Probiotics, to an appropriate extent, are defined as living microorganisms with beneficial properties that have been accepted for both treatment and prevention of pathogens. The aim of this study was to investigate the effects of a diet containing probiotics on hematology and oxidative stress indices in Dareshoor mares.

For this purpose, 5 horses were fed a diet containing probiotic Bio-Equine (10 g per day) for one month. Blood samples were taken before and after taking probiotics. In stages, complete blood count (Hematocrit, Red blood cell, White blood cell, and percentage of each), serum malondialdehyde levels, total antioxidant capacity, and glutathione peroxidase and superoxide dismutase enzymes were measured. The obtained data were analyzed using t-test statistical method.

The results showed that the addition of probiotics to the diet had no effect on hematocrit and red blood cell count, but the number of white blood cells and the percentage of neutrophils and lymphocytes in the blood of horses increased with probiotic nutrition, although this increase was not significant (P>0.05). Consumption of probiotics for one month led to an increase in serum antioxidant status, although this increase was only significant for glutathione peroxidase (P<0.001).

Overall, the results showed that the addition of Bio-Equine probiotics to the diet improved the immunity and antioxidant activity of saline horses.