# Light intensity and cage position affect meat quality by regulating intestinal flora, inflammation and oxidation in broilers

## TL;DR

This study shows that light intensity and cage position affect chicken meat quality by influencing gut bacteria, inflammation, and oxidation in broilers.

## Contribution

The study reveals how light intensity and cage position interact to impact meat quality through changes in gut microbiota and physiological markers.

## Key findings

- Higher light intensity (4 lx) improved meat color and reduced cooking and drip loss.
- The Hm group (4 lx–middle) showed reduced inflammation and enhanced antioxidant capacity.
- Certain gut bacteria were linked to better meat quality and lower inflammation.

## Abstract

With improvements in living standards, high-quality food has become the preferred choice for high-quality living, leading to an increasing demand for chicken meat quality. Light intensity and cage position are crucial environmental factors in intensive farming systems and serve as environmental stressors linked to systemic inflammation and oxidative status in broilers. This study investigated the effects of light intensity and cage position on Jinling yellow-feather broiler meat quality.

A total of 1,200 male yellow-feathered broilers were randomly assigned to a 2 × 3 factorial arrangement. Treatments included two light intensities (4 lx and 1.5 lx) and three cage positions (upper, middle, and lower). There were six treatment groups: 4 lx–upper (Ht), 4 lx–middle (Hm), 4 lx–lower (Hs), 1.5 lx–upper (Lt), 1.5 lx–middle (Lm), and 1.5 lx–lower (Ls). Each group contained 10 replicates (cages) with 20 broilers each.

The 4 lx treatment significantly improved pH, and meat color (p < 0.05) while reducing cooking loss and drip loss (p < 0.05). Breast muscle and leg muscle pH24h in the middle showed significantly higher than the upper (p < 0.05). Significant light × cage position interactions affected breast muscle pH24h, meat color, protein content, IMF, Tyr, and C16:0 (p < 0.05); leg muscle pH45min, pH24h, cooking loss, Glu, and SFA (p < 0.05). Briefly, the Ht and Hm groups had higher levels of meat quality. In terms of serum inflammatory status and oxidative levels, with the exception of GSH-Px, all indicators were significantly influenced by the interaction of light intensity × cage position. The Hm group had significantly higher IL-10 levels and total antioxidant capacity, indicating reduced systemic inflammation and enhanced antioxidant capacity. Furthermore, Alistipes and Barnesiella were significantly enriched in the Hm group, negatively correlated with cooking loss in the breast muscle, and positively correlated with T-AOC. Faecalibacterium, unclassified_f_Lachnospiraceae, and Ruminococcus_torques_group were negatively correlated with drip loss in both breast and leg muscles and positively with IL-10.

These findings suggest that light intensity and cage position interact to affect meat quality, with observed improvements potentially linked to concomitant changes in gut microbiota, inflammation and oxidative status.