Quantification, characterization and carry over effect of aflatoxin in broiler chicken raised in Nairobi City County, Kenya
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Date
2023
Authors
Kirinyet, Ruth C.
Journal Title
Journal ISSN
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Publisher
Kenyatta University
Abstract
Aflatoxin is a threat and a food safety concern particularly in developing countries due to the climatic conditions that favor the growth of the aflatoxin fungi. Consequently, this a major risk to feed ingredients used in the manufacture of animal feed and subsequently is a great risk to human consumers due to the detrimental effects of these toxins as they are regarded as Type 1 carcinogens. For that reason, a study to establish the carry over effect of aflatoxin in broiler chicken was carried out in Nairobi City County as there is limited data. The specific objectives of the study were to quantify and characterize aflatoxin levels in broiler feed and broiler meat, to determine carry over effect from broiler feed into broiler meat and to assess the knowledge of farmers on aflatoxin in Nairobi City County. The findings will provide a scientific basis for the endorsement of regulations that are key in the decision making process and policy formulation of food and feed with respect to Aflatoxins.The study utilized a cross sequential study design which included both cross sectional and longitudinal study. The longitudinal study was done for six weeks which corresponded to the period of raising broilers from day old chicks to slaughter. Detection and quantification of aflatoxin levels in broiler feed and meat was done using the (LC/MS-MS) technique. A structured questionnaire on knowledge of aflatoxin was administered and multistage randomn sampling was used. Two FGD comprising of twelve members each among farmers in two sub counties were conducted. A pretest of the questionnaire was carried out in Kiambu County. SPSS version 26 was used for quantitative analysis of questionairres and STATA version 12 was used to carry out one way and two-way ANOVA for laboratory analysis. NVIVO soft ware was used for analysis of data from FGDs. Tukey Kramer post hoc test was used for comparison of means and statistical significance was determined at 5%. Ethical approval was sought from relevant authorities before commencement of the study and consent was sought from the participants before taking part in the study. Results of the study show that majority of the farmers (58.2%) had knowledge on aflatoxin. There was a significant association (p<0.05) between socio demographic characteristics of farmers and knowledge on aflatoxin. Aflatoxin levels in broiler starter were; B1(17.26±3.07), B2 (2.44±0.84), G1 (8.87±2.41), G2 (0.9±0.44) and Total AF (29.47±6.13). Aflatoxin levels in broiler finisher were B1 (17.17±3.09), B2 (2.68±1.18), G1 (9.25±2.7), G2 (1±0.45) and Total AF (30.1±6.88). There was a significant association (p<0.05) in AFB1 and Total Aflatoxin levels in the gizzard, liver and muscle per week. AFB1 levels in the gizzard were below the WHO/FAO limit of 5 ppb however they were above the EU limit of 2ppb in week 5 and 6. In the liver AFB1 levels were above the EU limit in week 4, 5 and 6 and above the WHO/FAO limit in week 6. In the muscle AFB1 levels were all below the WHO/FAO and EU limit. Total Aflatoxin levels in the liver were above the EU limit in week 4, 5 and 6 and above the WHO/FAO limit in week 6. In the muscle Total Aflatoxin levels were all below the WHO/FAO and EU limit. There was a statistical significant difference (p<0.05) in the carry over ratio of aflatoxin per week. The highest carry over ratio of >10% was observed in the liver, followed by the gizzard and the least was in the muscle. The highest transfer ratio was observed in week 5 and 6 in the liver and in week 6 in the muscle. The carry over ratio in the muscle was below 1%. This study concluded that the farmers had adequate knowledge on aflatoxin occurrence in feeds and methods to reduce the occurrence, but had no knowledge on carry over effect. Although there were appreciable amounts of aflatoxin in the broiler feeds and broiler meat, the carry over effect was low in the muscle but higher in the liver and gizzard. The study recommends that there is need constant monitoring of Aflatoxin levels in poultry feed & products by KEBS & national & county government and application of stringent allowable limits in feed and feed ingredients.
Description
A research thesis submitted in partial fulfillment of the requirements for the award of the degree of doctor of philosophy in environmental health in the school of health sciences of kenyatta university, June, 2023
Keywords
Quantification, characterization, aflatoxin, broiler chicken, Nairobi City County, Kenya