4 Ndng suat uong ^u triing
Thdi gian xudt hiin PL, ty Ii sdi^ va nang sudt cda tdm PL khi uong nudi du triing tdm cdng xanh ciia bdn ngudn tdm dupe thi hien qua Bang 5. Kit qua nghiin cihi cho thdy ngay xudt hien tdm PL ciia 4 ngudn tdm dao dpng tii 22 - 24 ngay khdc biet khdng cd y nghia tiidng ke (p>0,05). TJ Ii sdng va ndng suit tdm PLi5 cua ngudn tdrn Long An thdp nhdt khac biet cd ^ nghia thing ki Bang 5: Thdi gian xu^t hiin PL, t j Ie sing vi nang s
(p<0,05) so vdi ngudn tdm Can Tho nhung khdng khac so vdi ngudn tdm Ca Mau va Ddng Nai. Ty Ii sdng tdm PLis ciia ngudn tdm Cdn Tho 56 ± 13,5 %, nang suit tdm PLis la 33,6 ± 8,1 cao nhit so vdi ba ngudn ldm cdn lai, tuy nhiin su chinh lich nay khac biel khdng cd y nghia thdng ki (p>0,05) so vdi ty 16 sing va ndng suit torn PLjs cua ngjidn tdm Ca Mau va Ddng Nai.
i^t tdm PLis 1 eu
Ngay xuat hien PL (ngay) Ty le s6ng (%) Nang suit t6m PLis (con/lit)
Ca Mau 24 ±2"
49,2 ±11,8"
29,5 ± 7 , 1 "
Nguon t3m Can Thff Long An
23 ±2" 22 ± 3"
56 ±13,5' 37,8 ±14,24"
33,6 ± 8 , 1 ' 22,7 ±8,54*
Dong Nai 24 ±2"
46,9 ±17,07"
28,1 ± 10,24"
Cdc gid trf tren cung 1 ddng co chit cdi khdc nhau thi khdc biet cd y nghia ihdng ke (p<0,05) 3.5 Ddnh gid chit lugmg ciia tdm PL15
Qua ket qua Bdng 6 cho thay ty li co/rupt trung binh cua tdm PLis ngudn Ddng Nai dat 34,9±0,8 % vd ty I# sing khi soc formol, sdc ammonium dgt 100% cao nhat so vdi ba ngudn tdm cdn lai. Tuy nhiin, sy chinh lich ndy khdc biit khdng cd y nghTa thdng ki so vol ngudn tdm Long An (p>0,05) nhung khdc biet cd y nghia thdng ki so vdi ngudn tdm Can Tha va Ca Mau (/K0,05). Hdu nhu khdng phat hien cd su nhiem ky sinh trung va virut due than Uen tdm PLis tir 4 ngudn tdm. Ddi vdi PL tdm su trong qua trinh sic forraol ty Ie tdm chit va yiu dual 5% Id tdm cd chdt lupng tdt (Bd thuy san, 2001). Theo Figueroa-Lucero et al.
Bang 6: Cdc chi tiiu ddnh gia tdm PLis
(2011), ndng dp LC50 ciia ammonium trin tdm Macrobrachium tenellum la tii 9,39-85,16 mg/L.
Theo Nhan et al. (2009), khi thi nghiim sdc ammonia Uen hau au Uiing tdra cang xanh cua 4 ngudn tdm bo me khac nhau dupe nudi v5 Id ngudn tdm tii thiin nhiin cua Viet Nam dupe danh bit tai Bin Tre thudc ha luu sdng Mekdng, ao nudi d Cii Chi-Thanh phd Hd Chi Minh, tdm gidng nhdp cd ngudn goc tu Hawaii vi nudi d tinh An Giang nam 2005 vd nguon gdc tir tdm gidng nhdp tir Trung Qudc, lac gia cho rdng khdng cd sy khac biet ve siic chiu dyng cua hdu an trung cac n^udn tdm ndy vdi ammonia. Qua do cho thay h|u du ngudn tdm cang xanh Ddng Nai cd sir vupt tipi ve kha n3ng chju dung sic forraol va ammonium.
Ty 1^ co/ruOt (%) Miic do nhilm ky sinh triing Nhilm virut due than (Macrobrachium nodavirus) Soc formol
SSc ammonium
Ca Mau 33,5 ± 0,4' 0 0 99,2 ± 1,4' 99,7 ± 0,9'
N&u6n Can Thff
33 ± 0,2"
0
98,1 ±2,6' 99,1 ± 1,6"
torn Long An 34,8 ± 0,9' 0
100 ±0,0' 100 ±0,0'
Ddng Nai 34,9 ±0,8' 0
100 ±0,0' 100 ±0,0' Cdc gid Iri tren cimg 1 ddng cd chie cii khdc nhau thi khdc
4 KET LUAN VA DE XUAT 4.1 Ket lu?n
Cdc yiu to mdi trudng trong sudt qud trinh uang thich hpp cho iu triing vd hgu iu trimg smh uudng va phdt triin tdt.
Giai doan 11 va PLis ciia ngudn tdm Dong Nai cd tdng irudng vi chiiu dai la tdt nhit so vdi ngudn tdm Cd Mau, Can Tho vd Long An.
biit CO y nghia thong ki (p<0,OS)
- Ty Ii sdng PLis ciia ngudn tdm Ddng Nai cao hem ngudn tdm Long An vd tuong duang vdi ngudn tdm Cin Tha va Cd Mau.
Ty Ie sdng ciia PLis khi gay sdc bdng formol va ammonium cua ngudn tdm Ddng Nai va Long An cao han so vdi 2 ngudn tdm Can Tha va Ca Mau.
Tgp chi Khoa hgc Truong Dgi hpc Cdn Tha Phan B: Ndng nghiip, Thity sdn vd Cdng nghi Sink hpc: 34 (2014): 64-69
- PLis cua 4 ngudn tdm khdng cd binh ki sinh trimg vd virut dye thdn.
4.2 Dexuit
- Chpn tdra PL ciia ngudn tdra Ddng Nai di gia hoa cho cdc thi hi tiip theo.
TAI LIEU THAM KHAO 1. Ang K.J, 1985. The evolution of an
enviromentally friendly hatchery technology for Udang Galah, the king of freshwater prawn and a limpe into fiiture of aquaculture in 21st century. University Pertanian Malaysia.
2. Bp Thuy sdn, 2001. Tdi lieu hudng ddn nuoi tdra sii ludn canh vdi Udng Iiia 13 trang.
3. Dinh Himg, Nguyen Thanh Vii va Nguyen Vdn Hdo, 2011. Kit qud budc ddu chuang trinh chpn giong tdm cang xanh (Macrobrachium rosenbergii) bang phuang phdp chpn lpc gia dinh tai Viit Nam. Tuyin tdp nghi cd sdng Cuu Long 2011.
4. FAO, 2002. Farming freshwater prawns - A manual for the culmre of the giant riiver prawn ^Macrobrachium rosenbergii). 212pp.
5. G. Figueroa-Lucero et al, 2011. Acute toxicity of ammonia on Macrobrachium tenellum (SMITH) lavare. Rev. Int. Contam.
Ambie. 28(2)145-150.
6. Margarete Mallasen, Wagner Cotioni Valenti, 2006. Effect of nitiile on larval development of giant river prawn Macrobrachium rosenbergii. Original Research Article Aquaculture, Volume 261, Issue 4, 11 December 2006, Pages 1292-1298.
• New, M. B., and S. SinghoIka,1985.
Freshwater Prawn Farming: A manual for
culture of Macrobrachium rosenbergii.
FAO Fisheries Technical Paper (212).
8. New, M. 2002. Farming Freshwater Prawns:
A Manual for the Culture of the Giant River Prawn (Macrobrachium rosenbergii). FAO Fisheries Technical Paper 428,2I2pp 9. Nguyin Thanh Phuong va Tran Van Biii,
2006. Anh hudng ciia ngudn tdm rae lin sOru sinh sdn va chat lupng au triing tdm cdng xanh (Macrobrachium rosenbergii).
Tap chi Thiiy sdn 2006; 124-133.
10. Nguyin Thanh Phuong, Tran Ngpc Hdi, Trdn Thi Thanh Hiin va Marcy N. Wilder, 2003. Nguyin Iy va ky thugt san xuat gidng tdm cdng xanh (Macrobrachium rosenbergii). Nha xudt bdn Ndng nghiep Tp.
Hd Chi Minb, 127 trang.
11. Nguyin Thj Thanh Thuy, 2000. Ky thuat san xuat giing tdm cang xanh (Macrobrachium rosenbergii). Nha xudt bdn Ndng nghiip. TP Hd Chi Minh.
12. Nguyin Viet Thing, 1995. KJ tiiuat nudi tdm cang xanh. NXB Ndng nghi?p, 149 trang.
13. Dinh The Nhan, M. Wille, L. T. Hung, P.
Sorgeloos, 2009. Comparison of reproductive performance and offsprmg quality of giant freshwater prawn (Macrobrachium rosenbergii) broodstock from different regions. Aquaculture, 298, 36-42.
14. Rao K.L. and Troipatiii S.D. 1993. A manual on Giant Freshwater prawn hatchery. CIFA.
15. Uno, Y. and K. C. Soo, 1969. Larval development of Macrobrachium
rosenbergii reared in laboratory. J. Tokyo^^sB Univ. Fish., 55(2): 79-90.
