text 1986 Penyakit Hewan Vol.18 (31). 1986 The rapid egg-yolk agglutination test was used to detect the presence of Mycoplasma gallisepticum infection in 38 flocks of parent stock chickens from 14 breeding farms (3 from Jakarta: 2 from Bandung, West Java; 3 from Surabaya East Java; 1 from Denpasar, Bali and 5 from Medan, North Sumatera). With 1272 sample of egg from 1272 eggs tested, 149 yolk gone postitive agglutination against M. gallisepticum (S6_) antigen. The positive reactors origi- nally case from 30 flocks, averaged from 1.18% to 50% of samples. The egg-yolk test seemed to be a valuable, practical and simple method for routine investigation for M. gallisepticum infection in breeder flocks. The influence of mycoplasma infection on egg fertility and hatchability need to be properly investigated and evaluated further. Supar; Poernomo Sri (Balai Penelitian Veteriner, Bogor) MYCOPLASMA GALLISEPTICUM ARTVET2331 ARTVET2331 210827 20210827010602 INLIS000000000017751 Converted from MARCXML to MODS version 3.5 using MARC21slim2MODS3-5.xsl (Revision 1.106 2014/12/19)