High-zinc diets accelerate molting and recovery by remodeling the cecal microbiome in laying hens
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Published on: October 29, 2021
Ling Chang1,2,3, Fang Peng1,2,3, Yue Zuo4
1College of Animal Science and Technology, Hunan Agricultural University, Changsha, Hunan, China.
Introduction:
Conventional fasting molting can restore laying performance but imposes substantial physiological stress and welfare concerns. High-zinc diets (2% ZnO) have been proposed as a less stressful alternative, but their mechanisms remain unclear.
Methods:
This study compared fasting-induced molting with zinc oxide supplementation in 384 Lohmann Pink hens (65 wk). Serum, cecal contents, and ovaries were sampled across six stages from pre-molt to post-molt recovery.
Results:
ZnO accelerated cessation of lay (5.75 vs. 8.87 d) and earlier recovery to 50% production (15.25 vs. 16.62 d) with lower weight loss (25% vs. 30%). Multi-omics revealed that high-zinc feeding enriched beneficial microbes (e.g., Coprenecus pullicola, Fournierella spp.) involved in amino acid and cofactor biosynthesis, consistent with activated glycine/serine/lysine metabolism. ZnO also reduced inflammatory and barrier-injury signals (IL-1β, LPS, DAO) and promoted earlier recovery of reproductive hormones (higher IGF-1, earlier increases in E2 and LH). Both treatments improved post-molt egg quality; zinc better preserved albumen height and Haugh unit, while fasting increased shell thickness and yolk color.
Discussion/Conclusion:
These findings support that a high-zinc-associated microbial-metabolic profile mitigates stress, accelerates ovarian reset, and shortens the time to restore production.
