Early life environment affects behavior, welfare, gut microbiome composition, and diversity in broiler chickens

Abstract

This study aimed to identify whether early-life conditions in broiler chickens could affect their behavior and welfare, and whether or not this was associated with an altered gut microbiome composition or diversity. Broilers were tested in a 2 x 2 factorial design with hatching conditions [home pen (OH) or at the hatchery (HH)] and enrichment (dark brooder (EE) or no brooder (NE) until 14 days of age) as factors (N = 6 per treatment combination). Microbiota composition was measured in the jejunum on days (d) 7, 14, and 35 and in pooled fecal samples on day 14. A novel environment test (NET) was performed on days 1 and 11, and the behavior was observed on days 6, 13, and 33. On day 35, composite asymmetry was determined and footpad dermatitis and hock burn were scored. In their home pen, HH showed more locomotion than OH (P = 0.05), and NE were sitting more and showed more comfort behavior than EE at all ages (P <0.001 and P = 0.001, respectively). On days 6 and 13 NE showed more eating and litter pecking while sitting, but on day 33 the opposite was found (age*enrichment: P = 0.05 and P <0.01, respectively). On days 1 and 11, HH showed more social reinstatement in the NET than OH, and EE showed more social reinstatement than NE (P <0.05). Composite asymmetry scores were lower for EE than NE (P <0.05). EE also had less footpad dermatitis and hock burn than NE (P <0.001). Within OH, NE had a more diverse fecal and jejunal microbiome compared to EE on day 14 (feces: observed richness: P = 0.052; jejunum: observed richness and Shannon: P <0.05); the principal component analysis (PCA) showed differences between NE and EE within both HH and OH in fecal samples on day 14, as well as significant differences in bacterial genera such as Lactobacillus and Lachnospiraceae (P <0.05). On day 35, PCA in jejunal samples only showed a trend (P = 0.068) for differences between NE vs. EE within the OH. In conclusion, these results suggest that especially the dark brooder affected the behavior and had a positive effect on welfare as well as affected the composition and diversity of the microbiome. Whether or not the behavior was modulated by the microbiome or vice versa remains to be investigated.

Enhancing their quality of life: environmental enrichment for poultry

“…Dark brooders simulate the hen and provide a warm and dark resting place. Broilers provided with a dark brooder until d 14 of age showed less footpad dermatitis as compared to the control group without brooders ( de Jong et al., 2022 ).…”

The Hatching Time of Broiler Chickens Modifies Not Only the Production Traits but Also the Early Bacteriota Development of the Ceca

“…Several studies reported that the delay in access to feed may affect the microbiota development. A huge increase in microorganisms occurs in the chicken's intestine after the first ingestion of feed [50][51][52]. According to our results, the early-hatched birds, which were longer without feed, had more diverse cecal microbiota than the late-hatched birds.…”

Designing a More Sustainable and Environmentally Friendly Food Supply: A Roadmap for Future Food and Agricultural Research

“…149−151 Research is therefore being carried out to better quantify animal welfare (e.g., using video surveillance), 152,153 to reduce the pain and distress animals experience throughout their lifetimes (including during handling, transportation, and slaughter) 154,155 and to develop methods of reducing the number of animals used in agricultural research (e.g., by using in vitro digestion methods rather than in vivo feeding studies). 156,157 Research is also being carried out to better understand the relationship between the gut microbiome of livestock animals and their welfare. 158,159 This knowledge could then be used to optimize feed and living conditions to promote the establishment of a healthy microbiome.…”

“…There is interest in improving animal welfare due to ethical concerns about the large-scale production of meat, eggs, and milk (especially in intensive farming facilities) as well as because this may lead to improvements in productivity and nutritional quality. − Research is therefore being carried out to better quantify animal welfare (e.g., using video surveillance), , to reduce the pain and distress animals experience throughout their lifetimes (including during handling, transportation, and slaughter) , and to develop methods of reducing the number of animals used in agricultural research (e.g., by using in vitro digestion methods rather than in vivo feeding studies). , Research is also being carried out to better understand the relationship between the gut microbiome of livestock animals and their welfare. , This knowledge could then be used to optimize feed and living conditions to promote the establishment of a healthy microbiome. Researchers are also developing alternatives to conventional antibiotics and vaccines with the aim of improving animal health, reducing pollution, decreasing food contamination, and reducing the risks of antibiotic resistance. − In general, an improved understanding of the various factors impacting animal health and disease would increase the sustainability of the livestock industry by optimizing productivity and reducing losses.…”