**1. Introduction**

Beef is the third most widely consumed meat in the world and is considered to be a highly nutritious and valued food [1]. Intended for culinary and meat-processing purposes beef meat must meet certain qualitative requirements in terms of its sensory characteristics such as a suitable color, a desirable flavor features, an appropriate texture and a high level of tenderness [2]. The characteristics of beef carcass have a significant effect on meat quality and play a decisive role in determining its value. The value of the animal carcass and the cost of producing that carcass determine the profitability in cattle production systems [3]. Furthermore, major factors that affect the value of the carcasses and the cost of meat production include the animal's genotype, nutritional and management practices applied on the farm. The quality classification systems of carcasses are widely used as tool in the beef industry, making the business transactions easier while at the same time support the primary sector by providing it with useful information. The term "classification" defined as a set of descriptive terms describes the features of the carcass, which are useful to those involved in the trading of carcasses [4]. In the European Union (EU), the adoption of the SEUROP classification system within the member states established in 1981 is obligatory to record, monitor and collect data according to EU legislation [5] that concerns the carcass weight, the gender and the age of slaughter, the muscular conformation and the

state of fattening of the carcass. Therefore, these data are measurable indicators that determine the quality characteristics and define the economic value of the carcass.

The general view by all sectors involved (slaughterhouses, producers, services) for the beef carcass classification system in the EU is that it operates well and provides, mainly for producers, a reliable basis for the deadweight sale of finished cattle [6]. Although in a recent study [7] is considered that, the SEUROP grid may be based on global indicators but it does not consider the carcass as a complex and heterogeneous entity, so, in the same SEUROP classification, it could include different muscles with higher or lower commercial value. The lack of a strong and clear link between sensory scores and European carcass classification standards shows that the European beef industry can not only rely on them but also needs to integrate quality into the carcass value [8]. Therefore, a study proposed alternative measures to be included in the SEUROP system in order to enable meat quality and to deliver consistent beef quality to the consumers [8].

While the SEUROP carcass grading system can be appropriate today, the ongoing changes in the production and marketing of cattle internationally could require in the future providing additional meat quality characteristics. A significant number of research studies tried to investigate the relationship between meat quality characteristics and the carcass parameters of SEUROP system mainly muscle conformation and fat deposit. Regarding marbling, a recent study [9] indicated that European classification scores explain only a slight proportion of the variance in marbling score (32%, 46%, 34% and 21% for the entire cattle group, young bulls, females and steers, respectively). Moreover, a significant correlation was observed among carcass yield and SEUROP conformation and fatness scores with intramuscular fat, slaughter body weight and hot carcass weight [10]. As a first step in developing a new way to assess the overall quality of beef carcasses in Europe it was proposed [11] a set of 5 indicators to include in the SEUROP system [hind quarter weight, meat color, retail-cut yield, rib-eye area and marbling score].

Beef production in the EU is approximately stable around 600,000 tons per month and holds the 3rd position after the United States of America (USA) and the Federative Republic of Brazil. In 2018, almost 7930 million tons of bovine meat (calve, young cattle, heifer, cow, bull and bullock) were produced in the EU from 87 million bovine animals. The highest production of European beef meat came from France (19%), Germany (15%) and the United Kingdom (12%), while almost half of the veal production in EU came from Spain (23%) and the Netherlands (23%) [12]. Considering that, the primary production of beef in EU consists of almost two thirds of dairy cows it is obvious that milk production is the main objective for most European cattle farms and only a small part of their income comes from beef production.

The average carcass weight in EU increased by about 24 kg/head from 2000 to 2015 [13], despite the fact that the EU beef consumption corresponds to 10.9 kg/capita/year with large fluctuations between its member states [14].However, beef consumption in the developed world has been declining for the past 20 years, with rates falling to 12% in the EU, 19% in the USA and 20% in Australia [15]. Many studies have evaluated the causes of this declining trend that could be attributed to the negative criticism received by beef meat on issues related to the environment, public health, safety and authenticity, including the lack of consistency in the quality of beef meat [15–18]. Since 2003, the World Health Organization (WHO) has developed specific guidelines that pointed out the relationship between dietary fat and incidence of lifestyle diseases [19]. Supporting not only sensory and nutritional quality is therefore a priority issue for the beef meat industry in order to overcome the decline trend in consumption [7]. However, consumers increasingly appear to prefer high-quality meat cuts that are, characterized by consistently high levels of eating quality [18].

Numerous studies evaluating the endogenous factors that affect the quality characteristics of carcasses, pointed out the effect of genotype and gender of the cattle [20–28]. Regarding the exogenous factors, regional differences due to climate and geographical morphology heterogeneity, affect the calving season, weaning weight, reproductive efficiency, feed costs and the animal's growth gain, configuring the final quantity and quality characteristics of the slaughtered cattle [29,30].

The beef sector in Greece has a great interest for study because it presents a lot of peculiarities. Being the southernmost country in Europe, it differs significantly, not only for the climatic conditions in contrast to the northern European countries, but also for the diversity in the breeding conditions of bovine animals. In addition, there is a large variety of cattle breeds that are bred and slaughtered in Greece, because local breeds do not meet the Greek beef meat's demand. Specifically, the Greek local breeds have not evaluated in the past according their carcass characteristics either compared with other European beef breeds.

This study aims:(i) to describe the effect of main factors (breed, gender, year of slaughter, farm's geographical region and month of slaughter) on the carcass weight and age of slaughter for various types of cattle carcasses (calve, young cattle, heifer and young bull); (ii) to evaluate the beef carcasses produced in Greece based on the SEUROP classification system. It is hypothesized that the information concerning the effect of the farm's geographical region on the carcass characteristics will give more insight on the development of the sector. In addition, for the first time it will be presented the carcass characteristics from four Greek meat breed carcasses (Greek Red, Greek Blonde, Vrachiceratiki or Greek Brachyceros and Local cattle) as well as from the Greek Buffalo (Bubalus bubalis).
