The objective of the study was to assess apoptosis and DNA defragmentation in equine semen diluted and chilled to +4°C. Semen was collected from nine fertile stallions, including four Arabian thoroughbreds and five coldbloods. Examinations were carried out immediately after semen collection (0) and at five storage times (24, 48, 72, 96 and 120 h). The basic semen evaluation was performed in terms of volume, sperm concentration, viable sperm percentage, progressive motility and morphology. Using flow cytometry, DNA defragmentation and cell membrane integrity of spermatozoa were determined. The results of basic tests did not demonstrate significant differences amongst stallions, except for progressive sperm motility, which was significantly higher (p < 0.05) in the semen of Arabian stallions. In the semen of the same stallions, a significant decrease in the percentage of alive spermatozoa was observed at 72, 96 and 120 h of storage, whereas a significant increase in the number of spermatozoa with DNA defragmentation was found after 24 h storage. In the semen of coldblood stallions, significantly reduced live spermatozoa percentage was observed at 96 and 120 h, while increased DNA defragmentation was observed at 48 h. These findings demonstrated that the semen of Arabian stallions chilled to +4°C retained original characteristics until 24 h of storage, whereas in coldbloods, these were preserved up to 48 h of storage.

The aim of the study was to evaluate physiological changes in hematological and biochemical parameters in mares in perinatal period. Blood samples were collected from 24 pregnant Polish Konik breed mares which were divided into two groups. The first group (Group -I, n=12) comprised mares living in the wild, in the reserve. The second group (Group -II, n=12) consisted of mares kept in stables. The blood was collected 2 weeks prior to the parturition, then 24 hours after the delivery, and then at the 7th and 21st day after foaling. When comparing the two groups before the parturition, no significant differences in terms of WBC, RBC, and Hb were found, however, there was a significant difference in MCV, MCH, LYM, NEU and SEG NEU (p≤0.05). In Group II, 24 hours after the parturition and at the 21st day after foaling, a significant raise in WBC, NEU and SEG NEU (p≤0.05) was detected. No significant differences in serum concentrations of proteins such as TP, Alb or Glb were observed. As to acute phase proteins, significant rise in SAA and Hp (p≤0.05) was found in the two examined groups 24 hours after the parturition. Yet, this rise remained within physiological range. The study revealed a certain degree of fluctuations in hematological parameters, in serum concentrations of acute-phase proteins and total proteins in the mares in the perinatal period. However, these changes remained still within physiological ranges and thus they do not indicate potential susceptibility to disorders of perinatal period.

IntroductionPregnancy is a physiological state in which the immune system undergoes certain changes. On the one hand, by depleting cell defence mechanisms, it favours development and maintenance of the pregnancy. At the same time cells of the immune system ensure resistance to many risk factors, including infectious agents.Material and MethodsThe study was carried out on 24 Polish Konik breed mares which were divided into two equal groups. The first group (group I) included mares living in the reserve. The second group (group II) comprised mares maintained under conventional conditions in the stables. The blood samples were collected for the first time in the perinatal period, i.e. 2 weeks before parturition (trial 0), then within the first 24 h after delivery, and then on 7th and 21st day after foaling. Flow cytometric analysis of lymphocyte expressing TCD4+, TCD8+, CD2+, and MHC class II antigens was performed.ResultsBefore the delivery, in group I there was a significantly higher CD4:CD8 ratio compared to group II (P ≤ 0.05). Similarly, significantly increased CD4:CD8 ratio in group I was noted within 24 h after parturition (P ≤ 0.001) and it was also observed on 7th day (P ≤ 0.03) and 21st day after foaling (P ≤ 0.02). In the first 24 h after parturition, a significant decline of lymphocytes CD8+ (P ≤ 0.02) was noted. No significant differences in terms of lymphocytes CD2+ and CD3+ were observed. Expression of MHC-II molecules before and after the parturition was higher in group I compared to group II; however, the difference between the groups was not significant.ConclusionThe results obtained indicate that mares living in the reserve display higher activity of cell defence mechanisms.