Seasonal changes in the white blood cell system, lyzozyme activity and cortisol level in Arabian brood mares and their foals.

The study investigates seasonal changes in blood cell activity and hormone levels in different groups of Arabian horses. The findings suggest that factors such as age and physiological state, such as pregnancy, can affect these changes.

Study Participants and Grouping

• The researchers selected 34 pure-breed Arabian horses for the study, which they divided into four distinct groups based on their age and reproductive status.
• Group I included ten pregnant mares, Group II comprised seven barren mares, Group III consisted of ten foals born in 1981, and Group IV included seven foals born in 1982.

Measurement Parameters

• They analyzed the seasonal changes in the white blood cell system, cortisol level, and lysozyme activity.
• The white blood cells they studied included lymphocytes, segmented neutrophils, eosinophils, stab neutrophils, basophils, and monocytes.

Results and Findings

• Seasonal periodicity was observed for several metrics, including the number of lymphocytes, segmented neutrophils, and eosinophils, as well as cortisol levels in all groups.
• Leukocyte periodicity was discovered in three groups but was not found in barren mares.
• Periodic change in lysozyme activity was found in three groups, however, it wasn’t observed in the youngest foals.
• For stab neutrophils, basophils, and monocytes, the researchers did not notice any seasonal cycle.

Impact of Age and Physiological State

• The results showed an influence of the age of horses (whether they were mature or young) and the physiological state of the mares (pregnant or barren) on the studied indices.

Conclusion

• This research suggests that seasonal changes in certain blood cell levels and hormone activity in Arabian horses are affected by factors such as the age of the horse and its reproductive state.