THE EFFECT OF MYCOPLASMA GALLISEPTICUM TS11 VACCINATION ON EGG PRODUCTION

Abstract

Chronic respiratory disease caused by Mycoplasma galliseplicum (MG) is known
to cause economic losses among poultry industries. One of the economic losses is
due to egg production drops. Prevention using MG vaccine is reported to have good
protection against MG infection and egg production drops. A vaccination trial to
determine the efiects of TS-ll vaccine, a mutant strain of MG, against MG infection
and egg production drops was carried out on 13 week-old of pullets. Three groups of
eight pullets were vaccinated with TS-1 l, MG80083M and MG80083L,
respectively. The other 6 groups of pullets were not vaccinated. Each chicken was
kept in a single wire cage. Fifieen weeks afier vaccination the chickens were
challenged. The first three groups were challenged with a virulent Ap3AS strain of
MG, and groups 4, 5, 6, 7 and 8 (non vaccinated groups) were challenged with
Ap3AS, MG80083M, MG80083L, TS-11 and broth medium via intra-abdominal air
sacs respectively, whereas the last group of chickens (group 9) was not challenged
kept as controls. The egg production was recorded 7 weeks before and afier
challenge starting from 22 weeks of age. The results showed that the egg production
of the vaccinated hens were not affected by the challenge and was not statistically
different from the non-vaccinated non-challenged control chickens (group 9). The
egg production of the non-vaccinated hens challenged with Ap3AS (group 4),
MG80083M (group 5), MG80083L (group 6) was declined dramatically and was
significantly lower (P<0.01) than that of the non-vaccinated hens challenged with
TS-ll (group 7). The egg production of hens in group 7 was not afiected by TS-ll
challenge and was not statistically difierent from the non vaccinated hens injected
with broth medium (group 8) or the control chickens (group 9).