<abstract xmlns="http://www.w3.org/1999/xhtml"><bold>Introduction:</bold> The purpose of the current study was to evaluate the blood glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) levels under seasonal variations in dairy cows during transition period, and to assess the relationship between chosen reproductive parameters, GSH-Px, and MDA.<bold>Material and Methods:</bold> Holstein cows calving in January were assigned into winter group (n = 42), while cows calving in August were assigned into summer group (n = 42). Blood samples were collected from the jugular vein 21, 14, and 7 days before calving, at calving (0 day), and 7, 14, and 21 days after calving. Reproductive parameters obtained from farm records were evaluated.<bold>Results:</bold> In both groups of cows, GSH-Px activity decreased from 21 days before calving to day 0, and it gradually continued to increase until 21 days after calving. GSH-Px activity was higher in winter group compared to summer group during the transition period (P &lt; 0.05). MDA levels in both groups increased over time starting from 21 days before calving to 0 day, but it gradually decreased thereafter. MDA levels were higher in summer group compared to winter group during the transition periods (P &lt; 0.05). Summer group of cows showed higher intervals of calving-to-oestrus, calving-to-conception, and higher insemination index (P &lt; 0.01). Negative correlation was recorded between GSH-Px and MDA during all examination days (P &lt; 0.01). MDA levels correlated with calving to conception interval on day 21 before calving and day 0 (P &lt; 0.01) and insemination index on day 0 and 21 days after calving (P &lt; 0.01). GSH-Px activity was negatively correlated with calving to conception interval on day 21 before calving, day 0, and 21 days (P &lt; 0.01) after calving. Negative correlation on day 21 before calving and day 0 was also determined between GSH-Px and insemination index (P &lt; 0.01).<bold>Conclusion:</bold> This study showed that blood oxidant and antioxidant levels have affected the fertility parameters in cows under seasonal variations.</abstract>

Introduction: The purpose of the current study was to evaluate the blood glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) levels under seasonal variations in dairy cows during transition period, and to assess the relationship between chosen reproductive parameters, GSH-Px, and MDA.Material and Methods: Holstein cows calving in January were assigned into winter group (n = 42), while cows calving in August were assigned into summer group (n = 42). Blood samples were collected from the jugular vein 21, 14, and 7 days before calving, at calving (0 day), and 7, 14, and 21 days after calving. Reproductive parameters obtained from farm records were evaluated.Results: In both groups of cows, GSH-Px activity decreased from 21 days before calving to day 0, and it gradually continued to increase until 21 days after calving. GSH-Px activity was higher in winter group compared to summer group during the transition period (P < 0.05). MDA levels in both groups increased over time starting from 21 days before calving to 0 day, but it gradually decreased thereafter. MDA levels were higher in summer group compared to winter group during the transition periods (P < 0.05). Summer group of cows showed higher intervals of calving-to-oestrus, calving-to-conception, and higher insemination index (P < 0.01). Negative correlation was recorded between GSH-Px and MDA during all examination days (P < 0.01). MDA levels correlated with calving to conception interval on day 21 before calving and day 0 (P < 0.01) and insemination index on day 0 and 21 days after calving (P < 0.01). GSH-Px activity was negatively correlated with calving to conception interval on day 21 before calving, day 0, and 21 days (P < 0.01) after calving. Negative correlation on day 21 before calving and day 0 was also determined between GSH-Px and insemination index (P < 0.01).Conclusion: This study showed that blood oxidant and antioxidant levels have affected the fertility parameters in cows under seasonal variations.

MDA and GSH-Px activity in transition dairy cows under seasonal variations and their relationship with reproductive performance

Department of Obstetrics and Gynecology, Faculty of Veterinary Medicine

Department of Biostatistics, Faculty of Veterinary Medicine

Department of Internal Medicine, Faculty of Veterinary Medicine

Veterinary Medicine, Farm Animal Management Practitioner

Journal of Veterinary Research

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Introduction: The purpose of the current study was to evaluate the blood glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) levels under seasonal...

MDA and GSH-Px activity in transition dairy cows under seasonal variations and their relationship with reproductive performance

Published Online: Dec 27, 2017

Page range: 497 - 502

Received: Jul 09, 2017

Accepted: Dec 05, 2017

DOI: https://doi.org/10.1515/jvetres-2017-0067

Keywords
cow, glutathione peroxidase, malondialdehyde, reproductive performance, season

© 2017 Hatice Esra Colakoglu et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

MDA and GSH-Px activity in transition dairy cows under seasonal variations and their relationship with reproductive performance

Published Online: Dec 27, 2017

Page range: 497 - 502

Received: Jul 09, 2017

Accepted: Dec 05, 2017

DOI: https://doi.org/10.1515/jvetres-2017-0067

Keywordscow, glutathione peroxidase, malondialdehyde, reproductive performance, season

© 2017 Hatice Esra Colakoglu et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
cow, glutathione peroxidase, malondialdehyde, reproductive performance, season