Organic Selenium and Zinc: Their Effects in Feed on Blood Profiles and Antioxidant Capacity in Early-Lactating Dairy Cows

During early lactation, dairy cows often experience reduced immune cell function, including lymphocytes,and changes in blood metabolites, which can impact their health and production. Essential trace minerals (TM), such as selenium and zinc. They support enzyme function, immune response, and antioxidant defences. Moreover, this current research assessed the impact of supplementing organic selenium and zinc on dairy cows’ blood biochemical, haematology,and total antioxidant capacity (T-AOC) during early lactation. Sixteen crossbred Friesian Holstein cows were divided into two distinct groups. The first group (control: CON) was provided with a basal diet. In contrast, the treatment group (SUP) received the same basal diet but with added selenium and zinc supplements at dosages of 0.45 mg/kg and 60 mg/kg of dry matter (DM), respectively, based on our previous studies. The selenium and zinc were provided in organic chelated-methionine forms. The experimental feeding lasted for 49 days. Blood samples were drawn from each cow at the trial's conclusion and placed in tubes containing anticoagulants. Whole blood was used for haematological analysis with a haematology analyzer. Additional samples were collected in sterile tubes without anticoagulants and centrifuged to obtain serum. The serum was then used to assess blood biochemistry parameters and T-AOC with an automatic biochemical analyzer and a commercial kit. The findings showed no significant changes in the levels of AST, ALT, total protein, glucose, BUN, triglycerides, cholesterol, HDL, LDL, or creatinine (P>0.05) due to supplementation.However, the SUP group showed a significant increase in WBC (41.50), lymphocyte count (74.70), and MCHC (2.20) (P<0.05), with no influence on other haematological parameters (P>0.05). Additionally, the SUP group exhibited significantly higher T-AOC levels (63.28) (P<0.05). In conclusion, supplementing with combined organicselenium and zinc (0.45 and 60 mg/kg DM) can improve the antioxidant status of early-lactating dairy cows without negatively affecting their blood metabolite profiles. These results suggest potential implications for using essential organic TM during early lactation. However, further research with a longer duration related to dairy cow productivity is needed to confirm these findings. © (2024), (ResearchersLinks Ltd). All rights reserved.