# Ammonia mitigation and welfare enhancement in broilers using zeolite–clay–rice husk ash bedding supplement

## TL;DR

A new bedding material made from zeolite, clay, and rice husk ash improves broiler welfare and reduces ammonia levels in poultry houses.

## Contribution

The study introduces a novel zeolite–clay–rice husk ash bedding formulation that effectively mitigates ammonia and enhances broiler welfare.

## Key findings

- The ZCR bedding formulation reduced in-house ammonia concentrations by up to 50%.
- Broilers on ZCR bedding showed lower stress indicators and fewer footpad lesions.
- ZCR-treated litter had lower pH, moisture, and ammonia emissions compared to rice husk alone.

## Abstract

Ammonia (NH₃) accumulation in broiler houses poses serious environmental and welfare challenges, causing respiratory irritation, impaired immunity, and footpad dermatitis. To address the limited long-term effectiveness of conventional materials like rice husk, this study evaluated a novel zeolite–clay–rice husk ash (ZCR) bedding formulation on broiler performance, welfare, litter quality, and in-house ammonia concentrations under commercial-like conditions. A total of 476, female Ross 308 broilers were randomly allocated to four treatments following a completely randomized design (seven replicate pens per treatment): control (5 cm thickness of rice husk, T1) or rice husk supplemented with ZCR bedding formulation at 10 % (T2), 20 % (T3), or 40 % (T4) of rice husk weight in T1 group. Birds were reared for 38 days in an evaporative-cooled house. Growth performance, including body weight, average daily gain, and feed conversion ratio, did not differ significantly among treatments (P > 0.05). In contrast, welfare indicators were significantly improved in birds reared on the 40 % ZCR bedding. Compared with the control, T4 birds exhibited lower heterophil-to-lymphocyte ratios, reduced serum cortisol concentrations (approximately 30 % reduction), and decreased footpad lesion severity (P < 0.05). T4 also maintained lower in-house NH₃ concentrations, reaching 50 % lower levels than the control at the end of the grow-out period. Litter collected at day 38 from ZCR-treated pens exhibited lower pH, reduced moisture content, and markedly lower NH₃ emissions. Correlation and orthogonal polynomial analyses further demonstrated dose–response relationships between graded ZCR inclusion, ammonia reduction, and welfare-related parameters. In conclusion, the novel ZCR bedding formulation effectively reduced NH3 emissions, reduced physiological stress and improved broiler welfare without compromising growth performance. These benefits are particularly relevant for tropical poultry production systems, where high humidity accelerates litter degradation and NH3 release.