Tgp chi Khoa hpc Truong Dgi hpc Cdn Tha Phdn B: Ndng nghiip, Thiiy sdn vd Cdng nghi Sinh hgc- 35 (2014): 104-110
Tap chl Khoa hpc Tru'dng Dai hgc Can Thd website: sj.ctu.edu.vn
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KHA NANG Sf DUNG RONG BUN {ENTEROMORPHA SP.) VA RONG MEN (CLADOPHORACEAE) KHO
LAM THtrc AN CHO CA TAI TU'OfNG {OSPHRONEMUS GORAMY)
Nguydn Thi Ngoc Anh', Nguyin Thien Toan^ va Tran Ngoc Hai' ' Khoa Thity sdn, Truong Bgi hgc Cdn Tho
^Hgc vien cao hgc, Tnrdng Bgi hgc Cdn Tho Thong tin chung:
Ngdy nhgn: 31/05/2014 Ngdy chdp nhgn: 30/12/2014 TUle:
Potential use of dried gut weed (Enterormorpha sp.) and blanket weed (Cladophoraceae) for the giant gourami (Osphronemus goramy)
TO- khda:
Osphronemus goramy, Enterormorpha sp., Cladophoraceae, hiiu qud su dung thuc dn
Keywords:
Osphronemus goramy, Enterormorpha sp., Cladophoraceae, feed efficiency
ABSTRACT
Evaluating the potential use of dried gut weed (Enleromorpha sp.) cmd blanket weed (Chaladophoraceae) lo replace the pellet feed for the giant gourami (Osphronemus goramy) was carried out. Experiment composed oj eight treatments with three replicates. In 3 control treatments (single diets), fish was fed daily either by pellet feed or gut weed or blanket weed.
In five other treatments, fish was fed two alternative feeding regimes consisting of 1 day gut weed or blanket weed and I consecutive day pellet feed or and 2 consecutive days gut weed or blanket weed, and I day gut weed following I day blanket and 1 consecutive d(^ pellet feed. After 56 days of culture, survival of experimental fish was not affected by Ihe feeding treatments and ranging ft-om 93 3 to 100%. Growth rales offish in the alternative feeding treatments were comparable to the control treatment. Application of the combined feeding regimes, feed conversion ratio and cost of pellet feed could be reduced from 43.2 to 62.8%. These results indicated that dried gut weed and blanket weed can be used as feed sowce to partially substitute pellet feed for rearing the giant gourami.
T 6 M TAT
Btinh gid khd ndng sir dung rong bim (Enleromorpha sp.) vd rong min (Chaladophoraceae) khd ihay Ihi thuc dn viin cho cd tai luong (Osphronemus goramy) dugc thuc hien. Thi nghiim gdm ldm nghiim thuc vdi ba ldn lap lgi. Trong 3 nghiem ihuc doi chung (khdu phdn dan), mdi ngdy cd dugc cho dn mgi trong ba logi thuc dn Id: thirc dn vien, rong bitn hogc rong min. Trong ndm nghiim thiec cdn lgi. cd dugc cho dn 2 che dg ludn phien gdm 1 ngdy rong bun hogc rong min vd 1 ngdy thuc an viin; 2 ngdy rong biin hogc rong men vd I ngay thuc dn vien, vd kit hgp 1 ngdy rong biin, I ngdy rang min vd 1 ngdy thitc dn vien. Sau 56 ngc^ nuoi, li li sdng cda cd tai tugng khdng bi dnh hudng bai nghiem thuc thirc dn vd dao dgng tit 93,3 din 100%. Toe do tang Iruang ciia cd a nghiem thuc cho dn ludn phien rong bun vd rong men vdi thiic an viin tuang duong vdi nghiim thuc ddi chimg. Ap dung chi dg cho dn kit hgp, hi sd lieu ldn ihuc dn vd chi phi thirc dn viin cd the dugc gidm lir 43,2 din 62,8%. Kit qud nghiin cuu cho thdy rong biin va rong min khd cd ihi dugc su dung ldm thuc dn thay the mgt phdn thiic an viin trong nudi cd tai luang.
Tgp chi Khoa hoc Trudng Dai hpc Cdn Tha Phan B: Ndng nghiip, Thiiy sdn vd Cor^ nghi Sinh hpc: 35(2014): 104-1W Bang 1: Thanh phin stah hda (% khoi lugng
kho) cua rong bua va rong miu khd va thttc aa viia (Growbest)
1 GIOITHI^U
Rong biin [Enleromorpha spp.) vd rong min (Chaladophoraceae) touOc nganh rong Iuc xudt hien tu nhien quanh nam d cdc thuy vuc nude Ig d Ddng bing sdng Cihi Long (DBSCL), vdi sinh Iugng rong tuoi trung binh 1-3 kg/m^ (1TB- Vietoam, 2011). Ca hai Ioai rong nay cd gia tri dinh dudng cao nhu giau cac axit amin va axil beo thiit yiu, sic id va khoang. Chung cd toe dugc stt dyng Iam ngudn dam toay toe mgt phin bdt ca ttong thttc dn hoac lam tottc an true tiip cho cac loai ca cd tirto an thiin vi touc vat hogc frong md hinh nudi touy san kit hgp (Khuanttairong and Traichaiyapom, 2009; Nguyen Thi Ngpc Anh vd c/v.,20I3).
Cd lai tugng {Osphronemus goramy) la lodi cd
^ d fri kinh ti khd cao, cd kich toudc ldn, dugc nudi phi biin d tirto Tiin Giang, Bin Tre vd VTnh Long. Nhttng ndm gan ddy, ca tai tugng cung dugc nudi d cac touy vuc nude Ig nhu Bge Liiu, Sdc Trang. Cd tai lucmg Id loai an lap toiin vi thuc vdt nhu cac logi rong beo, touc vdt bdc cao... vd sdng dugc Uong mdi tnrdng nude Ig (6-796o) vd cd kha nang chiu dugc diiu kiin mdi trudng khdc nghiet (Thai Ba Hd vd Ngd Trpng Lu, 2006). Theo todng tm diiu tra vi vai ttd ciia rong biin ttong ao tdm qudng canh ciia du an rong ITB-Vietnam (2011), cac hd ndng ddn d DBCSL toudng vdt bd rong bun va rong min de hgn chi chiing phdt triin qua mttc (tten 30% diin tich ao) si gay bit Igi trong ao nudi.
Do dd, nghiin cttu kha ndng stt dung biin vd rong min khd lam tottc an thay toi mOt phan tottc dn vien trong nudi ca tai tugng dugc touc hiin, nhim tan dyng ngudn rong dd bi vdt bd ttt ao quang canh Idra tottc an cho cac loai ca cd tinh an thiin ve touc vat, gdp phan gidm chi phi tottc an va nang cao thu nh$p.
2 PHU'OfNG PHAP NGHIEN CUtJ 2.1 Nguda thirc Sa
Rong biin vd rong min dugc tou ttt ao quang carto d Bge Lieu, rtta sgch va phai khd ttong bdng rdm khodng 2-3 ngay, bao quan d nhiit dp phdng.
Thttc dn vien (Growbest logi dung cho ca cd vay) dugc mua d ctta hang ban le d Thanh phd Can Tho.
Thanh phan sinh hda ciia rong bun, rong min khd dugc phdn ti'ch toeo phuang phap AOAC (1995) va toanh phan sinh hda cua tottc an vien Growbest toeo todng tin ciia nha san xuit (Bang 1).
TP sinh Roag boa Rong men Thttc an hoa kho kho vien DO ira 13,17±0,93 12,54±0,84 <11 Protein 13,33±4,22 14,84±3,27 >30 Lipid 1,53±0,53 l,47±0,48 > 6 Tro 28,82±3,32 25,48±2,03 < 14 Xa 4,15±1,48 8,79±0,92 < 6 NFE 52,16±2,41 49,42±3,56 -_
1.1 Bi tri thl nghifm
Thl nghiira gdm 8 nghiim tottc, mdi nghifm tottc dugc lin lap Igi 3 Ian. Rong bun va rong men khd dugc stt dung lam tottc dn true tiip toay toe thttc an viin toeo phuong tottc cho an ludn phiin.
Mdi ngay ca chi dugc cho an hoac la tottc 3n viin hogc Id rong bttn hogc rong min vdi tin suit (ngay) nhu sau:
Nghiem thttc I: Thttc dn viin (TA), Nghiem tottc 2: Rong biin (RB), Nghiira tottc 3: Rong min (RM), Nghiem tottc 4: 1 i^ay rong biin 1 ngdy tottc an vien (IRB-ITA), Nghiem tottc 5: 1 ngay rong min 1 ngdy thttc an vien (IRM-ITA), Nghiera thttc 6: 2 ngay rong biin _I ngdy tottc an vien (2RB-1TA), N h i i r a thttc 7: 2 ngdy rong min_l ngay touc an viin (IRM-ITA) vd Nghiem tottc 8: I ngdy rong bun_l ngdy rong men_l ngay tottc an vien (RB-IRM-ITA).
2.3 Hi thing thi aghif m va quaa ly He thong toi nghiem dugc bd tti ttong trai cd mai che phia ttin, toi tich bi nudi la 120 L. Ca tai tugng gidng dugc chpn ddng cd vdi khdi lugng ban diu trung binh la l,72g. Sd lugng ca tod nudi la 20 con/bi trong nude ngpt va cd sue khi liin tuc.
Ca toi nghiim dugc cho an toda man 2 ldn/ngay vdo 8:00 vd 16:00 gid, ca toi nghiim chi dugc cung cip rapt Ioai thttc an Uong ngdy hoac tottc dn vien hodc rong biin/rong min. Rong bttn va rong men khd dugc cit thanh dogn ngin va ngam trong nude khoang 15 phut trudc khi cho an. Lugng thttc an toira dugc tou sau 1,5 gid cho an vd dugc phoi khd din khdi lugng khdng ddi di tinh he sd tottc an toeo khdi lugng kho. Cac bi nudi dugc toay nude 3-5 ngay/lin, m6i lin khoang 30-50% lugng nude trong bi. Thdi gian toi nghiera dugc lien hdnh trong 8 tuin.
Tgp chi Khoa hpc Tmdng Dgi hgc Cdn Tha Phdn B: Ndng nghiip, Thuy sdn vd Cong nghi Sinh hpc: 35 (2014): 104-110 2.4 Thu thgp so lieu
Cac yiu t6 mdi trutmg: Nhiet dO-pH dugc 2 lan/ngay vao 7:00 va 14:00 gid bdng mdy do nhiit dd-pH. Ham Iugng NO; va NH3/NH4 (TAN) dugc xac dirto hdng tuin bing bd test SERA, Dttc. Mdu nude ttong bi nudi dugc tou trudc khi toay nude.
Cdc chi tiiu ddah gia ca tai tugag: Khii Iugng cd ban dau dugc xdc dirto bdng each bit ngdu nhiin 30 con vd cdn tttng ca toe de tinh gid ttj tnmg binh. Tdng hordng ctta cd dugc dinh ky tou raau 1 Ian/2 min. Khi kit toiic tiu nghiem, ca to!
nghifm dugc cdn khdi Iugng tifrig cd toe di ti'nh khoi lugng cudi, tang ttpng, tdc dO tang tnrdng tucmg ddi vd tuyit ddi, va tinh ti Ii sing.
Lugng thttc an an vao, hi sd tieu ton thttc dn (FCR) va chi phi tottc an. Trong dd, chi phi thttc = (lugng tottc an viin cung cap/kg ca tdng frgnglfgid tottc dn) + (lugng rong cung cap/kg cd tang frpng x chi phi tou gom rong).
Bdng 2: Cac yea to mdi trudng troag thoi giaa thi
2.5 Xfr i;^ so lieu
Cdc sd Hfu dugc tinh gia tti trung binh va dp lich chudn bang phan mim Excel. Su khdc biet giiia cdc nghiim tottc dugc pban tich todng ke bing jrfiuoi^
phdp ANOVA vdi phep thtt TUKEY d mttc y n ^ a pO,05, stt dung chuang ttinh SPSS 14,0.
3 KET QUA VA THAO LUAN 3.1 Cac yeu td mdi trucmg
Nhiit dp vd pH ttong ngay dao ddng trung binh ttong khoang 26,2 29,0°C va pH 7,8-7,9. Nhin chung, toi nghiim dugc thuc hien d dieu kien ttong phdng vd diiu kiin bi nudi giing nhau do do nhiit dO nude va pH ttong cac bi nudi biin d^ng trong ngay khdng nhiiu va gitta cac nghiera tottc tuong tu nhau. Trong tu nhiin, cd tai nrgng sinh trudng tdt d nhiet dO frong khoang 25-30''C vd pH tfr 6,5- 8,5 (Thdi Ba H i va Ngd Trpng Lu, 2006). Nhu vgy, nhiet dO va pH trong qua trinh ihi nghiim nam ttong khoang thich hpp cho su phdt uiin cua ca tai tugng aghiem
Nghidm thuc TA RB RM IRB-ITA IRM-lTA 2RB-1TA 2RM-1TA IRB-IRM-ITA
Nhidt dd Sine 26,2*0,7 26,2*0,9 26,0*0,9 26,3*0,9 26,5*0,7 26,3*0,8 26,3*0,9 26,3*0,8
i("C) Chidu 28,7*1,6 29,0*1,8 28,8*1,6 28,7*1,7 28,8*1,7 28,6*1,7 29,0±1,7 28,7*1,8
pH Sans 7,8*0,4 7,8*0,4 7,8*0,3 7,8*0,3 7,8*0,4 7,8*0,4 7,8*0,5 7,8*0,4
Chieu 7,8*0,5 7,9*0,5 7,9*0,4 7,9*0,5 7,8*0,5 7,8*0,5 7,8*0,4 7,9*0,4
TAN (mg/L) 0,44*0,24' 0,22*0,12*
0,19*0,09"
0,32*0,21' 0,30*0,15"' 0,28*0,14"
0,27*0,13"' 0,26*0,12"'
NOi-(mg/L) 0,70*0,37' 0,14*0,12' 0,20*0,11"
0,33*0,20' 0,33*0,17' 0,25*0,21"'' 0,27*0,10"
0,25*0,14a'' Cdc gid tri trung binh trin ciing mdt Cpt CO chit cdi khdc nhau ihi hiin s^ khdc biit coy nghJa (p<0.Q5)
Kit qua Bang 2 cho tody hdm lugng TAN vd NO2" trung binh d cdc nghiira' thugdagdgfl^jrpng^
khodng 0,19-0,44 va 0,14-6,70 mg/L, toeo thtt tu, vdi gid Iri cao nhat dugc tim thdy d nghiim thttc cho dn hoan todn toftc an viin (TA). Khi tin suit cho dn rong biin vd rong min xen ki vdi tottc an cdng ngjiiip cang cao toi hara Iugng NO2" va TAN cdng giam vd toap nhat d nghiem tottc stt dung hodn toan rong bien Iam tottc an. Ket qud todng ki biiu thj nghiim tottc chi stt dung tottc dn viin khac bift cd y nghia todng ki (p<0,05) so vdi cac nghiem touc cdn lgi.
Kit qud ndy khd tucmg ding vdi nghiin cttu stt dung rong bun tuoi va khd toay toi tottc an touong mgi cho cd rd phi (preochromis nllolicus) cua Siddik (2012). Tdc gia nh§n thdy cdc bi nudi chi cho dn rong biin hogc cho dn kit hgp rong bttn vdi tottc dn vien cd ham Iugng TAN va N02' to^ han
cac bi nuoi chi cho an tottc an vien. Tuang tu, , nghiin cttu gin day ciing tim thay cdc ao nudi cho an rong bttn tuoi kit hgp voi tottc an viin Uong nudi touong phdm ca nau (Scatophagus argus) a ao nude lg cd chat lugng nude tit hon so vdi chi cho dn tottc an viin (Nguyin Thi Ngpc Anh vd ctv., 2013). Nhu vdy, viic stt dung rong bttn va rong min khd Idm tottc an cho cd lai tugng da cai toiin chdt Iugng nude ttong bi nudi. Nghiira tottc ddi chttng cd ham lugng TAN va NO2' cao nhit nhung vdn nim ttong khodng chiu dung cua ca tai tirgng (Thai Bd H i vd Ngd Trpng Lu, 2006).
3.2 Ti li sing va tang trudng cua ca tai tugag sau 56 agay audi
Sau 56 ngdy thi nghiim, ty Ii sdng ciia ca tai tugng dgt cao va khdng cd su khdc biit todng ke (p>0,05) gitta cdc nghiira tottc, dao dOng ttong khodng 93,3-100% (Bdng 3). Diiu ndy biiu toi
Tgp chi Khoa hpc TrudngDgi hgc Can Tha Phdn B: Nong nghiip, Thuy sdn vd Cong rtgft# Sinh hpc: 35 (2014): 104-1 !&
dn chtta bOl ca). Dgc biil khi cho an kit hop tottc dn ddi chttng vdi rong biin tuoi ca cd ti 1$
sdng cao nhit
Khdi Iugng ttung binh ciia ca tai tugng theo thdi gian dugc ttinh \^y frong Hinh 1. Kit qua cho tody ca lai tugng cd khdi Iugng trung binh ban dau la I,72±0,22 g; sau 14 ngay nudi frd di, thfrc an cd dnh hudng din tang trudng cua ca biiu toi cd su chinh lich vi khii lugng gitta cac nghiim tottc.
Khi ket thuc thf i^Juin) vdo ngay 56, nghiim tottc doi chiing stt dung hoan loan tottc an viin cd khdi lugng frung binh Idn ban cac nghiim tottc cho an kit hgp vdi rong bun vd rong min vd nghiem tottc chi cho dn hogc rong bttn hoSc rong men.
nghiem thttc tottc an khdng dnh hudng den ty li sdng ciia ca tai tugng.
Kit qua tuong tu ddi vdi cac nghiin cttu so sanh kha ndng stt dung rong bttn lam touc dn true tiip toay toe thttc an cdng nghiip cho cd rd phi ciia Siddik (2012) vd cd nau nudi Uong ao dat cua Nguyin Thj Ngpc vd ctv. (2013). Theo hai tac gia nay viic cho an rong biin hodn loan hoac cho an kit hgp vdi thttc an. viin, ti Ii song (80-85%) ctta cd khdng khdc biit y nghia so nghiim tottc dii chttng cho dn hoan loan tottc an vien. Tuy nhiin, Yousif et al. (2004), stt dung rong bun {Enleromorpha sp.) khd bd sung vao khdu phdn an cho ca dia {Siganus canaliculatus) tou dupe ti Ie song khd lit han vdi nghiim thttc ddi chiing (tottc
QTA DDRB n R M
^ 0 IRB_1TA
— f^ -^ B lRM_iTA
•2RB_1TA g. ^ 1 S2RM_1TA
a IRB IRM ITA
^ 4 H ~ ~
S
Thtri gian nu6i (ng&y)
Hiahl
Tdng ttpng, tdc dO tdng trudng tuyit doi (DWG) vd tdng trudng tuong doi (SGR) ctta nghiira thttc ddi chftng (TA) cao hon cac nghiira tottc khac va tang trumig giam toeo sv tang tin sudt cho an rong bttn hogc rong min luan phiin vol Bang 3: Ti If song va taag trudag cua cd tai tugag
Khii lupng (g) cua ca tai tugng theo thdi giaa audi
tottc an vien. Tuy nhien, nghiem tottc cho an kit hgp rong bun va rong men vdi thttc an viin (IRB- IRM-ITA) cd cd tic dd tdng trudng tuong duong vdi nghiira tottc IRB-ITA va khd tdt han so vdi nghiem thttc IRM-iTA.
Nghifm thttc Khdi lugng Khoi lugag Taag trpng
DWG (g/ngay) SGR Ti le soug
(%)
TA RB RM IRB-ITA IRM-lTA 2RB-1TA 2RM-1TA IRB-IRM-ITA
1,72*0,22 1,72*0,22 1,72*0,22 1,72*0,22 1,72*0,22 1,72*0,22 1,72*0,22 1,72*0,22
6,10*0,88' 4,60*0,70"
4,54*0,80"
5,97*0,83' 5,68*0,72"
5,28*0,86' 5,15*0,72"
5,96*0,81'
4,38*0,88' 2,88*0,70"
2,82*0,80"
4,25*0,83' 3,95*0,72"
3,56*0,86' 3,43*0,72"
4,24*0,81'
0,078*0,016' 0,051*0,012"
0,050*0,014"
0,076*0,015' 0,071*0,013"
0,064*0,015' 0,061*0,013"
0,076*0,014'
2,24*0,26' 1,74*0,27"
1,71*0,31"
2,20*0,25' 2,12*0,23"
1,98*0,28' 1,94*0,25"
2,20*0,24' 98,3*2,9' 95,0*5,0"
95,0*5,0"
100,0*0,0"
96,7*2,9"
93,3*2,9"
96,7*2,9"
100,ft±0,0"
Cdc gid Irj trung binh trong citng mpi cpt cd chU cdi khdc nhau thi khdc biil cd y nglua thang ki (p<0, OS)
Tgp chiKhoa hpc TmdngDgi hpc Cdn Tha Phdn B: Nong nghiip, Thiiy sdn vd Cdng nghi Sinh hpc- 35 (2014): 104-110 Kit qua phdn tich thing ki cho thiy i^hiem
thttc ddi chttng khdng cd su khac biit toing ke (p>0,05) so vdi cac nghiem thuc IRB-ITA; IRM- ITA vd IRB-IRM-ITA nhung khac nhau cd y n ^ i a (p<0,05) so vdi cdc nghiim tiittc 2RB-ITA;
2RM-1TA; RB va RM. Ngodi ra, kit qua biiu toi nghiem tottc chi cho an hoac la rong biin hodc Id rong min cd tic dO ldng trudng toap nhat va khac bi$t so vdi cac nghiim tottc cdn lai (Bang 3).
Nhiiu nghiin cftu chiing minh ring su dimg rong biin Idm tottc an cho ca khac nhau toeo Ioai va logi rong biin stt dimg (FAO, 2003; Wassef e/
al., 2005; Gtfroy, et al., 2007). Thim vao dd, Tolentino-Pablico et al. (2007), dd tim toiy rong biin touOc hp rong Igc gdm cdc gidng rong Cladophora, Enleromorpha va Ulva dugc ua toich bdi nhiiu lodi ca an touc vdt nhu Scartichihys viridis (Blennidae), Girella spp. (Kyphosidae), Sarpa salpa (Sparidae), Siganus spp. (Siganidae).
Nghien cttu khdc stt dyng bin Ioai rong biin gdm Enleromorpha infestlnalis, Graleloupia filicina, Gracllarla verrucosa and Polysiphonia sertularioides ldm thttc dn cho cd Rohu va ca Mrigal.
Trong toi nghiem nay, ca dugc cho an rong biin cd tic dp tang ttudng khd tdt hom so vdi ca dugc cho dn rortg min. Diiu nay co the bi dnh hudng bdi hdm Iugng xo khac nhau ctta 2 logi rong, ham Iugng xa trung binh ciia rong min la 8,79% cao gap 2 Idn so vdi rong biin (4,15%). Theo Tran Thi Thanh Hiin vd Nguyin Anh Tuin (2009), tottc dn cd ham lugng xo cao cd toi ldm gidm su hdp tou chat dinh dudng trong tottc dn hodc cd dO tiiu hda toap din din cd tang trudng cham hon. Nghien cttu ttudc cho toiy cd Mrigal tdng ttudng tit khi tottc Bang 4: Hi'si tiiu ton thttc an cua ca tai tirgag
an chtta rong Polysiphonia serlularioide va ca Rohu la tottc an cd rong Gracilaria verrucosa. Su khac nhau ndy co toi khdng chi vi ham Iugng protein md cdn khac nhau vi cac axil amin va axit beo thiit yen dugc bd sung ttt logi rong biin khdc nhau (Swain and Padhi, 2011).
Ket qua tang trudi^ frong nghien cttu nay phd hgp vdi nhdn dinh cua Siddik (2012), cd rd phi (O.
nilotlcus) dugc cho an xen ki rong biin tucri hodc rong bttn khd vdi thttc an viin vdi tin suit 1 ngay tottc an va 1 ngdy rong bun cho cd rd phi (O.
nllolicus) tou dugc tdc dp tang trudng khdc biit khdng cd y nghTa todng ki so vdi nghiim thiic tottc an viin (p<0,05).
Dii vdi nghiira tottc cho an kit hop rong biin vd rong men cd tdc dO ldng irudng cao hon so vdi nghiim toftc chi cho 5n Aon touin hodc Id rong bttn hogc la rong rain. Kit qua nay tuang tu vdi nghiin cuu ciia Roy el al (2011) tdc gia nhdn toiy ca rd phi dugc cho an hdn hgp nhiiu Ioai tdo {Phormidium valderianum, Spirulina subsalsa, Navicula minima, Chlorococcum infusionum vd Rhizoclonium riparium) khdng nhflng cho tang trudng tit cao han cd ^ nghia so vdi cac nghiem thfte stt dimg mOt logi tao ma cdn giup cdi thiin hieu qua stt dung protein ciia cd.
3.3 H i s i tiiu tda thttc an
Bang 4 cho thay hi sd tiiu tdn tottc dn (FCR) tdng d cdc nghiim tottc cho an hoan todn rong biin khd hodc rong rain khd lin lugt Id 2,63 va 2,73, tang cao so vdi nghiem tottc cho an tottc dn viin (1,75). Cdc nghiim thttc cho dn kit hpp rong bien vd thttc an cd FCRtdng dgt gid fri trung gian (1,67- 1,96).
Nghiim thur H i so tieu tda thttc aa (FCR)
Thfrc aa viia (TA) Rong biin (RB) Rong min (RM) FCR tdag TA
RB RM IRB-ITA IRM-ITA 2RB-ITA 2RM-1TA IRB-IRM-ITA
1,75±0,09
0,84±0,04 0,94±0,02 0,78±0,03 0,80±0,04 0,58±0,02
2,63±0,08 0,83±0,05 1,19±0,04 0,59±0,04
2,73±0,24 0,91±0,03 1,16±0,11 0,61±0,03
I,75±0,09"
2,63±0,08'' 2,73±0,24'' I,67±0,09=' I,85±0,05=
1,97±0,07"
1,96±0,15=
1,78±0,09^
Cdc gid trj irung binh trong cimg mpi cpt co chU cdi khdc nhau ihi khdc biet cd y nghTa thdng ki (p<0,OS) Qua phan tich todng ki cho toiy FCR ting cua
nghifm tofrc doi chttng cho an hoan todn tottc an viin chi khdc bift cd -^ nghTa (p<0,05) so vdi nghifm thttc cho dn hoan loan rong bftn (RB) vd
rong min (RM). FCR tottc an vien cd khuynh hu6mg giam toeo su gidm tan suat cho dn tottc an viin, trong dd nghiim Ihftc cho an kit hgp rong
Tgp chiKhoa hgc TrudngDgi hgc Cdn Tha Phdn B: Ndng nghiip, Thiy son vd Cong nghf Sinh hpc: 35 (2014): 104-1 fS bttn, rong min va tottc an cd FCR tottc an vien
t h ^ nhdl (0,58).
Sema el aL (2003), danh gia anh hudng ciia ham Iugng protein khac nhau (30, 35, 40, 45 va 50%) ttong tottc dn din tdng trumig cua ca, tai tugng. Kit qua cho tody tic do tdng ttudng ctta ca tai lugng tang cao theo su tang hdm Iugng protein ttong tottc an. Tu^ nhiin, Sithajaruwal (2000) nghiin cttu vi nhu ciu protem cua ca tai tugng ldc gid nhdn tody toftc dn phdi chi cd ham Iugng protein 30- 35% toich hgp cho ca d giai doan gidng. Thi nghiim hiin tgi stt dyng thttc an vien cd ham lugng protein 30% frong khi rong biin va rong rain cd ham lugng protein trung binh 13,33% va 14,84%, toeo tott tu (Bang !) thip hon nhieu so vdi tottc an vien. Do dd, khi ca chi dugc cho an hogc Id rong bttn hoac la rong min khdng toda man nhu cdu protein cho ca tai tugng ddn din cd tdng tifrdng
cham, kit qua la cd hi sd tottc an cao hon so voi tottc dn vien.
3.4 Chi phi thfrc an
Kit qua cho thiy chi phi tottc an cho Hin quan true tiep din tdc dp tdng trudng va hi sd tieu tdn tottc an. Khi tdng din tan suit rong bttn va rong men ttong khau phin an cua ca tai lugng tfii lugng toftc an vien giam din dan din chi phi tiiftc an vien cho ca tang ttpng dugc giam toip. 6 nghiem tottc xen ke 1 ngay thttc an viin 1 ngdy rong (IRB-ITA va IRM-lTA) cd mttc giam chi phi 43,24-49,08%
va nghiim tottc 2 ngay rong- i ngay tottc an (2RB- ITA, 2RM-1TA va IRB-IRM-ITA) cd mttc giam chi phi tottc an so vdi ddi chirng ttt 50,81,49 den 62,83%. Trong dd, i^hiim tottc chi cho an rong biin hogc rong min cd mttc gidm chi phi thttc an viin nhiiu nhdt (91,32-91,65%) so vdi n ^ i m toiic cho dn hodn todn tottc dn viin (Bdng 5).
Bang 5: Chi phi tbutc an viia khi cbo ca da ludn pbiea roag bun, roag mia vdi thfrc da viia Lugng thttc an vien Lirpng roag bieo cho Chi pbt thuc aa Nghiim thfrc cho cd taag troag ci taag troag (kgTA cbo ca tang troag
(kgTA cuag cdp/kg ca) cung cap/kg ca) (d/kg) Muc giam so vfri
doi cbuag (%) TA
IRB-ITA IRM-lTA 2RB-1TA 2RM-1TA IRB-IRM-ITA RB RM
1,94*0,08 0,94*0,05 1,04*0,02 0,86*0,03 0,88*0,03 0,65*0,01
-
0,92*0,04
-
1,01*0,01 1,32*0,03 1,28*0,10 1,33*0,01 2,92*0,07 3,03*0,21
34916*1478 17780*767 19820*204 16845*472 17174*700 12979*109 2917*70 3031*214
49,08*2,20
-
43,24*0,58 51,75*U5 50,81*2,01 62,83*0,31 91,65*0,20 91,32*0,61 Gid bdn li thirc dn viin (Gowbest) logi 30%protein Id 18.000 ddng/kg
Chi phi thu gom vd phoi rong bdn vd rong min udc tinh khodng 1.000 d/kg rong khd
Ngbien cuu cua Mukherjee et al. (2011) ddi vdi ^ i t qud cho toiy hi sd tottc an gidm din khi cd Rohu dugc cho dn tottc an' kit, hgpf3'pjm/^^^^,h.y toi tiiuc an cdng nghiep bing rong bun va rong men kho, kel qua nay cung toe men dugc vai platensis va Enleromorpha ' intestinalis fioac"
Phormidium valderianum va Catenella repens da cdi toiin tdng irudng cua ca va hi sd tiiu tin toftc an so vdi nghiira tottc ddi chirng va n^iem tottc sft dung mdt logi tao lam tottc an.
Kit qua thi nghiim nay phu hgp vdi nghiin cihi cua Siddik (2012), stt dung rong bttn tuai va khd Iam ihttc an true tiip toay toi tottc an viin, FCR cd khuynh hudng giam nhiiu d cac n ^ i m tottc cho dn kit hgp vdi rong bun vd tottc an viin ding todi chi phi tottc an cho ca tdng ttpng giam ttt 41 din 46% so vdi nghiem toftc chi cho an tottc an viin.
Kit qud tuang tu ddi vdi nudi ca nau touong phdm ttong ao dit ciia Nguyen Thi Nggc Anh vd ctv.
(2013), stt dung rong bun lam tottc an kit hgp vdi toftc an vien cho ca nau FCR vd chi phi tottc an giam tii 48 din 55%.
ttd quan ttpi^ cua rong biin vd rong men ttong nudi ca tai tugng, giup gidm chi phi thttc an.
Mat khdc, stt dung hai Ioai rong nay Idm thttc an true tiip cbo cd tai tugng gdp phdn cai thien mdi trudng nudi.
4 KET LUAN
Cac nghiim toftc cho an rong bun va rong min cd hdm Iugng TAN va NO2" toip han so vdi nghiim tottc cho an hoan toan tottc an viin.
Ty If sdng cua ca tai nrgng sau 56 ngay nudi dgt kha cao, dao dgng hi 93,3 din 100% va khdng hi anh hudng bdi nghiim tottc tottc an. Ca tal tugng dupe cho dn luan phien 1 ngay long bun hogc rong men va 1 ngdy tottc an vien hoac cho an
Tgp chi Khoa hpc Trudng Dgi hpc Cdn Tha Phdn B: Nong nghiep. Thiiy sdn vd CongngM Smh hoc: 35 (2014): 104-110 kit hgp 1 ngay rong bun-1 i ^ y rong men vd 1
ngay tottc dn viin cd tic dO ldng trudng khdng khac bift vdi nhdm cd dugc cho an hoan tiidn tottc an viin. Cho dn kit hpp rong bftn va rong min vdi thttc dn vien, chi phi tottc an vien cd toe giam ttt 43,24 din 62,83%. Kit qud biiu toi roi^ bun va rong min khd cd toi stt dung Idra tottc an cho ca tai lugng thay thi mOt phin tiittc an vien gdp phan giara chi phi tottc dn ddng todi cdi thien mdi trucmg nudi.
TAJ Ll£U THAM KHAO
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1234 pp.
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