INOVOCOX™
ONSET OF IMMUNITY AFTER IN OVO DELIVERY TO BROILERS
V. W. Doelling, R. M. Poston, C. L.
Heggen-Peay, G. F. Mathis2, A. Martin, J. R. Upton,
and L. M. Charniga.
1Embrex Inc., P. O. Box 13989, Research Triangle Park,
NC 27709
2Southern Poultry Research, Athens, GA 30607
vdoelling@embrex.com
Broiler
eggs were vaccinated in ovo at 18 days of embryonation
with Inovocox™, a coccidiosis vaccine consisting
of live sporulated oocysts of E. acervulina, E. tenella
and two strains of E. maxima. Vaccine safety was demonstrated
by comparable percent hatch for vaccinates and non-vaccinated
controls. At hatch, chicks were vent-sexed and male
chicks were selected. Birds were placed in 5 floorpens
per treatment with 45 birds per pen. To assess efficacy,
a subset of birds (5 per pen; 25 per treatment group)
were weighed and orally challenged with mixed Eimeria
sp (homologous strains) on days 14, 21/22, 28, and
35. Six days post challenge, birds were individually
weighed and lesions evaluated in the upper, mid, and
cecal regions of the intestines. Results indicated
a progression in development of immunity over time.
Following challenge, statistical improvement in weight
gain and some decrease in lesion formation was observed
as early as day 14. By day 21/22, full immunity was
achieved with improved weight gain and lower lesion
scores for all Eimeria species demonstrated in vaccinated
birds when compared with non-vaccinated birds. These
data establish that in ovo vaccination with live oocysts
is safe and efficacious in broiler chickens.
