NGHllN CÎ U TRAO DOI 0 NHIEM IVlOl TRUONG 00 CHAN NOOl miN TB4A/« y4 mt ?«/4? kilAC PH(JC 1 Dat van de Viet Nam la mdt nude ndng nghiep vdi khoang 70% sd dan sdng d vung ndng thdn San xuit ndng nghie[.]
NGHllN CI^U - TRAO DOI NHIEM IVlOl TRUONG 00 CHAN NOOl: miN TB4A/ô y4 mt ?ô/4? kilAC PH(JC ã PGS.TS Nguyin Kim Ou'O'ng Dat van de Viet Nam la mdt nude ndng nghiep vdi khoang 70% sd dan sdng d vung ndng thdn San xuit ndng nghiep ddng vai trd rat quan trgng nen kinh te xa hdi nude ta Nhu'ng nam qua, nganh chan nudi phat triln kha manh vl ca sd lugng lan quy md Tuy nhien, viec chan nuoi nhd le ndng hg, thilu quy hoach, nhat la cac viing dan cu ddng diic da gay d nhiem mdi trudng cang trim nhilm mdi trudng chan nudi gay nen chu yeu tu' cac ngudn chat thai rin, chit thai Idng, bui, tieng In, xac gia siic, gia cim chit chon lip, tieu hiiy khdng diing ky thuat Mdt kit qua kiem tra miic nhiem khuan chudng nudi gia sue cho thiy, ting so vi khuan khdng d chudng nudi cao gap 30-40 lan so vdi khdng ben ngoai Dii vdi cac co sd chan nudi, cac chat thai gay d nhiem mdi trudng cd anh hudng true tilp tdi sue khde ngudi, lam giam sii'c dl khang vat nudi, tang ty le mie benh, cac chi phi phdng tri benh, giam nang suit va hieu qua kinh te Sii'c dk khang ciia gia siic, gia cam giam siit se la nguy co gay nen bung phat dich benh Vi vay, WHO [2005] khuylifcao phai cd cac giai phap tang eudng viec lam sach mdi trudng chan nudi, kilm soat, xu ly chit thai, giu' vung dugc an toan sinh So Ten nguyen to Kem (Zn) Dong (Cu) Mangan (Mn) Thiiy ngan (Hg) Cadimi (Cd) Asen (As) Chi (Pb) Sd 11/2011 hgc, tang eudng sue khde cac dan gidng Cac chat thai chan nudi gay d nhilm mdi trudng vi sinh vat (cac mim benh truyin nhilm) la dac biet nguy hilm, vi nd se lam phat sinh cac loai djch benh nhu ia chay Id mdm long mdng, tai xanh, Ciim gia cim H5N1 Theo tinh toan thi lugng chit thai rin ma cac vat nudi cd thi thai (kg/eon/ngay) la: bd 10, trau 15, Ign 2, gia cim 0,2, vay hang nam, dan vat nudi Viet Nam thai vao mdi trudng khoang 73 trieu tin chit thai rin (phan khd, thii'c an thiia) va 25-30 trieu khIi chit thai Idng (phan Idng, nude tilu va nude rua chuong trai) Trong dd, khoang 50% lugng chat thai rin (36,5 trieu tin), 80% chit thai Idng (20-24 trieu m^) xa thing mdi trudng, hoac sii dung khdng qua xu ly se gay d nhiim mdi trudng nghiem trgng U'de tinh mot tan phan chudng tuoi vdi each quan ly, su dung nhu hi?n se phat thai vao khdng khoang 0,24 tin CO2 quy ddi thi vdi tdng khdi chit thai neu tren se phat thai vao khdng 17,52 trieu tin CO2 Cac nha nghien ciiu da udc tinh dugc rang chan nuoi gay 18% gay hieu li'ng nha kinh lam cho nhiet trai dit tang len (biln ddi hau toan cau), Idn hon ca phan giao thdng van tai gay Cac ylu to gay d nhiem mdi trudng tir chat thai chan nudi CO nhieu, nhung bai viet mudn de cap den hai yeu to la NH3 va cac kim loai nang nhiem moi tru-dng Icim loai nang gay 2.1 Qui dinh cua Nhd nu&c ve hdm luang kim loai nang thuc phdm Quy dinh ciia Bd Ndng nghiep va Phat trien ndng thdn vl ham lugng tdi da mdt so nguyen td khoang va kim loai nang (tinh bang mg/kg thii'c an hoan chinh cho gia siic, gia cim Quylt djnh sd 104/2001/QD/BNN, 31/10/2001) nhu sau: Ham lirgng toi da (mg/kg thuc an) Ga Lon De trung Nuoi thit 250 250 250 35 35 < thang tudi: 175 > thang tudi: 100 250 250 250 0,1 0,1 0,1 0,5 0,5 0,5 2 5 Bo 250 50 250 0,1 0,5 Thdng tin KH-CN Nghe An (25] 2.2 O nhiem kim loai ndng chdt thdi chan nudi gdy O Viet Nam hien nay, tdng khdi lugng chat thai chan nudi binh quan khoang 73 trieu tin/nam, dd chat thai chan nudi Ign ehilm khoang 24,38 trieu tin/nam tuong duong 33,4% (Xuan Ky, Xic ly d nhiem mdi trudng, phdt trien ben viing ndng nghiep, ndng thdn, Bao Nhan Dan, 08/03/2009) Ddng (Cu) va kem (Zn) tdn du chat thai chan nudi la hai nhieu ylu to gay d nhiem kim loai nang ddi vdi dit Viec bd sung oxit kem (ZnO) vdi ham lugng qua cao thiic an cho Ign so vdi quy djnh de phdng ngira tieu chay la nguyen nhan co ban dan den tinh trang 2.3 Ngudn kim loai ndng gdy d nhiem mdi trudng Kim loai nang gay d nhiem mdi trudng cd thi nhieu ngudn nhu: chat thai cdng nghiep, chat thai chan nudi, phan bdn, cac chat hda ndng Trong dd, viec cho them kem vao thuc an chan nudi cdng nghiep ciia vat nudi nham phdng benh va tang kha nang tieu hda cung dugc xem la ylu td gay nen sir d nhiem kim loai nang cho mdi trudng cin dugc quan tam Theo dng Huynh Thanh Hiing (Khoa Ndng hgc - Dai hgc Ndng Lam Thanh Ho Chi Minh): Phan Idn ngudi trdng rau deu sii dung phan chudng (Ign, ga), cac vat nudi dugc nudi bing thuc an tdng hgp Thuc an dang cd nhieu khoang da lugng, vi lugng Ham lugng kim loai nang phan ciia vat nudi se xam nhap vao dat trdng rau va ton luu cac ndng san, dac biet la ddi vdi cac loai rau an la nhu cai nggt, cai xanh, xa lach 2.4 O nhiem kem, tdc hai cua nhiem kem Mdt cudc tham dd dugc tien hanh hang nam d Anh va xii Wale ve chat thai cd chiia kim loai nang tir phan gia siic da cho thiy, miic kim loai nang cao nhat thai vao dat ndng nghiep la kem (len den 3,3kg/ha) va ddng (len den 2,2 kg/ha) tai khu vuc chan nudi Ign d vimg Tay Anglia va Humberside (Chambers et al., 1999) Lugng kem thai tii phan vat nudi gay d nhiem mdi trudng chiem den 35% so vdi cac yeu to gay d nhiem kim loai nang khac Kim loai nang cd xu hudng tich luy dat, dac biet d ldp dat gin bl mat va gay ddc hai ve lau dai Tinh ddc cua kim loai nang se gay nen sir sut giam sd lugng va sir da dang cua vi sinh vat dat, anh hudng len vi sinh vat cd Igi cho dat (vi sinh vat se phan giai cac chit nguy hai dd (Burton and Turner, 2003) Sir du thiia Zn Zn tich tu cjua cao dat cung gay ddc ddi vdi cay trdng, gay benh mat diep luc Su tich tu Zn cay, qua nhieu cung lien quan den miic du lugng Zn co the ngudi va gdp phin tang su tich tu Zn mdi trudng (Nguyin Thi Nggc An va Duong Thi Bieh Hue, 2007) Nhieu nghien cuu da chiimg minh ring, nlu lugng kim loai nang dat qua cao cd thi gay sir roi loan he thdng enzyme tren dgng vat dugc nudi d nhimg viing va an phai cac loai thuc an dugc san xuat tai dd (Burton and Turner, 2003) f f sinh vat cai thien sir hd hap cua dat, phan huy chit huu co, co dinh nito ) Kim loai nang gian tilp lam giam sir phan huy thudc trii sau va nhiing chat hihi co khac viec tieu diet cac loai vi khuan va nam ma dieu kien binh thudng cac vi S6 11/2011 Thdng tin KH-CN Nghd An (26) NGHIEN CUU - TRAO Odi Zn la vi khoang thilt ylu cho co the ngudi, chii ylu tich tu gan Than cd kha nang Igc toi da khoang 2g Zn/ngay Nlu thira Zn Idn cd thi gay ung thu, ngd ddc he thin kinh, anh hudng len tinh nhay cam, sinh san, gay ddc he mien dich Sir thieu hut Zn co the cd the gay liet duong, teo tinh hoan, mii mau, viem da, benh ve gan va mdt so trieu chiing khac (Nguyen Thi Nggc An va Duong Thj Bieh Hue, 2007)! Van dl thai NH3 vao khong cua chan nuoi Ammoniac (NH3) cd khi, trudc het la tii sir phan huy va bdc hoi ciia cac chat thai vat nudi Cac hoat ddng san xuat ndng nghiep (chan nudi, sii dung phan bdn) da dugc xac dinh la cac ngudn Idn thai NH3 mdi trudng Sd lugng cua dan vat nudi da va dang tang dang ke, cung tuong tvr la su phat thai ciia NH3 tii phan bdn nito (Sutton et al 1993) Sir gia tang manh nhat gay bdi nhdm vat nudi Ign va gia cam Trong cac hoat dgng chan nudi, su thai NH3 vao mdi trudng trudc hit la hi chudng trai, nudi vd beo md (hd), che bien va du trii phan, sii dung phan bdn tren dit Nito dugc thai d dang ure (ddng vat cd vii) hoac axit uric (chim) va NH3, nitrogen hilu co phan va nude tilu cua vat nudi De bien ure hoac axit uric NH3 can cd enzyme urease Sir biln ddi xay rat nhanh, thudng la it Biln ddi cac dang phiic hgp nitrogen huu CO phan xay cham hon (hang thang hojc hang nam) Trong ca trudng hgp, nitrogen dugc biln ddi ammonium (NH4"^ dilu kien pH axit hoac trung tinh hoac ammoniac (NH3) dilu kien pH cao hon NH3 thai anh hudng Idn tdi chit lugng khdng qudc gia, khu vuc va toan ciu Sir tich luy NH3 khdng cd the gay sir phi nhieu nude mat, vay lam cho tao ddc hai tang trudng nhanh va se lam giam nhilu loai thuy sinh, dd cd cac doi tugng kinh tl Cac loai cay nhay cam nhu ca chua, dua chudt va cac loai hoa qua dugc gin khu vuc cd NH3 thai Idn se bj hu hai NH3 ling dgng tang (van der Eerden et al S6 11/2011 1998) Su ling dgng NH3 dat vdi kha nang dem thap cd thi gay nen axit hda dit hoac riit hit cac cation co ban Dilu dang quan tam dac biet la NH3 khdng chuong nudi thudng xuyen dugc tich tu chudng kem thdng thgang, tang miic NH3 se anh hu'dng xiu (-) ddi vdi siic khde va nang suit vat nudi Ddng thdi NH3 cd the tac ddng xiu (-) len sue khde ngudi, du chi d miic thap ciing cd the gay sung phdi, sung mit, anh hudng tdi hd hap va tim mach Cac giai phap de lam giam thieu o nhiem chat thai chan nuoi Viec bo sung kem dxit thuc an cdng righiep cho vat nudi thudng la khdng thi thilu va lugng bd sung tiiy thudc vao timg giai doan Tren thuc te, lugng kem huu dung chi ehilm khoang 5-20% tren tdng lugng kem bd sung, phin cdn lai (80-95%) dugc thai qua phan vao mdi trudng (Burton and Turner, 2003) Sir d nhilm Zn chit thai chan nudi cd thi dugc khac phuc tdt hon nlu sii" dung san pham ZnO bd sung thuc an cdng nghiep cd ty le huu dung cao van dam bao viec phdng ngua tieu chay tren Ign Nhu vay, van de d nhiem mdi trudng dat bdi kim loai nang se dugc khic phuc tung budc nhd giam tdi da lugng kem phan thai mdi trudng Theo dng Hoang Kim Giao (Cue trudng Cue chan nudi Bd Ndng nghiep va Phat trien ndng thdn): "Cd nhdm bien phap CO ban han ehl d nhiem chan nudi (I) Can quy hoach lai, dua chan nudi xa dd thi, khu dan cu, khu cdng nghiep va nhit thilt phai thuc hien quy djnh chan nudi an toan gin vdi bao ve mdi trudng (II) Su dung ky thuat cho vao thiic an va chit thai chan nudi cac men, cac ehl phim sinh hgc nhim han che ddc hai va vi sinh vat cd hai (Ill) Ung dung tien bg ky thuat than thien vdi mdi trudng Tdy dieu kien cu thi tiing noi dl lira chgn mdt quy trinh xii ly chit thai nhu: bl ling - him biogas - ao sinh hgc, him biogas - ao sinh hgc va him biogas - thiing sue - ao sinh hgc; dd trgng tam la chan nudi theo md hinh VAC va su dung Jiim biogas" 4.1 Quy hoach, xay dung chuong, trai Lira chgn vj tri xay dung chudng trai, dien tich chudng nudi, mat va bd tri, sap xep cac day chuong.nudi, xay dung cdng trinh xii ly chit thai, ve sinh chudng trai Xung quanh khu vuc chan nudi tiln hanh trdng cay xanh nhu: nhan, vai, keo dau, mudng dk tao bdng mat va chin dugc gid lanh, gid ndng Ngoai ra, cay xanh cdn quang hgp hiit CO2 va thai O2 rit tot cho mdi trudng chan nudi 4.2 Xay dung he thdng h^m biogas Hai bien pha^ xii ly d nhilm mdi trudng dugc danh gia cd nhilu uu dilm, la.sii dung cdng nghe sinh hgc (biogas) va su dungxhe phim sinh hgc EM Viec xay dung cac him biogas dk xii ly chit thai tii chan nudi la mdt bien phap mang lai tae dung Idn Ngudn phan tJiai sau dua vao bl chiia dugc phan hiiy hit, giam miii hdi, rudi nhang va Thdng tin KH^CN Nghe An [ii] tieu diet ki sinh triing hau nhu bi Ben canh dd, su dung ham biogas cdn cd the tai tao dugc ngudn nang lugng sach tii phe thai chan nudi, tao CH4 phuc vu viec dun nau, thap sang 4.3 U phdn bdng phuang phdp sinh hgc cdng vdi viec che phu kin Phan chudng sau dugc lay khdi chudng nudi cin danh ddng Trong qua trinh danh ddng, phan dugc rai timg ldp mdt (mdi ldp khoang 20cm) rdi rai them mdt it (mdt ldp mdng) tro bep hoac vdi bot, cii lam nhu vay cho den het lugng phan cd dugc Sau ciing, su dung biin ao hoac nhao dit mjn vdi nude tao biin de trat kin, deu len toan bd be mat cua ddng phan Ciing cd the sii dung cac tam (nilon, bat ) phu kin ddng phan de giam thilu cac loai sinh (CO2, NH3, CH4 ) thoat mdi trudng Ddng thdi, qua trinh li ddng phan se cd hien tugng, sinh nhiet, vay cac mam benh (triing, au triing, vi khuan, nam ) se bj tieu diet, han che phat tan, lay lan cac mam benh 4.4 Xu ly nude thdi bdng cdy thuy sinh Nude thai tu cac trai chan nudi chiia rit nhieu nitrogen, phosphorus va nhiing hgp chit vd co cd the hda tan dugc Rat khd tach nhiing chit thai khdi nude bang each quet riia hay Igc thdng thudng Tuy nhiSn mdt sd loai cay thuy sinh nhu beo luc binh, cd mudi nude cd the xu ly nude thai, viia it tdn kinh phi lai than thien vdi mdi trudng Cay mudi nude (cdn ggi cay cin tay nude), cay beo luc binh (beo Nhat Ban) la cac loai ban dja cua viing ' r t f Ddng Nam A, than va la cd the an sdng hoac an chin nhu mdt loai rau Nd sinh san theo each phan chia re va sinh trudng tdt mdi trudng nude ndng cho tdi 20em Cay beo luc binh (beo Nhat Ban) cd nguon gdc Nam My, sinh trudng va phat triln nhanh, khde va ndi tren rnat nude Nude thai tii cac chudng gia siic trudc tien cho chay vao be lang, de chat thai rin lang xudng day Sau vai cho nude thai bl lang chay vao be md cd beo luc binh hoac cd mudi nude Mat nude be dugc cay che phu (mat So 11/2011 khoang 400 cay/bl) NIU la beo luc binh, bl cd thi lam sau tiiy y, ddi vdi cd mudi nude thi dk nude ndng mdt chut, sau bl xu ly khoang 30cm Cd mudi nude can thdi tilt mat me, cdn beo luc binh phii hgp vdi thdi tilt im Kich cd ciia bl tiiy thudc vao lugng nude thai can dugc xii ly Vi du, chat thai ciia 10 gia siic vao khoang 456 lit, se cin be mdi canh 6m, sau 0,5m B I phai cd.tdng khdi lugng 18m^ va dien tich be mat 36m^ B I cd the chiia nude thai chudng nudi khoang 30 Nude thai dugc giu be xu ly 10 Trong thdi gian nay, lugng phospho nude giam khoang 57-58%), 44%> lugng nito dugc loai bd BODs (la phuong phap xac djnh miic vat chat hiiu co nude) Trong thdi gian giam xu ly 10 ngay, BOD5 giam khoang 80-90% Nhiing bien phap xu ly nude thai theo each dap ling tieu chuan tdi thieu Nude thai sdng hd, sudi mdt each an toan ma khdng can xu ly them Ngoai ra, cac cay thiiy sinh cd the thu hoach va diing lam phan hiiu ca Ban than chiing cd the true tiep lam phan xanh hoac phan trdn 4.5 Su dung Zeolit, dung dich dien hoat hoaAnolit, cdc che pham sinh hgc (EM) Zeolit la loai vat lieu khdng gay ddc ddi vdi ngudi va vat nudi cd ung dung hieu qua ITnh vuc nudi thiiy san, ndng nghiep, chan nudi, bao ve mdi trudng dugc nghien ciiu va san xuat cdng bdi cac chuyen gia bd mdn Hda.hiiu co, Khoa Cdng nghe Hda hgc, Dai hgc Bach khoa Ha Ndi Zeolit dugc san xuat dudi dang hot hoac dang vien xdp tu cao lanh tu nhien san cd d Viet Nam Nhd cau true cua cao lanh bi pha vd hoan toan va tu chiing sap xip lai tao Id rdng, nen nd cd kha nang hap phu cac ion kim loai, amoni, chat huu co ddc hai lo lung nude va tu chim xudng day Khi cai tao ao, dim, ngudi san xuat cd the khai thae chiing de tai chS lam phan bdn phuc vu cho viec trdng trgt Ngoai ra, ngudi ta cdn cd the dung loai san pham trdn lan vdi phan bdn de tao mdt loai phan bdn phan huy cham, viia cd tac dung tiet kiem lugng phan bdn, giir im ma cdn cd tac dung dilu hda pH cho dat Che pham zeolite lam phu gia thiic an cho Ign va ga vi dugc trdn vao thiic an che pham se hap thu cac chit^dge -trgng co thi vat nudi, tang kha nang khang benh, kich'thiqlt tieu hda va tang trudng Su dung dung djch dien hoat hda AndlitrVieh Cdng nghe Mdi trudng phdi hgp vdi Trung tam Chin doan Thii y Trung uong, Cue Thu y, Trung tam kilm tra ve sinh Thu y TWl, Vien Chan nudi qudc gia da nghien ciiu va khao nghiem cdng kha nang sii dung dung dich hoat hda dien hda Andlit lam chat khu triing chan nudi Dung djch hoat hda dien hda Andlit da dugc ap dung tai nhieu nude tien tiln nhu mdt chit khu trung hieu qua cao va "than thien vdi mdi trudng" Dung djch cd kha nang khu triing nude sinh hoat, bao quan ndng san, che bien thiiy san, san xuit tdm giong, khu triing cac co sd y tl, chan nudi Thdng tin KH-CN Nghe An (28) NGHIEN CUU - TRAO o6l Ngoai ra, dung djch hoat hda dien hda Andlit cd tac dung diet virus H5N1 an toan, khdng gay ddc ddi vdi sinh vat cap cao, cd thi dugc su dung lam dung dich phun tieu ddc cho cac co sd chan nudi Cac kit qua nghien ciiu hi$u qua khu triing cua Andlit tren hien trudng san xuat, chan nudi gia cim (tai Trung tam nghien ciiu gia cim Thuy Phuong) cung da cho nhan xet: Phuong phap khii triing nen chuong bing Andlit, cd thi ap dung cd hieu qua doi vdi chudng nudi vira xuit lua hoac dang chuan bj dua vao nudi liia mdi Vdi Andlit 250ml/m^, mat tdng vi khuin hilu giam trung binh 2-3 bac, Coliforms va Salmonella thuc te dugc loai hoan toan Cac thi nghiem tuong tu thuc hien vdi chit khu trung Virkon^S 0,5%) cung cho kit qua tuong tu nhu khu trung bing Andlit, song gia dit hon tdi lin so vdi viec su dung Andlit Sii dung ehl pham vi sinh vat hifu hieu EM chan nudi se lam cho chat thai nhanh phan hiiy, khii miii tdt va giam quin thi cdn triing ruoi mudi, giam nguy CO lay lan djch benh Cho gia siic, gia cim udng hoac an thii'c an thd cd trdn che phim EM cdn giam dugc nguy co mie b?nh dudng rudt 4.6 Chan nudi tren nen dim lot sinh thdi Trong vai nam gin day, mdt sd nude ciing nhu d Viet Nam dang phat trien mdt hinh thiic chan nudi mdi, dd la chan nudi tren nIn chudng dem lot vdi cac vi sinh vat cd ich Hinh thiic chan nudi cdn dugc ggi la chan nudi vdi dem Idt sinh thai hay chan nudi dem Idt len men Thay vi nudi cac vat nudi tren nIn xi mang hoac gach ciing, ngudi ta da nudi cac vat nen chudng bang dat nen, sau hon mat dit (-, am), tren nIn chudng rai mdt Idp dem Idt day 60cm va tren bl mat dem Idt cd phun mdt dung djch men (hdn hgp cac vi sinh vat cd ich) Dem Idt thudng la cac nguyen lieu thuc vat nhu miin cua, trau, than cay ngd va Idi bap ngd khd nghiln nhd Binh thudng, dem Idt sinh thai cd the su dung dugc nam Ngoai ra, qua trinh hoat ddng chuong nudi dem Idt sinh thai, vat nudi cd the an men vi sinh vat cd dem Idt se giiip tieu hda thuc an tdt hon, lam tang kha nang hip thu axit amin, qua tang mem, vi nggt tu nhien cho thjt so vdi san pham lam tu chan nudi thdng thudng, dong thdi ngudi chan nudi cd thi tilt kiem dugc 80%) nude, 60% nhan lire, 10% chi phi thiic an, thudc thii y phdng tru dich benh Dae biet, dem Idt chiia cac vi sinh vat cd Igi nen se rit hieu qua viec phdng chdng cac benh dich cd hai nhu Id mdm long mdng, tai xanh, ciim 4.7 Diiu chinh phdn khau phdn dn Mdt nhom nghien ciiu da thur nghiem cdng thuc phdi trdn Vdi cac ket qua thu dugc qua thii nghiem, hg da chgn bai thudc (ky hieu la CP2) cho hieu qua tdt nhit cd phin nhu sau: mach nha (25%), son tra (15%), thin khiic (20%), su quan (5%), xa tiln (5%), nguu tit (30%) Su dung ehl phim CP2 vdi lilu lugng l.OOOg CP2/1 tin thiic an hdn hgp cho nudi Ign thit se cho khdi lugng tang trgng/ngay cao hon doi chung la 4,42%), tieu tdn thiie an/kg tang trgng thip hon 9,58%, chi phi thii'c an/kg tang trgng giam 7,89%) Ddi vdi chan nudi Ign nai nudi con, su dung CP2 vdi lilu lugng nhu tren cho kit qua: gdp phin lam giam dang kl miii hdi cua chudng nudi; d chudng nudi Ign thit, ham lugng NH3 giam 41,30% va ham lugng H2S giam 44,44% so vdi Id ddi chiing; d chudng nudi Ign nai sinh san, NH3 giam 45,26%, H2S giam 43,90% so vdi Id doi chung./ Tai lieu tham khao H6 Kim Hoa, L6 Thanh HiSn, Trkn Thi Dan, 2005, Tinh hinh qudn ly chdt thdi chan nuoi a mgt s6 huy?n a TP H6 Chi Minh vd ba tinh Idn cdn, T^p chi Chan nu6i s6 1-2005 Cyc Chan nuoi 2006, Bdo cdo tong kit chan nuoi trang trai tap trung giai doan 2001-2006, dinh huang vd gidi phdp phdt triin giai dog^n 2000-2015 Ti6u chuin ng^nh 10 TCN 679-2006, Tieu chuan v# sinh khong chudng nuoi Tieu chudn, quy dinh nganh thu y (V$ sinh thuyvd v# sinh an todn thifc phdm), Nxb N6ng nghi$p, 2007 Ti6u chuan nganh 10 TCN 6678-2006, Tieu chudn v? sinh nu&c thdi chan nuoi Tieu chudn, quy trinh nganh thu y (v$ sinh thuyvd v$ sinh an todn thifc phdm), Nxb Nong nghi?p, 2007 Battye, R., W Battye, C Overcash, and S, Fudge 1994, Development and Selection of Ammonia Emission Factors EPA/600/R-94/190 Final report prepared for U.S Becicer, J.G., and R.E Graves 2004 Ammonia emissions and animal agriculture In Proceedings Mid-Atlantic Agricultural Ammonia Forum Woodstock, Va March 16 Meisinger, J.J., and W.E Jokela 2000 Ammonia losses from manure Proceedings 62'"' Cornell Nutrition Conference for Feed Manufacturers, 109-116 Ithaca, N.Y Van der Eerden, L.J.M., P.H.B de Visser, and C.J Van Dijk 1998 Risk of damage to crops in the direct neighbourhood of ammonia sources Environmental Pollution 102(S1): 49-53 WHO, 2005 Avian influenza: assessing the pandemic threat, 64 pages S6 11/2011 Thdng tin KH-CN Nghd An (29) ... Chan nu6i s6 1-2005 Cyc Chan nuoi 2006, Bdo cdo tong kit chan nuoi trang trai tap trung giai doan 2001-2006, dinh huang vd gidi phdp phdt triin giai dog^n 2000-2015 Ti6u chuin ng^nh 10 TCN 679-2006,... an cdng righiep cho vat nudi thudng la khdng thi thilu va lugng bd sung tiiy thudc vao timg giai doan Tren thuc te, lugng kem huu dung chi ehilm khoang 5-20% tren tdng lugng kem bd sung, phin cdn... trudng Su dung dung djch dien hoat hda AndlitrVieh Cdng nghe Mdi trudng phdi hgp vdi Trung tam Chin doan Thii y Trung uong, Cue Thu y, Trung tam kilm tra ve sinh Thu y TWl, Vien Chan nudi qudc gia