The aim of this study was to establish reference interval for biochemical parameters in blood of alpacas on the basis of large population of clinically healthy animals, and to determine the influence of sex, age and season on nitrogen and lipid metabolites, enzymes, electrolytes, vitamins and minerals in blood of alpacas. Blood samples were collected from 311 alpacas (61 males and 201 females > 6 months of age and 49 crias (21 males and 28 females) ⩽ 6 months of age). Selected farms were located in Central Europe (Czech Republic and Germany). We determined 24 biochemical parameters from blood serum. We performed the comparison of results by the sex of animals and for the older group also the comparison of the results with regard to the season, respectively, to the feeding period. We found no highly significant difference (P < 0.01) between males and females with the exception of γ-glutamyl transferase (GGT), alkaline phosphatase (ALP) and cholesterol. We found 15 significantly different parameters between the group of crias 6 months of age and the older alpacas. Based on our findings we suggest for most parameters to use different reference intervals (especially ALP, cholesterol, total protein, globulin, non-esterified fatty acids (NEFA), GGT and phosphorus) for the two above-mentioned age groups. Another important finding is the differences between some parameters in older group of alpacas in summer/winter feeding period. Animals in the summer feeding period have higher values of parameters related to fat mobilization (β-hydroxybutyrate, NEFA) and liver metabolism (bilirubin, alanine aminotransferase). The winter period with increased feeding of supplements with higher amount of fat, vitamins and minerals is characteristic by increased values of cholesterol, triglycerides, vitamins A and E, and some minerals (K, Ca, Mg and Cl) in blood serum. Clinical laboratory diagnosis of metabolic disturbances may be improved with use of age-based reference values and with consideration of seasonal differences.Keywords: alpaca, llama, reference ranges, clinical pathology, seasonal differences ImplicationsOne of the important methods of monitoring health status is evaluation of blood. To interpret results correctly we need to consider species-specific differences, and influence of other factors: gender, age, nutrition, season and environment. South American camelids -especially alpacas -are growing in popularity all over Europe and yet there is lack of knowledge of above-mentioned factors on their blood parameters. This study evaluated influence of these factors on blood parameters of alpacas. The result should help veterinarians and alpaca breeders with correct interpretation of blood tests to diagnose clinical and subclinical metabolic health problem and possible nutritional disturbances.

ABSTRACT:The aim of this study was to establish reference intervals for the haematological profile of alpacas on the basis of a large population of clinically healthy animals, and to determine the influence of sex, age and season on these indicators. Blood samples were collected from 243 alpacas (53 males and 156 females over six months of age and 34 crias -12 males and 22 females -under six months of age). The selected farms were located in Central Europe (Czech Republic and Germany). We determined 13 haematological indicators. Comparison of the results was performed with respect to the sex of animals and for the older group also with regard to the season and to the feeding period. We found no highly significant (P > 0.001) differences between males and females. We did find highly significant differences (P < 0.001) between the group of crias under six months of age and the older alpacas (mean corpuscular volume -MCV, mean corpuscular haemoglobin concentration -MCHC, red cell distribution width -RDW, white blood cell count -WBC, neutrophil count). Based on our findings we suggest that for some indicators different reference intervals (esp. WBC and differential cell counts) be used for the two above mentioned age groups. We found some highly significant differences (P < 0.001) in haematological indicators in the older group of alpacas between the summer and winter feeding period (haemoglobin concentration, MCHC). Clinical laboratory diagnosis may be improved by the use of age-based and season-based haematological reference values.

ABSTRACT:The aim of this study was to determine the relationship between selenium concentration and activity of glutathione peroxidase (GSH-Px) in the whole blood of sheep and reference ranges for the activity of GSH-Px for evaluation of the selenium status of sheep in the Czech Republic. Selenium concentration and activity of glutathione peroxidase were determined in whole blood samples collected from 92 sheep in six herds. The GSH-Px activity in the samples was measured using the photometric method. Selenium in the sample was measured using the hydride technique atomic absorption spectrometry. Data on both parameters were processed using correlation and regression analysis in order to obtain reference values of GSH-Px for the indirect evaluation of the selenium status of sheep. The two variables showed a close and significant correlation (r = 0.95; P < 0.01). The regression line, defined by the equation y = 7.5857x -121.87 (linear) or y = -0.0167x 2 + 11.993x -355.57 (polynomial), allowed us to determine the GSH-Px activity of 637, resp. 677 μkat/l as equivalent to selenium concentration in whole blood of sheep 100 μg/l. Mean selenium concentration and mean GSH-Px activity found in whole blood samples were 123.42 ± 57.84 μg/l and 814.34 ± 463.64 μkat/l, respectively. In this study, a close dependence of GSH-Px activity on the selenium concentration in the blood of sheep was found. Activity values of GSH-Px were determined for use in the diagnosis of sufficient selenium status in sheep in the Czech Republic (GSH-Px activity greater than 600 μkat/l of whole blood).

The aim of this study was to evaluate the effect of supplementation with an organic form of manganese on its concentration in blood, hair, and organs of goat kids. A total of 27 kids were divided into control and experimental groups on the day of their birth (Day 1). The kids were on mother's milk only diet until the day of weaning (Day 70). After weaning the kids received pellets at doses 0.3 kg/head/day for next 70 days. The control group received pellets (manganese content 36.7 mg/kg) and the experimental group received pellets with extra manganese addition in the form of manganese proteinate at the amount of 220 mg/kg. Blood samples were taken on days 1, 70, 105, and 140; hair samples on days 1, 70, and 140. At the end of experiment, 7 kids from each group were slaughtered and samples of heart, liver, spleen, pancreas, kidney, muscle, and brain were taken. Manganese concentration was determined from fresh tissues after microwave digestion by electrothermal atomic absorption spectrophotometry. Kids of the experimental group had a significantly higher manganese concentration in the liver (4.90 vs. 3.06 mg/kg), heart (0.47 vs 0.28 mg/kg), kidney (1.29 vs. 0.87 mg/kg), brain (0.33 vs 0.26 mg/kg), and hair (4.25 vs. 3.14 mg/kg) compared to the control group. The manganese concentration in blood was not affected by supplementation. Results of this study indicate that using the mentioned organs and hair for evaluation of the manganese status in an organism is more suitable than the determination of manganese concentration in blood.

The aim of this study was to monitor the content of trace elements in the hair of South American camelids and to evaluate the effect of coat colour, species, age, and sex on their concentration in the hair. The samples were collected from 77 animals -23 llamas (Llama guanicoe f. gllama) and 54 alpacas (Llama guanicoe f. pacos) during a spring health check. The concentrations of copper (Cu), zinc (Zn), and manganese (Mn) were determined by Flame Atomic Absorption Spectrometry and selenium (Se) by Hydride Generation Atomic Absorption Spectrometry. We found the following concentrations (mean ± standard deviation; mg/kg dry matter) in the llama hair: Cu 9.70 ± 4.69; Zn 145.20 ± 21.07; Mn 12.49 ± 10.14; Se 0.25 ± 0.14. In alpaca hair we found the following concentrations: Cu 10.22 ± 2.90; Zn 129.81 ± 19.01; Mn 12.67 ± 13.85; Se 0.48 ± 0.24. We found a significant difference between llamas and alpacas in Zn and Se concentrations in the hair. From all the evaluated factors we found that coat colour had the highest effect on Mn and Se concentration. Dark haired animals had significantly higher concentrations of these trace elements than other coloured groups. The evaluation of the concentration of trace elements in the hair of llamas has a potential to be used for the evaluation of long-term status of trace elements in the body; however, it is necessary to continue with experimental work in this area. Our findings can serve as a pilot study for further works in this field.