THUC NGHIEM NUOI TOM THE CHAN TRANG THAM CANH VOI MAT D 0 KHAC NHAU TRONG HE THONG TUAN HOAN Le Quoc Viet1, Trtfdng Qu6c Phu1, Tran Ngoc Hai1 TOM TAT Nghien ciiu nham xac dinh mat do tom nuoi thich ho[.]
THUC NGHIEM NUOI TOM THE CHAN TRANG THAM CANH VOI MAT D KHAC NHAU TRONG HE THONG TUAN HOAN Le Quoc Viet1, Trtfdng Qu6c Phu1, Tran Ngoc Hai1 TOM TAT Nghien ciiu nham xac dinh mat tom nuoi thich hop cho sii tang tnldng, ty le song va dong thdi nang cao nang suat tom nuoi he thdng tuan hoan ket hop da loai Thi nghiem diioc bo tri be co the tich 10 m3, man 15%o, kiem til 137,1 -138,9 mg C aC 03/L, thdi gian nuoi tom 70 He thong gom be nuoi tom vdi mat khac (100 con/m3, 200 con/m3, 300 con/m3), be ca ro phi, be rong, va be gia the Tom co khoi lilOng va chieu dai ban dau lan loot la 0,28 g va 3,41 cm Sau 70 nuoi d mat 200 con/m3, tom phat trien tot nhat vdi khoi loong 16,15 g/con, ty le song 95,4%, sinh khoi 3,1 kg/m3 va gia thOc an de tang kg tom la 34.111 dong, thich hop de nuoi thoong pham TO khoa: Tom the chan trang (Litopenaeus vannamei, Boone 1931), he thong tuan hoan, mat I DAT VAN DE Thu Hien (2020), san ltldng tom niidc Id tren ca Nganh nuoi thuy san dong vai tro quan niidc dat 773,3 nghin tan, tom su dat 185 trong nen kinh te niicfc ta, tom the nghin tan, tom the chan trang dat 588,3 nghin tan chan trang (Litopenaeus vannamei) la doi tiiqng Hien nay, nuoi thuy san diicfc quy hoach phat nuoi quan vdi san hiong khong ngiing tang trien theo hiidng tham canh va sieu tham canh, qua cac nam Tom the chan trang co nhieu tiu diem nhien van de moi tnldng va dich benh la thach nhti: toe sinh triidng nhanh, thdi gian nuoi ngan thde ldn Nam 2020, ca niidc bi thiet hai hdn 38.763 va nuoi diiOc d mat cao mang lai hieu qua kinh nghin nuoi tom anh hiidng cua dich benh va te cao cho ngtidi nuoi (Wyban et a t, 1995) Theo moi tnldng (Hai Ly, 2020) Viec phat trien cac he 1Khoa Thuy san, Tnrbng Dai hoc Can Tho 108 Tap chi Khoa hoc va Cong nghe Nong nghiep Viet Nam -So06(127)/2021 thong nuoi nang suat cao, ben vflng, than thien moi triidng va giam thieu rui dich benh la van de can diipc quan tarn hang dau hien Nhieu mo hinh nuoi tom da diipc phat trien nhii ap dung quy pham thUc hanh nuoi thuy san tot (GAP, BMP - best management practice), nuoi an toan sinh hoc (bio security shrimp culture), nuoi co trach nhiem, nuoi ket hdp va nuoi sinh thai (Phimg Thi Hong Gam va ctv., 2014) Trong do, cac mo hinh nuoi tom ket hop da loai - tuan hoan co the dildc xem la mot nhutng dinh hiidng phu hop d cac tinh ven bien Dong bang song Ciiu Long (DBSCL) Viec nghien cdu sii dung cac tac nhan sinh hoc la xu hiidng tich cv£c gop phan on dinh moi tnidng va han che dich benh ao nuoi, thong qua mo hinh nuoi ket hop vdi biofloc hay ghep vdi ca ro phi (Ta Van PhiiOng va ctv., 2014) Nuoi tom ghep vcfi ca ro phi se dat ket qua tot hdn ao nuoi tom dcfn nhii tom dat kich co lcfn, ty le song, nang suat tom cao; ben canh thu diiqc ca ro phi vdi nang suat 923 kg/ha/vu (Tien Hai Ly, 2006) Them vao do, nuoi ket hop vdi rong bien hoac dong vat than mem gop phan nang cao nang suat va chat liicfng tom thu hoach (Ngo Thi Thu Thao va ctv., 2010) Cac nghien cdu nuoi ket hop vdi cac doi tiiOng khac giup cai thien chat liiqng niidc nhii giam bdt ham liiOng chat hflu cO co nguon goc tii dam hoac lan Do do, nghien cdu diipc thiic hien nham xac dinh mat nuoi thich hop cho sii tang triidng, ty le song va dong thdi nang cao nang suat tom nuoi he thong tuan hoan ket hop da loai, lam cO set de dng dung vao th iic te san xuat II DOI TUONG VA PHl/ONG PHAP NGHIEN CtfU 2.1 Doi tiiOng nghien ciiu Tom the chan trang (L vannamei) giong co chieu dai trung binh 3,41 cm/con va tUOng dng vcri khoi liiqng 0,28 g/con 2.2 Phiidng phap nghien ciiu 2.2.1 B o tri th i nghiem Thi nghiem diiqc bo tri he thong tuan hoan, gom cac be co the tich 10 m3 He thong g6m be nuoi tom, be nuoi ca ro phi, be rong cau va be loc sinh hoc (sit dung 200 lit/m3 gia the hat nhiia) Viec bo sung gia the nhiia nham lam gia the cho vi khuan bam tren be mat gia the va chuyen hoa dam Theo Eding va cong tac vien (2006), qua trinh chuyen hoa Amon N 2" nhd vi khuan Nitrosomonas va vi khuan Nitrobacter se chuyen hoa N NOs Niidc tii be loc se diiqc bom cung cap cho be nuoi tom, sau tit be nuoi tom se lan loot chay qua be ca ro phi, be rong cau, sau quay ve be loc sinh hoc va tiep tuc chu ky tuan hoan (Hinh 1) Hinh So he thong bo tri thi nghiem Node he thong tuan hoan co man 15%o lupng rong cau dope bo tri theo bang Rong cau va Idem ban dau la 140 mg C aC 03/L Rong cau dope tha veo, moi co dien tich m2 va va ca ro phi diipc bo tri ciing thdi gian vcfi be tom dope dat be 10 m3 Moi mat tom dope nuoi Mat tom nuoi, kich co tom, ca ro phi va khoi lap lai lan theo thdi gian khac 109 Tap chi Khoa hoc va Cong nghe Nong nghiep Viet Nam - So 06(127)/2021 Bang Mat va ki'ch cd tom, ca ban dau bo tri d cac be nuoi Be Mat Chieu dai (cm) Khoi luqng (g) Tom 100 con/m3 3,41 ± 0,30 0,28 ± 0,07 Tom 200 con/m3 3,41 ± 0,30 0,28 ± 0,07 Tom 300 con/m3 3,41 ± 0,30 0,28 ± 0,07 Ca ro phi con/m3 18,0 ± 2,7 110,5 ±41,7 Rong cau kg/m3 2.2.2 C ham soc va qudn ly Tom dvtcfc cho an lan/ngay (4 lan an thdc an tong hop vao luc 7h00, 10h30, 13h30, 17h00 va lan an bi vao luc 21h00) Doi v6i bl diicrc cho an dang tiioi va bam nho bang vdi klch cb cua vien thdc an theo klch cd tom Thdc an cho tom the co tit 40 - 42% dam, ldOng thufc an dao dong tit - % khoi lddng than/ngay LUdng thdc an cho tom an dupe dieu chinh ngay/lan (dda vao khoi lUdng tom cua tdng be) Trong suot qua trinh nuoi 70 ngay, khong thay nUdc, khong si phong va chi bo sung luong nude that thoat Doi vdi ca ro phi: Khong cho an, chi tan dung cac vat chat lo ldng cac be tom lam thdc an 2.2.3 Cac chi tieu theo d o i vaphU dngphap xdc dinh - Cac chi tieu moi trUdng nUdc: Nhiet va pH dUOc hang bang may HANNA ngay/lan vao luc gib va 14 gib Ham luong nitrite, nitrat, TAN, P 43 va kiem dUOc b tat ca cac be dinh ky ngay/lan bang bo test SERA cua Ddc Ham luong oxy cac be cung dUOc bang may OXY GUARD ngay/lan - Chi tieu theo doi tom: Tang trUbng cua tom dUOc xac dinh 14 ngay/lan Thu ngau nhien 20 tom/be, sau do chieu dai tong va can khoi luqng cua tdng ca the de xac dinh toe tang trUdng cua tom Toe tang trUdng cu a tom dUOc xac dinh theo - kg/6m3 Ty le song cua tom dUOc xac dinh vao th b i diem ket thdc th i nghiem bang each dem toan bo so lUtfng tom lai be nuoi Sinh khoi (kg/m3) = khoi ldong tom thu dUOc moi be/the tich nude Xac dinh he so thdc an (FCR): FCR cua tom bang tong lddng thdc an cho tom an/tang cua tom Xac dinh gia thdc an cho kg tom thdong pham = [(FCR bi x dcfn gia) + (FCR thdc an vien x don gia)] - Chi tieu theo ca ro phi va rong cau: Ca ro phi ddOc chieu dai va can khoi ldOng tdng ca the ket thuc thi nghiem Rong cau dUOc can mau dinh ky 14 ngay/lan, bang each can toan bo khoi ldong rong cau 2.2.4 P han ttch so lieu Cac so lieu thu thap ddoc tinh toan cac gia tri trung binh, lech chuan, phUOng phap phan tich ANOVA mot nhan to vdi (p < 0,05) va ve thi bang phan mem Microsoft Excel 2016 2.3 Thbi gian va dia diem nghien cdu Nghien cdu ddoc tien hanh td thang 2/2021 den thang 5/2021 tai Trai thde nghiem Bo mon Ky thuat nuoi Hai san, Khoa Thuy san, TrUbng Dai hoc Can Tho cac cong thd c sau: Tang trUdng theo ve khoi luqng: DWG (g/ngay) = (We - Wd)/T Tang trUdng tUOng doi ve khoi luong: SGRw (%/ngay) = 100 x (LnWc - LnWd)/T Tang trUdng theo ve chieu dai: DLG (cm/ngay) = (L - Ld)/T Tang trUdng tUdng doi ve chieu dai: SGRl (%/ngay) = 100 x (LnLc - LnLd)/T (Trong do: W d khoi Itfdng tom ban ddu, (g); W c khoi liidng tom thu cuoi, (g); Ld: chieu dai tom ban ddu, (cm); Lc: chieu ddi tom thu cuoi, va T: So nuoi) 110 III KET QUA VA THAO LUAN 3.1 Cac yeu to moi trUbng 3.1.1 N hiet do, p H vd oxy Nhiet nude buoi sang va buoi chieu gida cac nghiem thdc thi nghiem dao dong khoang 26,32 - 27,76°C Doi vdi pH cd bien dong ngay, buoi sang dao dong khoang td 8,01 - 8,15, buoi chieu dao dong khoang td 8,12 - 8,29 Doi vdi oxy hoa tan (DO), dao dong td 3,31 - 4,87 mg/L (Bang 2) Theo Boyd (1998), khoang pH thich hop cho sd phat trien cua dong vat thuy san la 6,5 Tap chi Khoa hoc va Cong nghe Nong nghiep Viet Nam -So06(127)/2021 - 9,0 va khoang bien dong nho hon 0,5 Nhii vay, nhiet do, pH, oxy hoa tan thifc nghiem nam khoang phu hop cho tom phat trien Bang Nhiet va pH trung binh cua cac be thcfi gian thtfc nghiem Be pH Nhiet (°C) DO (mg/L) Sang Chieu 8,15 ±0,10 8,29 ± 0,10 4,82 ± 0,09 8,06 ± 0,10 8,20 ± 0,08 4,20 ± 0,04 Tom 26,32 ± 1,56 Tom 26,32 ± 1,49 Chieu 27,65 ± 1,00 27,67 ± 1,03 Tom 26,41 ± 1,46 27,76 ± 1,06 8,02 ± 0,13 8,12 ± 0,09 4,48 ±0,13 Ca ro phi 26,38 ± 1,44 27^27 ± 1,04 8,09 ±0,11 8,28 ± 0,12 4,87 ± 0,08 Rong cau 26,45 ± 1,47 27,72 ± 1,11 8,01 ± 0,16 8,24 ± 0,14 3,31 ± 0,06 Be loc 26,45 ± 1,43 27,56 ± 1,14 8,14 ± 0,08 8,18 ± 0,09 4,67 ± 0,42 Sang 3.1.2 Ham liiqng tong dam Amon (TAN), nitrite, nitrat, PO„3' va kiem Cac yeu moi triidng node qua trinh nuoi diiqc trinh bay bang Ham liiqng nitrite dao dong td 0,96 - 2,48 mg/L, nitrate bien dong til 27,17 - 40,00 mg/L, TAN bien dong td 0,22 - 0,71 mg/L Ket qua cho thay, ham liiqng TAN giam vi khuan Nitrosomonas chuyen hoa amonia nitrite sau vi khuan Nitrobacter chuyen hoa nitrite nitrate, vi khuan Pseudomona, Achromobacter chuyen hoa nitrate nito va diiqc rong cau va tao hap thu lai Ham liiqng P 43- bien dong 3,92 - 4,49 mg/L va kiem dao dong td 137,1 178,9 mg CaCOj/L Theo Boyd (1998), ham liiqng nitrite ao nuoi thuy san khong viiqt qua 10 mg/L (tot nhat la nho hon mg/L) Chen va Chin (1998) chi nong TAN gay chet 50% of loai tom khac nam khoang 30 - 110 mg/L Bang Trung binh ham liipng nitrite, nitrat, TAN, P 43' va kiem d cac be thefi gian thi nghiem Nitrite (mg/L) Nitrate (mg/L) TAN (mg/L) P 43 (mg/L) Do kiem (mgCaCO,/L) Tom 1,90 ± 0,77 35,38 ± 4,47 0,44 ± 0,09 4,44 ± 1,97 137,5 ± 3,2 Tom 2,12 ± 0,93 36,71 ± 5,24 0,56 ± 0,09 4,49 ± 1,90 138,9 ± 3,0 Tom 2,33 ± 0,41 38,63 ± 7,25 0,71 ± 0,09 4,46 ± 1,97 137,1 ± 5,5 Ca ro phi 2,38 ± 0,13 39,83 ± 6,13 0,52 ± 0,17 4,29 ± 1,75 138,8 ± 5,3 Rong cau 2,18 ± 0,03 40,00 ± 7,07 0,39 ± 0,09 4,20 ± 1,63 137,1 ± 5,5 Be loc 0,96 ± 0,16 27,17 ±5,19 0,22 ± 0,10 3,92 ± 1,79 138,9 ± 3,0 Be Ket qua bang cho thay, nuoi tom the chan trang he thong tuan hoan da gop phan cai thien chat liiqng niidfc dang ke Ham liiqng nitrite, nitare va TAN d cac be tom co khuynh hiidng tang dan theo mat nuoi (tang td Tom den Tom 3) Khi node chuyen sang be ca ro phi thi ham liiqng TAN (0,52 mg/L) va P 43 (4,29 mg/L) giam so vdi cac be tom, dieu cho thay ca ro phi da sd dung cac vat chat lcf ldng (chat thai td tom) va giup chat liiqng niidc diiqc cai thien hdn Ham liiqng TAN va P 43" d be rong cung giam so vdi be ca ro phi, theo Nguyen Hoang Vinh va cong tac vien (2020) rong cau chi Gracilaria tenuistipitata co kha nang hap thu cac hop chat dam va lan nddc thai nuoi tom, vdi nong TAN ban dau la 4,64 mg/L va sau xd ly d nghiem thde kg/m3 co sue giam xuong 0,14 mg/L vdi hieu suat xd ly la 96,98% va mat rong kg/m3 sau xd ly nong TAN 0,24 mg/L tiidng dng vdi hieu suat xd ly 95,04% Tiidng td, ham liiqng nitrite, nitrate va TAN d be loc cung giam dang ke so vdi be rong, dieu cho thay be loc (chda gia the loc va lam gia the cho vi khuan bam) co tac dung rat tot den qua trinh chuyen hoa dam va cai thien chat liiqng niidc he thong tuan hoan (Eding et al , 2006) Do kiem thich hop nuoi tom the chan trang td 10 -150 mg C aC 03/L (Ebeling et a l, 2006) Theo Charantchakool (2003), kiem ly tddng cho tang triidng va phat trien cho tom the chan trang la 120- 160 mg C aC 03/L neu kiem thap hon 40 mg C aC 03/L se anh hiidng den she khoe cua tom nuoi I ll Tap chiKhoa hoc va Cdng nghe Nong nghiep Viet Nam - So 06(127)/202 ? 3.2 Tom the chan trang 3.2.1 Tang trtfdng ve chieu d Tom qua trinh nuoi co toe tang triidng lien tuc Ket qua cho thay, sau thdi gian 70 nuoi tom dat trung binh td 12,55 - 13,59 cm, cao nhat la nghiem thde mat 100 con/m3va khac biet khong co y nghia thong ke (p > 0,05) so vdi nghiem thde mat 200 con/m3va 300 con/m3 Toe tang triidng ve chieu dai dao dong tit 1,86 - 1,98%/ngay, cao nhat la mat 100 con/m3 va khac biet khong co y nghia thong ke (p > 0,05) so vdi nghiem thde mat 200 con/m3 va 300 con/m3 (Bang 4) Nuoi tom the chan trang ket hop vdi ca ro phi he thong biofloc, sau 90 toe tang triidng ve chieu dai cua tom la 0,08 - 0,09 cm/ngay (Le Quoc Viet va ctv., 2015) Bang Toe tang triidng ve chieu dai cua tom sau 70 nuoi Mat (con/m3) Ld (cm) Lc (cm) DLG(cm/ngay) SGR1(%/ngay) 100 3,41 ± 0,30 13,59 ± 0,23a 0,15 ± 0,01a 1,98 ± 0,15a 200 3,41 ± 0,30 13,07 ±0,12a 0,14 + 0,01a 1,92 ± 0,14a 300 3,41 ± 0,30 12,55 ± l,03a 0,13 ± 0,01a 1,86 ± 0,18a Ghi chu: Cac gia tri ciing mbt cot co ky tUgiong thi khac biet khong co y nghia thong ke (p > 0,05) 3.2.2 Tang triidng ve k h o i Itfdng Sau 70 nuoi, tom dat khoi lilpng trung binh tit 14,80 - 18,40 g, cao nhat la nghiem thde mat 100 con/m3 va khac biet co y nghia thong ke (p < 0,05) so vdi nghiem thde mat 200 con/m3 va 300 con/m3 Toe tang triidng ve khoi ldpng dao dong tit 5,72 - 6,03%/ngay, cao nhat d nghiem thde mat 100 con/m3va khac biet khong co y nghia thong ke (p > 0,05) so vdi nghiem thde mat 200 con/m3 va 300 con/m3(Bang 5) Toe tang triidng ve khoi litqng cua tom nuoi tom the vdi cac mdc kiem khac thi toe tang triidng ve khoi litqng cua tom dat tit 0,09 - 0,13 g/ngay (Ta Van Philcfng va ctv., 2014) Bang Toe tang tnldng ve khoi lilqng cua tom sau 70 nuoi Mat (con/m3) Wd(g) 100 ! Wc(g) DWG (g/ngay) SGRw(%/ngay) 0^8 ± 0,07 18,40 ± 0,39b 0,26 ± 0,00b 6,03 + 0,30a 200 0^8 ± 0,07 16,15 ± 0,78* 0,23 ± 0,01a 5,84 ± 0,26a 300 0,28 ± 0,07 14,80 ± 0,58* 0,21 ± 0,01a 5,72 ± 0,39a Ghi chu: Cac gia tri cung mot cot co ky tUgiong thi khac biet khong co y nghia thong ke (p > 0,05) 3.2.3 Ty le songva sink khoi cua tom sau 70 nuoi 10.0 9.0 Hinh cho thay ty le song tom sau 70 nuoi 8.0 d cac nghiem thde dao dong trung binh tit 75,9 -0 6.0 S 98,4%, ty le song cao nhat d nghiem thde 100 con/m3 5-0 khac biet khong co y nghia thong ke (p > 0,05) so vdi ** nghiem thde mat 200 con/m3, nhitng khac biet co 3.0 2.0 y nghia thong ke (p < 0,05) so vdi nghiem thde mat 1.0 300 con/m3 Sinh khoi tom nuoi d cac nghiem thde 0.0 100 200 300 dao dong tit 1,9 - 3,4 kg/m3, thap nhat la d nghiem M$tdQQuoi(con/m3) thde mat 100 con/m3 (1,9 kg/m3) khac biet co y nghia thong ke (p < 0,05) so vdi hai nghiem thde mat Hinh Ty le song va sinh khoi cua tom sau 70 nuoi 200 con/m3 (3,1 kg/m3) va khac biet co y nghia Ghi chu: Cac gia tri co ky ttf hoa (A, B) va thUdng (a, b) thong ke (p < 0,05) nghiem thde mat 300 con/m3 giong thi khac biet khong coy nghia thong ke (p > 0,05) (3,4 kg/m3) Theo Ta Van Phdcfng va cong tac vien (2014), nuoi tom the quy trinh biofloc vdi cua tom dat td 75,0 - 97,3%; nuoi tom d mat mat 300 - 500 con/m3 sau 60 nuoi, ty le song 100 con/m3 cho ty le song cao nhat, nhdng ^ 112 Tap chf Khoa hoc va Cong nghe Nong nghiep Viet Nam - So 06(127)/2021 xet ve nang suat thi nuoi d mat 300 con/m3 va 500 con/m3 cho nang suat cao hem tit 2,5 - 3,28 lan Khi nuoi tom the chan trang ao vdi mat 152 con/m2, sau 90 nuoi thi nang suat dat 15,6 tan/ha/vu (tiicJng ditong 1,56 kg/m3) (Phung Thi Hong Gam va civ., 2014) thong ke (p < 0,05) vdi cac nghiem thiic mat 200 con/m3 va khac biet co y nghia thong ke (p < 0,05) so vdi nghiem thiic mat 300 con/m3 Theo Le Quoc Viet va cong tac vien (2018), bo sung 10% bi lam thiic an cho tom the thi chat liiOng cua tom diioc cai thien va chi phi sv£ dung thiic an thap (37.262 d/kg tom thiiOng pham) Liidng thiic an 3.2.4 Ltidng thtic an s i dung cho kg tom va g ia sd dung cho kg tom thiidng pham co gia thanh thiic an cho l k g tom thtidngpham dao dong tii 29.810 - 45.639 dong/kg tom, d mat He so thiic an vien cua tom the chan trang 100 con/m3 khac biet khong co y nghia thong ke cac nghiem thiic dao dong tii 0,88 - 1,35, (p > 0,05) so vdi mat 200 con/m3, va khac biet co y thiic an vien cua nghiem thiic mat 100 con/m3 nghia thong ke (p < 0,05) so vdi mat 300 con/m3 khac biet co y nghia thong ke (p < 0,05) so vdi hai Kich cd tom dao dong tii 52,5 - 67,0 con/kg, d mat nghiem thiic mat lai Bi tii 0,27 - 0,39 100 con/m3 khac biet co y nghia thong ke (p < 0,05) cho kg tang cua tom, nghiem thiic d mat so vdi hai mat lai 100 con/m3 thap nhat va khac biet co y nghia Bang Liicfng thiic an sil dung cho kg tom, gia thiic an /kg tom thiiOng pham va kich c5 tom Mat (con/m3) Thiic an vien (kg) Bi (kg) Gia thiic an (d/kg tom) Cd tom (Con/kg) 100 0,88 ± 0,08“ 0^7 ± 0,01“ 29.810 ± 2.549“ 52,5 ± l,3b 200 1,01 ± 0,14ab 0,29 + 0,01b 34.111 ±4.439ab 60,9 ± l,5a 300 1,35 ± 0,15b 0,39 ± 0,01c 45.639 ± 4.510b 67,0 ± 3,5a Ghi chu: Gia thiic an vien 30.450 dong/kg va hi 9.000 dong/kg (1 kg bi loai bo rudt 0,8 kg tUdng dUdng vdi kg thit bigia 11.250 dong) dat ty le song 100% Theo Le Quoc Viet va cong tac vien (2015), sau 60 nuoi doi vdi ca ro phi diioc nuoi ket hop vdi tom the chan trang thi dat ty le song 100% d tat ca cac nghiem thiic, toe tang triidng ve chieu dai va khoi liiOng dao dong tii 0,09 - 0,12 cm/ngay va 0,82 - 1,28 g/ngay 3.3 Tang triidng cua ca ro phi va rong cau Bang cho thay sau 70 nuoi, toe tang triidng ve chieu dai va toe tang triidng ve khoi liiOng cua ca ro phi co toe tang triidng cham lan liicft la 0,05 cm/ngay va 0,85 g/ngay Doi vdi ca ro phi diioc nuoi ket hop nghien cdu Bang Toe tang triidng va ty le song cua ca sau 70 nuoi Ty le song (%) Khoi luting Chieu dai Lo 18,0 ±2,7 Wo 110,5 ±41,7 L7o 21,3 ± U W-0 169,7 ±41,9 DLG (cm/ngay) 0,05 ± 0,02 DWG (g/ngay) 0,85 ± 0,01 SGR( (%/ngay) 0,24 ±0,14 SGR^V(%/ngay) 0,64 ± 0,20 Hinh cho thay khoi liiOng rong cau ban dau (6 kg) tang triidng lien tuc den thil 42 (7,8 kg) va giam den thii 56 (7,1 kg) sau giam lad vao thii 70 (6,5 kg) Trong qua trinh nuoi tom ket hop vdi rong cau, cho thay rong cau hap thu cac hop chat dam va lan giup rong cau gia tang sinh khoi va cai thien moi triidng nuoi Theo 100 Nguyen Thi Ngoc Anh va cong tac vien (2019), nuoi ket hop rong cau chi - tom sii (1,97 g) tang triidng va nang suat cua tom d nghiem thiic nuoi ket hop cho an 50% nhu cau khong khac biet thong ke so vdi nghiem thiic doi chiing tiiOng ling vdi chi phi thiic an co the giam den 49%, diipc xem la miic giam thich hop 113 Tap chi Khoa hoc va Cong nghe Nong nghiep Viet Nam - So 06(127)/2021 10.00 -T ru n g b ln h v io t -T n m g btahv&o2 -T n m g b iah to n g 9.00 8.00 7.00 6.00 5.00 4.00 3.00 2.00 • - Trm g binb, v6o I Tnmg b la h v io binh r£ng v i o 3.00 3.00 6.00 14 3.15 3.15 6.30 28 3.40 3.40 6.80 42 3.90 3.90 7.80 56 3.55 3.55 7.10 70 3.25 3.25 6.50 Thdi gUm (ng&y) Hinh Bien dong sinh khoi cua rong thdi gian nuoi IV KET LUAN VA DE NGHI 4.1 Ketluan Chat ldo'ng nddc he thong nuoi gom: Nitrite, nitrate va TAN P 43“va kiem nam khoang thich hdp de tom phat trien Sau 70 nuoi, tom mat 200 con/m3 la tot nhat vdi khoi lddng 16,15 g/con, ty le song 95,4% va sinh khoi 3,1 kg/m3 va gia thdc an de tang kg tom la 34,111 dong, thich hop de nuoi thiiong pham 4.2 De nghi Mo hinh nuoi tom the chan trang he thong tuan hoan can trien khai dng dung d qui mo ldn hon de danh gia hieu qua cua mo hinh nuoi LOICAMON De tai dUoc tai trO bdi Dd an Nang cap Triiong Dai hoc Can Tho VN14-P6 bang ngudn von vay ODA tvi Chinh phu Nhat Ban tAi l ie u tham khao Nguyen Hu Ngoc Anh, Nguyen Hoang Vinh, Lam My Lan va Tran Ngoc Hai, 2019 Anh hddng cua cac mdc cho an khac len chat lifong nude, tang trddng va hieu qua sd dung thde an cua tom su (Penaeus monodon) nuoi ket hop vdi rong cau chi (Gracilaria tenuistiptata) Tap chi Khoa hoc TrUdng Dai hoc Can Thd, 55 (3B): 111-122 Phiing Thi Hong Gam, Vo Nam Son va Nguyen Thanh PhiiOng, 2014 Phan Tich hieu qua san xuat cac mo hinh nuoi tom the chan trang va tom su tham canh d Ninh Thuan Tap chi Khoa hoc Triidng Dai hoc Can Thd (chuyen de thuy san), 2: 37-43 ThuHien,2020 Tongsdn lUdngthuysan 11 thdngnam2020 dat 7,7 trieu tan, tang 1,6%, truy cap 20/3/2021 Dia chi: https://tongcucthuysan.gov.vn/vi-vn/khaith%C3%Alc-th%El%BB%A7y-s%El%BA%A3n/khai-th%C3%Alc/doc-tin/015375/2020-12-02/tongsan-luong-thuy-san-ll-thang-nam-2020-dat-77trieu-tan-tang-16 114 Tien Hai Ly, 2006 Thvfc Nghiem nuoi ket hop ca ro phi don tinh ao nuoi tom su tham canh d Bac Lieu Tap chi Khoa hoc Tritdng Dai hoc Can Thd, 2: 187-191 Hai Ly, 2020 Dien tich thuy san thiet hai tang manh, truy cap 10/1/2021 Dia chi: https://thuysanvietnam com.vn/dien-tich-thuy-san-thiet-hai-tang-manh/ Ta Van PhiiOng, Nguyen Van Ba va Nguyen Van Hoa, 2014 Nghien cdu nuoi tom the chan trang theo quy trinh biofloc vdi mat va man khac Tap chi Khoa hoc Triidng Dai hoc Can Thd (chuyen de thuy san), 2: 44-53 Ng6 Thi Thu Thao, Huynh Han Chau va Tran Ngoc Hai, 2010 Anh hiidng cua nuoi ket hop cac mat rong sun (Kappaphycus alvarezii) vdi tom the chan trang (Litopenaeus vannamei) Tap chi Khoa hoc TrtidngDai hoc Can Thd, 12a: 100-110 Le Quoc Viet, Tran Minh Phu va Tran Ngoc Hai, 2018 Danh gia kha nang bo sung bi (Cucurbita pepo) lam thdc an cho tom the chan trang (Litopenaeus vannamei) Tap chi Khoa hoc, TrUdng Dai hoc Can Thd, 54 (9B): 88-96 Le Quoc Viet, Tran Ngoc Hai, Ly Van Khanh, Tran Minh Nhdt va Ta Van Phildng, 2015 Ung dung biofloc nuoi tom the chan trang (Litopenaeus vannamei) vdi mat khac ket hop vdi ca ro phi (Oreochromis niloticus) Tap chi Khoa hoc TrUdng Dai hoc Can Thd, 38:44-52 Nguyen Hoang Vinh, NguySn Thi Ngoc Anh va Tran Ngoc Hai, 2020 Nghien cdu kha nang hap thu dam (N) va lan (P) nddc thai td nuoi tom su tham canh cua rong cau chi (Gracilaria tenuistipitata) d cac mat va che sue khac Tap chi Khoa hoc TrUdng Dai hoc Can Thd, 56 (2): 59-69 Boyd, 1998 Pond water aeration systems Aquaculture Engineering 18:9-40 Charantchakool, P., 2003 Problem in Penaeus monodon culture in low salinity areas Aquaculture Asia, (1): 54-55 Chen, J C and T S Chin, 1998 Accute toxicity of nitrite to tiger prawn, Penaeus monodon, larvae Aquaculture, 69: 253-262 Ebeling, J.M., Timmons, M.B and Bisogni, J.J., 2006 Engineering analysis of the stoichiometry of photoautotrophic, autotrophic and heterotrophic removal of ammonia-nitrogen in aquaculture systems Aquaculture, 257: 346-358 Eding, E.H., Kamstra, A., Verreth, J.A.J and Huisman, E.A., Klapwijk, A., 2006 Design and operation of nitrifying trickling filters in recirculating aquaculture: A review Aquaculture Engineering, 34:234-260 Wyban J., William A Walsh and David M Godin, 1995 Temperature effects on growth, feeding rate and feed conversion of the Pacific White Shrimp (Penaeus vannamei) Aquaculture, 138 (1-4): 267-279 Tap chi Khoa hoc va Cong nghe Ndng nghiep Viet Nam - So 06(127)/2021 Intensive culture of white leg shrimp in the integrated recirculating system at different stocking densities Le Quoc Viet, Truong Quoc Phu, Tran Ngoc Hai Abstract This study aimed to determine the appropriate stocking density of white leg shrimp for better performance in growth, survival, and productivity of shrimp in an integrated recirculating aquaculture system (RAS) The experiment was set up in 10 m3tanks operated at a salinity of 15%o, alkalinity of 137.1 - 138.9 mg CaC03/L for 70 days The culturing system consisted of three shrimp tanks with different stocking densities (100, 200 and 300 ind./m3) connected to tilapia tank, seaweed tank and biofilter tank, sequentially The shrimp juveniles were initially recorded at 0.28 g of body weight (BW) and 3.41 cm of total length (TL) After 70 days of culturing at a density of 200 ind./m3, the shrimps grew best with a BW of 16.15 g/ind, the survival rate of 95.4% and biomass of 3.1 kg/m3 and the cost of feed for increasing kg of shrimp was 34,111 VND, suitable for commercial farming Keywords: White leg shrimp (Litopenaeus vannamei, Boone 1931), recirculating aquaculture system, stocking density Ngay nhan bai: 20/5/2021 Ngay phan bien: 16/6/2021 Ngiidi phan bien: TS Vu Viet Ha Ngay duyet dang: 29/6/2021 ... culture), nuoi co trach nhiem, nuoi ket hdp va nuoi sinh thai (Phimg Thi Hong Gam va ctv., 2014) Trong do, cac mo hinh nuoi tom ket hop da loai - tuan hoan co the dildc xem la mot nhutng dinh hiidng... ket qua tot hdn ao nuoi tom dcfn nhii tom dat kich co lcfn, ty le song, nang suat tom cao; ben canh thu diiqc ca ro phi vdi nang suat 923 kg/ha/vu (Tien Hai Ly, 2006) Them vao do, nuoi ket hop... than/ngay LUdng thdc an cho tom an dupe dieu chinh ngay/lan (dda vao khoi lUdng tom cua tdng be) Trong suot qua trinh nuoi 70 ngay, khong thay nUdc, khong si phong va chi bo sung luong nude that