Abstract

Mycoplasmosis in poultry is associated with a wide range of disease conditions, such as those affecting the respiratory and reproductive systems and causing Chronic Respiratory Disease (CRD), and salpingitis, respectively, with consequent drop in egg production in laying flocks. This paper reports an outbreak of Mycoplasma and its management in a laying chicken flock. Twenty-five choanal cleft swabs from a flock of 1,000 laying hens were aseptically sampled into 1 mL avian Mycoplasma Pleuropneumonia-like Organism (PPLO) broth medium from a flock with no apparent clinical disease but having a substantial drop in egg production. The swab samples were analysed according to the protocol of the Mycoplasma Research Laboratory, National Veterinary Research Institute (NVRI), Vom, Nigeria. The cultured swabs inoculated onto PPLO agar plates yielded 60.0% (15/25) positive colonies with fried-egg-shaped colonies (tiny, smooth circular, translucent mass with a dense raised central area) under a stereomicroscope (10x) after 5 days of incubation, which indicated a positive result/growth for Mycoplasma species. The case was successfully managed using Aivlosin (Tylvalosin Tartrate 625 mg/g) granules (40g sachet/200 litres in drinking water) given for 5 consecutive days based on the manufacturer's instructions. This resulted in a 30% increase in egg production immediately upon commencement of treatment, and it reached 80% production by the fifth day. Furthermore, the litters were evacuated and replaced with new wood shavings midway through the treatment (day 2), and the poultry pen was fumigated with Virkon S at a dilution rate of 1:200 (0.5%) by spraying to reduce the bacterial burden. This report thus recommends vaccination of birds, all-in-all-out farming practices, and enhanced biosecurity to control and eradicate the disease on the farms.

Key words: Chicken, Egg production, Isolation, Laying flock, Mycoplasma