Influence of forage substrates on environmental and egg microbiology in cage-free aviary housing flocks.

Authors: Garcia, Javier; Jones, Deana; Gast, Richard; ROBISON, CARA - Michigan State University; REGMI, PRAFULLA - University Of Georgia; KARCHER, DARRIN - Purdue University

Submitted to: Journal of Applied Poultry Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/13/2021
Publication Date: 3/20/2022
Citation: Garcia, J.S., Jones, D.R., Gast, R.K., Robison, C.I., Regmi, P., Karcher, D.M. 2022. Influence of forage substrates on environmental and egg microbiology in cage-free aviary housing flocks. Journal of Applied Poultry Research. https://doi.org/10.1016/j.japr.2021.100225
DOI: https://doi.org/10.1016/j.japr.2021.100225

Interpretive Summary: In commercial aviary housing systems, hens are provided with open litter areas to practice natural behaviors such as dust bathing and foraging. However, research is limited on the impact of forage substrates on environmental and egg microbiology. The objective of this study was to examine the impact of forage substrates on environmental and egg microbiology in commercial cage-free aviary housing. Hens were housed in commercial, cage-free multi-tier aviary with open litter areas, which contained one of three forage substrates (straw, artificial turf, and pine wood shavings) or bare concrete floors. Environmental and egg sampling occurred at hen ages: 25, 37, 51 and 64 wk of age. Aerobic bacterial levels from drag swabs taken from the litter area were lower in the artificial turf group compared to the other groups. Over time, yeast and mold levels were lower in the litter area of the artificial turf group compared to the other groups. No differences in pathogen prevalence (Salmonella, Campylobacter, and Listeria spp.) were observed between the substrate groups. More research is needed but the lower levels of aerobic bacteria and yeast and mold in the artificial turf group may suggest artificial turf might a good forage substrate for cage-free aviary housing systems.

Technical Abstract: Within aviary housing systems, open litter areas are provided to allow hens to practice natural behaviors such as dust bathing and foraging. However, data is limited on the influence forage substrates have on environmental and egg microbiology. The objective of this study was to examine the impact of forage substrates on environmental and egg microbiology in commercial cage-free aviary housing. Bovan white hens were housed in a commercial, cage-free multi-tier aviary with open litter areas, which contained one of three forage substrates (straw, artificial turf, and pine wood shavings) or bare concrete floors. Environmental and egg sampling occurred at hen ages: 25, 37, 51 and 64 wk of age. Drag swab aerobic bacteria levels from the litter area of the artificial turf group were lower (6.86 log cfu/mL) compared to the other substrate groups (P < 0.001; concrete: 7.39 log cfu/mL; straw: 7.40 log cfu/mL; pine wood shavings: 7.16 log cfu/mL) as the flocks aged. As the flocks aged, lower levels of yeasts and molds were also observed in the litter area of the artificial turf group (6.72 log cfu/mL) compared to the other substrates (P < 0.02; concrete: 7.54 log cfu/mL; straw: 7.36 log cfu/mL; pine wood shavings: 7.61 log cfu/mL). No differences in pathogen prevalence (Salmonella, Campylobacter, and Listeria spp.) were observed between the substrate groups. Although aerobic bacteria, Enterobacteriaceae, yeasts and molds, and pathogens were present in the environment of the various substrate groups, it did not impact egg microbiology. Lower aerobic bacteria and mold and yeast levels may suggest that artificial turf could be a good forage substrate for commercial cage-free aviary housing however further research is needed.