Managing health issues in broilers: first-week mortality

As a significant factor, the first-week mortality for broiler flocks indicates the health status and performance of the broiler flocks during the rearing period. Several factors, which include animal-related factors, egg and incubation-related factors, and external factors, have been shown to affect the first-week mortality. A first-week mortality rate up to 1% is unavoidable, and the pattern of the first-week mortality could be the source of potential factors. Animal-related factors are discussed such as strain, sex, and breeder flock age. Besides, the first-week mortality could be affected by egg source (clean, nest, floor, or washed eggs), egg weight, egg storage duration, egg shell conditions (dirty, stained, clean), and incubation environmental properties. The chick transportation conditions, preplacement holding time, season, broiler flock size, stocking density, type of ventilation, litter quality, and type of drinkers are discussed as external factors of the first-week mortality. The first-week mortality has been shown to be an indicator of the broiler flock health and previous animal-related, egg, and incubation factors, as well as external environmental conditions. The first-week mortality can provide information not only about farm environmental conditions but also about sources of the eggs or the chicks besides infections. Therefore, there is a need to put more effort into the first 7 days of the chicks’ lives to make sure they develop good drinking and feeding behavior and thus can cope with potential challenges quickly.