Date of Graduation


Document Type


Degree Name

Master of Science in Poultry Science (MS)

Degree Level



Poultry Science


Billy Hargis

Committee Member

Karen Christensen

Second Committee Member

Wayne Kuenzel

Third Committee Member

Jacob Lum


Embryos, Formaldehyde, Hatchery, Heat stress, Weight


Formaldehyde has been used as a disinfectant in poultry hatching cabinets to aid in controlling key pathogenic organisms, such as Salmonella and Escherichia coli (E.coli). There is some evidence that prolonged exposure of chicks to formaldehyde can reduce tracheal ciliary function and thus reasons to believe that exposure to formaldehyde, in the absence of pathogen challenge, may reduce chick vitality. It has been found that elevated temperatures during incubation may adversely affect body weights of broiler chicks, as well as post-hatch environmental heat stress on performance in poultry. Post-hatch environmental heat stress has been shown to impact performance in poultry. The objective of these experiments was to analyze the effect of formaldehyde treatment or heat stress in the hatch cabinet on body weights (BWs) and body weight gain (BWG). In Exp. 1, 18 day embryos were randomly assigned to either a control, non-treated hatcher or a formaldehyde treated hatcher, where formaldehyde was applied to achieve 1-2 ppm during the hatch period. Chicks from each group were weighed and neck-tagged with discrete numbers, and were then co-mingled post-hatch for determination of BW and BWG days 0, 7, and 10. At day 7 and day 10, we measured significantly (p<0.05) lower BW and BWG for chicks in the formaldehyde group as compared to control, non-treated chicks suggesting that this level of formaldehyde exposure in the hatching environment (1-2 ppm) may negatively impact early performance. In Exp. 2, 18 day embryos were randomly assigned to a control, non-treated hatcher, formaldehyde- treated hatcher (1-2 ppm), or heat stress (37.8˚C) treated hatcher. At day 10, BWG was significantly (p<0.05) lower for the formaldehyde and heat stressed treated groups than the control, non-treated group. Based on these results, formaldehyde treatment (1-2 ppm) or heat stress (37.8˚C) in the hatching environment may negatively influence early broiler performance. While hatching cabinet treatment with formaldehyde under commercial conditions has known beneficial effects on controlling microbial blooms during late hatch, and has been associated with improved livability, formaldehyde treatment, or heat stress, may also be limiting performance potential of broiler chicks.