Risk factors for cumulative mortality in broiler chicken flocks in the first week of life in Taiwan

Abstract

(1) Factors influencing the survival of chickens in the first week of life in Taiwan were identified by modelling data from 63% of the annual national broiler production database (4769 broiler flocks). (2) Broiler chicks raised in rooms with open-curtain ventilation had the lowest mean first week cumulative mortality (CM), 1.30%, relative to those raised in rooms with negative pressure ventilation (1.42%) and water-cooled ventilation (1.37%). Increasing flock size reduced the CM. Broiler chicks shipped distances within 50 km had the lowest CM (1.22%), while broiler chicks raised in mountain areas showed the highest CM (1.65%). (3) Multiple regression analysis results indicate that ventilation type, flock size, shipping distance and delivery route influence CM in broiler chickens. Broiler chicks kept in rooms with negative pressure ventilation have an 11.22% greater CM compared to those in rooms with open-curtain ventilation. For each 1000-chicken increase in flock size, CM is reduced by 0.12%. For each kilometre increase in shipping distance, CM increases by 0.05%. Broiler chicks delivered via mountain routes show a 9.48% increase in CM compared to delivery via flat terrain. (4) Negative pressure ventilation and delivery via mountain routes are the most critical factors affecting the survival of chicks up to one week old.

Effects of a combined hatching and brooding system on hatchability, chick weight, and mortality in broilers

“…After hatch, the thermoregulatory system of chickens is limited (Nichelmann and Tzschentke, 2002) and warmth is a critical need to young birds. Early mortality in chickens and poults has been related to suboptimal truck temperatures and longer duration of transport from the hatchery to the farm (Carver et al, 2002;Chou et al, 2004). Low temperatures in the brooding phase lead to increased early mortalities in broiler chicks (Bruzual et al, 2000) and improper brooding conditions are a major important factor for decreased flock performance (Cobb-Vantress, 2008).…”

“…If long transporta-tion is involved, this period may be increased up to 72 h. Suboptimal conditions during transport and a delay in the moment of placement and the first feed and water intake are associated with higher early mortality in chicks and poults (Kingston, 1979;Carver et al, 2002;Chou et al, 2004) and impaired performance throughout the growout period (Halevy et al, 2000;Gonzales et al, 2003).…”

Comparison of flock characteristics, journey duration and pathology between flocks with a normal and a high percentage of broilers ‘dead-on-arrival’ at abattoirs

“…This contrasts with a previous study (Chauvin 397 et al, 2010), were an increasing on-farm mortality has been associated with an 398 increasing DOA %. Mortality during the first week of production is a measure of chick 399 quality and health (Chou et al, 2004), and even though the total mortality rate during 400 production not affected DOA % it can be hypothesized that a poor chick quality may 401 persist thorough out the production period and give increased mortality in transit. caused by necrotic dermatitis on the plantar surface of the foot.…”

Effects of White Roman gosling quality on their growth parameters, intestinal villus morphology, blood biochemistry, and nonspecific pathological lesions

“…Heier et al (2002) found that the mortality rate during the first week was 1.54%, and the average weekly cumulative mortality was 0.48% during the growing period. Chou et al (2004) showed that broilers raised indoors with open-curtain ventilation had the lowest mean first week cumulative mortality, 1.30%, relative to those raised indoors with negative pressure ventilation (1.42%) and water-cooled ventilation (1.37%). Weak goslings had higher mortality rates during the growing period.…”