# A Decade of Evidence on Broiler Chicken Dead-on-Arrival Rates and Risk Factors: A Scoping Review

## TL;DR

This review examines how often broiler chickens die before reaching slaughter and identifies factors that increase the risk, such as poor health and stressful conditions.

## Contribution

The study provides a comprehensive synthesis of risk factors for dead-on-arrival broiler chickens over the past decade.

## Key findings

- Mean dead-on-arrival rates ranged from 0 to 0.85%.
- Key risk factors include journey duration, ambient temperature, and body weight.
- Improving handling and aligning practices with environmental conditions can reduce deaths.

## Abstract

Broiler chickens can experience significant distress during the period before slaughter, and some birds die before they arrive at the slaughter plant. These early deaths raise serious animal welfare concerns. The aim of this review was to examine existing research to understand how often these deaths occur and what factors increase the risk. We examined published studies from the past decade that reported rates and factors linked to these deaths. The review identified several risk factors that could be grouped into four main areas: poor bird health, distress, exposure to extreme temperatures, and physical injury. Factors related to flock health, catching and loading methods, transportation duration and distance, and environmental conditions were especially important. Overall, this review shows that many factors can contribute to an early death, but there are also opportunities to reduce the issue. Consideration of the bird’s health, careful handling, reducing duration, and adjusting practices to weather conditions can improve animal welfare and reduce death rates.

The preslaughter phase for broiler chickens is distressing and can result in death prior to slaughter. The severity of this animal welfare concern warrants the exploration of the rates and risk factors. The aim of this scoping review was to synthesize current knowledge on rates and associated farm, flock, and preslaughter risk factors for dead-on-arrivals (DOA). Peer-reviewed experimental or observational studies were included that were written in English, published between January 2014 and December 2024, and that reported broiler chicken DOA with rates or associated risk factors in Google Scholar and ScienceDirect. A total of 344 articles were identified, and 24 articles met the eligibility criteria. Mean DOA rates ranged from 0 to 0.85%. In total, nine on-farm or flock-level and 11 preslaughter risk factors were identified, which could be categorized under four major causes of DOA: poor health, distress, thermal stress, and trauma. The risk factors most commonly identified were journey duration and distance, season, ambient temperature, lairage duration, and body weight. The findings highlight multiple opportunities to reduce DOA, including greater consideration of flock characteristics in preslaughter decision making, growing flocks that are at reduced risk of DOA, improvements in catching and loading practices, and better alignment of preslaughter management with environmental conditions.