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

Abstract

SUMMARY: Within aviary systems, open litter areas are provided to allow hens to express a more robust behavioral repertoire. 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 aviary housing systems. Hens were housed in a commercial, cage-free multitier aviary with open litter areas, which contained one of three forage substrates (straw, artificial turf, and shavings) or bare concrete floors. Environmental and egg sampling occurred at hen ages: 25, 37, 51, and 64 wk. 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; shavings: 7.16 log cfu/mL) as the flocks aged. As the flocks aged, lower levels of yeasts and molds were 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; shavings: 7.61 log cfu/mL). No differences in Salmonella, Campylobacter, and Listeria spp. prevalence were observed between the substrate groups. Although aerobic bacteria, Enterobacteriaceae, yeasts and molds, and pathogens were present in the environment of the substrate groups, it did not impact egg microbiology. The lower microbial and yeasts and molds levels in this study suggest that artificial turf could be an appropriate forage substrate for commercial cage-free aviary housing, however further research is needed.

Keywords

• eggs
• aviary
• microbiology
• forage substrate