Date of Graduation


Document Type


Degree Name

Master of Science in Poultry Science (MS)

Degree Level



Poultry Science


Billy M. Hargis

Committee Member

Guillermo Tellez

Second Committee Member

Lisa R. Bielke


Chickens, Hatchability, In ovo, Marek's disease vaccine, Probiotic


It has previously been shown that effective probiotics can accelerate gut maturation and the development of a normal microflora in poultry. This results in increased resistance to enteric pathogens encountered by chicks early in life. Our objective in experiments 1 and 2 was to evaluate the effect of in ovo administration of FloraMax®-B11 (FM) on Marek’s disease (MD) herpesvirus of turkeys (HVT) vaccine protective efficacy. In Exp. 1, day 18 White Leghorn embryos were randomly distributed in four groups, 1) HVT vaccinated, no MDV challenge, 2) HVT + FM vaccinated, no MDV challenge, 3) HVT vaccinated, challenge with virulent MDV, 4) HVT+ FM vaccinated, challenge with virulent MDV. Exp. 2 was designed the same as Exp. 1, except chicks were challenged with a very virulent MDV strain. There was no significant difference (P> 0.05) in MD incidence between birds vaccinated with and without FM in the HVT vaccine. In Exp. 3 and 4, day 18 commercial broiler embryos were in ovo injected with either saline or FM to measure hatchability, microbiota composition, morphometric analysis, and Salmonella enterica serovar Enteritidis (SE) infection in chickens. The administration of the probiotic did not negatively affect hatchability, but significantly reduced (P