AFLATOXIN B1 CONTAMINATION IN THE RATION OF LACTATING DAIRY COW AND REDUCTION OF ITS CARRY-OVER INTO THE MILK
IKA SUMANTRI, Prof. Dr. Ir. Ali Agus, DAA, DEA.
2014 | Disertasi | S3 Ilmu PeternakanDisertasi ini terdiri atas 4 tahap penelitian, yaitu: (1) survei untuk mengetahui tingkat kejadian dan cemaran aflatoksin B1 (AFB1) dalam pakan sapi perah serta aflatoksin M1 (AFM1) dalam susu segar; (2) kajian pendahuluan untuk mengetahui karakteristik transfer AFB1 pakan menjadi AFM1 susu pada sapi Friesian Holstein (IFH); (3) seleksi adsorben yang memiliki kapasitas dan stabilitas pengikatan AFB1 tertinggi secara in vitro rumen; (4) pengujian efektifitas adsorben terseleksi untuk menurunkan kadar AFM1 susu dan pengaruhnya terhadap produksi dan komposisi susu serta konsumsi dan kecernaan nutrien. Pada penelitian tahap pertama, survei dilaksanakan di Kabupaten Sleman, Daerah Istimewa Yogyakarta, serta Kabupaten Boyolali dan Kabupaten Klaten, Propinsi Jawa Tengah. Data yang dikumpulkan adalah kadar cemaran AFB1 dalam pakan sapi perah, konsumsi pakan, produksi susu dan kadar cemaran AFM1 dalam susu segar, serta perhitungan persentase transfer aflatoksin. Pada penelitian tahap ke 2, kajian karakteristik transfer aflatoksin untuk sapi IFH dilakukan secara in vivo menggunakan 4 ekor IFH laktasi yang memperoleh pakan terkontaminasi AFB1 dosis rendah (3,4 Kg per ekor per hari) dan dosis tinggi (350 Kg per ekor per hari) selama 2 minggu. Pada tahap ke 3, seleksi untuk mendapatkan adsorben yang memiliki kapasitas dan stabilitas pengikatan terbaik dilakukan secara in vitro terhadap 3 macam adsorben alami (arang aktif, bentonit dan zeolit) dan 1 adsorben mikotoksin komersial. Pengujian dilakukan pada 3 macam medium in vitro (aquades steril, cairan rumen steril, dan cairan rumen non steril) dan dua rasio AFB1:adsorben (1:1000 dan 1:10.000). Inkubasi dilakukan selama 2 jam menggunakan inkubator gojok dengan penggojokan 70 rpm dan suhu 38,5oC. Selanjutnya medium disentrifugasi pada 3500 X g selama 15 menit. Supernatan diambil untuk analisis kadar AFB1 yang tidak terikat. Endapan dilarutkan dengan aquades dan diinkubasi kembali. Setelah sentrifugasi, supernatan dianalisis untuk mengetahui kadar AFB1 yang terlepas. Data yang diperoleh dianalisis statistik menggunakan prosedur general linear model dengan program SPSS versi 16.0. Pada tahap ke 4, adsorben terpilih selanjutnya diuji secara in vivo menggunakan 6 ekor IFH laktasi dengan rancangan cross-over design. Secara acak ternak mendapat pakan dengan tambahan adsorben (0,1% dari campuran konsentrat) atau tanpa tambahan adsorben. Setelah periode 15 hari, pakan ditukar dan proses diulang kembali. Produksi susu dicatat setiap hari dan sampel susu diambil pada hari 13 hingga 15 untuk analisis komposisi susu dan kadar AFM1. Konsumsi pakan, volume urin total dan berat feses total diamati pada hari ke 13 hingga 15 dan dilakukan pengambilan sampel pakan, sisa pakan serta feses untuk analisis komposisi proksimat, sampel pakan dan feses untuk analisis kandungan AFB1 dan sampel urin untuk analisis kandungan AFM1. Data dianalisis menggunakan uji-t berpasangan dengan program SPSS versi 16.0. Survei memperlihatkan semua sampel pakan tercemar AFB1 dengan rata-rata 47 ppb dan lebih dari 83% sampel melebihi ambang batas kandungan AFB1 yang diperbolehkan dalam pakan sapi perah menurut USDA. Meskpiun tidak nyata secara statistik, kadar AFB1 pakan semakin tinggi dengan semakin panjang rantai pemasaran. Konsumsi AFB1 harian menunjukkan ternak terpapar AFB1 pada dosis yang tinggi (320–362 Kg/ekor/hari). Semua sampel susu segar tercemar AFM1 dengan rata-rata 75 ppt. Kadar AFM1 antar kelompok responden berbeda secara sangat nyata dengan kadar tertinggi ditemukan dari sampel susu segar koperasi. Merujuk pada aturan Uni Eropa, 95% sampel tidak layak untuk konsumsi anakanak dan 68% tidak layak untuk konsumsi orang dewasa. Kajian memperlihatkan transfer aflatoksin yang rendah dari sapi IFH, yaitu dari 0,32 hingga 0,85% pada survei dan antara 0,05 hingga 0,07% pada pengujian in vivo. Aflatoksin M1 terdeteksi 10 jam setelah konsumsi pakan mengandung AFB1 dan mencapai steady-state pada 24 jam setelah pemberian pakan tercemar AFB1. Kadar AFM1 masih terdeteksi dalam susu hingga 5 hari setelah ternak tidak mendapat pakan tercemar AFB1. Pengujian in vitro memperlihatkan bentonit alam memiliki kapasitas dan stabilitas pengikatan terbaik, yaitu 75 dan 99,5%. Kapasitas pengikatan bentonit menurun dengan naiknya pH medium, namun stabilitas pengikatan tidak terpengaruh oleh perubahan pH medium. Penggunaan bentonit sebesar 0,1% pada pakan yang mengandung AFB1 pada kadar 23 ppb dapat secara sangat nyata (P < 0,01) menurunkan kadar AFM1 susu dan transfer aflatoksin. Penggunaan bentonit tidak berpengaruh secara nyata terhadap produksi susu, komposisi susu, serta konsumsi dan kecernaan nutrien.
This dissertation research is consisted of 4 studies, those are: (1) survey to obtain data on the occurrence and levels of aflatoxin B1 (AFB1) contamination in dairy feed and aflatoxin M1 (AFM1) in raw milk from dairy farming, dairy cooperatives, and feedmills; (2) preliminary study on the carry-over of aflatoxin in lactating Indonesian Friesian Holstein (IFH); (3) in vitro assay to select a natural aflatoxin adsorbent which has high binding capacity and stability in ruminant gastro-intestinal tract; and (4) evaluation the efficacy of selected adsorbent in reducing aflatoxin transfer and to study the effects of its inclusion on milk production and nutrient digestibility of IFH cow. In study 1, survey was conducted in Sleman district in Daerah Istimewa Yogyakarta, and Klaten and Boyolali districts in Central Java Province. Data on the level of AFB1 in ration, feed intake, level of AFM1 in raw milk, and milk production were used to determine the percentage of carry-over of AFB1 from feed into AFM1 in milk among respondent groups. The characteristics of carry-over of IFH cow were studied by an in vivo experiment in study 2.The concentration of AFM1 in milk was observed in period of 2 weeks in four lactating IFH cows that received low dose (3.4 Kg per cow per day) and high dose (350 Kg per cow per day) of AFB1 in feed. In study 3, an in vitro assay was conducted to compare the binding capacity and stability of 3 natural adsorbents (bentonite, zeolite, and activated charcoal) and 1 commercial product of mycotoxin adsorbent. Three in vitro solutions (sterilized aquadest, sterilized rumen fluid, and non sterilized rumen fluid) were used in the experiment. In vitro assay was carried out in the ratio between AFB1 and adsorbent of 1:1,000 and 1:10,000 (w/w). Flasks containing solution, AFB1- contaminated feed, and adsorbent were incubated for 2 hours in a shaking incubator at 70 rpm and 38.5oC. Solution was centrifuged for 15’ at 3500 X g and supernatant was recovered for the determination of the unbound AFB1. Precipitate was resuspended in aquadest, and then reincubated. After centrifugation, supernatant was analyzed for released AFB1. Data was analyzed using general linear model procedure of SPSS version 16.0. The efficacy of selected adsorbent was determined in an in vivo experiment in study 4. Six midlactating IFH cows randomly fed AFB1-contaminated diet without or with selected adsorbent (0.1% by concentrate weight). Diets were switched after a period of 15 days and the process was repeated. Milk production was recorded daily and milk samples were collected on days 13 to 15 for determinations of AFM1 content and milk composition. Feed intake, total urine volume and feces were recorded on days 13 to 15 and samples were composited for proximate analysis of feed and feces chemical composition, ELISA test of AFB1 contents in feed and feces, and ELISA test of AFM1 content in urine. Collected data was subjected to a paired ttest analysis using SPSS version 16.0. Survey showed all of feeds samples contaminated by AFB1 by the average of 47 ppb. More than 83% of samples contained AFB1 exceed the USDA limit for AFB1 content in dairy feed. AFB1 content was not significantly different among groups of respondents; however the average of AFB1 content was increased by longer feedmarket chain. AFB1 daily intake (320–362 Kg per cow per day) indicated high exposure of aflatoxin on IFH cows. All of raw milk samples contained high level of AFM1 with the average of 75 ppt and very significantly different among group of respondent, in which, the highest AFM1 content was observed in the sample from cooperative. According to EU regulation, 95% of sample was not allowed for infant consumption and 68% of sample was not allowed for adult consumption. Indonesian Friesian Holstein expressed low carry-over of aflatoxin; those were ranging from 0.32 to 0.85% in survey study and from 0.05 to 0.07% in in vivo experiment. Aflatoxin M1 was detected 10 hours after AFB1 ingested by animal, and reached the steady state in 24 hour after AFB1 included in the diet. Aflatoxin M1 was still detected in milk until 5 days after AFB1 was removed from diet. In vitro assay showed natural bentonite has the highest binding capacity and stability to AFB1 compare to other adsorbents; those were 75 and 99.5%, respectively. Binding capacity of bentonite was decreased with higher pH range (P < 0.05). Application of 0.1% natural bentonite in the diet containing AFB1 at 23 ppb was effective to reduce AFM1 content in milk and the carry-over rate of aflatoxin (P < 0.01). Bentonite inclusion had no effects on milk production, milk composition, nutrients intake, and nutrients digestibility.
Kata Kunci : Aflatoksin B1, Aflatoksin M1, Persentase transfer aflatoksin, Indonesian Friesian Holstein, Adsorben alam
