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Browsing School of Engineering and Technology by Subject "Aflatoxin B1"

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    Occurrence of aflatoxins in animal feeds and raw milk: the case of Kondoa District in Dodoma Tanzania
    (Sokoine University of Agriculture, 2024) Robert, Onesmo Andrew
    Aflatoxins in animal feeds and milk are common problem mostly reported among many regions in Tanzania, in Africa, and worldwide. Studies have revealed a high occurrence of aflatoxins in feeds and milk, which is largely due to a lack of knowledge among various stakeholders along the milk value chain, particularly smallholder dairy farmers (SHDF), animal feed processors, and feed suppliers. This has led to aflatoxins contamination of animal feeds during processing, storage, and feeding. The most common and highly carcinogenic aflatoxins is aflatoxin B1 (AFB1), which, when consumed, is metabolized into aflatoxin M1 (AFM1) and can be found in milk, meat, and eggs. Other types of aflatoxins include aflatoxin B2, G1, G2, and M2. The formation of aflatoxins is mostly caused by Aspergillus flavus or Aspergillus parasticus, which, under adverse environmental temperatures and humidity, can grow in livestock feeds such as maize bran, sunflower seedcakes, silage, hay, and, rarely, in the grass, leading to the production of toxins that referred to as aflatoxins. This study was conducted to assess the level of awareness of aflatoxins in animal feeds and fresh milk among smallholder dairy farmers and to determine the contamination of AFB1 in animal feeds and the occurrence of AFM1 in milk. The study involved both qualitative and quantitative methodologies, including surveys and laboratory determinations of aflatoxins in animal feeds and milk. Semi-structured questionnaires were used, involving 120 SHDFs who had at least one dairy cow from six wards in Kondoa district namely Soera, Kikiro, Haubi, Kolo, Borisa, and Kondoa mjini. In the laboratory, 20 feed samples and 25 milk samples were collected from 25 SHDFs selected among 120 SHDFs and analysed for aflatoxin B1 and M1 respectively using High-Performance Liquid Chromatography (HPLC), with samples prepared following various steps before injection into the HPLC for aflatoxins detection and quantification. The results of this study provide a basis for the recommendation of more training programs and awareness campaigns on aflatoxins supplemented with close monitoring of the dairy value chain by extension officers across regions in Tanzania. The results of this study demonstrate that, majority of SHDFs have awareness of aflatoxins. About 88.3% of the surveyed SHDFs have heard of aflatoxins through village meetings coordinated in collaboration with extension staff, where aflatoxins awareness was one of the agenda. Other sources of information included seminars, newspapers, radio, and television. Additionally, 77.5% were aware of the possible factors and control measures for aflatoxins in animal feeds and milk, and 68.2% understand that aflatoxins can harm both animal health and human health resulting in liver cancer. Furthermore, 63.3% knew the possible transmission of aflatoxins from animal feeds to milk. Additionally, more than 55% of the surveyed farmers were aware of at least one factor for aflatoxins contamination and control measures to prevent aflatoxins. The results by High Performance Liquid Chromatograph (HPLC) analysis of animal feeds and milk revealed that 55% of all samples tested positive for AFB1 in animal feeds, where only 5% were above the permissible safe limit of 20 μg/kg for dairy cattle feeding. The mean AFB1 was found to be 8.6 (±5.9) μg/kg, ranging from the lowest limit of detection (LOD) to 21.1 μg/kg. The analysis of milk samples revealed that 44% of the samples tested were positive for AFM1, with 12% of the sample above the level recommended by the Tanzania Bureau of Standards (TBS), the European Union (EU) and the World Health Organization (WHO). The mean AFM1 was found to be 0.07 (±0.08) μg/L, ranging from the limit of detection to 0.23 μg/L. However, there was no milk sample that exceeded the US Food and Drug Administration (USFDA) and Codex standards of 0.5 μg/L for milk to be consumed by the public. Findings from this study demonstrate that the majority of farmers had information about aflatoxins in animal feeds and raw milk, despite many awareness programs conducted for agricultural crop producers. Some farmers were aware of factors and the control measures for aflatoxins, also they were able to mention at least one sign of possible aflatoxins-contaminated feeds. This helped in their routine practices of feed preparation, storage, and feeding cattle. The findings of the survey reflect the real situation in the field, as the majority of feeds and milk samples were within the levels recommended by TBS, EU, WHO, USFDA, and Codex Alimentarius standards for dairy cattle feeding and milk for public consumption. In conclusion, it was found, smallholder dairy farmers were aware of aflatoxins animal feeds and milk. However, there are some fees and milk samples contain aflatoxin calling for more training programs to be established and implemented to spread awareness on aflatoxins causes and effects, and hence ensure that the community is aware of the problem and contribute to the effort to prevent aflatoxins. Monitoring of SHDFs practices along the dairy value chain is also recommended to encourage voluntary participation to prevent aflatoxins contamination in animal feeds and milk and throughout the food system in general