Ministry of Livestock Development and Fisheries, Box 9152, Dar-es-Salaam, Tanzania; Veterinary Investigation Centre, PO Box 1068, Arusha, Tanzania; Tropical Veterinary Services, PO Box 266, Karatu, Tanzania
Swai, E.S., Ministry of Livestock Development and Fisheries, Box 9152, Dar-es-Salaam, Tanzania; Sanka, P.N., Veterinary Investigation Centre, PO Box 1068, Arusha, Tanzania; Daborn, C.J., Tropical Veterinary Services, PO Box 266, Karatu, Tanzania
Questionnaire and microbiological-based surveys were conducted, during the period of March to August 2011, in 5 commercial broiler and layer hatcheries located in northern Tanzania to evaluate hatchery hygiene. Information on farm/hatchery history, hygienic practices and bio-security measures employed was collected. Hatchery samples (n=59), comprising day old dead chicks (DOC), dead-in-shell embryos (DES) and walls/ premises swabs (SWB), were aseptically collected for detailed bacteriological screening. Both non-selective (nutrient plate agar), selective and differential media (MacConkey agar plate) prepared according to the manufacturer's instructions, were employed to differentiate between Gram-positive, Gram-negative and lactose fermenting organisms. Culture positive colonies were characterized further using Triple Sugar Iron (TSI) in order to establish the presence of enteric based pathogens. Overall, 3 units in Kilimanjaro and 2 units in Arusha were visited and bio-security measures reported to be used in order to avoid disease occurrence was routine usage of disinfectants (n=4; 80%), strict entry prohibition of non-authorized personnel (n=4; 80%), avoidance of mixing birds of different production purposes together (i.e. layers viz broilers, n=1; 20%) and change of clothes after each unit operation (n=1; 20%). The most cited targeted areas for disinfection were unit floor (n=5; 100%) and poultry and hatchery walls (n=4; 80%). The colonies that grow on the agar plates were about 2-4mm in size, irregular and whitish in colour. Stained colonies revealed that Gram negative bacteria were the commonest microorganisms, comprising 92% of all culture positives. Pathogen isolation rate was highest in hatchery D followed by hatcheries A, C and B with negative results in hatchery E. The isolation rate was highest in the DOC and DES derived samples and lowest in the SWB samples. Characterisation of positive culture samples, using the TSI biochemical test, revealed the following proportions of bacterial agents: Proteus vulgaris (60.7%), Enterobacter aerogenes (42.8%), Enterobacter cloacae (17.8%), Salmonella vulgaris (10.7%) and Salmonella typhi (7.1%). The high isolation rate and wide range of microbial pathogens found by this survey, reveals a serious problem of inadequate biosecurity practice indicating that there is considerable room for improvement in hatchery operations particularly with regards to hygiene and sanitation. Adequate training of hatchery operators is needed to raise awareness of the crucial role hygiene and biosecurity plays in ensuring high chick quality and their consequent survivability rates.