Date of Graduation


Document Type


Degree Name

Master of Science in Poultry Science (MS)

Degree Level



Poultry Science


Billy Hargis

Committee Member

Lisa Bielke

Second Committee Member

Guillermo Tellez


Bacteria, Diminish, Formaldehyde, Microbial, Probiotic


Formaldehyde has been used for decades as a disinfectant in the poultry hatchery. Hatch cabinets are treated with formaldehyde to control the microbial bloom that occurs inside of the hatch cabinet as the hatch progresses. Even with formaldehyde being a known human carcinogen and the detriment that it has on living creatures millions of chicks are exposed to formaldehyde in the hatch cabinet. In these experiments we tested a lyophilized probiotic spray inside of the hatch cabinets from day nineteen to day twenty one to control the microbial bloom that occurs. Hatch cabinet environments were sampled in six experiments. Media used allowed for the recovery of Gram-negative bacteria, non-selective bacteria, and presumptive lactic acid bacteria. Intestinal samples were taken on day of hatch in three experiments. The probiotic mixture consisted of Lactobacilli and Bacillus subtilis isolates. In these trials the probiotic treatment was shown to colonize the gastrointestinal tract of the newly hatched chicks. The probiotic treatment was also able to suppress the early Gram-negative microbial bloom that occurs inside of a hatch cabinet. Later on in the hatch period the probiotic treatment was not able to match formaldehyde for Gram-negative suppression. While the probiotic treatment could not suppress the Gram-negative microbial bloom as well as formaldehyde it did alter the gut microflora on day of hatch. In three separate experiments the probiotic treated chicks had significantly lower levels of Gram-negative bacteria recovered from intestinal samples than the formaldehyde treated chicks. In the third experiment this significant reduction in Gram-negative bacterial recovery by the probiotic continued out to twenty four hours post-hatch as well. When intestinal samples were pasteurized and plated on Tryptic soy agar plates in experiments two and three the only growth was that of the Bacillus subtilis. Probiotic hatch cabinet treatment did not have a significant impact on presumptive lactic acid bacteria except for in experiment two where the formaldehyde treated cabinet had significantly higher levels of presumptive lactic acid bacteria recovered.