## 4 Discussion  
### Methodology  
The main object of this study was to assess the marbling level of carcasses from young bulls produced for the German beef market. This study included only 174 carcasses of bulls and the selection of the sample was limited. It needs to be increased to a representative sample of German bull carcasses. However, the very heterogeneous nature of the sample enabled comparisons of the results of VIA at different positions in a wide variation of carcasses. Furthermore, when butchers are not familiar with the different cuts, and when the process line is not adapted to the US rib-eye cutting systems, training for accurate rib-eye cutting is essential.  
In the current study, a high number (\(n\) = 126) of carcasses could not be assessed because of the lack of cutting routines. In future, this obstacle could be easily solved by adapting the slaughter line and the VIA hardware to focus on the 10 th/11 th rib section and training slaughterers. Other international beef grading systems show that new cuts can be quickly learned and routinely adapted into the slaughter line. To develop and validate a general formula, the VBG 2000 camera has to be adapted to the different size of the 10 th/11 th rib position to reduce the type of placement errors which occurred in the current study and further research has to be conducted. The assessment of marbling scores using VBG 2000 has been validated in earlier studies with high accuracy and repeatability at the 12 th rib-eye position [10; 20; 21; 22]. VBG 2000 showed close relationships (r = 0.94 and r = 0.84)  
Figure 2: Distribution of marbling scores at the 10 th/11 th and the 12 th/13 th rib-eye position.  
with the chemical analysis of Intramuscular fat content (IMF) [21; 23]. The close correlations of marbling scores at the 10 th/11 th rib-eye position and the 12 th/13 th rib-eye position in this study are in accordance with the results of a recent explorative investigation using VBG 2000 at these two positions [18]. In contrast, [PERSON] et al. [16] compared French and Polish beef carcasses at different muscles using near-infrared spectroscopy and image analysis based on Beef Analyzer II Software. The results of trained graders using the USDA marbling scores and the Australian grades reached a lower correlation coefficient (r = 0.53) between the different positions. The authors emphasized that the prediction of marbling at one position might be used for the classification of the entire carcass quality, but the variation of marbling between different positions needs to be considered. [PERSON] et al. [23] used BeefCam, a technique that is based on VIA (_n_ = 288) to classify Uruguayan beef carcasses at the 10 th rib-eye section and explored the use of self-created software to assess marbling scores at the 12 th/13 th rib position. The authors concluded that marbling could not be estimated precisely with the applied equipment. Considering the high correlations of assessed marbling scores at both positions in the current study, VBG 2000 could be easily used to assess marbling scores at the 10 th rib with high comparability to the US position, although the threshold borders of rib-eye would have to be adapted to the different rib-eye size at the 10 th/11 th rib-eye position.