Data evaluation of broiler chicken rearing and slaughter—An exploratory study

Abstract

To process and evaluate the data from broiler fattening and slaughtering, we investigated the production data of 107 straight run flocks of the commercial meat-type breed Ross 308 (Aviagen, EU). All flocks were raised and slaughtered in Germany and the average slaughter age was 37 days. The health outcomes of interest were mortality, average weight, and the slaughter results. First-week mortality, cumulative mortality, stocking density, flock size, season, production week of the parental flock, farm, antibiotic treatment, and the interaction between antibiotic treatment and season were considered as possible influencing factors. The average first-week mortality (FWM) and cumulative mortality percentages were 0.66 and 2.74%, respectively. First-week mortality was influenced by flock size, production week of the parental flock, and the interaction between antibiotic treatment and season, whereas cumulative mortality was influenced by antibiotic treatment, farm, and first-week mortality. The average weight (mean 2.30 kg) was influenced by season, stocking density, flock size, farm, and the interaction between antibiotic treatment and season. The condemnation rate was on average 1.48%, with the most common causes being deep dermatitis (mean 0.63%), ascites (mean 0.53%), and not suitable for production/general disease (mean 0.25%). Several factors influenced the causes of condemnation, with season being the most predominant one, followed by the interaction between antibiotic treatment and season, the antibiotic treatment alone, and stocking density.

Comparison of carcass condemnation causes in two broiler hybrids differing in growth rates

“…Ascites develops gradually and might compromise the bird's welfare over a long time period. The condemnation prevalence of ascites in Ross is in line with the ndings in recent studies in Finland and Germany 23,24 .…”

“…In the present study we report a seasonal effect, with the estimated prevalence of ascites being highest during winter and lower in the summer for both hybrids; however, with a more pronounced seasonal effect in Ross compared to Hubbard. The nding of seasonal variations in the prevalence of ascites is not surprising, as earlier studies have shown that higher oxygen demand in a cold climate might increase the risk of ascites 24,26 . The smaller seasonal effect on Hubbard suggests that slower growing hybrids are less sensitive to seasonal changes than faster growing broilers.…”

Footpad dermatitis, hock burns and condemnation rates at slaughterhouse as on-farm welfare indicators

“…The average condemnation rate per ock of 1.40 (range between 0.10% and 10.48%) was similar to the obtained by Haslam et al [12], Saraiva et al [4] and Junghans et al [35] with an average rejection rate of 1.23 (range 0.07 and 5.51%), of 1.53 (ranging from 0.32 to 7.29%) and 1.48 (ranging from 0.12 to 4.63%), respectively. In the present study, the most frequent cause of condemnation was emaciation (0.59%), followed by abnormal color (0.49%), cellulites (0.15%) and ascites (0.10%).…”

“…However, differences in the condemnation rate of small broilers could have been due to differences in disease occurrence on farms or culling management within companies. An increased prevalence of these broilers is a sign of weakened welfare of the broiler ock on-farm [20,35] and is usually a sign of long-standing disease as locomotor problems and inability to reach food [16,34].…”

“…Slaughterhouse A and C showed signi cant differences from slaughterhouse B regarding the condemnations rates by ascites (P = 0.002) with slaughterhouse B showing the highest percentages (0.20 ± 0.27%). Ascites is a result of a pulmonary hypertension syndrome, which is a consequence of a rapid growth rate and is a signi cant condemnation cause in many European countries such as Denmark (0.20%) [13], the UK (0.45%) [36] and Germany (0.53%) [35]. The low temperatures in cold weather may force farmers to reduce ventilation in order to keep the poultry houses warm leading to high levels of ammonia which predisposing lung diseases and ascites [21] and this might be the main circumstance responsible for the development of ascites in broilers from the present study which was performed throughout cold weather.…”