A new study from Indian Council of Agricultural Research institutes reports that two interventions applied at very different life stages—warming embryos inside the egg before hatch, and supplementing young chicks with turmeric and ginger in the feed—can together improve heat resilience, immune indicators, and body weight in CARI-Debendra, a slow-growing Indian poultry line.
The research, published in Frontiers in Physiology, combined embryonic thermal conditioning (ETC) with early post-hatch herbal supplementation. In the ETC treatment, eggs were exposed to 39.5 degrees Celsius at 60 to 70 percent relative humidity for five hours daily during embryonic days 11 to 16.
About 224 chicks from control and ETC groups were divided into herbal-supplemented and non-supplemented groups and followed for 12 weeks in a 2 × 2 factorial design. Turmeric (Curcuma longa) and ginger (Zingiber officinale) were each added to the diet at a 1 percent inclusion level. Before feeding, both herbs were chemically screened using Fourier-transform infrared spectroscopy (FTIR) and gas chromatography–mass spectrometry (GC-MS) to confirm their active constituents.
The phytochemical profiling identified curcumin, 1-decanol, 2-hexyl-, and 1-heptacosanol in turmeric, while ginger showed gingerols and shogaols, zingiberene, limonene, and several other compounds. According to the authors, these constituents exhibit antioxidant and immunomodulatory activities, which may explain the physiological changes observed in the supplemented birds.
Growth results favored the ETC group, whose birds reached higher body weights than controls (p < 0.01). However, ETC birds had lower thigh percentage (p < 0.05), spleen weight (p < 0.05), and intestinal weight (p < 0.01) than control birds, and the conditioning did not alter intestinal architecture. An interaction effect between ETC and post-hatch herbal supplementation on body weight appeared only at the third and fifth weeks, suggesting the combined benefit on growth was transient rather than sustained across the whole rearing period.
The most telling signals came from blood measurements. Serum thyroxine (T4) levels and creatine kinase activity were elevated in the ETC plus herbal supplementation group, while the heterophil-to-lymphocyte (H/L) ratio—a classic indicator of stress in birds—and triiodothyronine (T3) levels were lower. A reduced H/L ratio alongside these hormonal shifts suggests the treated birds were coping better with heat, pointing to improved thermotolerance rather than simply altered metabolism.
The study’s scope and limitations deserve emphasis. It was conducted on a single slow-growing breed under tropical coastal conditions, with a modest number of birds over 12 weeks, and the growth interaction appeared at only two time points. The authors also note that ETC had adverse effects on thigh weight, spleen weight, and intestinal weight relative to controls, so the intervention is not without trade-offs. The herbal compounds are described as potential alternate candidates for further investigation to improve growth performance, egg quality, and economic efficiency in poultry—not as proven replacements for conventional interventions.
Nevertheless, the conclusion drawn by the research team is that combining ETC at 39.5 degrees Celsius and 60 to 70 percent relative humidity for five hours daily during embryonic days 11 to 16 with natural feed additives like turmeric and ginger improved heat resilience, immune competence, and productivity of CARI-Debendra poultry under tropical conditions.
Subject of Research: Combining embryonic thermal conditioning with turmeric and ginger feed additives to improve heat tolerance in slow-growing poultry
Article Title: Assessing the combined effects of embryonic thermal conditioning and herbal feed additives on acquired thermotolerance of slow-growing poultry in a coastal climate
Article References: Nayak, N., Bhanja, S. K., Chakurkar, E. B., Sahu, A. R., Palai, S., & Pattanaik, A. K. (2026). Assessing the combined effects of embryonic thermal conditioning and herbal feed additives on acquired thermotolerance of slow-growing poultry in a coastal climate. Frontiers in Physiology, 17, Article 1861569. https://doi.org/10.3389/fphys.2026.1861569
Image Credits: AI Generated
DOI: 10.3389/fphys.2026.1861569
Keywords: poultry, thermotolerance, embryonic thermal conditioning, turmeric, ginger, heat stress, feed additives, CARI-Debendra, phytochemicals, tropical agriculture, Assessing, combined
News Source: Drew Townsend. (October 30, 2026). Warm Eggs Before Hatch Plus Turmeric and Ginger Boost Heat Tolerance in Chickens. Scienmag.
