*3.5. Enzymatic Profile*

Enzymatic profile indicators (AST, ALT, ALP) (Table 5) were in physiological range according to Tschour et al. [50]. Determination of enzyme activity is necessary in order to exclude hepatopathy. Furthermore, AST and ALT values were comparable with Rahman et al. [60]. The GGT values were under the limit recommended by Tschour et al. [50], Lepherd et al. [61], and Shek Vugrovecki et al. [24], but in accordance with reference values according to Al-Hadithy et al. [62]. After the GP feeding non-significant lower AST (*p* = 0.512) values and higher ALT (*p* = 0.490), ALP (*p* = 0.124) and GGT (*p* = 0.857) values were observed. Similarly, Chedea et al. [25] did not confirm the effect of GP feeding in dairy cows (diet contained 15% dried GP) on AST, ALP, and GGT. Iannaccone et al. [26] also did not find the effect of GP addition in calves (10% dried GP meal in concentrate) on AST and ALT values. In the study of Nudda et al. [63] the effect of grape seeds addition (300 g per day) on sheep AST and ALT parameters was not found but statistically significant higher ALP and lower GGT were observed. Comparable with the present study, a decrease in AST values in the lambs after feeding of GP (5%, 10%, and 20% in dry matter) with the lowest value in variant with 5% addition, was reported by Jin et al. [64].
