David Kemboi

Mr. David Kemboi

Chuka university, Department of Animal Science
+1
orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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8 September 2021 in Toxins
Verified
Journal Article
Open access
PDF file
Phillis Emelda OchiengPhillis Emelda Ochieng
Phillis Emelda Ochieng
MSMarie-Louise Scippo
Marie-Louise Scippo
DKDavid Kemboi
David Kemboi
Siska CroubelsSiska Croubels
Siska Croubels
SOSheila Okoth
Sheila Okoth
Gunther AntonissenGunther Antonissen
Gunther Antonissen
The poultry industry in sub-Saharan Africa (SSA) is faced with feed insecurity, associated with high cost of feeds, and feed safety, associated with locally produced feeds often contaminated with mycotoxins. Mycotoxins, including aflatoxins (AFs), fumonisins (FBs), trichothecenes, and zearalenone (ZEN), are common contaminants of poultry feeds and feed ingredients from SSA. These mycotoxins cause deleterious effects on the health and productivity of chickens and can also be present in poultry food products, thereby posing a health hazard to human consumers of these products. This review summarizes studies of major mycotoxins in poultry feeds, feed ingredients, and poultry food products from SSA as well as aflatoxicosis outbreaks. Additionally reviewed are the worldwide regulation of mycotoxins in poultry feeds, the impact of major mycotoxins in the production of chickens, and the postharvest use of mycotoxin detoxifiers. In most studies, AFs are most commonly quantified, and levels above the European Union regulatory limits of 20 μg/kg are reported. Trichothecenes, FBs, ZEN, and OTA are also reported but are less frequently analyzed. Co-occurrences of mycotoxins, especially AFs and FBs, are reported in some studies. The effects of AFs on chickens’ health and productivity, carryover to their products, as well as use of mycotoxin binders are reported in few studies conducted in SSA. More research should therefore be conducted in SSA to evaluate occurrences, toxicological effects, and mitigation strategies to prevent the toxic effects of mycotoxins.

3 December 2020 in Toxins
Verified
Journal Article
Open access
PDF file
DKDavid Kemboi
David Kemboi
Phillis Emelda OchiengPhillis Emelda Ochieng
Phillis Emelda Ochieng
Gunther AntonissenGunther Antonissen
Gunther Antonissen
Siska CroubelsSiska Croubels
Siska Croubels
MSMarie-Louise Scippo
Marie-Louise Scippo
JGJames Gathumbi
James Gathumbi
Mycotoxins are common in grains in sub-Saharan Africa and negatively impact human and animal health and production. This study assessed occurrences of mycotoxins, some plant, and bacterial metabolites in 16 dairy and 27 poultry feeds, and 24 feed ingredients from Machakos town, Kenya, in February and August 2019. We analyzed the samples using a validated multi-toxin liquid chromatography-tandem mass spectrometry method. A total of 153 mycotoxins, plant, and bacterial toxins, were detected in the samples. All the samples were co-contaminated with 21 to 116 different mycotoxins and/or metabolites. The commonly occurring and EU regulated mycotoxins reported were; aflatoxins (AFs) (70%; range 0.2–318.5 μg/kg), deoxynivalenol (82%; range 22.2–1037 μg/kg), ergot alkaloids (70%; range 0.4–285.7 μg/kg), fumonisins (90%; range 32.4–14,346 μg/kg), HT-2 toxin (3%; range 11.9–13.8 μg/kg), ochratoxin A (24%; range 1.1–24.3 μg/kg), T-2 toxin (4%; range 2.7–5.2 μg/kg) and zearalenone (94%; range 0.3–910.4 μg/kg). Other unregulated emerging mycotoxins and metabolites including Alternaria toxins, Aspergillus toxins, bacterial metabolites, cytochalasins, depsipeptides, Fusarium metabolites, metabolites from other fungi, Penicillium toxins, phytoestrogens, plant metabolites, and unspecific metabolites were also detected at varying levels. Except for total AFs, where the average contamination level was above the EU regulatory limit, all the other mycotoxins detected had average contamination levels below the limits. Ninety-six percent of all the samples were contaminated with more than one of the EU regulated mycotoxins. These co-occurrences may cause synergistic and additive health effects thereby hindering the growth of the Kenyan livestock sector.

1 September 2023 in Journal of Agricultural and Food Chemistry
Verified
Journal Article
Closed access
Phillis Emelda OchiengPhillis Emelda Ochieng
Phillis Emelda Ochieng
Siska CroubelsSiska Croubels
Siska Croubels
DKDavid Kemboi
David Kemboi
SOSheila Okoth
Sheila Okoth
SBSiegrid De Baere
Siegrid De Baere
GAGunther Antonissen
Gunther Antonissen

3 January 2023 in Toxins
Verified
Journal Article
Open access
PDF file
SBSiegrid De Baere
Siegrid De Baere
Phillis Emelda OchiengPhillis Emelda Ochieng
Phillis Emelda Ochieng
DKDavid Kemboi
David Kemboi
MSMarie-Louise Scippo
Marie-Louise Scippo
SOSheila Okoth
Sheila Okoth
Siska CroubelsSiska Croubels
Siska Croubels
Aflatoxins (AFs) frequently contaminate food and animal feeds, especially in (sub) tropical countries. If animals consume contaminated feeds, AFs (mainly aflatoxin B1 (AFB1), B2 (AFB2), G1 (AFG1), G2 (AFG2) and their major metabolites aflatoxin M1 (AFM1) and M2 (AFM2)) can be transferred to edible tissues and products, such as eggs, liver and muscle tissue and milk, which ultimately can reach the human food chain. Currently, the European Union has established a maximum level for AFM1 in milk (0.05 µg kg−1). Dietary adsorbents, such as bentonite clay, have been used to reduce AFs exposure in animal husbandry and carry over to edible tissues and products. To investigate the efficacy of adding bentonite clay to animal diets in reducing the concentration of AFB1, AFB2, AFG1, AFG2, and the metabolites AFM1 and AFM2 in animal-derived foods (chicken muscle and liver, eggs, and cattle milk), chicken and cattle plasma and cattle ruminal fluid, a sensitive and selective ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method has been developed. High-throughput sample preparation procedures were optimized, allowing the analysis of 96 samples per analytical batch and consisted of a liquid extraction using 1% formic acid in acetonitrile, followed by a further clean-up using QuEChERS (muscle tissue), QuEChERS in combination with Oasis® Ostro (liver tissue), Oasis® Ostro (egg, plasma), and Oasis® PRiME HLB (milk, ruminal fluid). The different procedures were validated in accordance with European guidelines. As a proof-of-concept, the final methods were used to successfully determine AFs concentrations in chicken and cattle samples collected during feeding trials for efficacy and safety evaluation of mycotoxin detoxifiers to protect against AFs as well as their carry-over to animal products.

30 November 2022 in Microorganisms
Verified
Journal Article
Open access
PDF file
Phillis Emelda OchiengPhillis Emelda Ochieng
Phillis Emelda Ochieng
DKDavid Kemboi
David Kemboi
MSMarie-Louise SCIPPO
Marie-Louise SCIPPO
JGJames Gathumbi
James Gathumbi
EKErastus Kangethe
Erastus Kangethe
SOSheila Okoth
Sheila Okoth
Warm and humid climatic conditions coupled with poor agricultural practices in sub-Saharan Africa favor the contamination of food and feed by Aspergillus flavus and Fusarium verticillioides fungi, which subsequently may produce aflatoxins (AFs) and fumonisins (FBs), respectively. The growth of fungi and the production of mycotoxins are influenced by physical (temperature, pH, water activity, light and aeration), nutritional, and biological factors. This study aimed at optimizing the conditions for the laboratory production of large quantities of AFs and FBs for use in the animal experiments. A. flavus and F. verticillioides strains, previously isolated from maize in Kenya, were used. Levels of AFB1 and total FBs (FB1, FB2, and FB3) in different growth substrates were screened using ELISA methods. Maize kernels inoculated with three different strains of A. flavus simultaneously and incubated at 29 °C for 21 days had the highest AFB1 level of 12,550 ± 3397 μg/kg of substrate. The highest level of total FBs (386,533 ± 153,302 μg/kg of substrate) was detected in cracked maize inoculated with three different strains of F. verticillioides and incubated for 21 days at temperatures of 22–25 °C in a growth chamber fitted with yellow light. These two methods are recommended for the mass production of AFB1 and FBs for animal feeding trials.

17 January 2023 in Journal of Agricultural and Food Chemistry
Verified
Journal Article
Closed access
DKDavid Kemboi
David Kemboi
GAGunther Antonissen
Gunther Antonissen
POPhillis Ochieng
Phillis Ochieng
Siska CroubelsSiska Croubels
Siska Croubels
SBSiegrid De Baere
Siegrid De Baere
JGJames Gathumbi
James Gathumbi