Study of aflatoxins incidence in cow feed and milk in serbia during 2013/ Studija o nalazu aflatoksina u hrani za zivotinje i sirovom mleku u srbiji tokom 2013. godine

Atypical weather and climate conditions during the spring and summer 2012 were assumed to be the main reason for the aflatoxins contamination of corn crops in Serbia. High humidity in spring, and summer temperatures above the average contributed to the increased possibility of mycotoxins occurrence in cereals in the fields. As a consequence, at the beginning of 2013 the contaminated corn used for dairy cows diet had negative impact on the safety of cow milk. The routine laboratory control data revealed an increased content of aflatoxin [M.sub.1] in milk samples. Large number of raw milk and various feedstuff samples were collected from February to April 2013 and were analyzed for the presence of aflatoxin [M.sub.1] ([AFM.sub.1]) and aflatoxin [B.sub.1] respectively. The collected samples were a part of enhanced self-control plans of the large dairy farms. Quantitative competitive and sandwich types of ELISA tests were used for the screening analysis of the feed and milk samples. Confirmation of the positive results obtained by ELISA tests was performed by UPLC-MS/MS method. Out of 281 samples of complete mixtures for dairy cows, 67 samples (24%) contained aflatoxin [B.sub.1] quantities higher than the MRL of 0.005 mg/kg [4]. Corn samples were also tested for the presence of aflatoxin [B.sub.1] revealing contamination of 22% above the MRL (0.03 mg/kg). Aflatoxin [M.sub.1] content in the 934 positive milk samples ranged from 0.005-1.25 µg/kg. The corresponding feed samples of sunflower meal, hay silage, corn silage and sugar beet pulp were screening negative, with the content of aflatoxin B1 less than 2 µg/kg. The main sources of aflatoxins were corn samples, wholemeal and feed mixtures derived from contaminated corn. The contamination peak was during March 2013, when 65% of milk samples contained amounts of aflatoxin [M.sub.1] higher than 0.05 µg/kg, and 13% of milk samples contained amounts higher than 0.5 µg/kg. Keywords: Aflatoxins * Feed * Milk * ELISA * UPLC-MS/MS Vremenski i klimatski uslovi koji su bili atipicni za umereno kontinentalno prolece i leto 2012. godine smatraju se jednim od razloga kontaminacije useva mikotoksinima u Srbiji. Upotreba hrane za zivotinje poreklom iz zetve 2012. god. za posledicu je imala pojavu aflatoksina [M.sub.1] ([AFM.sub.1]) u mleku krava. Kvantitativni ELISA testovi korisceni su za analizu uzoraka hraniva, odnosno mleka. Konfirmacija pozitivnih rezultata dobijenh imunoenzimskim testom obavljena je pomocu UPLC-MS/MS me