Evaluation of hygienic practices and establishment of critical control points and raw milk quality in the smallholder supply chain of Nakuru and Nyandarua County, Kenya

Abstract

The milk marketed in Kenya has been reported to be of poor quality and does not meet national and international standards due to high bacterial load, high somatic cell count, adulteration and antibiotic residues. The study investigates the raw milk quality, adherence to hygienic code of practice and identifies the critical control points for improved raw milk quality in the smallholder supply chain. Compliance to hygienic code of practice was assessed using questionnaires. The factors that could contribute to raw milk quality deterioration were identified through observations using the hazard analysis critical control point principles. To establish the raw milk quality, physico-chemical and microbiological tests were carried out. Statistical analysis for laboratory experimentation involved analysis of variance and means were separated using least significance difference whenever the sampling level effect was significant P ≤ 0.05. The results indicated low conformance to the hygienic code of practice including ineffective hand washing procedure before milking, use of plastic containers in milk handling, unawareness of the food safety concerns related to antibiotic residues in milk, delayed milk delivery and use of reusable udder cloth. The critical control points identified included milking, bulking milk in fifty liters can, transportation, the reception platform and the cooling tank. A quality control plan for the smallholder supply chain was developed. The means separation indicated that the average total plate count was 6.72×108and 1.37×107 cfu/ml for Ngorika and Olenguruone respectively while the coliform count was an average of 3.18×106cfu/ml and 1.34×105 in Ngorika and Olenguruone respectively. The antibiotic residues analysis was conducted using Delvo test and the positive results were 35% and 54% for Ngorika and Olenguruone respectively. Somatic cell count was analyzed using California Mastitis Test and 65% and 55% of the samples analyzed were within a range of 150-500 somatic cells count/1,000 ml. Water adulteration was analyzed using cryoscopyand 23.8% and 36.8% were positive for Ngorika and Olenguruone, respectively.There were no significant P ≤ 0.05 correlation between total plate count and the resazurin test at route level for both locations. The study verified non-compliance to the hygienic code of practice and nonconformance of raw milk quality to the Kenyan standards. The study however developed the critical control plan which if adopted could guide on the corrective action at every node in the collection chain and improve the quality of raw milk in Kenya.