PARENT SESSION
MALE REPRODUCTIVE TRACT

Monday, August 2, 2004
10:30 AM–12:30 PM
Buchanan Courtyard

(180) VACCINATION WITH AVIAN INFECTIOUS BRONCHITIS VIRUS: CAUSE OF REDUCED FERTILITY IN ROOSTERS.

Zimmerman, Claire¹, Boltz, David¹, Howell, Rebecca¹, Bahr, Janice¹, ¹ Department of Animal Sciences, Urbana, IL

ABSTRACT- Roosters vaccinated with the live attenuated avian infectious bronchitis virus (AIBV) have decreased serum testosterone concentrations, epididymal stones, and reduced fertility. An extensive study of adult roosters showed that fertility in roosters with epididymal stones was reduced 40% and 35% following natural mating and artificial insemination, respectively. To gain a better understanding of this compromised fertility in AIBV vaccinated roosters, our objective was to characterize differences in sperm concentration, morphology, sperm storage and fertilization between vaccinated (VAC) and non-vaccinated (NON-VAC) roosters. Specific pathogen free Leghorn roosters were divided into two groups and either vaccinated or not vaccinated with the live attenuated AIBV according to industry practice. Semen was collected from birds 26-32 wks of age and sperm were counted. Semen samples from vaccinated roosters had significantly reduced sperm concentrations compared to non-vaccinated roosters (VAC: 4.58x10⁹ ± 1.54x10⁹ vs. NON-VAC: 6.29x10⁹ ± 1.67x10⁹ sperm/ml, P<0.03). In addition, sperm staining with eosin-nigrosin showed an increased incidence of cytoplasmic droplet retention on sperm heads from vaccinated roosters. To study sperm storage and fertilization in the female tract, hens (≥ 3 hens per rooster) were artificially inseminated with an equivalent number of sperm from either vaccinated or non-vaccinated roosters. Eggs were collected for the following 7 days, perivitelline membranes were examined in the area surrounding the germinal disc, and the number of holes made by sperm was counted as an indicator of the number of sperm attempting to fertilize the egg. The number of holes produced by sperm from vaccinated roosters was reduced compared to the number of holes produced by sperm from non-vaccinated roosters (P<0.01). We conclude that vaccination of roosters with AIBV causes a reduction in sperm number, an alteration in sperm maturation, and a decrease in the ability of sperm to survive in the female reproductive tract and/or to fertilize the egg. Supported in part by NIH PHS 2 T32 GM07283 (C.R.Z.), NIH PHS T32 HD07028 (D.A.B.), and Hatch ILLU-538-373 (J.M.B.)

KEY WORDS: Avian Infectious Bronchitis Virus, rooster