Associations between on-farm welfare measures and slaughterhouse data in commercial flocks of turkey hens (Meleagris gallopavo)

Abstract

There is a growing demand for documentation of animal welfare in meat production industry. Research on turkey welfare has mainly focused on toms at the end of production cycle, and information on the relationship between on-farm welfare and slaughterhouse recordings for turkey hens is currently lacking. The aim of this study was to investigate the relationship between routinely collected slaughterhouse data from turkey hens and their on-farm welfare measured by transect walks, to identify potential retrospective welfare indicators. The study was conducted between November 2017 and March 2018 in 20 commercial turkey flocks in Norway. On-farm welfare was evaluated using the transect walk method when the turkey hens were 11 wk old, recording the number of birds that were immobile, lame, small, featherless, dirty, sick, terminal, or dead and had visible head, tail, or wing wounds. Slaughterhouse data was provided for each flock. Univariate and multivariate linear regression models were used to investigate the associations between the variables. The results showed significant associations between several measures on farm and at slaughter. Flocks with more lameness on farm had more birds rejected at the slaughterhouse owing to leg and joint issues ( P = 0.03, r = 1.01). Featherlessness and dirtiness on farm were positively associated with airsacculitis ( P = 0.005; r = 0.42 and P = 0.0008; r = 0.57, respectively). The results suggest that slaughterhouse registrations may provide both practical and feasible retrospective information on the welfare of turkey hens that potentially could be implemented in future welfare assessment schemes. Further studies are needed to investigate the causal factors behind the identified relationships.

Developing a novel welfare assessment tool for loose-housed laying hens – the Aviary Transect method

“…The transect method has been shown to be an effective tool for early detection to predict welfare issues and production results in broilers ( BenSassi et al, 2019a , b ) and turkeys ( Marchewka et al, 2019 , 2020 ; Vasdal et al, 2021 ). As production cycles in laying hens last longer, application of the Aviary Transect method at an early production stage may be even more valuable, as emerging issues will cause larger problems over longer production periods ( Drake et al, 2010 ).…”

Evaluation of Welfare in Commercial Turkey Flocks of Both Sexes Using the Transect Walk Method

“…Dirtiness before slaughtering the hens has also been reported by other authors, although not with such a high prevalence as in our study. In a study conducted in Norway, an average of 0.36% dirty males and 0.15% females were observed at 11 weeks [ 9 , 11 , 30 ]. In Italian commercial turkey flocks, dirtiness was recorded in 0.022% of females.…”

“…The percentage of sick birds was low, but the difference between the sexes was significant. For classifying a bird as sick, other studies also included birds with pendulous crop [ 7 , 8 , 9 , 11 , 30 ]. In our study, birds with pendulous crop were recorded separately, and so no direct comparison could be made.…”

“…While walking, the observer records every bird affected by health and welfare indicators such as small size, dirty or featherless birds, birds with head, back, or tail wounds, immobile, lame, sick, terminally ill, or dead birds, and birds showing aggressive behavior toward other birds or humans [ 10 ]. The transect walk can be used at different ages in turkeys, provides relevant information on animal welfare during the rearing period, and allows farmers to make changes and improve welfare for current flocks [ 11 ]. The health and welfare of commercially farmed turkeys supposed to be attributed to the high growth potential of the commonly used commercial hybrids [ 12 , 13 ], and also depend on environmental factors such as air quality [ 14 , 15 ], ambient temperature [ 16 , 17 ], light intensity and duration of day length [ 18 , 19 ], and stocking density [ 2 , 20 ].…”

“…Hens are slaughtered when the birds reached an average body weight of 9 kg at around 14 weeks, while toms are reared until 21 to 22 weeks of age. There are limited field studies on welfare in such mixed flocks during the fattening period because most previous studies have been carried out before slaughter [ 7 , 8 , 11 ]. The aim of this study was to identify transect-based on-farm welfare indicators of commercial turkeys of both sexes at three different points in time during the fattening cycle; 3 to 4 weeks after placement and before slaughtering the hens and toms.…”