Dynamics of some biochemical parameters in two local sheep breeds depending on the season, altitude and the presence of parasites

The aim of the present study is to evaluate the values of some enzymes and metabolites - ALT, AST, ALP, serum iron and glucose of two herds of Bulgarian native sheep breeds raised at different altitudes, depending on the season, their body condition score (BCS) and the presence of gastrointestinal parasites. The research was conducted with 20 animals each in farms in the village of Mirkovo (715 m above sea level) with Sofia (Elinpelin) sheep breed and in the village of Gubesh (1040 m above sea level) with Central Balkan sheep breed. Body condition assessment was performed during sampling by one individual using an adapted system. Fresh faeces (total sample) were also collected for parasitological tests (coproovoscopy and coprolarvoscopy). Analysis of biochemical parameters was performed in extracted blood plasma with a BTS-350 semi-automatic biochemical analyzer. AST and glucose levels were normal, ALP and Fe were lower in both seasons, and ALT was higher than reference values limits only in summer for both breeds. There were significant differences between the two breeds in summer for BCS, ALT and glucose (p<0.001, p<0.05 and p<0.01 respectively), in winter - only for Fe (p<0.001) and in both seasons for HCT (p<0.001 and p<0.01 respectively), AST (p<0.001 and p<0.05 respectively) and ALP (p<0.001 each). Regarding the activity of AST, there are no significant differences between the two seasons and in both breeds, however, there are such differences only in Central Balkan sheep for BCS and Fe (respectively p<0.01 and p<0.001), and in both breeds together with different degrees of freedom - for all other indicators (HCT, ALT, ALP and glucose).