## 1 Introduction  
Lipid oxidation is one of the most important processes leading to deterioration in meat quality and is often crucial for food product shelf life [1]. The process is induced by oxygen in the presence of initiators, such as high temperature, light and metal ions and is related to the unsaturation degree of the substrate [2, 3]. Therefore, food products with high content of polyunsaturated fatty acids (PUFAs) are more exposed to lipid oxidation. For example, rabbit meat has many desirable nutritional features as a result of its lipid component, characterised by low levels of fat and cholesterol, a high level of unsaturated fatty acids and a good ratio of _n_-6/_n_-3 PUFAs with respect to other types of meat [4, 5]. However, the higher amount of PUFAs leads to increasing oxidation with a consequent decrease in product stability during storage and cooking [3, 6]. In addition to altering taste and nutritional quality, lipid oxidation involves the formation of reactive and toxic compounds, which may pose a risk to the consumer [2, 6]. The major primary products, hydroperoxides, which are essentially odourless, are relatively unstable and decompose into a wide variety of secondary compounds among which aldehydes, in particular malondialdehydedehyde (MDA), are considered to be the most important due to their great contribution to the development of rancid off-flavours and odours [6, 7]. One of the major strategies for preventing lipid oxidation in food is the use of antioxidants, and a wide variety of compounds, from synthetic to natural, such as vitamin E (VE) and spices, has been studied [8; 9]. However, there is still uncertainty regarding the effectiveness of many antioxidants and the optimal quantity to be used. For example, while the role of VE in stabilising meat colour and reducing lipid oxidative processes has been widely studied and assessed, including in rabbit [4; 10; 11], the effects of selenium (Se) have been less studied and are still not conclusive. Selenium dietary supplementation has been more extensively studied in cattle, pig and poultry [12; 13; 14], but only a few studies have considered rabbits, despite their meat susceptibility to lipid oxidation. Recently, some authors have described a positive effect of Se supplementation on oxidative status and mineral profiles in rabbits [15; 16; 17], and [PERSON] et al. [5] found a protective effect against oxidative events in both the _Longissimus dorsi_ and _Biceps femoris_ muscles. Other authors have also found in pigs a synergistic effect between the administration of Se in the diet and the accumulation of VE in muscles [18]. Additionally in pigs, the synergistic effect between Se and VE in combined dietary administration was also described, where an increase in lipase activity was observed with a consequent enhancement in post mortem lipolysis processes [19]. However, to the best of the authors' knowledge, the mechanism of action of Se has not yet been fully clarified, and the effects on the oxidative processes have, for the most part, been evaluated by quantifying thiobarbituric acid reactive substances (TBARS). In terms of the specificity of the oxidative process, the choice of the best oxidation markers is very important for testing the antioxidant capacity and the extent of the lipid substrate oxidation [2]. In the food industry, the most widely used methods measure changes in primary or in secondary products. Therefore, when oxidation occurs at a more accelerated rate, lipid oxidation is best assessed by measuring the secondary products, mainly aldehydes and ketones, due to their quick accumulation [20]. TBARS analysis is one of the oldest and most commonly used methods of assessing lipid oxidation in food, and it is based on the spectrophotometric determination of MDA, a product of oxidation, directly in the food [2]. The TBARS test is often used to evaluate oxidative status owing to its simple procedure and its high correlation with sensory scores [21]; however, it has often been the object of criticism.