Feed and feed storage factors in relation to aflatoxin M 1 contamination in bulk milk of smallholder dairy farms

Abstract

The aim of the study was to determine feed and feed storage factors asso- ciated with aflatoxin M1 (AFM1) contamination in bulk milk of dairy farms. The study was conducted from May to July 2016, at all smallholder farms in Mae Wang dairy cooperative, Chiang Mai, Thailand. Data on feed and feed storage factors were collected from the farmers using interviews and observations. For feed, we included type of roughage and physical appearance of concentrated feed, and for feed storage factor, we included storage method of roughages. AFM1 concentration was measured using the Charm® ROSA® MRLAFMQ (afla- toxin M1) Test. Fisher’s exact chi-square test was used to determine the associa- tion of feed and feed management factors with AFM1 contamination. From a total of 67 farms, 50 farms were included in the analysis. AFM1 contamination was observed in 46% of the samples. Farms using factory-corn silage had a sig- nificantly higher percentage of AFM1 contamination (62.5%) than farms that did not use factory-corn silage (30.8%). AFM1 contamination in farms that used con- centrates with cracked pellets was significantly higher (64.3%) than in those that did not (22.7%). For feed storage, roughage stored in piles within the barn was associated with significantly higher AFM1 contamination than that stored out- side (61.5% and 29.2%, respectively). In addition, AFM1 contamination for rough- age piles with mold on the surface was higher (60%) than that for roughage piles without mold (25%). Our results indicate that type of feed and feed storage fac- tors