Wijesinghe, W.M.H.H.2021-03-192021-03-192012UWU/ANS/08/0039http://www.erepo.lib.uwu.ac.lk/bitstream/handle/123456789/6142/UWULD%20ANS%2008%200039-09042019094151.pdf?sequence=1&isAllowed=yCow milk is an important source of nutrition in human, especially in infants. a Contamination of milk with aflatoxin M1 (AFM1), when cows are fed with aflatoxin B1 (AFB1) contaminated feed, is a threat to human health as well as to the animals and dairy farmers. The aim of this study was to determine the levels of aflatoxin M, in raw milk obtained from high producing cows and evaluate the relationship between feeding type and detected AFM1 levels. Ten dairy farms were randomly selected from Hatton Veterinary Surgeon's area for the collection of raw milk samples and they were analysed for AFM1 using the Official Methods of Analysis of Association of Official Analytical Chemists (AOAC) International in addition to detecting AFM1 levels by High Performance Liquid Chromatography (HPLC) equipped with a fluorescence detector, consisting 360 nm and 440 nm for excitation and emission wavelengths respectively. Identification of AFM1 in the milk samples was based on its retention time with respect to the daily prepared AFM1 standard (500 [tg U1). OcCurrence of AFM1 was detected in 50% of the collected samples ranging from 8 ng U 1 to 36 ng L-1 with a mean level of 11.1 ng L-1. None of the samples were exceeded the European Communities/Codex Alimentarius recommended limit of 50 ng L-1. Grasses given to the animals' diets showed no relationship with the occurrence of AFM1 while concentrate feeds had a significant relationship with AFM1 contamination. Out of the three types of concentrate feeds given to the animals, coconut poonac had the highest correlation with the occurrence of AFM1 having a value of 0.65, while compound cattle feed and beer pulp having correlations of 0.52 and 0.41 respectively. Occurrence of AFM1 had increased with concentrate feeds. Increasing grass content in the diet had reduced AFM1 occurrence in milk. The results suggest the importance of protecting feeds, especially concentrates, from aflatoxin like fungal growth during storage to minimize the risk of contamination of raw cow milk which is considered to be a health hazard threat.enAnimal Science Degree ProgrammeThesis