KHOA HOC CdNG NGH|
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Nghi&n Clhl dugc tiiuc hiSn nham dinh gii inh huong cua cac lo?i thiic an khic nhau l6n sinh trudng vi ty 1§ sdng ciia dc buou ddng (Pila polita). Mdi nghiem thiic co 3 lap lai vi cic loai thiic an sii dung bao gdm: 1) cim min; 2) b$t khoai mi; 3) thiic an cong nghiep. 6c dupc uong ttong bd compozit voi mit dp 150 con/bd Ochdi lucmg va chidu cao ban diu li 0,03 g vi 4,5 mm). Sau 35 ngiy uong, ty Id sdng khi cho an cam mjn (94,44±3,01%) cao hon so vdi bpt khoai mi (93,33±2,9196) vi ttiirc in cdng nghidp (93,78±3,91%), ttiy nhidn khic biet khong co y nghia (P>0,05). Ty Id tang smh khdi cao nhit khi cho an thiic an cdng nghidp (2027±263%) va i^t khic bidt (P<0,05) so voi tiuic an cam min (727±59%) vi bpt khoai mi (992±293%). Khdi lupng va chidu cao trung bmh cda 6c cho Sn bang thiic an c6ng nghidp (0,71±0,09 g vi 14,79±0,56 mm) cung khac bi^t co y nghla (P<0,05) so vdi cho 3n bing cam min (0,26±0,02 g va 10,55±0,26 mm) hoSc b^t khoai mi (0,36±0,05 g va 11,65±0,66 mm). Uong dc buou dong bing thiic Sn cong nghidp c6 hi§u qua su dyng tiuic in cao nh^t (722±20%) va khac bi§t (P<0,05) so vdi cho an bang bOt khoai mi (52fti=5596) ho^lc cim mm (472±19%). Kdt qua thi nghidm cho th^y uong dc buou ddng bing thiic an cong nghidp da lam tang sinh trudng va hi§u qua sii dung thtic an so voi su dung cam hoac bdt khoai mi.
TCr khda; Oc buou ddng, Pila polita, sinh trudng, thiicSn, tyld sdng.
i.BATVJinfii£
Oc buou ddng Ii loii dpng vat thim mdm nudc ngpt cd gii trj kinh td cao do tiiit thom ngon, giau chat dinh dudng (dc buou ddng chiia 11,9% profit 0,7% Upit cic vitamm Bl, B2, PP; cic mudi can xi, phdt pho. Oe eung eip 86 calo/100 g thit). Chiing dupc su dung lam cac mdn i n d i n d i hay nhung mdn an die sin, v.v...Theo Burch vi ctv. (1989) va Pusadee Sri-aroon vi ctv. (2005) dc buou ddng dupc xem l i mpt trong nhimg loai dc nudc ngpt ed vai trd rat quan trpng trong y hpc. Thaewnonngiw vi ctv.
(2003) cho bidt dc buou ddng dang dupc xem l i mdt bidt dupc de chira bdnh vd da eiia ngudi d i n dia phuong b midn Nam Thai Lan. Vidt Nam la mrdc nim ttong khu vyc nhidt ddi, cd nhidu ao, hd, sdng, sudi, nhieu radng triing la tidm ning lon dd nudi cic ddi tupng mrdc ngpt ttong dd co de buou ddng. Tuy nhidn nhdm cac ddi tupng-nudi nudc ngpt edn ngheo nan chua tuong xiing voi tidm ning da dang sinh hpc v i str da dang vd didu kidn smh thii cua dat nu6c eiing nhu nhu eiu eiia sin x u i t
Ngudn lpi dc buou ddng trong tu nhidn dang ngiy mdt giam siit do nhidu nguydn nhin; Khai tiiic qui miic, mdi tiirdng ngiy cang d nhidm do chua quan ly chat ttiai, sii dung thudc tiir siu, didt eo, h o i ' Khoa Thuy sin, Trudng D^i hpc Chn Tho
chat trong ndng nghidp. Cac nghidn cihi vd dpng v|tt thin mdm ttong nudc mdi ehi tip trung vao cic ddi tirpng nudc lp-, nudc m i n nhu bio ngu, tu hii, dc hirong, hiu, vem, 6c len.... Hidn nay ttdn thd gidi vi if Vidt Nam ehua c6 nghidn ctiu nhidu vd ky ttiuit sin xuit gidng ciing nhu ky thuit nudi tiiuong phim loai dc nay. Vide nghidn ciiu uong dc con mdi no li v ^ dd can thidt de dip iing nhu ciu cua tiii trudng, giim i p luc khai thic, bao vd v i khdi phye ngudi lpi dc tu nhidn, da dang h o i ddi tupng nudi ttong nghd nudi ttdng tiiuy san. Nghidn ciiu niy dupc tiiuc hidn nhim tun ra l o ^ tiuic i n thich hpp cho qui trinh uong gidng dc buou ddng.
2. v«T u ^ Vk vmm PHAP NGHDI ciiu
Bpc tning dc buou ddng sinh san ty nhidn dupc thu or Ddng T h i p v i dupc vin chuydn vd Tr?i Thuc nghidm DOng vit Than mdm - Bd mdn Ky tiiuit Nu6i Hii san - Khoa Thiiy san - Trudng Dai hpc Cin Tho.
Thi nghidm dupc bd tri ttong bd compozit cd tiid tich 200 ht, nudc ttong bd uong duy tri b muc khoing khoang 30 lit v i lip dat hd thdng sue khi trong qui trinh uong, m?it d^ uong 150 con/hd (khdi lupng vi chidu eao ban d i u la 0,03 gam v i 4,5 mm). Trong sudt q u i trinh uong ed thay nuoe v i g i i thd bdo 7 ngay/lan, tiiay 100% lupng nudc va gii tiid bdo ttong hduong.
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N6NG NGHIEP VA PHAT TRIEN N6NG TH6N - K? 2 - THANG 9/201?
KHOA HOC CdNO NGHl
Hinh 1. Hd thdng Ihi nghidm 6 e buou ddng dupc cho Sn c i c ngudn thiic 5n
khic nhau l i eim min, bdt khoai mi v i thiie i n edng nghidp (TACN, sii dung thirc i n chuydn dung cho c i cd vay Proconco ciia Cdng ty Cd phan Vidt Phip San xuit Thuc an Gia siic f*roconco, 18% dam), tiiirc an dupc xay nhuydn v i sing qua mat ludi 200 ^mi, thi nghidm gdm cd 3 nghidm thuc, moi nghidm thiic lip lai 3 lan. Hing ngiy dc dupc cho i n 3 - 5% khdi luong thin vi lupng thiic an thay ddi theo khdi lyong ca thd dc uong. Mdi ngay cho i n 2 lin vio liic 7 gid sing v i 17 gid chidu.
Cic d u tidu theo ddi
Cie ydu td mdi tnrdng; Nhidt dd (do bing nhidt kd thiiy ngin liic 7 gid v i 14 gid hing ngay); tdng dam CTAN), NO2"; kidm v i pH dupc x i c dinh hang ttiin bing bd tt:st SERA (Germany). Kich tiiudc, khdi lugng va ty Id sdng dc con ttong bd dupc xic dinh 7 ngiy/lin dd tinh tde dd ting trudng tuong ddi v i tdc dp tang trudng tuydt ddi vd chidu dii va khdi lupng.
Ty Id tang smh khdi (%) Lining smh khoi tSng (g/be)
Khoi lugrng dau (g/be) Ty Id sdng; SR (%) = (N2^100)/Ni.
Trong dd: Ni l i sd c i thd tha nudi ban diu; Nj la Bing 1. Bidn dQng cie ydu
sd c i thd tai thoi didm thu miu Ning s u i t P(g/mO = Pa, ^ S
Trong dd: P^, la khdi luong trung bmh (g/bd); S la didn tich bd uong (m^.
Hd so chuydn hda thiic an cung dupc tinh theo cac cdng thuc: FCR = m / P .
Trong dd; m la tdng lupng thiic i n da cho an (g); P la khdi lupng de gia tang (g)
Hidu q u i sii dung thiic an FE (%) Khdi lu(;mg ting ttpng (g) Khoi lugng thCrc Sn cho an (g) <100 Sii dung phin mdm Excel dd tinh cic gii tri himg bmh, dO ldch chu^n v i SPSS 16 dd so sinh thdng kd cic gii tri tiung binh giua cie nghidm thiic 0 mttc P<0,05 bing phdp so sinh Duncan.
S-KerquAVATHAOUIAN
3.1. Bidn ddng c i c ydu td mdi ttudng Nhidt dd tnmg binh ciia cic nghidm thiic ttong q u i trinh thi nghidm khdng khic bidt nhau (Bang 1).
Nhidt dp budi sing ttong c i c bd uong dao dpng 22,4- 24,1''C, ttung bmh 23,33''C v i nhidt dd budi chidu dao dpng 25,9-27,7"C, ttung binh 27,0°C . td mdi trudng trong bd uong
Chi aeu
NhiMd6sdng(°C)Nhiet do chiiu (°C)
pH KiimCmKCaCOv^L)
TAN (jag/L) NO, (mg/L)
Ngliiem thijc C ^
23,26 ± 0,16' 27,01 ± 0,29- 7,82±0,06- 89,10 ±3,4' 0,25 ±0,01- 0,30 ±0,01'
B6t Idioai mi 23,34±0,18- 26,90 ±0,29"
7,87 ±0,01- 81,98 ±1,71*
0,27 ±0,00' 0,28 ±0,01"
TACN 23,31 ±0,22"
26,93 ±0,31- 7,82 ± 0,05- 84,98 ±1,74'
0,3 ± 0,01' 0,62 ±0,04'
Crfc gii tzj cua mdi chl sd trong cdng mdt hing cd chu cii khic nhau thi khic bidt cd y nghfa thdng kd (P<0,05)
N O N G NGHliP VA PHAT TRI^N N O N G THdN - KY 2 - THANG 9/2013 85
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Theo Nguyen Thi Binh (2011) 6c buou dong con s^ng tot Idii nhiet dO 27°C vao buoi sang va 30°C budi chiiu. Nhiet dfl thich h(?p cho 6c buou d6ng 20-32°C, khi nhiet d6 xuong du6i 15°C thi 6c chuyfa sang tni d6ng (Lum Kong vi ctv, 1989). Nhu v4y. nhiet do trong qua trinh thi nghiem la Ihich hgp cho su phat triin ciia 6c buou d6ng.
Gik tri pH trung binh cua cac nghiem thilc la 7,8, dao ddng 7,5-8,0 (Bang 1). Kit qua nghien ciiu cua Nguyen Thi Dieu Linh (2011) cho thiy c6 thi nudi thuong pham 6c buou ddng khi pH tii 7,1 din 8,4.
Jahan vi ctv. (2001) nudi Pib globosa trong moi trudng sdng lu nhidn voi thuc an la thuc vat thuy sinh cd gia tri pH ntei trong khoang 7,7S8,25. Bdng vjt than mim cd vd Ak voi, khdng phan bd a vung nudc cd pH<7 (Nguydn Dinh Trung, 1998). Nhin chung, pH trong qua trinh thi nghiem diu n ^ trong khoang thich hpp.
Bang 1 cho thay ham lugng TAN a cac nghiem thiic khac biet cd y nghia thdng ke (P<0,05) khi cho an etal min hoac bdt khoai mi vdi TACN. Htai lupng TAN cao trong tuta dSu sau dd giam din din cudi chu ky uong d nghiem thiic cho ta ctai vk bpt khoai mi, trong khi cho ta TACN thi htai lupng TAN ttag d 21 ngay ddu va sau dd gitai dan d cac ngay tiip theo. Theo Boyd (1998) vk Truang Qudc Phii ra ctv (2006) htai lupng NH,* thich hpp cho thuy sta la 0,2- 2,0 mg/L. Kit qua cho thdy htai lupng TAN trong bi uong n ^ khotag an tota.
Trung binh htai lupng NO," cd str khde biet a ckc nghidm thiic cho ta cdm min (0,30 mg/L), bdt khoai mi (0,28 mg/L) vdi TACN (0,62 mg/L) va khac biet cd y nghia thdng ke (P<0,05). Ham lupng NO2" it biin ddng va giam dta din khi kit thuc thi
n g h i ^ d nghidm thiic cdm vd bdt khoai mi. Trong khi dd NOj- ttag nh? tii ngdy thii 1-14, sau dd tdng msnh din ngdy 28 vd cd xu hudng gidm din cudi chu ky uong bdng TACN (Hinh 3). Hdm lupng NO; taog a n g h l ^ thiic TACN cd thi Id do dc tang trudng nhanh, sta pham bdi tiit nhiiu hay chdt dinh duong ltag tu trong be. Theo kit qua nghidn ciiu cila Nguyin Thi Dat (2010) thi hdm lupng NOj- tnmg binh 0,7 mg/L, dao ddng 0,3-1 mg/L. Boyd (1998) cho rdng hdm lupng NOj- trong nudc ndn thdp hon 10 mg/L. Hdm luong NOi an tota cho thuy sta Id 34 mg/L (Le Vta Cdt ra ctv, 2006). Nhto djnh ndy cho thdy hdm luong NO2' trong b i uong ndm trong khotag an tota cho dc buou dong.
Trung binh dd kiim d cdc nghiim thiic tuong duong nhau: cdm (89 mg/L), bdt khoai mi (82 mg/l) vd TACN (85 mg/L) vd khde bidt khdng cd ]? nghia thdng ke (P>0,05). Cdc nghiem thiic cho ta bot khoai mi vd TACN dp kiim fliap cd flii do tdc do ttag trudng cua dc nhanh, 6c cdn mot lupng canxi ldn di hinh thtah vd cho qud trinh phdt triin. D6 kiim thich hpp cho cdc lodi thiiy sta Id 50-150 mg/L _ (Boyd, 1998).
3.2. T&ig trudmg dia 6c buou ddng 3.2.1. Ting trudng vd chidu cao
Tdc dp tang trudng chiiu cao tuydt doi (mm/ngdy) vd tuong ddi (JS/ngdy) cua dc tirong ddi on dtnh trong sudt thdi gian thi nghiim (Bdng 2).
Trung binh tdc dd tdng tmdng chiiu cao tuong d&
cua 6c dat eao 6 nghiim thiic TACN (2,999i/ngdy), ki din Id bdt khoai mi (2,49%/ng4y) vd thdp nhdt 14 cdm min (2,36%/ngdy) cd su khde biit cd y nghia thdng ke (P<0,05) vi chiiu cao ciia 6c khi cho So cdm min hoac bdt khoai mi vdi TACN.
Bdng 2. Tdc dd ttag tnidng chiiu cao tupng ddi vd tuyit d6i ciia 6c theo thdi gian Ngay uong
1-7 7-14 14-21 21-28 28-35 TB Thi nghi?m
Tuy?t doi (mm/ngay) Cfai
0,15±0,04"
0,14±0,01' 0,17±0,01"
0,20±0,01*
0,18±0,01' 0,14±0,01"
Bpt khoai mi 0,15±0,03' 0,17±0,02' 0,18±0,02' 0,21±0,01' 0,21±0,02' 0,15±0,01'
TACN 0,17±0,01' 0,25±0,01'' 0,27±0,02'' 0,28±0,02'' 0,29±0,01'' 0,21±0,01''
Tuong ddi (%/neay) Cfai
3,15±0,76*
2,64±0,25' 2,84±0,09' 2,97±0,07' 2,55±0,05' 2,36±0,28*
BOt khoai mi 3,08±0,61' 3,03±0,28*
3,02±0,28"
3,02±0,05"
2,79±0,26"
2,49±0,22"
TACN 3,21±0,2r 4,01±0,19°
3,85±0,18"
3,55±0,20"
3,32±0,08°
2,99±0,13°
Cic gii tri cua mdi chl sd tiong cung mqt hinged chd cii khic nhau thi khic bidt cd y nghfa thdngki (P<0,OS)
Theo kit qua nghidn cuu uong dc buou ddng trong bi vd 0,24-0,44 mm/ngdy khi uong tiong giai- cOia Nguyin Thi Binh (2011) thi toe dp ttag trudng Theo nghiin ciiu ciia Nguyin Thi Dat (2010) liU chiiu cao tuyit ddi d^t 0,22-0,32 mm/ngdy khi uong nudi 6c buou ddng Irong giai, sau 1 thdng nudi ifc
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N 6 N G NGHllP VA PHAT TRIEN N 6 N G T H 6 N - KV 2 - T H A N G 9/2013KHOA Hpc CdNO NOHt
buou ddng c6 tdc do tang truong chidu cao tuydt ddi li 9 mm/ngiy vi tuong ddi li 6,86%/ngiy.
Sau 35 n g ^ thi nghidm, chidu cao tiung bmh ciia dc cao nh^t vi khic bidt cd y nghia thdng kd (P<0,05) b nghidm thiic TACN (14,79 mm/con) vdi n^dm thtic bdt khoai mi (11,65 mm/con) va cam min (10,5 nun/con). Chidu cao trung binh ciia dc b dc n ^ d m ihuc trong qu& trinh ttii nghidm ting Udn h^c vi nhanh nhit b nghidm thiic TACN, ttong khi cim min vi bdt khoai mi vio thdi gian dau ting nhanh nhung sau ngiy ttiu 28 thi ting trudng chim 1^1 (Hinh 2). Nghidn cuu dia Conner vi ctv. (2008) vd inh huong mit dd uong ciia 6c hircni ving (Pomacea
paludos^ ban dia vi dc Midng bin dja, cho thiy sau 60 ngay uong thi chidu dii dc ban dia 5,19-5,27 mm/con va dc khdng bin dia 7,80-8,31 mm/con.
Theo kdt qua nghidn ciiu ciia Jahan vi ctv (2001) ngliidn ciiu nudi dc PUa globosa sau 42 ngiy tudi su dung cic loai thtic in khic nhau thi chidu dai trung bmh d^t 4,5-8,1 mm/con. Theo nghidn ctiu ciia Nguydn Thi Bmh (2011) cho dc buou ddng in cim min cd bd sung thdm li sin tu ngay 15 ddn khi kdt thiie ttii nghidm ttii chidu cao trung binh ciia dc li 13,09 mm/con (uong ttong giai) vi 11,52 mm/con (uong trong bd).
Ngdy thi nghidm(ng^y) 7 14 21 28 33 Ngiy thi nghi§m{ngay)
Hbh 2. Thing bmh khdi Iugng vi chidu cao ciia dc uong theo thdi gian 3.2.2. Ting truang vi khdi Iugng
Tdc dd ting trudng khdi lugng tuong ddi dn dinh vi ting din ddn ngiy thu 21 va sau dd giim ddn eudi thdi gian uong b 3 nghidm thtic, ttong khi dd tdc dd ting trudng tuydt ddi dn dinh hon va ting Udn ttic ttx)ng sudt qui trinh uong (Bing 3). Trung binh d nghidm tiitic cim mjn (4,30 mg/ngiy) th^p hon bdt khoai mi (4,80 mg/ngiy) vi TACN (9,80 mg/ngiy)
khic bidt cd y nghia tiidng kd (P<0,05). Tdc dd ting ttudng ttrang ddi dat cao nhit d TACN (8,20%/ngiy), kd ddn bdt khoai mi (5,85%/ngiy) vi tiiip nhit cim min (5,55%/ngiy). Khdi lugmg de tha ban diu b eie nghidm thiie li tuong duong nhau (0,03g/con). Sau 35 ngay irong khdi lugng dc cr nghidm tiuic cho in cim min (0,26 g/con), bgt khoai mi (0,36 g/eon) nhd hon rat nhidu so vdi TACN (0,71 g/con).
Bing 3. Tdc dd tang trudng khdi lupng tuydt ddi (nig/ng^)yi khdi lugng tuong ddi (%/ngiy) ciia dc uong
Ngiy uong1-7 7-14 14-21 21-28 28-35 TB thi nf^i^m
Tuy?t ddi (mg/ngay) Cdm
2,5I±0,83"
3,25±0,36"
4,8»±0,28"
6,56±0,36' 6,70±0,49"
4,30±0,13'
Bdt khoai ml 2,41±0,20' 4,11±0,77' 5,43±0,70' 7,22±0,34"
9,38±1,61' 4,80±0,39*
TACN 4,29±0,50°
7,98±0,67°
11,13±I,00°
15,81±!,31°
19,42±2,64°
9,80±0,34°
Tuong ddi (%/ngjl Cam
6,49±1,83' 6,56*0,50"
7,05±0,16' 6,99±0,24"
6,20±0,18' 5,55±0,26"
Bpt Idioai mi 6,20±0,88' 7,42±0,86' 7,31 ±0,69*
7,18±0,2I"
6,96±0,68' 5,85±0,47'
rt
TACN 9,61±l,2r 10,85±0,78°10,17±0,60°
9,70±0,2r 8,91±0,46°
8,20±0,47°
Gfc gid tri cua mdi chi sd tmng cimg mdt hing cd chd cii khic nhau thi khic bidt cd y nghfa thdng kd (P<0,05)
Theo Ahres vi ctv. (2006) thi 6c buou vdng (Pomacea lineate vi Pomacea bridgesO uong 30 ngdy tudi khdi lupng trung binh dfit 9,76 g/con. Kit qud nghiin cuu 6c buou vdng ciia VO Bd Quan (2003) cho
flidy kh6i lupng 6c sau 1 flitag 1,87 g/con. Theo FAO (1989) flii sau 45 ngdy hidi 6c buou vtag d?t kh6i lupng 2(V25 g/con, thdm ehi 4045 g/con. Theo Nguyin Thj Binh (2011) uong 6c buou ddng sau 28
M A M ^ ^ iLl^^ui^n \ii n u A T TniFki A I A A I ^ I
KHOA HOC CdNO NGHl
ngdy uong flii khdi lupng 6c dat 0,47 g/con (uong h-ong giai) vd 0,38 g/con (uong trong bi). Kit qud trdn eho thdy 6c buou ddng thi nghidm ed khoi lupng tuong duong vd cao hon so vdi kit qud nghidn ciiu Irudc day, tuy nhien so vdi 6c buou vdng flii thap hon.
3.3. Ty li s6ng, t^ li ttag sink khdi, ntag sudt vd hd s6 thtic ta ciia 6c buou ddng
Sau 35 ngay uomg ty Id sdng ciia dc buou ddng khi cho ta cam min (94,4%) cao hon so vdi bdt khoai mi (93,3%) vdTACN (93,7%) tuy nhidn khdng khde biet (P>0,05). Theo kit qud nghien eiiu ciia Nguyin Thi Binh (2011) sau 28 ngdy uong flii ty le sdng dc buou ddng dat 88,1% (uong trong giai) vd 90,9% (uong trong bi). Kit qud nghidn ciiu dnh hudng thiic ta va mat dd nudi dc buou ddng thuang
pham ciia Nguyin Thi Dieu Lmh (2011) cho thdy tf 16 sdng dat 72-78%. So stoh vdi cdc kit qua nghiai Cliu cua tdc gid khde cho thdy t^ Id sdng cia dc buou ddng trong thi nghiim ndy khd cao.
6e dupc cho ta TACN cd ntag sudt cao nhdt (195 g/m^, ki din Id bdt khoai mi (93 g/m^ vd fli^
nhdt Id cdm m(n (77 g/m^. Trung binh tJ li tang sinh khdi o nghiim thiic TACN (893%) va cao hon rdt nhiiu so vdi cam (363%); bpt khoai mi (429%) vd khde bidt cd y nghia flidng kd (p<0,05). Sinh khdi 6c tang nhe trong tuta uong ddu tidn o 3 nghiim flnic (Hinh 3), sau dd ttag rdt manh din cudi chu ky uong cr nghiim flnic TACN. Trong khi dd a nghiim flnic cho ta cam min vd bdt khoai mi thi tdc dp tang sinh kh6i tuong duong sau 28 ngdy uong.
Bang 4. Trung binh ty li sdng, tJ li tang smh khdi, nang sudt, hd s6 flnic ta vd hidu qud su dung flnic ta cia 6e blicru ddng trong cdc nghijm thic
Cdc chi tiiu theo ddi Tyle song (%) Tyle tang sinh khoi (%) Ntag suat (g.m'^
He sd flnic taFR
Hiiu qud su dung thic to FE (%)
Nghiim thiic Cdm
94,44 ±3,01' 362,62 ±26,52- 76,54 ±3,02' 0,47 ±0,02"
472,60 ±19,60"
Bdt khoai mi 93,33 ± 2,91"
429,37 ±93,75"
92,66 ±6,11' 0,39 ±0,01' 529,28 ±55,22"
TACN 93,78 ±3,91"
893,43 ± 45,96' 194,49 ±2,84' 0,33 ± o,or 722,71 ± 20,35' Cicffi bi cda mdi chl sd tiong cung mdt hing c6 chd cai khic nhau dii khic bidt c6 y nghfa thdngki (P<0,05)
Hd sd thuc ta cia dc d nghidm thic cam mjn (0,47) cao hon hot khoai mi (0,39) vd TACN (0,33), giiia ede nghiim thie khde bidt cd y nghia thdng kd (P<0,05). Kit qua cho thay s i dung thic ta edng nghiip uong 6e buou ddng thi FR thdp hon so vdi thic ta edm min hay bpt khoai mi. Theo kit qud nghiin eiu Nguydn Tht Dat (2010) flii hi so fliie ta dao ddng 1,85-5,59 Irong thdi gian 4 thdng va he sd
thic ta dao ddng 2-5 trong thdd gito 5 thdng Id kit qud nghien ciu eia Nguyin Thi Diiu Iinh, 2011. Ddi vdi 6c len hi s6 fliic ta 20,3-46,9 trong thdi gian nudi 3 flitog (Ngd Thi Thu Thao vi ctv., 2008). Kit qui eho thdy 6c buou ddng eung gi6ng nhu cdc d6i tupng thiy sta khde, giai doan nhd cd he sd thic ta ttidp hon giai doan trudng thdnh.
Ngiy Ihl nghijm (ngay) ' ' , . " . . . ,^' , ^ ' ' 6 J 6 -v ^ 6 J/ Ngiy thf nghidm (ngiiy)
Hinh 3. Trung binh ly li sdng vd ty 1$ tdng sinh khdi Clia 6c uong theo flldi gian
Trung binh hiiu qua su dvmg TACN dat cao nhdt *) • 1 * ^ Wi' «* * "sWa thdng ki (P<0,05). 6c sii (723%) vd flidp nhdt (437%) khi cho dc ta cdra (Bdng ^^S thic ta rdt tdt trong hai tudn ddu vd d?t hiiu
88 N 6 N G NGHllP VA PHAT TRIEN N 6 N G T H 6 N - KV 2 - THANG 9/2013
KHOA H p c C 6 H G H G H l
qua cao nhit (903%), sau dd giim nhe ddn cudi thai gian uong ff nghidm thtic TACN. Trong khi nghidm tiitrc cim min va hot khoai ml thi hidu qua sir dung tiitrc i n tdt ttong 21 ngay diu nhung ehi dat g i i tri cao nhit 637% (cim min) va 635% (bdt khoai rai), sau dd tidp h;tc giam ddn kdt tiitic thi nghidm. Kdt q u i cho Ihiy dc buooi ddng sii dting r i t tdt ngudn tiuic i n tinh bdt, ttong dd thiic i n cdng nghidp duoc sb dung hidu qua n h i t
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4.1. Kdt luin
Ty Id sdng ciia 6c buou ddng dat cao khi cho i n cim min va thap nhit khi eho i n bdt khoai mi.
Khdi luong va chidu cao trung binh cua dc cho in bing thiic i n c6ng nghidp dat cao hon so vdi cho in bing cim min hoic bdt khoai mi.
Ty Id ting sinh khdi cua dc dat cao nhit khi cho in thtic i n cdng nghidp, sau dd l i bgt khoai mi va cim min.
Uong dc buou ddng b i n g thtre i n cdng nghidp ed hidu qui sti dung thiie i n cao nhit so vdi eho in bing bdt khoai mi hoic c i m mjn.
4.2. Kidn nghi
Cd thd su dimg thiic i n cdng nghidp xay min cho de buou ddng i n ttong giai doan uong tir khi mdi nd ddn 1 thing tudi.
TJUlfUnUMKHAO
1. Alves T., Lima P., lima S. F. B., Ferri A. G., Bariffs J. C , Machado J., 2006. Growtii of Pomacea lineata and Pomacea bridgesl in different sb)ck densittes. An mtemational Joumal of Marine Sciences Thalassas, 22(1): 5 9 ^ .
2. Boyd, C. E., 1998. Watt;r Quahty ui pond for aquaculture. Department of Fisheries and AlUed Aquaculture Auburn University Alabama 36849 USA.
3. Burky, A. J., Paeheeo, J. and Pereyra, E., 1972.
Temperature, water, and respu^tory regunes of an amphibious snail, Pomacea urceus (Miiller), from the Venezuelan savannah. Biological Bulletin 143 pp, 304^16.
4. Conner S. L , C. M. Pomory and P. C. Darby, 2008. Density effects of native and exotic snails on growth m juvenile apple snails Pomacea paludosa (gastropoda: ampullariidae): a laboratory experiment
Department of Biology. University of West Florida, Pensacola, FL 32514, USA. 74:355-362.
5. Deshayes, G. P., 1830-1832. Encyclopedia methodique. Histoire naturelle des vers. Tome second. Agasse, Paris, vii+2564-594 p. Volume 2 (1): i- vii, 1-256 (February 1830); volume 2 (2): 1-144 (February 1830), 145-594 (September 1832).
6. FAO, 1989. Integrated "Golden". Kuhol management. FAO Intercountry programe for integrated pest conttol m rice in south and southtest Asia. Phihppine department of agriculture. 44 p.
7. L6 Vin Cat, Do Thi Hdng Nhung, Ngo Ngoc Cat, 2006. Chat lugng nuoc va giai phip cai thien chat luong nudc. Nha xuat ban Khoa hgc va Ky thuat Ha Ngi: 424 tt^ang.
8. Lum-Kong, A and Kenny, J. S., 1989. The reproducttve biology of the ampullariid snail Pomacea urceus (Miiller). Journal of Molluscan Studies 55 pp, 53-65.
9. Md. Sarwar Jahan, M s t Shahida Akter, Md.
Monimzzaman Sarker, Md. Redwanur Rahman and Md. Nasiruddm Prmanik, 2001. Growth ecology of PUa globosa (Swainson) (Gasttopoda: Pilidae) m sunulated habitat. Department of zoology. University of Rajshahi, Rajshahi - 6205, Bangladesh, 581 - 584.
10. Ng6 Thi Thu Thio, Hiia Thii Nhin va Huynh Han Chiu, 2008. Anh hudng ciia thiic i n len smh trudng, ty Id sdng v i tiiinh phin smh hda dc len (Ceritbidea obtusi). Tap chr Khoa hgc Dai hgc Cin Tha. Sd chuydn dd thtiy san quydn 2. Trang 113-123.
11. Nguydn Dmh Trung, 1998. Giio trinh Thuy hoa - Thd nhuong. Nha xuit bin NSng Nghidp.
12. Nguydn Thi Bmh, 2011. Tim hidu mdt sd die diem smh hgc smh s i n ctia dc buou ddng Pllapoh'ta va thti nghidm ky thuit san xuit gidng. Luin vin thac Sl. Truong dgi hpc Vinh. 105 ttang.
13. Nguydn Thj Dat, 2010. Anh hudng ctia m i t do va mgt sd loii thtic i n ldn tdc d6 tting trudng v i ty Id sdng ciia dc huffu ddng Pila poh'ta ttong nu6i thuong phim. Luin vin th?ic si ndng nghidp. Tnrdng Dai hgc Nong nghidp H i Ndi. 77 ttang.
14. Nguydn Thj Didu Iinh, 2011. Anh hudng ciia tiuic in, mit dd ddn ty Id sdng v i tdc dg tting ttudng ciia dc buou ddng L^a poh'ta nudi ttong giai b ao nuoc nggt tiianh phd Vmh. Luin vin thac si. Trudng Dai hgc Vinh. 107 ttang.
N 6 N G NGHlgP VA PHAT T R I I N N 6 N G T H 6 N - KY 2 - THANG 9/2013
KHOA HOC C O N G N G H t
15. Pusadee Sri-aroon, Piyarat Butrapom, 17. Truong Qudc P h i . NguySn Ld H o t a g Ydn v4 Jaremate Limsomboon, Yupa Kerdpuech, Manus Huynh Trudng Giang, 2006. Gido trinh p h t a ticfi Kaewpoolsri and Songtham Kialsiri (2005). chdt Immg nudc vd q u t a ly mdi tnidng nudc ao.
Freshwater molluslts of medical unportance in Khoa T h i y s t a . Dai hoc C t a Tho: 199 hang.
Kalasin province, northeast Thailand: 653^57.
18. Vu Bd Quan, 2003. Khdo sdt ddc didm vd Idii m Thaewnon-ngiw B Lauhachinda N., Sri- ^j^j, ^ ^ ^ ^ ^ „ ^ , ^ ^ ^ ^ ^ ^ ^ aroonP.,LohachitC., 2003. Distribution o f / W a p o i a „ , . , . . . , . i UA i.^.
,. T^ .1 J n . J- f .1. v t a g Pomacea canahculata va mdt sd bidn phap m a soulhem provmce Thailand. Proceedings of the ^ , , . ^. . Joint hitemaaonal Tropical Medicine Meeting 2002. Ph*ng « r tai mdt so tmh ddng bang sdng Cuu Long.
SoutheastAsianJ.Trop. Med. PublicHealth:34(suppl Luta ta thac si khoa hoc ndng h()C. Khoa Ndng 2) :128-130. nghidp. Trudng Dai hoc Cdn Tho. 105 trang.
EFFECTS OF DIFFERENT FOODS ON THE GROWTH AND SURVIVAL RATE OF BLACK APPLE SNAIL (/tfa/wAla Deshayes, 1830)
Le Van Binh, Ngo TW Tliu Tliao Summary
This study was conducted to evaluate the effects of different foods on the growth and survival rate of blacit apple snail Pila polita. Tliere were 3 replicates in each treatment and food used as follow: 1) rice bran; 2) cassava powder, 3) industrial pellet Snails were reared m the composite tanks with a density of 150 ind/tank (initial weight and shell height were 0.03 g and 4.5 mm). After 35 days of culture period, the survival rate in rice bran diet (94.44±3.01%) was higher than in cassava powder (93.33±2.91%) and pellet (93.78±3.91%), however there was no significant difference (p>0.05). Highest increased biomass was .obtained when feeding snails with pellet (2027.54±263.77%) and veiy significant difference (p<0.05)
compared to rice bran (727.35±59.48*) and cassava powder (992.29t293.65%). Feeding with peUet, snails also reached highest body weight and shell height (0.71±0.09 g and 14.79±0.56 mm) compared to feeding ; with rice bran (0.2fa0.02 g and 10.55±0.26 mm) or cassava powder (0.36±0.05 g and 11.65±0.66 mm). Snails were fed with pellet and casava powder presented highest feed efficiency (722.71±20.35%) and that was significant difference (p<0.05) compared to feeding with rice bran (472.60419.60%) or cassava powder (529.2a±55.22%). Results indicated that Pda polita viete fed with pellet showed better growth rate and feed efficiency compared to nce bran or cassava powder.
Keywords: Food, black apple snail, growth, F^la polita, survival.
Ngudi p h t a bidn: TS. Pham Anh T i d n Ngdy n h t a bdi: 24/4/2013 Ngdy thdng qua p h t a bidn: 28/5/2013 Ngdy duydt dtag: 4/6/2013
