Correlation between erythrocyte parameters and iron status in cyclic Spanish Purebred mares

The aim of this study was to evaluate the serum iron status and its relation to hematological indexes in cyclic mares. Blood samples were taken from 40 Spanish Purebred mares on days - 5, 0, + 5 and + 16 of their cycle. Concentration of transferrin (TRF) was significantly lower on day 0 than on days + 5 and + 16, transferrin saturation (TSAT) decreased significantly on days 0 and + 16 compared to day - 5, total iron-binding capacity (TIBC) on day + 16 was significantly higher than those on days - 5 and 0, and on day + 5 it was also significantly higher than that on day 0, unsaturated iron-binding capacity (UIBC) was reduced on day + 16 compared to days - 5 and 0, red blood cell (RBC) count on day + 16 was higher than that on days - 5 and 0 (p < 0.05), with no differences in the concentration of hemoglobin (HB) and packed cell volume (PCV). TRF and TIBC (r = 0.95), RBC and HB (r = 0.64), RBC and PCV (r = 0.78), and HB and PCV (r = 0.63) were positively and significantly correlated (P < 0.05). The estrous cycle in the Spanish Purebred mare is characterized by an increase in TRF and TIBC during the follicular phase and an increase in TSAT, UIBC and RBC in the luteal phase, without changes in other hematological parameters. The coordinated activity of these parameters guarantees an adequate iron (Fe) transfer and utilization during follicular development, ovulation, and the luteal period in the mare. Therefore, the estrous cycle must be considered in the evaluation of the mare's iron status, in light of significant changes observed both in early and at late luteal phases. The magnitude of these changes and the meaning to the physiology of the mares showed that in cyclic mares, hematological parameters and indicators of iron status evolve differently depending on the phase of the cycle, and their interpretation can help to veterinarians involved in equine practice.

Analysis of the season-dependent component in the evaluation of morphological and biochemical blood parameters in Shetland ponies of both sexes during exercise

Introduction

Determination of morphological and biochemical blood indices facilitates assessment of the health and welfare of horses, their nutrient demand, the effects of training already undertaken, and the horses' suitability for exercise. Identification of the season-dependent components and the effects of sex and exercise on changes in frequently referenced haematological and biochemical parameters was the main goal of the current study.

Material and Methods

The blood morphology of 21 healthy adult Shetland ponies (11 mares and 10 stallions) aged 6.5 ± 1.4 years from the central Pomeranian region in Poland was analysed. Blood samples were taken once per season for one year.

Results

No statistically significant season-dependent differences were found in the blood morphology parameters in either mares or stallions before or after exercise. Beta-coefficient results revealed the strength and type of the relationship of red blood cell distribution width (RDW) and granulocyte count (GRA) with the season, of red blood cell count (RBC), haematocrit, mean corpuscular volume and mean platelet volume with the sex, and of RDW, white blood cell count, GRA and RBC with the exercise factor. Biomarkers demonstrating the relationship between aerobic and anaerobic levels of energy metabolism in the blood did not show any sex dependency in regression analysis.

Conclusion

The sex-independence of energy metabolism biomarkers may indicate the universality of these parameters. Both seasonality itself and its combination with the exercise factor took part in the formation of effective adaptive reactions for maintenance of morphological blood indices in the ponies during exercise.

Age- and Sex-Related Modifications of Hematology in Spanish Purebred Horse

The purpose of this study was to test the hypothesis that age and sex significantly modulate the changes in hematological parameters of physiologically healthy Spanish Purebred horse, establishing the reference values. Blood samples were obtained on a total of 159 horses (n = 77 males and n = 82 females), classified in four age groups: group A (1-2 years; n = 39), group B (>2-3 years; n = 38), group C (>3-4 years; n = 41), and group D (>4-7 years; n = 41). By means ADVIA 2020i, red blood cell (RBC), hemoglobin concentration (HB), packed cell volume, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration, platelets (PLTs), as well as total and differential white blood cells (WBCs) were determined. Total plasma protein was determined by spectrophotometry. Results obtained showed that sex had a limited influence on these parameters, being the HB higher in males and WBC higher in females (P = .047). Age caused a reduction in RBC, with a compensatory increase of MCV and MCH, decrease in WBC, PLT, lymphocytes (LYMPs), as well as an increase of N/L ratio (P = .047). Interactions between age and sex showed higher RBC in males than in females of the group B, and higher HB and WBC in males than in females of the group D. According to hematological data, Spanish Purebred horse was classified as a warm- or cold-blooded horse. Decline of RBC, WBC, and PLT parameters is a natural condition of horse with the advance of age, indicating a decrease of the narrow bone response.