I NUOI TR6NG THUY SAN
Long nop Him a m
TRONG NUOI CA BIEN TAI VINH LAN HA
N G H E NUOI CA LONG HIEN DANG PHAT TRIEN MANH ME TREN TOAN CAU, N H U N G CHU YEU VAN SLT DUNG LONG LAM TU* LUOI NYLON VOI NHIEU HAN CHE NHU BI HAU, RONG REU BAM LUOI, LAM CHO NUOC LUU THONG KEM, XUAT HIEN KY SINH TRUNG GAY BENH... DE K H A C PHUC NHUlMG NHUOC DIEM CUA LONG NYLON, NGHE NUOI THUY SAN THE G I O I OA SLT DUNG TAM LLTOI OAN TlJ CAC SOI DAY HOP KIM DONG LAM LONG NUOI. TAI VIET NAM, VIEC NUOI CA SU" DUNG LONG HOT KIM DONG MOI OUOC NGHIEN CU'U VA THL/C HIEN THI DIEM TAI KHU VU'C BEN BEO, OAO CAT BA, HAI PHONG.
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Kjsinh trting khd Mm vao bi nil (0 luoi dSng
U'u diem cua long hp'p kim dong
Long nudi bang Iudi hop kim ddng (CAM) vupt trpi so vdi cac vgt lifu khac do dd'ng ed tinh khang khuan, chd'ng an mdn. Hpp kim ddng ngan chan eae chat hiiu co bam taen bf mat Iudi, giiip tang kha nang Iuu thdng nudc, duy tri Iupng dxy d miie cao hem, can trd ky smh trimg va mam bfnh phat trieh va lay nhiem cho ca, giup ca khde hon va dat nang suat eao hon.
Long CAM gan nhu khdng yeu
cau phai ve sinh, giiip giam thieu ehi phi bao duong va riii ro eho thp lan khi vf sinh long.
Vat lifu CAM cdn giiip duy tri the tich long nudi trudc nhirng ddng chay va eon sdng manh, tham chi ca trong difu kifn nudi xa bd. Ciing nhd Iudi dong khdng de bi bdp meo, cac Ioai san md'i nhu hai caiu, su tii bieh va ea map khdng bi mac k§t va cting khdng cd co hdi tan cdng ea nudi trong long.
Hom niia, Idng CAM cd thf sir dyng Uen tyc trong vdng 6
nam hoae hon, tiiy thupc vao difu kifn mdi trudng va hoan toan ed the tai chf giiip bii dap cho ehi phf dau tu cao ban dau, cting nhu giam tiiifu d nhiem mdi trudng.
Ket qua thu> nghiem thii^tS bu-ac dau tai dao Cat Ba
Tnmg tam Hop tac Qudc te Nudi taong va Khai thac Thiiy . san Ben viing (ICAFIS) da pheS j hpp ciing Hifp hpi Dong Quoc tl Khu vyc Ddng Nam A (ICASEA]
thuc hifn dy an sii' dimg long
NUOI TR6NG THUY SAN I
CAM taong nudi ca bieri tai vjnh Lan Ha, dao Cat Ba, thanh pho' Hai Phdng.
Dy an long ea diing vat lifu dong dupc tifn hanh thir nghifm tgi Iiai be nudi oia gia dinh dng Toan va dng Luyfn tai khu vyc Beh Beo thudc dao Cat Ba tir ngay 1/1/2014-30/6/2015. Moi be bd' tai 3 long CAM va 3 long nylon ddi ehting, trong dd, mdi long CAM nha dng Toan cd kfch thudc (3 x 3 X 3) m va mdi long CAM nha dng Luyfn ed kich tiiudc (2 x 2,5 X 3) m. Long CAM dupe Iam bang spi hpp kim cd dudng kinh 2 mm, trong dd ham Iupng dong chifm 65%, kem 34%, cdn Iai la mft sd' kim loai khac. Ddi tupng nudi du an lua ehpn la ca song gau (ca mii), kich thudc eon gidhg dgt tir 10-12 em, dupc kiem taa ham Iupng kim loai nang (ddng va kem) trudc khi tha nudi.
Ca dupe tha nudi tir ngay 30/6/2014. Trong qua trinh nudi, eae can bp nghien ciiu thucmg xuyen kifm tra td'c dp sinh trudng Clia ca, djnh ky 1 lan/thang, va cac yeii to vf mdi trudng nhu nhift dp, dp man, dxy, dp pH... Sau 12 thang nudi, so sanh vdi long nylon truyen thd'ng hifn dang dupe ngudi nudi sir dung rdng rai, Idng CAM da cho tha'y mpt so ket qua kha quan ban da'u.
Ca nudi trong long CAM sinh trudng to't hon so vdi Idng nylon, vdi td'c dp tang trudng eao hon tdi 26,5%. Ve ty le sd'ng Clia ca, long CAM dat miic trung b'lnh 36,1% so vdi miic 30,3% tgi long nylon. Trong dpt dich bfnh vao thang 12/2014, ty If ca chft
khi nudi bang long CAM chi la 49,4%, trong khi nuoi bang long nylon la 75,2%. He so' thiic an (FCR) Cling giam dang ke khi nudi ca bang long CAM, dat miie 9,1 so vdi miie 15,2 khi nudi bang long nylon. Long CAM cung khdng xay ra hifn tupng sinh vat bam tren ludi long trong khi long nylon sau 1 thang nudi ed rat nhieu hau va ha bam. Ham lupng dd'ng va kem khdng Iuu trong da, thit, gan ea nen ea ed chat lupng cao. Ca nudi taong Idng ddng it bj bfnh, mdi trudng nudc thdng thoang nen ca khde manh, it bfnh tat.
Xet ve hieu qua kinh tf mac dil ehi phi dau tu eho long CAM rat cao (gap 11 lan dau tu cho Idng nylon), nhung nfu tinh theo gia trj khaii hao, lgi nhuan thu ve khi nudi bang long CAM dgt 109,3 trieu, cao hon 48% so vdi miic 74 taifu khi nudi bang long nylon. Hon niia, khi so sanh hifu qua kinh tf giiia hai Ioai long, nhdm nghien a i u chua tinh dfn gia tri thu hoi oia long CAM. Theo cac chuyen gia, gia tri thu hdi eiia long CAM cd thf dgt tdi 60-70% gia tri Idng khi mua mdi.
Bfn cgnh dd, nudi ca bang Id'ng CAM rat than thifn vdi mdi trudng, do be mat Idng khdng ed vi sinh vat bam nfn khdng can sir dung may phat diesel co rira, khong sir dung nhien lifu hda thach, vgt lifu ddng cd the dupe tai chf sau khi khdng sii dung..., lpi nhugn thu dupc tir nudi ea long dd'ng gap 1,5 Ian so vdi long nylon,
Tir kft qua dy an eho tha'y.
viec sir dung long CAM rat phii hpp vdi nganh thtiy san Viet Nam, cd the pho bifn cong nghe cho ndng dan de iing dung rpng rai. Tuy nhien, nhiing ket qua thu dupe mdi chi dimg lai d so' lieu thd, ddi hdi phai cd nhiing nghifn eiiu va phan tich sau hon.
Hon nfl'a, can giam bot ehi phi dau tu ban dau cho ludi dong nhu sir dung mat ludi to hon va dimg day dong df bupc thay eho vifc diing d'c vft NK. Viet Nam Cling nfn tinh deh md hinh cho thue Id'ng thay vi ndng dan phai tu minh dau tu gdp phan thtic day nhanh ting dung vat lifu mdi trong nudi trong, nang cao gia trj Clia nganh thiiy san.
Theo Tieh sy Craig Craven, ehuyfn gia cdng nghe nuoi trong thiiy san Hoa Ky, day la vgt lieu ed nhieu uu diem taong chd'ng choi vdi thien tai, Nhung tiiy thupc vao eudng dp bao, trong trudng hpp bao to ldn van cd thf phai di ehuyfn long be dd vao noi an toan hon. Tuy nhien, theo kinh nghifm d cac nudc nhu Nhat Ban, Han Qud'c, hp sir dung Id'ng kich thudc khung sudn Idn nen ed thf chiu dymg dupc cac com bao to, do dd se khdng phai di ehuyfn cac long be nudi ca.
ICAFIS Cling eho biet se tifp tue tim eo hpi nghien ctiu hoan thifn du an, thir nghiem kft qua du an cho nudi tdm hiim, dd'ng thdi phdi hpp vdi tinh Khanh Hda, Phli Yen dua dy an vao ling dyng trong xay dimg ndng thdn mdi. •
Ngpc Tii
