BIOLOGY OF THE MALE REPRODUCTIVE TRACT
7:30 AM-10:00 AM
(571) AVIAN INFECTIOUS BRONCHITIS VIRUS: CAUSE OF EFFERENT DUCTULE STONES AND DECREASED SPERM PRODUCTION AND TESTOSTERONE CONCENTRATIONS.
Boltz, David1, Nakai, Masaaki1, Bahr, Janice1, 1 Department of Animal Sciences, Urbana-Champaign, IL
ABSTRACT- We have reported granular deposits (stones) of calcium carbonate in efferent ductules of the rooster. There was also an infiltration of immune cells in the interstitium of the testis and efferent ductules. The cause of stones is unknown but an infectious agent, the avian infectious bronchitis virus (AIBV), has been implicated. The goal of this study was to determine if administering the live attenuated AIBV vaccine increases the incidence of stones in rooster efferent ductules. Specific pathogen free birds were divided into two groups: a vaccine free group, and a group vaccinated for AIBV. The vaccine was administered at 2, 4, 10 and 14 wks of age. Blood was drawn weekly to monitor antibodies to AIBV. At 26 wks of age, blood was obtained to determine testosterone concentrations and reproductive tracts were harvested to analyze daily sperm production and to detect stones. 80% of birds given the vaccine developed stones whereas those not given the vaccine did not develop stones. Measurement of serum testosterone concentrations indicated that administration of the AIBV vaccine and subsequent stone formation adversely affected testosterone concentrations. Testosterone concentrations were reduced in birds given the vaccine (3.68 ± 0.30 ng/ml) when compared to birds not given the vaccine (7.13 ± 1.63 ng/ml). Testis weight was reduced in birds given the vaccine (12.10 ± 0.76 g), as compared to birds not given the vaccine (15.20 ± 0.81 g). Daily sperm production was lower in birds given the vaccine (5.03 ± 0.31 x 108 sperm/testis/day), when compared to birds not given the vaccine (7.43 ±0.52 x 108 sperm/testis/day). Comparing daily sperm production on a per gram basis, birds given the vaccine had 4.38 ±0.14 x 107 sperm/g testis that was slightly lower than birds not given the vaccine which had 5.17 ±0.17 x107 sperm/g testis. We conclude that the use of a live attenuated AIBV vaccine increases the incidence of stones in rooster efferent ductules. It is unknown whether AIBV is a direct cause of stone formation by infecting the reproductive tract or an indirect cause by eliciting an immune response. These data indicate that the use of a live attenuated AIBV vaccine is detrimental to poultry and other methods of vaccination should be pursued. Supported in part-USDA Animal Health and Disease Fund.
KEY WORDS: Avian Infectious Bronchitis Virus, Rooster, Efferent Ductules, Fertility