Maja Belić

Serum biochemical values in fallow deer (Dama dama L.) from different habitats in Croatia

Serum biochemical values were determined in blood samples collected from 48 shot fallow deer from the Brijuni islands and 45 sedated fallow deer (Dama dama L.) from hunting grounds in the continental part of Croatia. The parameters were compared with regard to age, sex and habitat. Statistically significant differences were found for serum total protein concentration, alkaline phosphatase, aspartate aminotransferase and alanine aminotransferase activity between young and adult island deer, as well as for total protein, triacylglyceride, cholesterol concentration and alkaline phosphatase activity between young and adult continental deer. In young animals, island males had higher albumin concentrations, while continental males had higher alkaline phosphatase values than females. In adult animals, island males had a higher blood urea nitrogen concentration, while continental males had higher albumin and cholesterol concentrations, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and creatine kinase activities. In this group, males exhibited lower bilirubin and triacylglyceride concentrations than females. Our results indicate that besides age, sex and sampling method, nutritional and environmental factors should be considered when evaluating serum biochemical parameters of fallow deer

Lipid mobilisation and oxidative stress as metabolic adaptation processes in dairy heifers during transition period

The objective of this study was to evaluate metabolic disorders and oxidative stress in dairy heifers during the transition period. Possible relationships between lipid mobilisation indicators and oxidative stress markers were investigated as well. Nineteen dairy heifers were included in the study. Blood samples were collected at the time of estrus synchronisation in heifers, at insemination, three weeks after insemination, one week before calving, at calving and 1, 2, 4 and 8 weeks postpartum. Common metabolic parameters, beta-hydroxybutyrate (BHB), free fatty acids (FFA), paraoxonase-1 (PON1) activity and total antioxidative status (TAS) were analysed. Around insemination, no significant difference was observed in the majority of tested parameters (P>0.05). However, the transition period markedly affected the concentration of triglycerides, total cholesterol, HDL-C, BHB, FFA, TAS and PON1activity. Positive correlations between PON1 activity and total cholesterol, HDL-C and triglycerides were noted but inverse correlations with FFA, BHB and bilirubin were found indicating that PON1 activity changed with lipid metabolism and was influenced by negative energy balance. These findings suggest that lipid mobilisation and oxidative stress are part of a complex metabolic adaptation to low energy balance which reaches equilibrium later in advanced lactation.

The influence of sex on biochemical markers of bone turnover in dogs

Biochemical markers of bone turnover have been shown to be useful as inexpensive and noninvasive tools for monitoring skeletal health. The reference range for bone markers in dogs has been set by different age groups. However, other sources of biological variations were not fully investigated in dogs. To explore whether sex influences the interpretation of bone marker data we examined serum bone markers in 33 male and 25 female dogs. The bone markers selected for this study were: bone alkaline phosphatase (BALP) and osteocalcin (OC) as indicators of bone formation, and C-terminal telopeptide (CTx) of type I collagen as marker of bone resorption. All concentrations of bone markers were lower, but still within the reference range reported for dogs. We found statistically significant differences of the median OC and CTx serum concentrations between males and females. The results of this study suggest that there are sex differences in biochemical markers of bone turnover in dogs which should be considered in interpretation of bone marker data.

Reliability of lactate Scout portable analyzer in agility dogs during multiple measurements

Abstract The aim of this study was to evaluate the reliability of multiple measurements with Lactate Scout portable analyzer in dogs during treadmill exercise. Ten Border collies were involved in the study and blood samples were taken before, three times during and twice after the treadmill exercise. Lactate concentration was measured in duplicate, by Scout portable analyzer and the reference biochemical analyzer in the laboratory, and the obtained values were compared. There was a high and positive correlation between these two methods (r=0.96, p=0.003). The Lactate Scout analyzer reveals a high degree of agreement with the laboratory method and therefore can be valid for use in research of veterinary sports medicine and emergency veterinary medicine where multiple measurements of lactate concentrations are often needed.

Dynamics of metabolic and oxidative stress parameters in dairy heifers during transition period

Dairy cows in early postpartum period experience a rapid increase in milk yield, whereas animal feed consumption ability rises slowly and can not follow increased needs for nutrients (Eicher, 2004). Therefore dairy cows enter a period of negative energy balance (NEB) and metabolic stress. NEB is associated with the change in body condition score (BCS) and the rise of some metabolites such as non-esterified fatty acids (NEFA) and beta- hydroxybutyrate (BHB) (Lassen and Fettman, 2004). Intensified energy metabolism during periparturient period is accompanied by enlarged rates of reactive oxygen species (ROS) production and may results in oxidative stress. Calving causes significant, but temporary, changes in the antioxidant system of cows’ blood (Gaal et al., 2006). Total antioxidant status (TAS) is a single measure that may effectively describe the dynamic equilibrium between pro-oxidants and antioxidant in plasma compartment (Ghiselli et al., 2000). Paroxonase-1 (PON1) is recognized as an important part of the mammalian natural anti-oxidative system (Mackness et al., 1991; Turk et al., 2008).