Ảnh hưởng của giảm lượng thức ăn lên tàng trưởng và tỷ lệ sống của ấu trùng và hậu ấu trùng tôm càng xanh (m acrobrachium rosenbergii) áp dụng cộng nghệ biofloc và không biofloc

Tap chi Khoa hoc va Cong nghe Nong nghiep Viet Nam - So 05(126)/2021 ANH H l/d N G CUA GL\M LUONG T H U t AN LEN TANG TRU ING VA T Y LE SONG CUA AU TRUNG VA HAU AU TRUNG TOM CANG XANH (M a cro b ch iu m rosen bergii) AP DUNG CONG NGHE BIOFLOC VA KH6NG BIOFLOC Tran Ngoc Hai1, Pham Minh Truyen2, Nguyen Van Hoa1, Chau Tai Tao1 TOM TAT Nghien cPu nham giam lPpng thPc an thich hop cho tang trPdng, ty le song va nang suat cua au trung va hau au trung tom cang xanh Thi nghiem gom nghiem thiic la (1) Cho an binh thPdng, khong tao biofloc; (2) Giam 20% lPpng thiic an, khong tao biofloc, (3) Giam 40% lPpng thiic an, khong tao biofloc (4) Giam 60% lPpng thiic an, khong tao biofloc (5) Cho an binh thPdng co tao biofloc, (6 ) Giam 20% liipng thiic an, co tao biofloc (7) Giam 40% liipng thiic an, co tao biofloc, va (8 ) Giam 60% liipng thiic an, co tao biofloc Be ilOng au triing co the tich 250 lit, mat Pdng 60 con/L, man 12%o Ket qua nghien cPu cho thay PL-15 d nghiem thPc giam 20% lPpng thiic an, co tao biofloc tang trPdng ve chieu dai (11,0 ± 0,7 mm) khac biet co y nghia thong ke (p < 0,05) so vPi nghiem thPc cho an binh thPcrng khong tao biofloc, nhUng ty le song (48,0 ± 3,3 %) va nang suat (28.801 ± 1.989 con/m3) khac biet khong co y nghia thong ke (p > 0,05) so vPi nghiem thPc cho an binh thoPng khong tao biofloc Vi vay co the ket luan rang, giam 20% lPpng thPc an Pong au trung tom cang xanh bang cong nghe biofloc la tot nhat de giup toi Pu chi phi san xuat Til khoa: Au trung tom cang xanh, biofloc, giam lPpng thiic an I d At v a n d e II VAT LIEU VA PHtfCNG PHAP NGHIEN CUU Tom cang xanh la doi tPpng dppc nuoi bien d Viet Nam Nhflng nam gan day phat trien nuoi rat manh vcfi mo hinh tom lua viing nPdc lp do nhu cau giong rat ldn Tuy nhien, giong va chat lPpng giong khong dam bao De tim dppc giai phap cho nghe san xuat giong tom cang xanh theo hpdng an toan sinh hoc thi viec ling dung cong nghe biofloc Pong au triing tom cang xanh de tao giong chat lPpng cao phuc vu cho nghe nuoi la rat can thiet Theo McIntosh va cong tac vien (2 0 ) biofloc co vai tro quan trong viec on dinh moi trPdng nPdc, an toan sinh hoc, ngan ngila mam benh, lam thiic an trPc tiep cho tom, tang cPcfng dPPng chat tP nhien Cho den da co cac cong trinh PPng au trung tom cang xanh bang cong nghe biofloc (Tran Ngoc Hai va ctv., 2019; Pham Minh Truyen va ctv., 2020; Le Thanh Nghi va ctv., 2020) Theo Loureiro va cong tac vien (2012), Ray va cong tac vien (2 ) cho rang da xac dinh dppc hat biofloc ong tieu hoa cua au trung tom cang xanh PPng bang cong nghe biofloc, nen nghien ciiu giam lPpng thiic len tang trPcfng, ty le song va nang suat cua hau au trung tom cang xanh dppc thPc hien nham giam chi phi de ling dung vao thPc te san xuat 2.1 Vat lieu nghien ciiu 1Khoa Thuy san, 2.1.1 Nguon ntfdc thi nghiem Nguon nPdc thi nghiem dppc pha til nguon nPcfc ot co man 80%o va nguon nPdic may de co dppc man 12 %o, xii ly bang chlorine vdi nong 50 ppm, sue manh til - cho het lPpng chlorine nfldc, sil dung sodium bicarbonate nang kiem len 120 mg C aC 03/L (Chau Tai Tao va Tran Minh Phu, 2015) roi bom vao be Pcfng qua thiet bi loc 1pm trPdc bp tri au trung 2.1.2 Nguon au trung tom cang xanh Nguon au trung dflpc thu til tom cang xanh me mang triing mau xam den, chat lPpng tot, khoe manh, kich cS til 40 - 60 g/con, mau sac tP nhien cho nd be 500 lit, man 12%o Sau tning nd au trung, chon au triing khoe co tinh hPdng quang manh roi dinh lPPng bo tri vao be PPng 2.1.3 Tao biofloc Biofloc dppc tao bang nguon cacbon til dPPng cat (Bien Hoa Pure) co 55,54% C (Le Thanh Nghi va ctv., 2020), ty le C/N = 17,5 (Pham Minh Truyen va ctv., 2020) DPdng cat hoa vao nPdc am 60°C, khuay deu, va u 48 gid trPdc cho vao be Pcfi^ tom Phppng thiic bo sung dPdng cat diia theo lP P i^th d c TrPdng Dai hoc Can ThP;2Nghien cPu sinh Nuoi thuy san Khoa 2017 Tap chi' Khoa hoc va Cong nghe Nong nghiep Viet Nam - So 05(126)/2021 an nhan tao la Lansy PL co 48% protein, dddng cat dddc bo sung moi LUpng dudng cat bo sung vao be de tao biofloc dddc tinh dpa theo cong thdc cua Avnimelech (2015) 2.2 Phddng phap nghien ciiu 2.2.1 Bo tri thi nghiem Thi nghiem dupe bo tri be 250 lit, man 12 %o, mat au trung 60 con/L va bo tri hoan toan ngau nhien vdi nghiem thdc, moi nghiem thdc co lan lap lai: Nghiem thdc : Cho an binh thudng, khong tao biofloc Nghiem thdc 2: Giam 20% lupng thdc an, khong tao biofloc Nghiem thdc 3: Giam 40% hipng thdc an, khong tao biofloc Nghiem thdc 4: Giam 60% lddng thdc an, khong tao biofloc Nghiem thdc 5: Cho an binh thddng, co tao biofloc Nghiem thdc : Giam 20% lddng thdc an, co tao biofloc Nghiem thdc 7: Giam 40% lddng thdc an, co tao biofloc Nghiem thdc : Giam 60% lddng thdc an, co tao biofloc 2.2.2 Cham soc va qudn ly he tidng Au trung va hau au trung tom cang xanh dddc cho an theo bang Bang thdc an la doi chdng, sau theo nghiem thdc ma giam lddng thdc an cho phu hdp Bang Bang hiidng dan cho au trung va hau au trung tom cang xanh an Giai doan au trung Loai thdc an Lddng thdc an Giai doan Giai doan -3 Giai doan -5 Giai doan - Giai doaui 9- PL15 Sd lan cho an Khong cho an Au trung (AT) artemia AT artemialmL nude Udng lan/ngay (7 h va 17 h ) Thdc an Lansy PL g/m3/lan lan/ngay (8 h, 11 h va 14 h) Au trimg artemia AT artemialmL nude Udng lan/ngay (17 h) Thdc an Lansy PL 1,5 g/m3/lan lan/ngay (8 h, 11 h va 14 h) Au trung artemia AT artemia/ml nUdc Udng lan/ngay (17 h) Thdc an Lansy PL Au trung artemia AT artemia/ml nUdc Udng g/m3/lan 2.2.3 Cac chi tieu theo doi va thu mdu phdn tich - Chi tieu moi trdPng nddc: Nhiet va pH dupe lan/ngay bang may pH Do kiem, TAN va N 2' phan tich ngay/lan Do kiem diidc phan tich bang phddng phap chufo acid, TAN dddc phan tich bang phddng phap Phenate va N dddc phan tich bang phUdng phap Diazonium (APHA, 2005) - Chi tieu biofloc: Kich cd hat biofloc (mm) diidc chieu dai va chieu rong ngau nhien 30 hat biofloc/ be bang kinh hien Nikon ECLIPSE Ti2 microscope with a DS-Qi2 camera (Nikon Corporation, Tokyo, Japan), the tich biofloc (ml/L) dddc xac dinh bang each dong lit nddc mau cho vao binh non imhoff va de lang khoang phut, ghi nhan the tich lang theo ddn vi ml/L (Santhana va cong tac vien., 2018) Cac chi tieu biofloc dupe thu mau phan tich d giai doan PL5, PLl0vaPL15 - Chi tieu vi sinh: Vi khuan tong so va vi khuan Vibrio nddc, diidc xac dinh ngay/lan Vi lan/ngay (8 h, 11 h va 14 h) lan/ngay (17 h) khuan tong so va vi khuan Vibrio tdm dddc xac dinh cuoi thi nghiem Xac dinh mat vi khuan theo phiidng phap cua Huys (2002) - Cac chi tieu theo doi tdm: Chi so bien thai cua au trung (LSI) diiac xac dinh ngay/1 lan, moi lan thu ngau nhien 10 au trung/be, chi so bien thai cua au trung tdm cang xanh theo doi den thd 24 Chieu dai au trung va hau au trung dddc d cac giai doan 1, 5, 11, PL1 va PL15, moi lan 30 con/ be Ty le song va nang suat cua PL15 dddc tinh bang phddng phap dinh liipng khoi lddng tdm td xac dinh dddc so tdm be 2.2.4 Phiidngphdp xii ly so lieu Cac so lieu thu thap dupe tinh toan cac gia tri trung binh, lech chuan bang phan mem Microsoft Excel 2010, so sanh sd khac biet gida cac nghiem thdc theo phUdng phap phan tich ANOVA mot nhan to vdi phep thd Duncan bang phan mem thong ke SPSS 22.0 d mdc y nghia (p < 0,05) Tap chiKhoa hoc va Cong nghe Nong nghiep Viet Nam - So 05(126)/2027 2.3 Dia diem va thdi gian nghien cdu Nghien cdu ddcfc thdc hien td thang den thang nam 2020 tai Trai thdc nghiem nddc Id, Khoa Thuy san, Trddng Dai hoc Can Thd III KET QUA VA THAO LUAN 3.1 Cac yeu to m i trddng Nhiet cac be ddng au triing tom cang xanh cua cac nghiem thdc dao dong khong dang ke va nam khoang td 28,3 - 30,7°C pH cua cac be ddng dao dong td 8,25 - 8,34, nam khoang thich hdp cho sd phat trien cua au trung tom cang xanh Nguyen Thanh Phiidng va cong tac vien (2003), cho rang nhiet td 28 - 32°C, pH td 7,5 - 8,5 la thich hdp cho ddng au trung tom cang xanh Bang Chi tieu nhiet va pH Nhiet (°C) Chi tieu Nghiem thdc Sang PH Chieu Sang Chieu 28,6 ± 0,1 30,4 ±0,4 8^7 ± 0,01 8,32 ± 0,01 28,6 ± 0,1 30,6 ± 0,1 8,26 ± 0,01 8,32 ± 0,02 28,7 ± 0,2 30,7 ± 0,1 8J.7 ± 0,01 8,33 ±0,01 28,4 ± 0,5 30,7 ± 0,1 8^7 ± 0,01 8,34 ± 0,01 28,3 ± 0,1 30,0 ± 0,5 8^5 ± 0,01 8,32 ± 0,01 28,4 ± 0,5 30,6 ± 0,1 8,26 ± 0,02 8,32 ± 0,03 28,4 ± 0,5 30,4 ± 0,4 8,25 ± 0,01 8,33 ± 0,02 28,2 ± 0,7 30,1 ± 0,9 8,25 ± 0,01 8,33 ± 0,01 Qua ket qua phan tich cho thay kiem be ddng cua cac nghiem thdc dao dong khoang 110 - 114 mg C aC 3/L Theo Chau Tai Tao va Tran Minh Phu (2015), thi kiem thich hdp cho au trung va hau au trung tom cang xanh td 100 - 120 mg C aC 3/L Ham lddng N 2" thi nghiem dao dong td 0,13 - 0,97 mg/L, theo ghi nhan cua Margarete va Wagner (2006) ham lddng N 2- < mg/L khong anh hddng den au trung Viec bo sung dddng cat giup he vi khuan nddc phat trien lam ham lddng TAN cac nghiem thdc co biofloc thap hdn cac nghiem thdc khong tao biofloc vi co sd hinh vi khuan chuyen hoa ham lddng TAN N 2", nhdng thdi gian ddng ngan nen he vi khuan chuyen hoa N N chda phat trien kip, dan den cac nghiem thdc co bo sung dddng cat de tao biofloc co ham lddng TAN thap nhdng N cao Tuy nhien, ham lddng TAN thi nghiem nam khoang td 0,17 - 0,93 mg/L, theo Sandifer va Smith (1985), ham lddng TAN dddi 1,5 mg/L la thich hdp cho sd phat trien cua au trung tom cang xanh Nhd vay cac yeu to moi trddng nhiet do, pH, TAN, N 2"va kiem cua thi nghiem deu nam khoang thich hdp cho ddng au trung tom cang xanh Bang Chi tieu kiem, N 02 va TAN Do kiem (mgCaC03/L) Chi tieu Nghiem thdc no2 (mg/L) TAN (mg/L) 112 ±3 0,23 ± 0,03 0,93 ±0,13 111 ± 0,16 + 0,02 0,83 ± 0/22 117 ±2 0,17 ± 0,03 0,79 ±0,17 114 ± 0,13 ±0,03 0,43 ±0,01 112 + 0,86 ±0,26 0,59 ± 0,26 110 + 0,97 ±0,14 0,41 ± 0,16 113 ±5 0,95 ±0,11 0,47 ±0,17 114 ±4 0,94 ± 0,26 0,17 ±0,01 3.2 The tich va kich cd hat biofloc 3.2.1 The tich biofloc O giai doan PL-5 the tich biofloc chi ghi nhan ddcfc nghiem thdc 5, den nghiem thdc , dieu lddng dddng cat bo sung tao biofloc dddc hinh nhanh hdn so vdi cac nghiem thdc khong bo sung dddng cat The tich biofloc ldn nhat d i^hiem thdc khac biet khong co y nghia thong ke (p > 0,05) so vdi nghiem thdc va 7, nhdng khac biet cd f nghia thong ke (p < 0,05) so vdi cac nghiem th iir r M lai Den giai doan PL-15 d tat ca cac nghirni A4C Tap chiKhoa hoc va Cong nghe Nong nghiep Viet Nam - So 05(126)/2021 deu hinh diicfc hat biofloc, the tich biofloc cao nhat d nghiem thiic cho an binh thiidng va co tao biofloc khac biet co y nghia thong ke (p < 0,05) so vdi cac nghiem thiic lai Bang The tich biofloc Giai doan thu Nghiem thiic PL-5 PL-10 PL-15 0,00 ± ,00 a 0,10 ± ,00b 0,13 + 0,06a 0,00 ± ,00 a 0,00 ± ,00“ 0,07 ± 0,06a 0,00 ± ,00 a 0,00 ± ,00 a 0,07 ± 0,06a 0,00 ± ,00 a 0,00 ± ,00 a 0,03 ± 0,06a 0,14 ± 0,01b 0,20 ± ,10c 0,30 ± 0,10b 0,10 0,07 ± 0,06b 0,07 ± 0,06ab 0,16 ± ,12a 0,06 ± ,01 a 0,10 ± ,01 a 0,13 ± 0,06a ± ,02 b 0,13 + 0,06bc 0,17 ± 0,06a Ghi chu: Cac gia tri ciing mot cot co ky tU chil cdi khdc thi khdc biet co y nghia thong ke (p < 0,05) 3.2.2 Chieu dai hat biofloc Chieu dai trung binh hat biofloc d giai doan PL-5 d nghiem thiic ldn nhat khac biet khong co y nghia thdng ke (p > 0,05) so vdi nghien thiic va nhilng khac biet co y nghia thong ke (p < 0,05) so vdi cac nghiem thiic laL Den giai doan PL-15 chieu dai hat biofloc d nghiem thiic ldn nhat khac biet co y nghia thong ke (p < 0,05) so vdi cac nghiem thiic lai Bang Chieu dai hat biofloc Giai doan thu Nghiem thiic PL-5 0,12 PL-10 PL-15 ± ,01 a 0,15 ± 0,01a 0,13 ± 0,03a : 0,13 ± 0,01* 0,15 ± 0,02a 0,13 + 0,04a 0,14 ± 0,01b 0,15 ± 0,01a 0,14±0,02a 0,14 ± 0,01b 0,14 ± 0,01a 0,15 ± 0,01a 0,20 0,18 ± ,02 c 0,24 + 0,0 lc 0,17 ± 0,03a 0,18 ± ,01 c 0,21 ± 0,05b 0,14 ± 0,02a 0,14 ± 0,02b 0,17 + 0,02a 0,16 ± ,02 a + ,01 c 0,27 + 0,02c 0,22 ± ,01 b Ghi chu: Cac gia tri cung mot cot co ky ttf chit cdi khdc thi khdc biet coy nghia thong ke (p < 0,05) 3-2~3 Chieu ronghat biofloc Cf giai doan PL-5 va PL-10 chieu rang hat biofloc d nghiem thiic cao nhat khac biet khong co y nghia thong ke (p > 0,05) so vdi nghiem thiic , nhiing khac biet co y nghia thong ke (p < 0,05) so vdi cac nghiem thiic lai Den giai doan PL-15 chieu rong hat biofloc d nghiem thiic cao nhat khac biet co y nghia thong ke (p < 0,05) so vdi cac nghiem thiic lai Bang : Chieu rang hat biofloc Giai doan thu Nghiem thiic PL-5 PL-10 PL-15 0,04 ± 0,01a 0,06 ± 0,03a 0,06 ± 0,01a 0,04 ± 0,01a 0,06 ± 0,01a 0,06 ± 0,01a 0,03 ± 0,01a 0,05 ± 0,01a 0,06 ± 0,01a 0,03 ± 0,01a 0,06 + 0,01a 0,05 ± 0,01a 0,06 ± 0,0 lb 0,08 ± 0,01b 0,09 ± 0,01b 0,05 ± 0,01b 0,08 ± 0,02b 0,07 ± 0,01a 0,04 ± 0,01a 0,06 ± 0,01a 0,06 ± 0,01a 0,03 ± 0,01a 0,06 ± 0,01a 0,06 ± 0,01a Ghi chu: Cac gia tri cung mot cot co ky tU chit cdi khdc thi khdc biet co y nghia thdng ke (p < 0,05) 3.3 Cac chi tieu vi sinh 3.3.1 Vi khuan tong nitdc Nhin chung, mat vi khuan tong niidc qua cac lan thu mau gida cac nghiem thiic khac biet khong co y nghia thong ke O lan thu mau cho thay, mat vi khuan tong thap nhat d nghiem thiic nhiing khac biet khong co y nghia thong ke so vdi cac nghiem thiic lai Tiidng tii d lan thu mau thii 2, va giCta cac nghiem thiic cung khac biet khong co y nghia thong ke (p > 0,05) Nhin chung, d nghiem thiic va co bo sung diidng cat nhieu de tao biofloc thi mat vi khuan tong cao hern cac nghiem thiic lai nhiing chiia du ldn khac biet co y nghia thong ke, co the cac nghiem thiic tao biofloc thi vi khuan gop phan hinh hat biofloc, nen lay mau niidc phan tich thi mat vi khuan tong khong cao dan den khac biet khong co y nghia thong ke (p > 0,05) gifla cac nghiem thiic Avnimelech (2015) cho rang, biofloc la cac cum ket dinh gom vi khuan, vi tao, dong vat nguyen sinh va cac vi sinh vat khac cimg vdi cac manh vun hiiu ccr ket cac hat biofloc co diidng kinh 0,1 den vai mm, vi khuan di diidng chiem liu the so vdi cac phan biofioc Tap chiKhoa hoc va Cdng nghe Nong nghiep Viet Nam - So 05(126)/2021 Bang Mat vi khuan tong mau nilcfc (104 CFU/mL) Nghiem thiic Thu m lu Ldnl Ldn2 Lan Lan 0,12 ± 0,2 l a 2,0 ± 0,42a 1,81 ± 0,14a 1,72 + 0,66a 0,27 ± 0,37a 2,3 ± 0,32a 1,5610,33' 1,75 ± 0,87a 0,28 + ,22 a 1,2 ± l,51a 1,47 ± 0,42a 1,87 ± l,00a 0,21 ± , 12 a 2,3 ± l,08a 1,65 ± 0,48a 1,93 ± 0,29a 0,31 ±0,13a 1,9+ l,15a 1,85 ± l,64a 1,97 ± 0,50a 0,16 ± ,22 a 1,3 ± 0,38a 1,51 + 0,26a 1,83 ± 0,48a 0,36 ± 0,18a 1,8 ± 0,23a 1,43 ± 0,22a 1,77 +0,1 l a 0,23 + 0,08a 1,9 ± 0,49a 1,57 ± 0,69a 1,87 ± 0,10a Ghi chu: Cdc gia trf ciing mot cot co ky tU chit cai khac thi khac biet co y nghia thong ke (p < 0,05) 3.3.2 Vi khuan Vibrio ntidc Ket qua xif ly thong ke cho thay mat vi khuan Vibrio is lan thu mau va giQa cac nghiem thiic khac biet khong co y nghia thong ke Den lan thu mau thii mat vi khuan Vibrio thap nhat is nghiem thiic khac biet co y nghia thong ke so vcfi cac nghiem thiic lai O lan thu mau mat vi khuan Vibrio gifla cac nghiem thiic khac biet khong co y nghia thong ke Bang Mat vi khuan vibrio mau nude (102 CFU/mL) Nghiem thiic Thu mau Ldn Ldn 0,09 ± 0,01a 0,12 0,11 0,50 ± 0,12a L dn3 1,41 ± 0,24b 1,79 ± 0,46* ± ,02 a 0,43 ± 0,02a 1,56 ± 0,36b 1,78 ± 0,82a ± ,02 a 0,52 ± 0,21a 1,53 ± 0,22b 1,85 ± 0,70“ 0,11 ±0,03a 0,12 ± ,10 a 0,39 ± 0,08a 1,64 ± 0,38b 1,96 ± 0,19* 0,49 ± 0,15a 1,15 ± 0,63a 1,67 ± 0,71* 0,53 ± 0,28a 1,52 ± 0,46b 1,89 ± 0,52“ 0,13 ± 0,02a 0,16 ± 0,08a 0,58 ± 0,27a 1,48 ± 0,32b 1,87 ± 0,71* 0,13 ± 0,08a 0,49 ± 0,19a 1,55 ± 0,39b 1,97 ± 0,19* L dn4 Ghi chu: Cdc gia tri ciing mot cot co ky tU chit cai khac thi khac biet co y nghia thong ke (p < 0,05) 3.3.3 Vi khuan tong vd Vibrio tom nghia thong ke va nam khoang thich hop cho Mat vi khuan tong va vi khuan Vibrio tom giiia cac nghiem thiic khac biet khong co y licfng au trung tom cang xanh Bang Mat vi khuan tong (104 CFU/g) va Vibrio (102 CFU/g) tom PL 15 Nghiem thiic Chi tieu Nghiem thiic Chi tieu Vi khuan Tong Vi Ichudn Vibrio 2,12 ± 0,54a 1,54 ± 0^6* 1,32 ± 0,79a 2,09 ± 0,76a 1,88 ± 0,43* 1,95 ± 0,65a 1,48 ± 0,87a 2.05 ± 0,43a 1,78 ± 0,65* 1,93 ± 0,42a 1,34 ± 0,97b 2,13 ± 0,72a 1,69 ± 0,66* Vi khuan Tong Vi khuan Vibrio 2,32 ± 0,67a 1,20 ± 0,29a 2,44 ± 0,24a Ghi chu: Cdc gid tri ding mot hang co ky tU khdc thi khac biet co y nghia thong ki(p< 0,05) Tap chi Khoa hoc va Cong nghe Nong nghiep Viet Nam -So05(126)/202 3.4 C hi so bien th a i (LSI) cua au tru n g tom cang xanh Chi so bien thai cua au trimg tom d thii ldn nhat d nghiem thiic khac biet co y nghia thong ke (p < 0,05) so vdi nghiem thhc , nhiing khac bi£t khong co y nghia thong ke p > 0,05) so vdi cac nghiem thiic lai Cf thii , va 12 chi so bi£n thai cao nhat d nghiem thiic va nghiem thiic 5, nhiing giQa nghiem thiic khac biet khong co y nghia thong ke (p > 0,05) Cf thii 15, nghiem thiic co chi so bien thai cao nhat la 7,70 ±0,17 khac biet khong co y nghia thong ke so vdi nghiem thiic , nhilng khac biet co y nghia thong ke vdi cac nghiem thiic lai Den thii 18, chi s6 bien thai cao nhat nghiem thiic (7,83 ± 0,23) va thap nhat d nghiem (6,90 ± 0,40), gifla hai nghiem thiic sii khac biet co y nghia thong ke (p < 0,05), nhien so sanh giiia hai nghiem thiic vdi cac nghiem thiic lai sii khac biet khong co y nghia thong ke (p > 0,05) Chi so bien thai cua au trimg d thii 21 d nghiem thiic (9,67 ± 0,25) cao nhat khac biet khong co y nghia thong ke so vdi nghiem thiic 1, nhiing khac biet co y nghia thong ke so vdi cac nghiem thiic lai Den 24 thi nghiem thiic co chi so bien thai cao nhat (10,63 ± 0,25) va khac biet khong co y nghia thong ke (p > 0,05) so vdi nghiem thiic va nghiem thiic 5, nhiing khac biet co y nghia thong ke (p < 0,05) so vdi cac nghiem thiic lai Bang 10 Chi so bien thai (LSI) cua au trung tom cang xanh Chi so bien thai (LSI) Ngay thii 2,97 ± 0,06ab 3,03 ± 0,06ab 3,03 ± 0,12ab 2,97 ± 0,12ab 3,13 ± 0,12b 2,97 ± 0,06ab 2,93 ± 0,06* 2,83 ± 0^1* Ngay thd 15 7,10 ± 0,30* 7,13 ± 0,29b 6,53 ± 0,47a 6,73 ± 0,15* 7,70 ± 0,17C 7,80 ± 0,20c 7,13 ± 0,15b 7,10 ± 0,50ab Ngay thii 5,53 ± 0,12b 5,33 ± 0,21ab 5,30 ± 0,17a 5,33 ± 0,06ab 5,33 ± 0,06ab 5,33 ± 0,06* 5^0 ± , 10“ 5,17 ± 0,06a Ngay thii 18 7,53 ± 0,31* 7,40 + 0,30lb 7,73 ± 0,51* 7,63 ± 0,40* 7,83 ± 0,23b 7,70 ± 0,61* 6,90 ± 0,40a 7,53 ± 0,59* Ngay thii 12 6,63 + 0,06c 6,47 + 0,15'' 6,43 ± 0,06bc 5,97 ± 0,15* 6,73 ± 0,23c 6,60 ± 0,46c 5,90 ± 0,53a 5,70 ± 0,17a Nghiem Ngay thii 24 thiic 10,63 ± 0,25c 9,97+ 0,711' 9,33 ± 0,40* 9,10 ± 0,36a 10,03 ± 0,21^ 9,33 ± 0,32* 9,37 + 0,23* 8,83 ± 0,51a Ghi chu: Cacgia tri trongciing mot hdng co ky tU khac thi khac biet coy nghia thong ki (p < 0,05) 3.5 C hieu dai au tru n g va h au au tru n g tom cang xanh O giai doan 1, chieu dai trung binh cua au trung tom cang xanh cac nghiem thiic la ,0 mm, khong co sii chenh lech giha cac nghiem thiic Theo Chau Tai Tao va cong tac vien (2014), chieu dai cua au trung tom cang xanh giai doan la 1,8 -1,9 mm Ket qua cho thay chieu dai au trung giai doan cao htfn nghien ciiu tren CJ giai doan 5, chieu dai au trung dao dong til 3,96 - 4,12 mm, cao nhat nghiem (4,12 ± 0,07 mm) khac biet co y nghia thong ke (p < 0,05) so vdi nghiem thiic (3,96 ±0,17 mm), nhilng so sanh hai nghiem thiic vdi cac nghiem rin k lai sU khac biet khong co y nghia thong ke Ngay thii 6.20 ± ,20 ' 5,90 -t 0,26 "■ 5,83 ± 0,15* 5,60 ± 0,20a 5,93 ± 0,06*c 6,00 ± 0,17bc 5,67 ± 0,06* 5,63 ± 0,2 l a Ngay thii 21 9,13 ± 0,40bc 8,57 ± 0,64* 8,07 ±0,42' 8,37 ± 0,21* 9,67 ± 0,25c 8,67 ± 0,42* 8,77 ± 0,59* 8,27 ± 0,60* (p > 0,05) Cf giai doan 11, chieu dai au trung dao dong tii 7,74 den 8,56 mm, cao nhat d nghiem thiic (8,56 ± 0,08) va khac biet co y nghia thong k£ (p < 0,05) so vdi cac nghiem thiic lai Theo Uno va Soo (1969), chieu dai cua au trung giai doan va 11 lan liiqt la 2,8 va 7,7 mm Chieu dai cua PL-1 d nghiem thiic thap nhat 7,16 ± 0,87 mm, khac biet co y nghia thong ke (p < 0,05) so vdi nghiem thiic , nhiing khac biet khong co y nghia thong ke so vdi cac nghiem thiic lai C hilu dai cua PL-15 d nghiem thiic co chieu dai tot nhat khac biet khong co y nghia thong ke (p > 0,05) so vdi nghiem thiic , nhiing khac biet co y nghia thong ke so vdi cac nghiem thiic lai Theo Loureiro va cong tac Tap chi Khoa hoc va Cong nghe Ndng nghiep Viet Nam - So 05(126)/2021 vien (2012); Ray va cong tac vien (2010) cho rang, au trung tom cang xanh an ddcfc hat biofloc, td cho thay nghiem thdc giam % lddng thdc an nhan tao va co tao biofloc nhdng tang triidng cua tom khong khac so vdi nghiem thdc cho an binh thiidng co tao biofloc Theo Chau Tai Tao va cong tac vien (2014), chieu dai trung binh au trung tom cang xanh giai doan 5, 11, PL-15 lan lddt la 0,28 ± 0,02 cm; 0,67 ± 0,03 cm; 0,91 ± 0,02 cm Nhd vay, ket qua nghien cdu co chieu dai au trung va hau au trung deu dai hon nghien cdu tren Bang 11 Chieu dai (mm) au trung va hau au trung tom cang xanh Giai doan thu Nghiem thiic Giai doan 2,0 ± 0,0a 2,0 + 0,0a 2,0 ± 0,0a 2,0 + 0,0a Giai doan 4,12 ± 0,07b 4,03 ± 0,09* 2,0 ± 0,0a 2,0 ± 0,0a 2,0 ± 0,0a 2,0 ± 0,0“ 3,98 ±0,05* 3,99 ± 0,04* 4,08 ± 0,04* 4,00 ± 0,04* 3,96 ± 0,17* 3,98 ± 0,03* Giai doan 11 739 ±0,11* Postlarvae 7,45 ± l,26*b 7,73 ± 0,09*b 7,70 ± 0,80*b 833 ± 0,74*b 7,16 ± 0,87* 8,15 ± 0,60* 7,79 ±037* 7,62 ±030* 833 ± 0,40* 8,76 ± 0,94b 836 ± 0,08c 7,74 ± 0,21* 7,69 ±0,11* 7,74 ± 0,08* 8^5 ±0,27b Postlarvael5 9,4 ± 0,7* 9,8 ± 1,0* 9,3 ± 0,9* 10,1 ± 1,2* 11,3 ± 0,6b 11,0 ± 0,7b 10,2 ± 0,9* 10,4 ± 0,6* Ghi chu: Cacgia tri ciing mot hang co ky tU khac thi khdc biet co y rtgftia thong k i (p < 0,05) 3.6 Ty le song va nang suat tom PL-15 IV KET LUAN VA DE XUAT Ty le song cua PL-15 gifla cac nghiem thdc dao dong td 23,1 - 49,8% Trong nghiem thiic co ti le song cao nhat la 49,8% khac biet khong co y nghia thong ke so vdi nghiem thiic va nghiem thiic , nhiing khac biet co y nghia thong ke (p < 0,05) so vcfi cac nghiem thiic lai TI le song cua PL-15 thap nhat 23,1% d nghiem thiic 4, khac biet khong co y nghia thong ke (p > 0,05) so vcfi nghiem thiic (27,4%), nhiing khac biet co y nghia thong ke (p < 0,05) so cac nghiem thiic lai 4.1 Ket luan Bang 12 Ty le song va nang suat cua PL-15 Chi tieu Giam hieing thiic an 20% co biofloc thi tang triidng, ty le song va nang suat cua PL15 khong khac so vcfi nghiem thiic cho an binh thiidng co biofloc va cao hdn nghiem thiic cho an binh thiidng, khong biofloc 4.2 De xuat Ling dung giam liidng thiic an 20% Ucfng au trung tom cang xanh theo cong nghe biofloc vao thuc te san xuat LOfI CAM ON De tai diidc tai trd bdi Dii an Nang cap Triidng Dai hoc Can Thcf VN14-P6 bang nguon von vay ODA td chinh phu Nhat Ban Nghiem thiic Tylesong(%) Ndng sudt (con/m3) 45,1 ± 5,0C 27.077 ± 3.010d 36,3 ± l, b 21.795 + 1.100c 33,6 ± 3,9b 20.163 ± 2.363bc tAi l ie u t h a m k h a o 23,1 ± ,8 * 13.867 ± 4.087* 49,8 ± 1,9C 29.859 ± 1.129d 48,0 ± 3,3C 28.801 ± 1.989d 35,8 ± ,lb 21.457 ± 3.631c 27,4 ± 7,6*b 15.249 ± 4.513*b Chau Tai Tao, Tran Minh Nhdt va Tran Ngoc Hai, 2014 Danh gia chat liicfng au trung va hau au trung cua mot so nguon tom cang xanh (Macrobrachium rosenbergii) d cac tinh phia nam Tap chi Khoa hoc, Dai hoc Can Thd, (34): 64-69 Chau Tai Tao, Tran Minh Phu, 2015 Anh hiidng cua kiem len tang trUdng va ty le song cua au trung va hau au trung tom cang xanh (Macrobrachium rosenbergii) Tap chi Ndng nghiep vd phot trial momg than, (3+4): 93-99 Le Thanh Nghi, Pham Minh Truyen, C h ia T ii 1S% Nguyen Van Hoa, Tran Ngoc HiL, 2020 A a h h a i> | cua cac nguon cacbon len tang tnidng va ty Udng au trung tom cang xanh (J ia o a ia a lM l Ghi chu: Cac gia tri ding mot hang co ky tU khac thi khac biet coy nghia thong ke (p < 0,05) Nang suat PL-15 cao nhat nghiem thiic khac biet khong co y nghia thong ke so vdfi nghiem thiic va nghiem thiic , nhiing khac biet c6 y nghia thong ke (p < 0,05) so vcfi cac nghiem thiic lai Tap chi'Khoa hoc va Cong nghe Ndng nghiep Viet Nam - So 05(126)/2027 rosenbergii) bang cong nghe biofloc Tap chi Khoa hoc Cong nghe Ndng nghiep Viet Nam, so 5(114): 117-123 Nguyen Thanh Phtfdng, Tran Ngoc Hai, Tran Thi Thanh Hien va Marcy N Wilder, 2003 Nguyen ly va ky thuat san xuat gi6ng tom cang xanh (Macrobrachium rosenbergii) Nha xuat ban Nong nghiep TP Ho Chi Minh: 127 trang Pham Minh Truyen, Le Thanh Nghi, Chau Tai Tao, Nguyin Van Hoa, Tran Ngoc Hai., 2020 Nghien Ciiu liong au triing tom cang xanh theo c6 ng nghe biofloc vdi cac ti le C/N khac Tap chi Khoa hoc Cong nghe Ndng nghiep Viet Nam, so 1(110): 102-108 Tran Ngoc Hai, Tran Thi Thanh Hien, Tnicfng Quoc Phu, Tran Thi Tuyet Hoa, Le Qu6c Viet, Ly Van Khanh, Tran Nguyen Duy Khoa va Chau Tai Tao, 2019 Nghien crfu bo sung nguon carbon d cac giai doan khac ifcfng au triing tom cang xanh (Macrobrachium rosenbergii) bang cong nghe biofloc Tap chi Khoa hoc, TrUdng Dai hoc Can Thd, 55(3B): 141-148 APHA, 2005 American Water Works Association, Water Pollution Control Association Standard Methods for the Examination of Water and Wastewater, 21“ edition American Public Health Association, Washington, DC, USA Avnimdech, Y, 2015 Biofloc Technology A Practical Guide Book, 3rd Edition The World 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: 35 pages Loureiro, K.C., Wilson, W.J & Abreu, P.C., 2012 Utilizaijao de protozoarios, rotiferos e nematodeos como alimento vivo para camaroes cultivados no sistema BFT Atlantica, Rio Grande, 34(1): 5-12 Margarete Mallasen, Wagner Cotroni Valenti, 2006 Effect of nitrite on larval development of giant river prawn Macrobrachium rosenbergii Original Research Article Aquaculture, 261(4): 1292-1298 McIntosh, B.J.; Samocha, T.M.; Jones, E.R.; Lawrence, A.L.; McKee, D.A.; Horowitz, S and Horowitz, A., 2000 The effect of a bacterial supplement on the high-density culturing of Litopenaeus vannamei with low-protein diet on outdoor tank system and no water exchange Aquacultural Engineering, : 215-227 Ray, A.J., Lewis, B.L., Browdy, C.L & Leffler, J.W., 2010 Suspended solids removal to improve shrimp (Litopenaeus vannamei) production and an evaluation of a plant-based feed in minimalexchange, superintensive culture systems Aquaculture, 299(1-4): 89- 98 SandiferP.A and Smith T.I.J., 1985 Freshwater prawns In Hunner, J and E.E Brown (Ed.), Crustacean and Mollusk Aquaculture in the United State Van Nostrand Rienhold, Newyord: 63-125 Santhana, K.V., Pandey, P.K., Anand, T., Bhuvaneswari, G.R., Dhinakaran, A., Kumar, S., 2018 Biofloc improves water, effluent quality and growth parameters of Penaeus vannamei in an intensive culture system / Environ Manag 215, 206-215 Uno, Y and K.C Soo, 1969 Larval development of Macrobrachium rosenbergii reared in laboratory / Tokyo Univ Fish., 55(2): 79-90 Effects o f feed reduction on growth and survival rate o f larvae postlarvae stages o f giant freshwater prawn (M a cro b ch iu m ro sen b erg ii ) applied biofloc and without biofloc technology Tran Ngoc Hai1, Pham Minh Truyen2, Nguyen Van Hoa1 and Chau Tai Tao1 Abstract This study is aimed to determine appropriate reducing feed amount for growth, survival and biomass of giant freshwater prawn at larva and postlarva stages The experiment was randomly designed with treatments: ( 1) Normal feeding, no biofloc; (2) reduced 20% of feed amount, no biofloc, (3) reduced 40% of feed amount, no biofloc (4) reduced 60% of feed amount, no biofloc (5) Normal feeding, biofloc, (6 ) reduced 20% of feed amount, biofloc (7) reduced 40% of feed amount, biofloc, and (8 ) reduced 60% of feed amount, biofloc The larvae were stocked in 250 liters, at 60 ind./L of stocking density and 12%o of salinity The results showed that PL-15 in the treatment reduced 20% of feed amount, biofloc growth performance (11.0 ± 0.7 mm in length) was statistically different (p < 0.05) compared to the treatment normal feeding, no biofloc, but survival rate (48.0 ± 3.3 %) and biomass (28,801 ± 1,989 PL/m3) was not statistically different (p > 0.05) compared to the treatment normal feeding, no biofloc Therefore, the present study suggests that giant freshwater prawn larviculture applied biofloc technology and reduced 20 % of feed amount could help to optimize production costs Keywords: Biofloc, reducing feed amount, larval of giant freshwater prawn Ngay nhan bai: 02/5/2021 Sgky phan bien: 20/5/2021 lOt Ngvfcfi phan bien: TS Le Van Khoi Ngay duyet dang: 04/6/2021 ... crfu bo sung nguon carbon d cac giai doan khac ifcfng au triing tom cang xanh (Macrobrachium rosenbergii) bang cong nghe biofloc Tap chi Khoa hoc, TrUdng Dai hoc Can Thd, 55(3B): 141-148 APHA,... Normal feeding, no biofloc; (2) reduced 20% of feed amount, no biofloc, (3) reduced 40% of feed amount, no biofloc (4) reduced 60% of feed amount, no biofloc (5) Normal feeding, biofloc, (6 ) reduced... tich bang phUdng phap Diazonium (APHA, 2005) - Chi tieu biofloc: Kich cd hat biofloc (mm) diidc chieu dai va chieu rong ngau nhien 30 hat biofloc/ be bang kinh hien Nikon ECLIPSE Ti2 microscope