Factors influencing bruises and mortality of broilers during catching, transport, and lairage

Abstract

A multilevel analysis was performed to identify and quantify risk factors associated with mortality and bruises occurring between catching and slaughter of broiler flocks. The effect of each factor in the final model was expressed as an odds ratio (OR). Data included 1,907 Dutch and German broiler flocks slaughtered in 2000 and 2001 at a Dutch processing plant. The mean dead on arrival (DOA) percentage was 0.46. Percentage of bruises was corrected for economic value. The mean corrected bruises percentage was 2.20. Factors associated with corrected bruises percentage were season, moment of transport, and ambient temperature. Unfortunately, these factors are quite difficult to manipulate. Factors associated with DOA percentage were ambient temperature, moment of transport, catching company, breed, flock size, mean BW, mean compartment stocking density, transport time, lairage time, and the interaction term transport time x ambient temperature. The most important factors that influence DOA percentage, and which can be reduced relatively easily, were compartment stocking density (OR = 1.09 for each additional bird in a compartment), transport time (OR = 1.06 for each additional 15 min), and lairage time (OR = 1.03 for each additional 15 min). In particular, reduction of transport and lairage times might have a major influence due to their large variations. Reducing or removing these factors will reduce DOA percentage. Consequently, profitability and animal welfare will increase.

Factors associated with mortality of broilers during transport to slaughterhouse

“…The temperatures recorded varied less than those reported in other studies (Nijdam et al, 2004). Consequently, the temperature and seasonal effects might have been less marked than suggested elsewhere (Petracci et al, 2006;Vecerek et al, 2006).…”

“…Space was considered ', the recommendations' when the ratio was , 100%, ' > the recommendations' when the ratio was > 100%. Mortality during broiler transport in the United Kingdom (Haslam et al, 2008), and 0.25% in the Czech Republic (Vecerek et al, 2006), but less than the 0.35% reported in Italy (Petracci et al, 2006), 0.38% in Manitoba and 0.46% in the Netherlands (Nijdam et al, 2004). The differences in DoA rates observed between countries may be partly attributed to weather differences.…”

“…The differences in DoA rates observed between countries may be partly attributed to weather differences. Very high and very low temperatures were recorded in Italy (Petracci et al, 2006) and the Netherlands, respectively (Nijdam et al, 2004), whereas medium temperatures were recorded in France, and the study carried out in the United Kingdom did not include period with hot weather (Haslam et al, 2008). However, the influence of other differences in genetics, rearing, catching or transport cannot be excluded, since the on-farm mortality rates reported in Manitoba with medium temperatures were also greater than those observed in France .…”

“…Most studies focused on the effect of one particular processing step, such as catching (Knierim and Gocke, 2003;Nijdam et al, 2005), transport (Nijdam et al, 2004;Vecerek et al, 2006), on-farm characteristics Haslam et al, 2008) or even the effect of the season (Petracci et al, 2006). To determine the risk markers for mortality during transport, it seemed important that all data regarding the rearing, catching and transport phases should be collected and examined at the flock level.…”

“…This relationship was also investigated on the basis of Dutch slaughterhouse data (Nijdam et al, 2004), and in Manitoba , high crating densities during transport were reported to be a stressor of highest importance for broilers (Delezie et al, 2007) resulting in avoidable economic losses to farmers. It has been hypothesized that thermal stress (hyperthermia) is involved through increased environmental humidity and insufficient ventilation rate (Nijdam et al, 2004). Nevertheless, a detrimental effect of low densities on injuries, which was not explored in this study, cannot be excluded.…”