/ A r' BQ G IAO DUC VA D A O TAO TRU’QNG DAI HOC NONG LAM THAI NGUYEN ■ ft PGS TS NGUYEN THI KIM LAN nh Ong benh ky sinh trung ph bi£ n ■ GIA CAM, LON VA LOAINHAI LAI VIET NAM (Sack chuyen khao dung cho &ao tao sau dai hoc) DAI HOC THAT X’GUYKN mUOKG PM NHA XUAT BAN NONG NGHIEP HANO I-2011 l i noi dau K y sinh trung phan bo rat rong thien nhien Hien tuang ky sink (Parasitism) la hien tuang sink vat song tren sink vat kia, giua hai co the mot ben duac lai, cdn ben bi hai Thuang thi vat ky sinh gay benh cho vat chit, rat it vat ch.ii khong phat benh Khi vat ky sinh sdng ca the vat chu thi vat chu tra nguon phat tan benh Net dac trung phan biet giua vat ky sinh vai vat song tu la moi quan he vai moi truang ben ngoai Dong vat song tu true tiep lien he vai moi truang ben ngoai, chiu tac dong cua hau, tho nhuang va cac yeu to sinh hoc; dong vat ky sinh phu thuoc vao vat chu, thong qua su tiep xuc cua vat chu vai moi truang ben ngoai f 9 \ \ y Viet Nam la nuac nam vungjchi hau nhiet dai nong dm Do dieu kien thai tiet hau thuan lai cho su ton tai, phat trien cua nhieu loai sinh vat, ma nuac ta co khu he dong - thuc vat rat da dang, phong phu Day cung la dieu kien thuan lai cho su ton tai va phat trien cua vo so giong, loai ky sinh trung a ngoai canh, de roi chung tit ngoai canh xdm nhap ky chic va gay benh Khac vai benh vi khuan va vi rut gay ra, benh ky sinh trung khong lam cho gia sue, gia cam dm va chet hang loot vai toe lay lan nhanh, song benh ky sinh trung thuang dien a the man tinh, lam cho vat nuoi edi coc, cham lan, giam kha nang sinh san, giam site de khang va de mac cac benh khac Vi vay, benh ky sinh trung da va dang gay tac hai lan doi vai sue khoe vat nuoi, gay thiet hai lan ve kinh te cho cac ca sa chan nuoi tap trung va chan nuoi gia dinh \ \ ? r Sau nhieu nam nghien cuu ve linh vuc ky sinh trung thic y, chung toi da tong ket duac nhung giong loai ky sinh trung va benh bien chung gay cho gia cam, l \ > i \ Cac tinh thuoc vung dong bang co dia hinh bang phang han so vdi cac tinh mien nui, mua mua thi nong am nhieu han, nhung mua kho thi cung dd lanh han Mat khac, vung dong bang co nhieu nai dat trung, tao nhieu ao, ruong, song, ho Day la dieu kien thuan lgi cho su ton tai va phat trien cua cac loai ky chu trung gian cua san la Ngugc lai, cac tinh mien nui co dia hinh phuc tap, vung thi nui non hiem trd, vimg lai lugn song nhap nho xen ke nhung thung lung nho hep, vung thi co nhieu ddi thoai thoai ke tiep Kieu dia hinh chiem den 3/4 dien tich, lai la mot so vung co dia hinh tuang ddi bang phang Do cao va tinh chat phuc tap cua dia hinh tang dan tir vimg dong bang len mien nui Su khac ve dia hinh gin lien vdi che nhiet, am dan den su khac ve hau giua cac vimg Vimg nui co it ao, ho va nhung cho nude dgng han nen ty le nhiem giun san, dac biet la san la thap han cac tinh vimg dong bang f \ > (V r ^ \ \ Dac diem kinh te xa hoi cua cac tinh thuoc vimg dong bang va vimg nui cung khac Cac tinh mien nui co phan dan toe tuang ddi da dang, moi dan toe deu co tap quan rieng ve sinh hoat va san xuat, trinh canh tac va tap quan chan nuoi cung co % > r ** y * If > > nhung dac diem rieng O cac tinh, ba nong dan deu chan nuoi gia sue, gia cam vdi quy mo nho: tu vai den vai chuc trau, bo, de; Ion; tir vai chuc den vai tram ga Tuy nhien, a mot so nod, phuong thuc chan nuoi nho le, chua co quy mo tap trung dong bo, chuong nuoi tarn bo, chan nuoi theo hinh thuc chan tha va tan dung thuc an sSn co tu nhien, thuc an bo sung hau nhu khong co, van de phong tri benh ky sinh trung hau nhu chua duqc quan tarn va de cap den r f r \ f \ Dieu kien tu nhien va dac diem kinh te, xa hoi nhu tren co M i huong rat Ion tod su phan bo va phat trien cua ky sinh trung Do chinh la nhung nguyen nhan true tiep va gian tiep lam cho ty le cam nhiem benh ky sinh trimg cua gia sue va gia cam rat cao f f f ^ f r ^ Bien phap hiru hieu de phong chong benh ky sinh trung a gia sue, gia cam la bien phap phong chong tong hop O nhung vung sinh thai nhat dinh phai dong thod su dvmg nhieu bien phap co hieu qua doi vod tat ca cac giai doan phat trien cua ky sinh trung a ngoai canh, a vat chu trung gian, a vat chu cuoi cung r 7 f f \ r Khau quan trong bien phap phong chong tong hop la dung thuoc diet ky sinh trung tren ca the gia sue, gia cam Trong cung mot ca the vat chu co the dong thod ton tai nhieu loai ky sinh trung, nhieu ca the ky sinh trung a cac giai doan phat trien khac Vi vay, tot nhat la chon thuoc co tac dung rong, co tac dung vod ky sinh trung a nhieu giai doan phat trien nham cung luc diet duac nhieu loai ky sinh trung, diet duqc ca ky sinh trung non va ky sinh trung truong Ngoai ra, cac bien phap tang cuang ve sinh thu y chuong nuoi, thuc an nuac uong, bai chan tha, xu ly phan bang phuong phap u nhiet sinh hoc, diet ky chu trung gian cua ky sinh trung, tang cuang cham soc, nuoi duang va quan ly vat nuoi la cac bien phap hun hieu lam giam su nhiem mam benh ky sinh trung a ngoai canh, giam ty le va cuang nhiem ky sinh trung a vat nuoi \ > > 7 f Nhung b$nh ky sinh trung phd biin d gia cim , lyn va lo ii nhai tai Vi$t Nam y Chirtmg BENH KY SINH TRUNG THU ONG GAP GIA CAM • • BENH GIUN TRON & GA m (Avian nematodosis) Trong nhung nam gan day, chan nuoi ga theo phirang thuc cong nghiep da dugc phat trien manh d cac dia phuemg Song, chan nuoi ga tha vudn d nude ta van chiem iru the Theo so lieu thong ke cua Bo Nong nghiep va phat trien nong thon (2008), nam 2008 nude ta co 242,2 trieu gia cam, co 181 trieu ga (trong ga tha vudn la 148 trieu con, chiem 81,6%, so lai la ga cong nghiep chiem 18,4%) Phuomg thuc nuoi tha vudn tan dung dugc mot phan thuc an sin co tu nhien cho ga, giam bdt chi phi chan nuoi, san pham cua ga nuoi tha vudn dap ling dugc thi hieu am thuc cua ngudi tieu dung Tuy nhien, nuoi tha vudn cung tao dieu kien thuan lgi cho trung va au trung giun tron co sue gay nhilm noi rieng, ky sinh trimg noi chung de dang xam nhap vao co the ga Benh giun tron lam cho ga gly ylu, cham ldn, giam kha nang san xuat thit va trung, giam sue de khang va d l mac cac benh khac t ** *9 r r *> GIUN TRON KY SINH GA Giun tron ky sinh d ga thuoc ldp giun tron Nematoda Ldp giun tron (Nematoda) thuoc nganh giun tron (Nemathelminthes) la mot nhung nhom dong vat co so lugng loai ldn va phan bo rang Chung co mat d khap mgi noi tren hanh tinh: d bien, d nude ngot, d dat, chung ky sinh d dong vat va thuc vat (Nguyen Thi Le va cs, 2000) f r ? 1.1 Vi tri cua giun tron ky sinh & ga he thong phan loai d§ng vat Nguyen Thi Le va cs (1996) cho biet, vi tri cua mot sd loai giun tron ga he thong phan loai dong vat nhu sau: r Nganh Nemathelminthes Ldp giun tron Nematoda Rudolphi, 1808 Bo Ascaridida Skrjabin et Schulz, 1940 Phan bo Ascaridina Skrjabin, 1915 Ho Ascaridiidae Skrjabin et Mosgovoy, 1973 f Giong Ascaridia Dujardin, 1845 Loai Ascaridia galli Freeborn, 1923 (Schrank, 1788) Chirong B$nh ky sinh trung thuvng gSp & gia d m Bo Ascaridida Skrjabin et Schulz, 1940 Phan bo Heterakina Chitwood M., 1971 Ho Heterakididae Railliet et Henry, 1914 Giong Heterakis Dujardin, 1845 Loai Heterakis gallinarum (Schrank, 1788) Dujardin, 1845 Loai Heterakis beramporia (Lane, 1914) Bo Trichocephalida Skrjabin et Schulz, 1928 Ho Capillaridae Neuveu - Lemaire, 1936 r Giong Capillaria Zeder, 1800 Loai Capillaria obsignata Madsen, 1945 Loai Capillaria bursata Freitas et Almeida, 1934 Loai Capillaria caudinflata Molin, 1858 Giong Eucoleus Dujardin, 1845 Loai Eucoleus annulatus Loper - Neyra, 1946 (Molin 1858) f Giong Thominx Dujardin, 1845 Loai Thominx anatis Skijabin et Schikhobalova, 1954 (Schrank, 1790) Loai Thominx collaris Skijabin et Schikhobalova, 1954 (Linstow, 1873) Loai Thominx contorta Travassos, 1915 (Creplin, 1839) Bo Spirurata Chitwood, 1933 Phan bo Spirurina Railliet, 1914 Ho Tetrameridae Travassos, 1914 Giong Tetrameres Creplin, 1846 Loai Tetrameres fissispina Diesing, 1861 Loai Tetrameres mohtedai Bhalerao et Rao, 1944 Ho Acuariidae Seurat, 1913 Giong Acuaria Bremser, 1911 Loai Acuaria hamulosa Diesing, 1851 Loai Dispharynx nasuta Rudolphi, 1819 Ho Streptocaridae Skrjabin, Sobolev et Ivaschkin, 1965 r Giong Streptocara Railliet, Henry et Sisofy, 1965 Loai Streptocara crassicauda Creplin, 1829 Nhung b$nh ky sinh trung phd biSn & gia cim, Ion v£i loai nhai lai Viet Nam Ho Thelaziidae Skrjabin, 1915 Giong Oxyspirura Drasche et Stossich, 1897 Loai Oxyspirura mansoni Cobbold, 1879 Ho Gongylonematidae Sobolev, 1949 Giong Gongylonema Molin, 1857 Loai Gongylonema caucasica Kuraschvili, 1941 Ho Habronematidae Ivaschkin, 1961 Giong Cyrnea Seurat, 1914 Loai Cyrnea euplocami Maplestone, 1930 Nguyen Huai Binh va cs (1966), Phan ThS Viet (1969), Trinh Van Thinh va cs (1982), Nguyen Thi Le va cs (1996) cho biet: Thanh phan loai giun tron ky sinh ga Viet Nam gom: Gidng Loai Ascaridia Dujardin, 1845 Ascaridia galli Freeborn, 1923 (Schrank, 1788) Heterakis Dujardin, 1845 Heterakis gallinarum Schrank, 1788 (Dujardin, 1845) Capillaria Zeder, 1800 Capillaria obsignata Madsen, 1945 Capillaria caudinflata Molin, 1858 Tetrameres Creplin, 1846 Tetrameres fissispina Diesing, 1861 Tetrameres mohtedai Bhalerao et Rao, 1944 Acuaria Bremser, 1911 Acuaria hamulosa Diesing, 1851 Dispharynx nasuta Rudolphi, 1819 Oxyspirura Drasche et Stossich, 1897 Oxyspirura mansoni Cobbold, 1879 Oxyspirura heleroclita Molin, 1800 Nguyen Thi Le (1998) cho rang, giun tron ky sinh gay benh nguy hiem cho ngudi va dong vat chit yeu gom cac dai dien thuoc cac bo sau: Trichocephaliadae, Strongyloidida, Oxyurida, Ascaridida, Spirurida 1.2 Dac diem hinh thai, cau tao cua mot so loai giun tron ky sinh o’ga 1.2.1 Giun dua Ascaridia galli Theo Nguyen Thi Kim Lan va cs (1999) cho biet: Ascaridia galli ky sinh d ruot non ga, ga tay doi ky sinh a ruot gia ga Giun co mau vang nhat hoac trang nga, than co van ngang, quanh mieng co la moi tren, moi la moi deu co rang Giun co kich thudrc tuong doi ldn Chuvng Benh ky sinh trung thu&ng g§p & gia cim 11 Giun dire dai 30 - 80mm, rong 0,6mm; co canh duoi va 10 doi gai choi, co ban hut trade hau mon hinh tron, co gai giao hop dai bang nhau, phia tren phinh to, dau gai rat nhon Duoi cong vung 16 hau mon duoi phinh tao canh duoi Giac truac huyet dang bau due nam a phia bung Duong kinh giac truac huyet 0,16 - 0,26mm, sau giac co nhung num nho Hau mon each mut duoi 0,48 - 0,85mm Num duoi tao nhom: doi truac, doi ngang va doi sau hau mon Giun cai dai 65 - 110mm, rong 1,6 - 1,8mm: am ho d phia truac, doan giua than (Phan Luc 2006) Hinh 1: Trung A s c arid ia g a lli m theo phan ngoai Trung hinh bau due, co kich thude: 0,075 - 0,092 x 0,045 - 0,057mm, mang ngoai nhan, mau tro nhat (Nguyen Thi Kim Lan va cs, 1999) 1.2.2 Giun kim Heterakis spp Nguyen Thi Kim Lan va cs (1999) cho biet benh Heterakis spp thudng hai loai H gallinae va H beramporia ky sinh a manh trang, co o' ruot non cua ga, ga tay Giun mau vang nhat, dau co moi (1 moi a lung va moi a bung), tui mieng hinh ong Phan sau thirc quan phinh to giong hinh cu hanh, chieu dai 0,27 - 0,33mm, rong 0,15 - 0,24mm f \ f \ - Loai Heterakis gallinae' Giun due dai 5,841 - 11,145mm, cho rong nhat 0,271 - 0,398mm Duoi nhon hinh chiec kim Phia truac each hau mon 0,148 - 0,156mm co mot giac hut hoi tron, duang kinh 0,07 - 0,082mm Co gai choi xep timg doi a hai ben giac hut Co gai giao hop, gai phai dai gap lan gai trai; phia cuoi gai phai rat nhon, dai khoang 2mm; gai trai to, dai 0,65 0,7mm Lo bai tiet d gan dau ve mat bung, each dau khoang 0,254mm f Giun cai dai 7,982 - 11,439mm, cho rong nhat 0,27 - 0,453mm, chieu dai thirc quan bang 1/9 ca the Cho phinh to cua thirc quan hinh cu hanh dai 0,273 - 0,332mm, \ 12 Hinh 2: Trim g H e te kis spp m m theo phan ngoai Nhung benh ky sinh trung phd biSn & gia cirri, Icyn va loai nhai lai Viet Nam rpng 0,187 - 0,234mm Hau mon gan duoi, each duoi 0,9 - 1,24mm Am dao uon khuc cong, bat dau tir am ho roi vong ve phla sau, sau chuyen ve phla truoc, cuoi cung lai vong ve phla sau Lo bai tiet each dau 0,47mm f \ \ \ ** ' r •> \ r \ > \ r r r / Trung hinh bau due, co lop vo, mot dau suot, te bao trung co hat lam tarn, mau xam, dai 0,05 - 0,07mm, rong 0,03 - 0,039mm - Loai Heterakis beramporia: r r r Rat giong loai H gallinae nhung phan biet cr gai giao hop ngan hon, mot gai dai ?50um, gai lai dai 300pm Nguyen Thi Le va cs (1996) da mo ta loai giun nhu sau: Giun due dai 5,5 - 5,7mm, cho rong nhat 0,20 - 0,21mm Phan truoc thuc quan dai 0,04mm, rong 0,022mm Phan sau thuc quan dai 0,616 - 0,625mm, rong 0,11 - 0,12mm Lo bai tiet each mut dau 0,335mm, vong than kinh each mut dau 0,285mm Duoi nhon, co cac canh ben Lo huyet each mut duoi 0,36mm Giac sinh due co cau tao cutin hinh dia nam each 16 huyet 0,055mm Co 13 doi num sinh due, do: doi truoc huyet, doi ngang huyet va doi sau huyet Co gai sinh due dai 0,340 - 0,364 va 0,0227 0,2500mm Giun cai dai 7,6 - 7,64mm, rong 0,250 - 0,286mm Chieu dai thuc quan 0,74 0,77mm, rong 0,050 - 0,055mm Duoi dai 0,14mm Lo sinh due hoi loi so vai phan than, each mut dau 4mm Am dao canh 16 sinh due tao nut huang ve phia sau co the Trung co kich thuoc 0,062 x 0,034 - 0,039mm 1.2.3 Giun toe Capillaria spp r r Co giong: Capillaria, Eucolens va Thominx thuong gay benh ga Cac giong thuoc ho: Capillaridae, Neveu - Lemaire, 1936 Phan The Viet va cs (1977) cho biet giun tron thuoc ba giong hinh dang giong nhau, nho, dai nhu sgi toe va co mot so dac diem sinh hoc giong Ky sinh duong tieu hoa cua ga / Giun co than manh, dai, mau trang Tuy tung loai, giun due co the dai - 25mm, giun cai dai 10 - 60mm Dai nhat la loai Encoleus amulata, giun cai dai toi 60mm •} Trung giun co vo day, mau vang nhat, hinh thoi, hai dau co nut, kich thuoc 50 - 65 x 23 28 pm Hinh 3: Trim g C apillaria spp mo,i theo phan ngoai Chuxyng Benh ky sinh trung thuvng gSp d gia c im 13 - Loai Capillaria obsignata: Skrjabin K I va cs (1979), Nguyen Thi Le va cs (1996) cho biet, loai C.obsignata ky sinh a ruot non, doi gap o ruot gia va manh trang Phan dau rat manh Giun due dai 8,6 - 10mm, rong nhat 0,053mm Gai giao hop dai 1,2mm, cuoi gai cong, phia tren loe rong (hinh pheu), mut gai tron Bao gai co soc ngang Lo huyet dugc mo a cuoi duoi va dugc bao quanh bod mot tui hinh chuy Moi ben cua tui co mot gai hinh suon Bao gai co nep gap ngang, dai 2,5mm Giun cai dai 10 - 18mm, rong nhat 0,031 - 0,085mm Phan truoc co the va > _ > \ manh Phan sau chua co quan sinh due Thuc quan dai 4,6 - 7mm Hau mon nam gan mut duoi Lo am ho nam gan cho chuyen tiep giua thuc quan va ruot /"W > O \ f f \ \ Trung hinh bau due, mau nau sang, co nut suot a hai dau Kich thuoc 0,05 0,062 x 0,02 - 0,027mm - Loai Euculeus annulatus: O f \ Co the trang, manh, mut dau co canh cutin Mieng hoi nho ra, khong co num Giun due dai 11,54mm, rong nhat 0,04 - 0,086mm Canh cutin bat dau tir cho each mut dau 0,010 - 0,013mm, keo dai den 0,018 - 0,021mm, chieu rong canh cutin 0,005 0,008mm Thuc quan dai 3,077mm, phan co dai 0,32mm Vong than kinh each mut dau 0,070 - 0,075mm Cuoi duoi co num tron, num ben bung to hon Lo huyet a cuoi duoi Giun cai dai 22,5 - 22,56mm, rong nhat 0,032 - 0,130mm Canh cutin bat dau a cho each mut dau 0,008 - 0,010 Thuc quan dai 4,6 - 5,0mm, phan co dai 0,57mm Vong than kinh each mut dau 0,086 - 0,09mm Lo sinh due nam a cuoi thuc quan, duoi tu, hau mon a mut cuoi ca the Trung tu cung co kich thuac 0,054 - 0,062 x 0,027mm \ \ y f - Loai Thominx collaris: Co the manh, thuon dan ve phia dau Giun due dai 11,5mm, rong nhat 0,063mm Thuc quan dai 5,07mm Gai sinh due tuemg doi phat trien, dai 1,55mm, ben suon co nhung vach ngang manh Mut gai sinh due that lai co dang tu, tron, goc gai phinh rong Xung quanh bao gai sinh due co gai nho huong ve phia truoc Cuoi duoi tu tron va co thuy cutin it phat trien f O * f O Giun cai dai 14mm, rong nhat 0,070mm Thuc quan dai 4,96mm Lo sinh due co dang moi hoi nho khoi be mat co the, nam o sau phan cuoi cua thuc quan Duoi thuon dan, co dang tu tron Hau mon nam o phia ben Trurng co kich thuoc 0,056 - 0,059 x 0,023mm 14 N benh ky sinh trung phd b iin d gia cim , Ign va loai nhai lai Viet Nam BENH CAU TRUNG GA 2.1 Dac diem dich te benh cau trung ga 2.1.1 Cac yeu td dnh hu’ffng t&i ty le nhiem cau trung& ga Co nhieu ylu to lien quan tdi benh ciu trung a ga: thai tiet hau, dieu kien chuong trai, cong tac quan ly va cham soc nuoi duang Cac yeu to tren deu co anh hudng true tiep hoac gian tiep den tinh hinh nhiem va su lay lan benh X ^ > % X - Bieu kien chuong trai chan nuoi ga: Chuong trai chan nuoi la yeu to quan lien quan den dich tl benh cdu trung ga Nuoi ga long va nuoi tren nen chuong co ty le nhiem cau trung khac Hoang Thach (1996, 1997, 1998) da khao sat ty le nhiem cau trung, thdy: ty le nhiem cau trung d ga nuoi long la 0,37%, ga nuoi chudng co dem lot la trau nhiem 22,49 - 57,38% Nhu vay, ga nuoi long khong tilp xuc voi phan thi ty le nhiem cau trung giam rat thap > - Tuoi ga cung la ylu to can chu y dac diem dich te cua benh: Bao Hiru Thanh va cs (1978) da nhan xet, benh cau trung ga co tinh lay lan manh, dac biet a ga dudi thang tuoi, dugc coi nhu mot benh truyen nhiem cua ga 10-49 tuoi Theo Ho Thi Thuan (1985), ga nuoi cong nghiep a mot so tinh phia Nam nhilm cau trimg chu yeu b giai doan - tuan tuoi r \ ? - Luang To Thu va cs (1993), Le Van Nam (1995) cho biet, ga nhilm cau trimg nang nhat a giai doan 20 - 56 tuoi, neu khong dugc dieu tri kip thoi co the chet toi 100% - Bieu kien thoi tiet am va am ubt thuan lgi cho Oocyst cau trung phat trien d ngoai canh, lam cho benh cau trung de lay lan: Theo Pham Van Khue va cs (1996), Nguyln Thi Kim Lan va cs (1999), Buong Cong Thuan (2003), moi trudng am udt va nhiet \ i y on hoa la nhung dieu kien rat thuan lgi cho su phat trien cua cau trimg Vi vay, mua xuan va mua he ga bi nhiem cliu trimg nhilu va nang han cac mua khac nam, viec phong benh cau trimg cho ga d mua xuan va mua he cung can chu y han - Nguon benh la nhung ga om hoac khoi nhung van mang cau trimg, hoac nhung ga ldn mang cdu trimg nhung khong phat benh Oocyst hang dugc nhung ga thai theo phan, phat tan tren nen chuong, dim lot, lan vao thuc an, nude uong, ga de nuot vao va bi benh Le Van Nam (1995), Pham Van Khue va cs (1996), Nguyen Thi Kim Lan va cs (1999) deu thong nhat rang, ga bi benh cau trimg la ngudn phat tan Oocyst clu trimg Ngoai ra, nhung ga mang cau trimg nhung khong the hien trieu chung lam sang la nguon mang can benh nguy hiem, vi chung la doi tugng ma ngudi chan nuoi it chu y (do khong the hien trieu chung lam sang) ' r •» m > r \ - Vat moi gidi truyen benh: Mot so dong vat song chuong nuoi ga hoac xung > ' ' ' quanh chuong nuoi co kha nang mang Oocyst cau trimg ga, nhu: ruoi, gian, kien, chuot 88 Nhung b$nh ky sinh trung ph6 bi§n d gia d m , Ipn vti lobi nhai lai Vi$t Nam Chung mang Oocyst cau trung d chan, tren long, da, canh , txong di chuyen se truyen Oocyst cau trung vao thuc an, nuac uong cua ga, lam cho ga nhiem cau trung X f X ** X f X Theo Pham Van Khue va cs (1996), Oocyst bi ruoi nuot vao, ducmg tieu hoa cua ruoi, chung van song va kha nang gay benh vong 24 gicr r r > x ts* Dung cu chan nuoi cung la cac yeu to mang Oocyst cau trung, gop phan gay nhiem cau trung cho ga X Hoang Thach (1999) da khao sat cac mau thu thap tir dung cu chan nuoi, ket qua thay, co 11,20% s6 mau phat hien co Oocyst, ung bao ho cua cong nhan chan nuoi nhiem 5,60%, nhieu dvmg cu khac su dung de chan nuoi ga cung co kha nang mang va truyen Oocyst cau trung tir ga benh sang ga khoe X X 2.1.2 ngoaicanh Anh hie&ng cua cac tdc nhan vat ly, hod hoc den su phat trien Oocyst & * Anh huang cua cac tdc nhan vat ly: Nhiet do, am va moi trucmg noi chung deu tac dong vao Oocyst Dieu co y nghla nghien cuu dich te hoc va phucmg phap phong chong benh cau trung cho ga 'f Theo Wamar (1937), Oocyst bam tren vo trung se chet ap trung a 38 - 40°C, am 40 - 70% Ellis (1938) cho ring, nhiet toi uu cho su phat trien Oocyst ciu trung E tenella la 26,6 - 32,2°C Cl nhiet 48°C 15 phut, doc luc cua Oocyst giam r5 ret © Theo Glullough (1952), Oocyst bi diet or 40°C sau 96 gior, 45°C sau gia va 50°C sau 30 phut Cl nhiet 12 - 20°C, Oocyst co sure gay benh ton tai dugc 14 ngay, nhung Oocyst chua co sue gay benh chi ton tai 56 gicr > > / Long P L (1952) cho rang, Oocyst cua loai cau trung E tenella co the song qua mua dong lanh gia, nhung khong chiu dugc dieu kien nhiet cao va anh nang chieu true tiep, song co dai da che phu va bao ve Oocyst Theo Smith (1963), cau trung ga co the ton tai den 14 tuan a san nuoi ngoai trcri ♦ X f X Kay M.W (1976) cho biet, Oocyst loai E tenella va E maxima khong chiu tac dong cua qua trinh len men chat don chuong * Anh huang cua tdc nhan hod hoc: y \ r r t r \ Oocyst cau trung ga co sue de khang voi mot so hoa chat khu trung, tay ue chuong traL Day la van de can chu y nghien cuu ve dich te hgc cua benh cau trung ga Penard (1925) va Iakimoff (1927) cho bilt, Oocyst loai E tenella co sue de khang kha tot voi dung dich muoi, axit, baza a nong tuang doi cao, dung dich formol, H2SO4, NH4OH, crezol gay anh hudng den su hinh tMnh bao tir Tuy nhien, mot so hoa chit co tac dung diet Oocyst nen da dugc su dung tieu doc chuong trai, vi du nhu dung dich amoniac (NH3) 10% (Smith, 1940), methyl bromid (Andrew va Taylor, 1943) m f X * Chuong B$nh ky sinh trung thudng gSp & gia cim 89 Williams (1997) da nghien curu tac dung cua dung dich NH 10% tdi Oocyst va cho biet, sau 12 gid, 100% Oocyst khong sinh bao tir, nen co the dung de tieu doc chuong nuoi ga 2.2 Dac diem benh ly va lam sang benh cau triing ga 2.2.1 Dac diem benh ly d) Dien bien cua benh gan lien vdi qua trinh sinh san noi sinh cua cau triing Williams va cs (1996) da theo doi tac dong gay benh cua cau trung, thay rang: sau ga nhiem E tenella ngay, niem mac manh trang da phu ne, xung huyet Tac gia cho biet, thu nhat sau nhiem, mot chua nhieu bao tir {Sporozoit) dugc giai phong tir Oocyst f t ' gay benh Cac Sporozoit xam nhap te bao bieu mo mot, lap tuc sinh san vo tinh nhieu dot, tao cac Schizont the he I, tir tao vo so Merozoit Ngay thu 2, cac Merozoit lai tiep f t y tuc xam nhap te bao bieu mo mot lanh, lai sinh san vo tinh tao cac Schizont the he II, tir tao hang loat cac Merozoit the he tiep theo Sau vai ngay, cac Merozoit the he cuoi cirng cua qua trinh sinh san vo tinh se phat trien te bao bieu mo cac Schizont va biet hoa cac tieu phoi tir (Microgamete) va cac dai phoi tir (Macrogamet) Tieu phoi tir va dai phoi tir giai phong khoi te bao bieu mo se ket hop voi hop tir f ? t t f f f f t _ t f f f t \ Qua trinh sinh san vo tinh va huu tinh te bao bieu mo mot thoat dau gay hien / f f y tuong xung huyet, sau la hoai tir va xuat huyet niem mac mot Sir pha va hang loat te bao niem mac ruot gay xuat huyet lan tran, te bao bieu mo bong troc O cac giai doan phat trien tiep theo, cau trung xam nhap sau vao vach ruot gay hoai tu, xuat huyet ca lop te bao niem mac va tuyen mot Ngay thu bat dau thay xuat hien Oocyst phan (Larry, 1991; Williams, 1991) 2.2.2 Trieu chung va benh tick Trieu chimg benh cau trung noi chung deu the hien hau qua cua qua trinh pha huy niem mac dubng tieu hoa cua cau triing Theo Trinh Van Thinh (1963), Pham Van Khue va cs (1996), Nguyen Thi Kim Lan va cs (1999), Duong Cong Thuan (2003), ga bi benh cau triing thudng Id dd, cham chap, an kem hoac bo an, long xu, canh sa, phan loang lan mau tuoi, khat nuoc, uong nhieu nude, de chet mat nude va mat mau f \ H in h : G a b | b e n h c a u tr u n g c o b ie u h ie n u ru , lo 5dey, k e m a n 90 f r f H in h : P h a n g a c o m a u d o n h ie m E Nhung benh ky sinh trung phd biSn & gia c£m, lan va loai nhai lai Viet Nam tenella Mo kham ga benh, thay benh tich ro nhat la hien tuong xuat huyet va hoai tir niem mac ruot N eu bi loai E tenella ky sinh, manh trang ga sung rat to, nhin ben ngoai thay mau nau den hoac den, cat thay long manh trang chua day mau tuoi lln chat chua mau den, mau co the dong nhung cue Ion nhon Hau mon vat uot, r o f f > long bet, xung quanh ca vong hau mon co nhung diem xuat huyet Hien tuong phu ne the hien ro a cac co quan va mo bao f f H m h 52: X u a t h u y e t va h o a i t u 6> m a n h f tr a n g H in h : X u a t h u y e t v a h o a i t u u r u o t H in h : B e n h t ic h v i th e 6> r u o t g a b j b e n h ca u tru n g Hop tu hinh te bao bieu mo ruot Schizont te bao bieu mo ruot Chuvng B$nh ky sinh trung thuvng gap d gia c im 91 2.3 M ien dich va vacxin phong benh cau tru n g cho ga 2.3.1 M ien dich cdu trung gd Trong chan nuoi gia cam, nguoi ta da chu y nghien curu va sir dung mien dich hoc cau trung vao viec che vacxin phong benh cau trung x r x Tyzzer (1929) da chung minh bang thuc nghiem, co hai muc mien dich benh cdu trung: Muc 1, mien dich dugc sinh ga nhiem mot so lugng It Oocyst co sue gay benh Trucmg hop d ga co mien dich yeu, neu gay nhiem cho chung mot lieu Oocyst cao thi ga se mac benh Mure 2, mien dich dugc sinh ga bi nhiem mot so lugng Ion Oocyst co sue gay benh Truong hgp d ga co mien dich ro ret, ga khong bi benh nhiem cau trung Tyzzer (1929) cung xac dinh tinh dac hieu theo loai cau trung bang mot thi nghiem sau: dung loai cau trung Eimeria tenella gay mien dich cho ga, sau man gay nhiem lan hai bang ba loai E tenella, E maxima, E acervulina Khi mo kham khong phat hien thay benh tich d manh trang (do E tenella), ma chi thay benh tich d ruot non (vi tri gay benh cua E maxima va E acervulina) ^ j M f ^ Mien dich cau trung g lm hai loai: m iln dich te bao va mien dich dich thi ^ ^ h e o Horton Smith (1963), dap ung mien dich cua gia cam vdi cdu trung la tin g hgp cua mien dich te bao va mien dich dich the ^ r / \ f - Mien dich te bao dong vai tro chinh viec chong lai cdu trung He thong mien dich hon hgp d ruot bao gom cac te bao thuc thi, cac t l bao dieu hoa m iln dich va cac te bao hieu ling mien dich Vai tro thuc bao cua cac te bao dai thuc bao rat quan trpng qua trinh uc che su phat triln cua Schizont (Adams va cs, 1984) Ngoai dai thuc bao, bach cau da nhan trung tinh, bach cau toan va bach cau kiem cung co vai tro quan trong dap ling mien dich cdu trung Theo Rahmat (1995), ga bi cdu trung thi so lugng bach cdu tang len X X vj - Mien dich dich the: Theo ca ch i dap ling m iln dich, bi cdu trung kich thich thi co the ga sinh khang the Mien dich cdu trung Eimeria chi hinh co su hien dien cua cdu trung Eimeria (Lillehoj, 1996) Ga nhilm cdu trung se co khang the mau va dich tilt cua niem mac Khang th i mau co chiia IgM va IgA Dac biet, IgA dugc phat hien thay ruot va mat cua ga nhiem cdu trung Khang the IgM va IgG huylt ga cao nhat vao man thii va sau nhilm Eimeria tenella, IgA dugc phat hien mat sau nhilm E acervulina man Su xam nhap cua Schizont va Merozoit vao cac te bao bieu mo ruot xay rat nhanh, vi vay, dap ling mien dich dich the cang dong vai tro quan trgng Duoi su kich thich cua Merozoit va Schizont, su ho trg cua te bao lympho T, te bao lympho B phan chia roi biet hoa tuomg bao (plasma), tuemg bao tiet khang the chong lai cac Merozoit va Schizont Ngoai ra, cytokin va lymphokin cung co vai tro m iln dich b ga f ** r r r 92 f * ^ x t r NhQng benh ky sinh trung b iin 6r gia c im , Ign va lo£i nhai lai Vi$t Nam gia cam, thuy cam va chim, tui Fabricius phat trien va tao mot quan the te bao lympho B rat phong phu Cac te bao lympho B sau nhan dien khang nguyen cau trung, mot nhom se biet hoa de tao khang the, mot nhom co vai tro la cac te bao "tri nhd mien dich" de cau trung xam nhap vao lin sau thi khang the dugc sinh nhanh va nhieu hem Cac ti bao lympho T sinh lymphokin de tieu diet cau trung, mot so co vai tro dieu hoa mien dich, mot so te bao lympho T man cam cung trd "te bao nho" Theo Tyzzer (1929), mien dich dugc tao tuong doi ben vung doi vai nhung loai cau trung phat trien sau mo bao va kem ben vung doi vai cac loai cau trung chi phat trien lop bieu mo niem mac mot Rahmat (1995) nhan thay, thdi gian mien dich keo dai hay ngan phu thuoc vao sir ton tai cua cau trung ca the x 7 r x x r ** Q Cl Viet Nam, ket qua nghien cuu cua Tran Tich Canh va cs (1996) cho thiy, mien dich d ga vdi cau trung E tenella co the tri dugc 60 Sue mien dich vai cau trung la ca sd khoa hoc cho viec nghien cuu ch6 tao vacxin phong benh cdu trung cho ga X X 2.3.2 Vacxin phong benh cau trung ga Theo Chapman (1996), hien viec nghien cuu che tao va su dung vacxin cau trung theo hai hudng chu yeu: ^ - Nghien cuu che tao va su dimg vacxin cau trung sdng: Thanh phan vacxin la cac Oocyst cau trung da dugc xu ly theo yeu cau cong nghe Nhung loai vacxin song da dugc su dung rang rai d Viet Nam nhu: Coccivac - B (My), Paracox (Canada) Ca che quan trgng la dua vacxin vao ca the ga, Oocyst cau trung vacxin khong gay benh cho ga, ma su ton tai cua chung se kich thich ca the ga san sinh khang the chong lai su xam nhap cua cau trung gay benh tu nhien Tuy nhien, mien dich khong ben vung Khi cau trung vacxin khong ca th6 ga, chi sau mot thdi gian ngan, ga khong sue mien dich va lai co kha nang cam nhiem cau trung gay benh tu nhien X r ^ , r - Nghien cuu che tao va su dung vacxin chet (vacxin vo hoat): Vacxin loai chi chua mot phan cua Oocyst, dai dien tlnh khang nguyen cua cau trung Do la mot protein dugc chiet xuat tir Oocyst cau trung loai Eimeria maxima a giai doan san sinh bao tu, dugc che dudi dang nhu hoa Vacxin dugc su dung bang each tiem cho ga bo me giai doan hau bi trude de, nham tao khang the dac hieu d muc cao Ca the ga san sinh khang the chong lai cac loai cau trung E tenella, E maxima, E acervulina Vacxin cung co kha nang tao mien dich thu dong cho ga sinh tir ga me dugc tiem phong vacxin X f f y Pham Van Chuc va cs (1991) da nghien cuu va san xuat vacxin phong benh cau trung ga bang phuang phap chieu xa gama, bude dau co ket qua tot Shirley va cs (1995) da nghien cuu che tao vacxin phong benh cdu trimg cho ga, ket qua thiy ga co mien dich vdi cau trung, nhien thdi gian mien dich khong dai Chuxyng B$nh ky sinh trimg thu&ng g$p & gia c im 93 ^T heo Phan Luc va cs (1999), su dung vacxin Coccivax phong benh cau trung cho ga tu tuoi co tac dung bao ho den 54 tuoi Bach Manh Bieu va cs (2000, 2004) da che vacxin nhugc doc bang phuomg phap chieu xa Oocyst cau trung, su dung cho ga tu tuoi cho kha nang bao ho den 36 sau su dung f *? Nhung kSt qua nghien cuu che tao va su dung vacxin phong benh cau trung cho ga da mo trien vong cho nhung nghien cuu tiep theo Prang lai, nham tien toi khong che benh cau trung a ga f r r \ ^ \ Cac loai vacxin phong benh cau trung dugc tong horp bang sau: Bang Cac loai vacxin phong b§nh cau trung cho ga Ten vacxin Coccivax K hang nguyen No’i san x u it Stenwin lab (My) H6n hp'p Oocyst cac loai ctfff ng (Jqc Cach dung Tuoi ga su> dyng (ngay) Thd i gian ddi Pha nirdc uong 4-14 1952 Pha nifacuong -7 1985 Pha m w c ulng - 1989 Pha nirdculng -9 1992 Pha niw c uong 7-10 1992 Pha nude ulng 7-10 1992 Hon h^p cac loai cuang dpc: Immucox Vetech lab (Canada) E tenella E maxima E acervulina E necatrix VAC M Elanco products Company Oocyst ciwng dpc loai E maxima (My) Cac dong tien noan nang cua: Paracox ■ E teneila Mallinkrodt veterinary Ltd (Anh) E maxima E acervulina E mitis E brunetti E praecox Livacox X D (Dung cho ga nuoi I6ng) Oocyst nhu’p'c dpc cua cac Bio Pharm loai: research Institute E tenella (cOng hoa Sec) E acervulina Livacox T (Dung cho ga nuoi nen co chit tfQn chulng) 94 Oocyst nhu’p'c dpc cua cac loai: Bio Pharm research Institute E acervulina (c$ng hoa Sec) E maxima E tenella Nhung benh ky sinh trung phd biin a gia cim, Icrn va loai nhai lai Vi$t Nam ^ 2.4 P h o n g tri b en h cau tru n g cho ga Co bien phap chinh phong tri benh cau trung cho ga: 2.4.1 Ve sinh thu y r Ve sinh thu y la cong viec lam thudng xuyen nhung dong vai tro het sue quan trong chan nuoi va phong dich benh Hien nay, d nhung nude tien tien, ngudi ta da lam rat tot cong tac ve sinh phong benh (ve sinh chuong trai, thuc an, nuoc uong, dung cu chan nuoi) nen da han che duoc viec dung thuoc va vacxin chan nuoi ga f f t Cf nuoc ta, chan nuoi gia cam da co nhieu tien bo: viec thuc hien quy trinh chan nuoi nghiem ngat hon, rieng van de ve sinh thu y cung tot hon rat nhieu so voi each day mot vai thap ky Tuy nhien, vdi dac diem thoi tiet hau cua nuoc ta, voi tinh trang khang thuoc cua ky sinh trung noi chung va cdu trung noi rieng thi kha nang bien doi va thich nghi cua chung rat Ion Mat khac, van de ve sinh thu y chua dong bo a tat ca cac co so tap the va tu nhan chan nuoi gia cam Do chinh la nguyen nhan lam cho benh cau trung ga van la mot nhung benh gay thiet hai ldn nhat cho chan nuoi ga, dac biet la ga nuoi cong nghiep va ga mdi nhap noi f r \ r ^ 2.4.2 Phong tri benh bang hod dirffc Phong tri benh cau trung bang hoa ducrc la phuong phap kinh diln va hieu qua Trong nhung nam gan day, co nhieu loai thuoc moi doi, co tac dung phong tri cau trung tot Tuy nhien, nhung thuoc cu da duoc dung nhieu thap ky, nhung co hieu lire cao van duoc tiep tuc sir dung Viec phong chong cau trung phai dua tren nguyen tac: khong nen dung mot luc nhieu loai thuoc, cung khong nen chi dung mot loai thuoc keo dai nhieu nam mot co so chan nuoi ga t% , ? f * \ r > r Nhung hoa duoc da va dang duoc sir dung phong tri cau trung gom: * Cac Sulfamid Sulfamid duoc sir dung bien la: Sulfadimedine, Sulfadimethoxin, Sulfachlozine, Sulfachlopyridazine, Sulfathiazol Co che tac dung cua Sulfamid la uc che su phat then cua vi sinh vat noi chung va cau trung noi rieng bang each canh tranh voi PABA (Para - Amino Benzoic - Axit), ngan can su tong hop axit folic, can thiet cho su sinh tnrcmg va phat trien cua cau trimg p r \ I P Hien nay, nhom Sulfamid van duoc dung kha bien, song ding co quan diem cho rang, neu dung don le Sulfamid thi khong tot cho gia cam, nhat la ga de va ngudi sir dung san pham * r r \ r Chuvng B$nh ky sinh trung thut/ng g§p d gia cim 95 * Nhom hod ducrc lam tang cudng hieu lire ciia Sulfamid: Cac chit co tac dung lam tang cudng hieu luc cua Sulfamid nhu: Diavedrine, Pyrimethamine Trade hit, Sulfamid canh tranh vdi PABA, lam cho cau trimg khong tdng hop dugc axit folic Sau do, cac hoa dugc tren phat huy tac dung, lam tac dung cua Sulfamid tang cuomg va keo dai hom Tac dung cua Sulfamid va chat tang cudng la tac dung hiep dong, co gia tri doi vdi cac vi sinh vat da quen va khang thude Ngoai ra, chat tang cudng lam cho sir khuech tan cua thuoc vao cau trung nhanh hom, dua lai tac dung tot hom Chat tang cudng dung phOi hgp vdi Sulfamid co the cho phep giam lieu Sulfamid xuong 10 lan so vdi chi dung Sulfamid dom le Sau day la mot so loai thuoc ma phan co sir phoi hgp Sulfamid va chat tang cudng: + Coccistop - 2000 (hang Intervet, Ha Lan san xudt): thude hot mau trang, dong goi 200 gam, tan nude Thanh phin gom: Sulfadimedine : 40 g Sulfadimethoxine :4 g Diavedrine :6 g Vitamin K :4 g Ta dugc VD : 200 g Thuoc co tac dung tren cac loai cau trimg E acervulina, E maxima, E tenella, E brunetti, E necatrix a giai doan sinh san noi sinh Lieu dieu tri benh: lg/lit nude, cho uong - lien tuc Lieu phong benh: lg/lit nude, cho uong - lien tuc + Esb3 (hang Novatis, Thuy Sy san xudt): phan chinh la Sulfachlozine sodium monohydrate (30%) Thuoc co tac dung len cac giai doan noi sinh san cua cau trimg Eimeria, dac biet tir cau trimg xam nhap den giai doan Schizont II Lieu didu tri benh: lg/lit nude, cho udng - Ndu chua khoi co th6 lap lai lieu trinh tren sau dung thuoc - * Cac hod duac khac: Nhom bao gom nhidu loai thuoc, co cac thude da sir dung tir lau nhu: Nicarbazin, Amprolium va cac thuoc mdi nhu Sacox, Baycox, Decox 96 NhCmg b$nh ky sinh trung phd bi6n & gia d m , ion va loai nhai lai Vi$t Nam f f + Amprolium: thuoc d dang bot trang hay vang nhat, tan nude (ten thuomg pham: Ampron, Ampronmic) Thuoc co tac dung chit yeu vdi cau trimg E tenella d manh trang, it tac dung vdi cac loai cau trung ruot non Amprolium tac dung theo co che ngan can sir tong hop protein cua cau trung d giai doan Schizont I va II (tuomg ung thu - sau nhiem) Hien nay, cau trung da xuat hien tinh khang thuoc Amprolium, thd hien d su giam hieu luc su dung + Rigecoccine (ten thuorng pham: Chlopidon, Metichlopidoc, Coyden) Thuoc co tac dung rong, tac dong vao giai doan Schizont II cua loai E tenella, E brunetti, E necatrix, E acervulina Ngoai ra, thuoc co tac dung kich thich sinh trudng va tang kha nang tan dung thuc an cua ga Thuoc co the tron vdi thuc an: Lieu di£u tri benh: trOn thuc an ty le 0,05%, cho an - lien tuc Lieu phong benh: tron thuc an ty le 125ppm Trong thuc te, ngudi ta dung lieu cao hon rat nhieu (co thl gap lin lieu tren) Hoac hoa vao nude cho uong: Lieu tri benh: lg/2 lit nuac, cho uong - lien tuc Lihxx phong benh: lg/4 lit nuac, cho uong ngay, nghi + Sacox (hang Hoechst, Due san xuat) Thuoc thuoc nhom thuoc khang cau trung the he mdi, tac dong theo co che lam thay doi su van chuyen va trao doi ion d mang te bao cau trimg f \ Sacox - 120 la mot loai thuoc dimg bd sung vao thuc an, dang hat nho, mau nau f xam, 1kg san pham co chrra 120 g hoat chat Salinomycine solium, co hoat luc rong vai nhieu loai cau trung Sacox co uu diem la tac dong len ca nhung loai cau trimg dang khang cac thuoc chong cau trimg khac Lieu phong benh: 50 g tron vdi 100kg thuc an Khong dimg Sacox de didu tri benh cdu trimg + Baycox (hang Bayer, Due san xuat) Thuoc co phan chinh la Toltrazuril (25mg) Baycox tac dong den tat cac cac giai doan phat trien cua cau trimg, ke ca sinh san vo tmh va huu tinh, dong thdi co tac dimg kich thich va tang cudng he thong mien dich cua co the ga Chirong B$nh ky sinh trimg thuung g$p & gia d m 97 LiSu dieu tri: lm l/lit nude (tuang duang vdi nong 25ppm) Uong lien tuc + Avicoc: Sulfadimerazine (Sodic) : 20,4 g Diaveridine :2,6g Ta dirac VD : 100 g ^ f \ Lieu phong benh: 1g/lit nuac, cho uong t ong lien tuc a tuan tuoi thu 2, va Lieu dieu tri benh: 1g/lit nuac, cho uong lien tuc lien + Anticoccid: Trong 20g thuoc co: Diaveridine : 5,45 g Sulfaquinoxalin : 5,46 g Trimethoprim :2,0g Thuoc co tac dung dac tri ciu trung ga, tho, be, nghe va phong cac benh roi loan ia chay Lieu phong benh: l,5g/lit nuac Lieu dieu tri: 3g/lit nuac, cho uong trorg - lien tuc ^ > f + Ancoban: Lieu dieu tri l,5g/lit nude, cho uong hen tuc + Salinomycin: Lieu dieu tri: tron thuc an theo ty le 120ppm, cho an lien tuc Hoang Thach (1999) cho biet, Baycox lieu lm l/lit nude, dieu tri - va Esb3 lieu l,5g/lit nude co hieu luc dat 96 - 98% Theo Bach Manh Dieu (2004), Baycox (lieu lm l/lit nude), Coccistop (lieu 1g/lit nude), Esb3 (lieu 1g/lit nude), Ancoban (lieu l,5g/lit nude), Rigecoccine (lieu tron thuc an ty le 400ppm), Salinomycin (lieu tron thuc an ty le 120ppm) dieu tri lam giam ty le ga benh xuong 73,4 - 93,4%, giam ty le ga chet cau trung 80 - 100% Trong cac thuoc tren, thuoc Baycox cho ket qua dieu tri tot nhat Ngoai viec phong tri cau trung bang hoa duac va ve sinh thu y, hudng su dung vacxin phong benh cau trung cung dugc chu y, song pham vi su dung han che nhieu nguyen nhan, co van de kho khan nghien cuu san xuat va gia vacxin 98 Nhung benh ky sinh trung phd bien & gia c im , lorn va loai nhai l$i Viet Nam El-Banna H A va cs (2005) da su dung thuoc Diclazuril hoa nude dung dich nong - lppm va Toltrazuril nong 25ppm tri cau trung cho 20.000 ga K§t qua cho thay, thuoc Diclazuril vdi lieu 5ppm nude udng co hieu qua tri cau trung tuong tu lieu 25ppm cua thuoc Toltrazuril (Baycox 2,5%) Arab H A va cs (2006) da nghien cuu ve tac dung dieu tri benh cau trung ga cua chat chiet thuc vat d tinh Yazd cua Iran Chat chiet cua cay Artemisia sieberi (viet tat la AS) dugc dung dieu tri benh cau trung Eimeria spp cho ga Broiler vdi lieu 2,5mg/kg/ngay, cho uong Ket qua cho thay, AS co tac dung vdi cau trung E tenella va A acervulina, khong co tac dung vdi cau trung E maxima r f / r f r Ogbe A O va cs (2009) da nghien cuu ve tac dung cua chat chiet tir nam dai Ganoderma lucidum doi vdi ga gay nhiem cau trung 120 ga Ross tuan tuoi chia nhom: Nhom A, B, C dugc gay nhiem E tenella lieu 36.250 Oocyst gay nhiem/ga Nhom D, E va F khong gay nhiem Luc tuan tuoi, ga nhom A dugc dieu tri bang chat chiet nam, ga nhom B dugc dieu tri bang Amprolium hoa nude uong lieu 200mg/ml lien tuc Khoi lugng co the, kha nang an, so Oocyst phan va mot so chi so mau dugc theo doi Ket qua cho thay: Tat ca ga d nhom A, B va C deu co dau hieu lam sang (om yeu, giam an) vao thu sau gay nhiem Vao thu sau gay nhiem, phan ga long, co mau va co so lugng ldn Oocyst dugc tim thay phan Vao thu sau dieu tri, so Oocyst phan ga d nhom A, B giam xuong va trieu chung giam nhe rat nhieu so vdi ga d nhom C khong dugc dieu tri Trong nhom doi chung (D, E va F) khong co Oocyst phan va khong co trieu chung lam sang r r r ' r r ^ Sau dieu tri ngay, ga cua nhom A va B khong Oocyst phan Khoi lugng ga nhom A va B luc - tuan tuoi chi thap hon mot chut so vdi ga doi chung, ga nhom C khoi lugng thap hon ro ret Dieu chung to, chat chiet tir nam ^ ^ ^ ^ dai G lucidum co tac dung dieu tri benh cau trung d ga, han che dugc tac hai cua cau trung doi vdi ga Theo ket qua nghien cuu cua Nweze N E va cs (2009), nude chiet tvr cay Ageratum conyzoides co tac dung vdi cau trung E tenella vdi lieu 250 - 3000mg/kg the trpng (cho uong) va khong gay doc cho ga Theo Chapman H D (2010), thu6c Monensin da dugc su dung phong chong cdu trimg cho ga tu nhung nam dau thap ky 70 Sau 40 nam thuoc van tac dung tot, dugc su dung rong rai chan nuoi ga d cac nude phat trien Chum g Benh ky sinh trung thutmg g$p d gia cim 99 TAI LIEU THAM KHAO Butcher Gary D (1997), Mien dich hoc ling dung gia cam, Hpi thao benh gia cim, Tai lieu dich tir nguyen ban tieng Anh Hiep hoi dau tuong Hoa Ky cung cap, tr 40-43 Tran Tich Canh, Hoang Hung Tien, Nguyen Duy Hang (1996), "Nghien cim san xuat vacxin chong benh cau triing ga bangphuongphap chieu xa", Vat ly va ky thuat hat nhaii, NXB Khoa hpc va Ky thuat, tr 503 - 507 Pham Van Chuc, Tran Tich Canh va cs (1991), "Nghien cuu va thu nghiem san xuit vacxin phong chong benh ciu trimg ga bang phuomg phap chieu xa Gama”, Bao cao khoa hoc tai Hoi nghf Khoa hoc ky thuat thu y cac tinh phia Nam Bach Manh Bieu (1999), "Nghien cuu mot so dac diem dich te hpc va bien phap phong tri benh ciu trung ga tai Trung tarn nghien cuu gia cim Thuy Phuong”, Tuyen tap cong trinh nghien cuu khoa hoc ky thuat gia sue va dong vat mai nhap (1989 - 1999) NXB N6ng nghipp, Ha Noi, tr 558 - 566 Bach Manh Di6u, Phan Luc, Nguyen Lien Huong, B6 Thi Nhung, Nguyen Quang Huy, Nguyen Van Thing, Duong Thi Oanh (2000), 'Tinh hinh nhiem clu trung o mot s6 gia cam nhap npi va ket qua nghien cuu thu vacxin phong benh cau triing ga ”, Bao cao khoa hoc chan nudi thu y 1999 - 2000, Hpi nghi khoa hpc, Bo NN & PTNT, 4/2001, tr 223 -231 Bach Manh Bieu (2004), "Benh cau trimg gia cam va giai phap phong tri cau trung cho ga, bo cau nuoi tai mot so khu vuc thupc cac tinh phia Bic”, Luan an Tien sy Nong nghiep, Ha Noi Luong Van Huin, Le Hiiu Khuong (1997), Ky sinh va b?nh ky sinh & gia sue, gia cam, tap II (Phan dong vat chan dot va nguyen bao (Arthropoda, Protozoa), Truong BH Nong Lam nghiep - Vien Dai hpc quoc gia TP Ho Chi Minh, tr 311 - 313, 359 - 367 Pham Van Khue va Phan Luc (1996), Ky sinh trung va b?nh ky sinh trung thu y, NXB Nong nghiep, Ha Npi Kolapxki P I., Paskin (1974), Benh cau trung &gia sue, gia cam (Nguyen Binh Chi va Tran Xuan Tho djeh tir nguyen ban tieng Nga), NXB Nong nghipp, Ha Npi, 1983, tr 100 - 164 10 Nguyen Thi Kim Lan, Nguyln Van Quang, Nguyen Quang Tuyen (1999), Giao trinh ky sinh triing thu y, NXB Nong nghiep, Ha Npi, tr 207 - 215 11 Nguyen Thi Kim Lan (2001), ‘Tinh hinh nhiem cau trimg o dan ga nuoi gia dinh tai Thai Nguyen ”, Tap chi Khoa hoc ky thuat Thuy, tap VIII, so 12 Pham Sy Lang, To Long Thanh (2006), Benh dcm bao ky sinh a vat nuoi, NXB Nong nghiep, Ha Noi, tr 148 - 155 13 Phan Luc, Bach Manh Bieu (1999), 'Tinh hinh nhilm ciu trimg ct gia cam va hieu qua sir dung vacxin phong cau trimg ga ”, Ket qua nghien cuu khoa hoc ky thuat, Khoa Chan nuoi Thu y, Truong BH Nong nghiep I (1996 - 1998), NXB Nong nghipp, HaNpi,tr 131 - 133 14 Le Tuyet Minh (1994), "Nghien cuu mot so dgc diem dich te hgc benh cau triing a ga Hybro HV85 tit - 49 tuoi", Luan van Thac sy Khoa hpc nong nghiep, Truong BH nong nghiep I Ha Npi 100 N b$nh ky sinh trung phd bi4n gia d m , !