The effect of using different forms of chromium on hematological parameters and antioxidant status of Afshar ewes in the transition period and their lambs under the influence of heat stress

The present study aims to investigate the effect of different forms of chromium (inorganic chromium, chromium-methionine and chromium nanoparticles) on blood parameters, antioxidant status and immunoglobin of Afshar ewes during the transition period and lambs. They were done under the influence of heat stress. 40 pregnant Afshar ewes from 42 ± 2 days before the expected parturition in a completely randomized design. Four experimental treatments were assigned with ten replications. Experimental treatments include basic diet without chromium supplement (control), basic diet containing 3 mg of chromium in mineral form per kg of dry matter, basic diet containing 3 mg of chromium in the form of chromium-methionine per kg of dry matter and The basic diet contained 3 mg of chromium in the form of chromium nanoparticles per kilogram of dry matter. The results showed that the addition of different forms of chromium to the ewes' diet caused a significant increase in the concentration of red blood cells, hemoglobin and blood hematocrit compared to the control group (P<0.05). Adding chromium to the diet of ewes caused a significant decrease in white blood cells (P<0.05). In experimental treatments, no significant difference was observed in terms of platelets, average volume of red blood cells, average concentration of red blood cells, neutrophils, lymphocytes, monocytes, and eosinophils. The concentration of superoxide desmutase, glutathione peroxidase, catalase, triiodothyronine and tetraiodothyronine in the blood in the treatments receiving different forms of chromium also increased compared to the control group (P<0.05). The results showed that the concentration of malondialdehyde and total antioxidant capacity in ewes and lambs receiving chromium supplementation was lower than the control treatment (P<0.05). However, there was no significant difference between different experimental treatments in terms of ceruloplasmin concentration and the ratio of T4 to T3 (P<0.05). The concentration of IgG and IgM in lambs receiving different forms of chromium also increased compared to the control group (P<0.05). In general, the use of chromium, especially in the form of chromium-methionine and chromium nanoparticles, is recommended during the transition period of ewes under the influence of heat stress.