Attempted transmission Of Brucella ovis between stags and
from stags To rams
D.M. West, K.J. Stafford, N.D. Sargison, S. G. Fenwick and M.P. Reichel
Institute of Veterinary, Animal and Biomedical Sciences, Massey
University 1 Central Animal Health Laboratory, P O Box 40063, Upper Hutt
Proceedings of the New Zealand Society of Animal Production. 1999, 59: 134-136
In August 1997 three 9-month-old Red x Wapiti stags were
inoculated intravenously with Brucella ovis. Between October 1997
and June 1998 these three stags were grazed with 8 control stags of a
similar age and 10 one-year-old Perendale rams, which had been confirmed
free from B. ovis infection before mixing. At monthly intervals
the 11 stags and 10 rams were blood sampled for B. ovis serology
and when infection was suspected, this was confirmed by bacterial
culture of a semen sample. Two of the three artificially infected stags
became persistently infected with B. ovis and shed the organism
in their semen. They remained positive to the B. ovis complement
fixation (CF) serological test throughout the trial. The CF titre fell
below the positive cut-off level 4 months after inoculation in the other
artificially infected stag which did not develop persistent B.
ovis infection.
During April and May 1998, 7 months after mixing with the artificially
infected animals, B. ovis infection was identified in 4 of the 8
control stags. There was no evidence of B. ovis transmission to
the control rams. The trial demonstrated the rapid transmission of B.
ovis infection between young stags during the rut. This would
suggest that sexual activity is important for B. ovis to spread,
although the exact means of transmission could not be determined. Rams
grazed in conjunction with B. ovis - infected stags have a lower
risk of becoming infected.
Keywords: NZSAPAB;
stags; rams; Brucella ovis.
Last Updated 06-08-1999
