Advances in Animal and Veterinary Sciences

Research Article
Adv. Anim. Vet. Sci. 9(12): 2095-2102
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Shimaa G. Yehia1, Eman S. Ramadan1*, Eissa A. Megahed2, Noha Y. Salem1

1Department of Internal Medicine and Infectious Diseases, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt; 2Veterinary Medicine Directorate - Giza, El Haram, Giza, Egypt.

Abstract | Seasonal variations and lactation are among stressors that have a significant impact on the blood metabolites of dairy cattle. The current study aimed to compare the impact of season, different lactation stages, and their combined effect on the hematobiochemical and oxidative stress variables in Holstein dairy cows. Forty (40) multiparous Holstein dairy cows with the age range of 5-7 years were enrolled in this study. This study was conducted during the Winter (January 2020) and Summer (August 2020). Cows were divided according to production period and season into early-lactating Summer group (n=10), mid-lactating Summer group (n=10), early lactating Winter group (n=10), and mid-lactating Winter group (n=10). One blood sample was withdrawn from each cow for hematological, selected serum biochemical, and oxidative stress parameters estimation. Regarding season, in Summer, significant elevation in triglyceride and malondialdehyde (MDA) were recorded. In Winter, total protein was significantly higher. Regarding the lactation stage, early lactation was associated with a significant decrease in glucose, cholesterol, and total antioxidant capacity (TAC) and a significant increase in non-esterified fatty acids (NEFA) and MDA compared to the mid-lactating stage. Significant increases in leukocytes and lymphocytes were recorded in the Summer season compared to the Winter season regardless of the lactation stage. Season and stage of lactation have influenced some of the blood biochemical, hematological, and oxidative stress parameters. Mild heat stress might influence the metabolites in the early lactation stage.


Keywords | Oxidative biomarkers, NEFA, Lactation stage, Season, Cow