Aflatoxins in dairy cattle feed in Senegal

Aflatoxins are toxic byproducts from moulds, especially Aspergillus flavus. These moulds grow on crops, and in particular maize and ground nuts are often contaminated. In humans, aflatoxins cause rare, high case fatality outbreaks (acute aflatoxicosis) while long term consumption leads to hepatocellular cancer (globally, around 20,000 deaths annually). Aflatoxins are also associated with childhood stunting, although a causal relation is not yet proven. Humans are exposed through the consumption of contaminated foods, including cereals, legumes and human and animal milk (as aflatoxins are excreted in milk). Similarly in livestock, aflatoxins cause hepatic disease, immunosuppression and reduced productivity. In tropical and sub-tropical developing countries, aflatoxins are common and 4.5 billion people are chronically exposed. In addition to the burden of this exposure, the reduction in livestock productivity impacts food security and trade and hence increases aflatoxins' total burden. Knowledge about aflatoxins in Senegal is scarce, especially in relation to the dairy cattle value chain. In this pilot project we measured aflatoxin B1 levels in dairy cattle feeds. Feed samples were obtained from low-input cattle farms in two regions in Senegal (the Thies and Diourbel regions) in August 2015, with between 16 and 36 samples per feed type. Aflatoxin levels were determined by a commercial competitive ELISA. Feeds with the highest levels of aflatoxin were purchased concentrate (with an average of 50 ppb, and a range of 0 to 305 ppb), ground-nut cake (45ppb, 0 to 187ppb) and millet bran (37ppb, 0 to186 ppb). A number of other feeds tested contained aflatoxins at lower levels, namely cornmeal (18ppb, 0 to 104 ppb), wheat bran (9ppb, 0 to 41 ppb) and rice bran (7ppb, 0 to 58ppb). The percentage of feed samples that were above the World Health Organisation's recommended limit for aflatoxin in animal feed (of 5ppb) was high, for example 96% for ground-nut cake, 80% for millet bran, and 69% for concentrate. Although, the aflatoxin levels reported may not significantly affect herd productivity, their impacts on susceptible livestock and carry-over to animal source food may be problematic. Overall, these results suggest the need for further investigation on aflatoxin in Senegal dairy

Investigation of the governance structure of Nairobi dairy value chain and its influence on food safety

The dairy value chain of Nairobi is comprised, in its majority, of small-scale independent enterprises that operate within a complex interlinked system. In this complexity, the coordination and power structures of the system may have major influences on the management of dairy food safety. Therefore, the aim of this study was to investigate the governance and challenges issues faced by stakeholders throughout the Nairobi dairy value chain and assess their potential implications on food safety. Qualitative data was collected through focus group discussions and key informant interviews based on a dairy value chain mapping framework previously developed. Thematic analysis enabled identification of governance themes, key challenges and their implication on food safety. Themes were organized depending on their association with farmers (informal settlement or peri-urban), dairy cooperatives, dairy traders, processing companies, retailers or government officers. The identified governance themes included: i) weak linkage between government and farmers, ii) inadequate compliance with government regulations by traders and retailers, iii) emphasis on business licenses and permits for revenue rather than for food safety, iv) multiple licensing resulting in high business cost and lack of compliance, v) fragmented regulation, vi) unfair competition and vii) sanctions that do not always result in compliance. The key challenges identified included, amongst others: i) inadequate farmer support, ii) harassment of traders and retailers and iii) high business costs by traders, retailers, dairy cooperatives and large processors. The implication of governance and challenges of food safety were, amongst others: i) inadequate extension services, ii) insufficient cold chain, iii) delivery of adulterated and low milk quality to bulking centres, iv) inadequate food safety training and v) lack of policies for management of waste milk. The range of issues highlighted are based on stakeholders’ perceptions and reflects the complexity of the relationships between them. Many of the governance themes demonstrate the linkages that are both beneficial or confrontational between the formal and informal sectors, and between industry and regulatory authorities, with possible direct food safety consequences. Findings obtained provide indications to decision-makers of potential governance areas that could help improve efficiency and food safety along the dairy value chain

Aflatoxin M-1 levels in different marketed milk products in Nairobi, Kenya

Milk is an important source of energy and nutrients, especially for children, and in Kenya, milk consumption is higher than other countries in the region. One major concern with milk is the risks of chemical contaminants, and reports of high levels of aflatoxin M-1 (AFM(1)) in milk in Kenya has been causing public health concerns. This study collected marketed milk products every month during 1 year, just as a consumer would purchase them from retailers and traders in a low-income area, and a major supermarket in a middle/high-income area. In total, 291 sampled milk products (raw, pasteurised, UHT milk, yoghurt and lala) were collected and analysed for AFM(1) using a commercial ELISA kit. More than 50% of the samples exceeded 50 ng/kg (the level allowed in the EU), but only three samples exceeded 500 ng/kg (the level allowed in the USA). Geometric mean AFM(1) level was 61.9 ng/kg in the 135 samples from the low-income area while it was 36.1 ng/kg in the 156 from the higher income area (p < 0.001). The levels varied significantly depending on the time of year, with lowest levels of milk in January. There were also differences between manufacturers and products, with UHT milk having lower levels. There was no difference depending on the price for all dairy products, but when only including milk, higher price was associated with lower levels of AFM(1). In conclusion, this study shows that milk purchased by a consumer is likely to contain AFM(1) above 50 ng/kg, and that further research is needed to find ways to mitigate AFM(1) contamination through working with farmers and milk processors both in the formal and informal sectors

Effectiveness of Training and Use of Novasil Binder in Mitigating Aflatoxins in Cow Milk Produced in Smallholder Farms in Urban and Periurban Areas of Kenya

Aflatoxins, which commonly contaminate animal feeds and human food, present a major public health challenge in sub-Saharan Africa. After ingestion by cows, aflatoxin B1 is metabolized to aflatoxin M1 (AFM1), some of which is excreted in milk. This study involved smallholder dairy farms in urban and periurban areas of Nairobi and Kisumu, Kenya. The objective was to determine the effectiveness of training and providing farmers with aflatoxin binder (NovaSil(R)) on AFM1 contamination in raw milk. A baseline survey was undertaken and 30 farmers whose milk had AFM1 levels above 20 ppt were randomly selected for inclusion in the study. Of these, 20 farmers were part of the intervention, and were given training on the usage of the NovaSil(R) binder, while 10 served as a control group. All farmers were visited biweekly for three months for interviews and milk samples were collected to measure the AFM1 levels. The AFM1 levels were quantified by enzyme linked immunosorbent assay. The NovaSil(R) binder significantly reduced AFM1 concentrations in the raw milk produced by the farmers in the intervention group over the duration of the study (p < 0.01). The control farms were more likely to have milk with AFM1 levels exceeding the regulatory limit of 50 ppt compared to the intervention farms (p < 0.001) (odds ratio = 6.5). The farmers in the intervention group perceived that there was an improvement in milk yield, and in cow health and appetite. These farmers also felt that the milk they sold, as well as the one they used at home, was safer. In conclusion, the use of binders by dairy farmers can be effective in reducing AFM1 in milk. Further research is needed to understand their effectiveness, especially when used in smallholder settings

Efficacy of mycotoxin binder on aflatoxin M1 and Mazzican on total bacterial count in raw milk among smallholder dairy farmers in Kisumu County, Kenya

Background: Worldwide, milk forms a major part of human diet especially for children and expectant mothers. However, milk in East Africa has been shown to be frequently contaminated with aflatoxin M1 (AFM1) and bacteria. The efficacy of NovaSil clay (NS), a mycotoxin binder, and Mazzican, a hygienic milk container, to reduce levels of aflatoxin M1 and total bacterial counts respectively were evaluated in raw milk samples collected from urban and peri urban areas of Kisumu, Kenya. Materials and methods: A baseline survey was conducted in 97 farms, and 72 raw milk samples were collected. Thirty farms identified as producing milk with AFM1 levels above 50 ppt, which is the recommended limit by EU, were randomized to either receive the intervention (including training, NS and Mazzican, n=20), or not receive intervention (control, n=10). NS was to be administered in 1-2 teaspoonful per 2 kg of concentrate feed while Maziccan was to be used during milking, milk storage and transportation to the market. Raw milk samples from trial participants were collected biweekly for three consecutive months. AFM1 metabolites were quantified by enzyme linked immunosorbent assay with a detection limit of 2 ppt. Total bacterial counts were obtained from colony counts of raw milk cultures. Results: Upon baseline testing, aflatoxin M1 levels in raw milk ranged from 0.001-151 ppt with a mean 29.40 ppt. The mean total bacteria count was 1.6×10⁷ ± 5.2×10⁷Cfu/ml. Cfu/ml ranged from 3.3×10² to 2.4×10⁸ Cfu/ml. Trial results indicate that giving 2 teaspoon of NS binder per 2 kg caused a significant statistical difference in reduction of AFM1 levels in the sampled milk, p=0.013, whereas this was not found when giving half the dose. Use of mazzicans revealed a statistical significance difference in reduction of total bacterial counts in the milk samples p<0.001. The study has 100% compliance in use of mazzican while 98% in NS use. Conclusions: Intervention effectively reduced AFM1 and bacterial counts in milk. The farmers were willing to invest in the intervention, therefore the possibility to supply farmers with NS and mazzican should be further investigated

Status of aflatoxin contamination in cow milk produced in smallholder dairy farms in urban and peri-urban areas of Nairobi County : a case study of Kasarani sub county, Kenya.

Introduction: Milk consumption in Kenya supersedes other countries in East Africa. However, milk contamination with aflatoxin M1 (AFM1) is common, but the magnitude of this exposure and the health risks are poorly understood and need to be monitored routinely. This study aimed at assessing the awareness, knowledge and practices of urban and peri-urban farmers about aflatoxins and determining the levels of aflatoxin contamination in on-farm milk in a selected area within Nairobi County. Materials and methods: A cross-sectional study was undertaken to assess aflatoxin contamination levels of milk in Kasarani sub-county. A total of 84 milk samples were collected from small-holder dairy farms and analyzed for AFM1 using Enzyme-Linked Immunosorbent Assay (ELISA). Results and Discussion: Ninety nine percent of the samples (83/84) analysed were contaminated with AFM1. The mean aflatoxin level was 84 ng/kg with 64% of the samples exceeding the EU legal limit of 50 ng/kg. Whereas 80% of the farmers were aware of aflatoxin, there was no correlation between farmers' knowledge and gender with AFM1 prevalence. Conclusion: This study concludes that AFM1 is a frequent contaminant in milk and there is need to enhance farmers awareness on mitigation