Volume 16, Issue 1 (3-2025)
Res Anim Prod 2025, 16(1): 85-98 |
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Ghaheri S M H, Ghasemian S O, Pedram B. (2025). Determining the Relationship Between Oxidative Stress and Subclinical Ketosis in Dairy Cows. Res Anim Prod. 16(1), 85-98. doi:10.61186/rap.16.1.85
URL: http://rap.sanru.ac.ir/article-1-1422-en.html
URL: http://rap.sanru.ac.ir/article-1-1422-en.html
1- Department of Veterinary, Shoushtar Branch, Islamic Azad University, Shoushtar, Iran
2- Department of Veterinary, Behbahan Branch, Islamic Azad University, Behbahan, Iran
2- Department of Veterinary, Behbahan Branch, Islamic Azad University, Behbahan, Iran
Abstract: (323 Views)
Extended Abstract
Background: The transition period is of great importance in the health, production, and profitability of dairy cows due to fundamental changes in nutrition, metabolism, hormonal changes, and immunity. During this period, a negative energy balance occurs due to the increased demand for milk production and the subsequent decrease in blood glucose levels. Subclinical ketosis is a disorder of energy metabolism in high-producing cows that causes a decrease in dairy cow performance without obvious clinical signs. Subclinical ketosis occurs without obvious clinical signs due to a decrease in dry matter intake in early lactation of dairy cows. This disease is diagnosed by ketone body tests, which are usually used for diagnosis from the beta-hydroxybutyrate (BHB) test in blood, serum, and plasma, as well as the acetostat test in urine. Malondialdehyde (MDA) is generally considered one of the best predictors of oxidative damage, which often shows good correlation with other stress parameters. The antioxidant enzymes, e.g., superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT), are considered the first line of intracellular defense against reactive oxygen species. Total antioxidant capacity (TAC) is a sensitive, reliable, and useful index for measuring the cumulative function of all antioxidants present in plasma. The present study aimed to investigate the relationship between subclinical ketosis and biochemical factors indicative of oxidative stress in the postpartum period of dairy cows.
Methods: This clinical study was conducted on 50 Holstein dairy cows in the industrial dairy farm of Shams Abad Dairy Complex, Qom province, Iran, over three months in the summer of 2022. The samples were selected randomly from apparently healthy cows in the last lactation period, present in the dry period. In total, the samples consisted of 17 heifers, 15 cows in the second calving period, six in the third period, and seven in the fourth period. The transition of cows to the close-up period was determined based on the average annual calving in the mentioned dairy farm at 251 days of gestation for heifers and 254 days of gestation for multiparous cows. To investigate subclinical ketosis and the effects of oxidative stress on it, it was decided to prepare and evaluate samples one week before and one week after calving. Accordingly, the initial sampling schedule was determined based on the transition time to the close-up period at 265 days of gestation for heifers and 268 days of gestation for multiparous cows. Then, the day of calving was recorded, and resampling was performed 1 week later. The general condition of the animals was recorded before and after calving. Urine samples were taken before and after calving to examine the amount of ketone bodies, pH, glucose, and specific gravity. Milk samples were taken at the time of calving to study the quality and the average milk record for the first 2 months after calving. Serum MDA, SOD, GPX, and TAC indices were measured by taking blood samples one week before and after calving. Serum antioxidant enzymes and biochemical indices were measured with commercial kits and the spectrophotometric method. Based on the level of BHB, cows were divided into two groups, healthy and those with subclinical ketosis, and the relationship of the obtained data with the level of BHB was examined as an index of subclinical ketosis. The data obtained from all experiments were analyzed by SPSS software, and the mean and standard deviation of the range were determined. Furthermore, their changes before and after calving were examined by the paired t-test, and these factors were compared in healthy and sick groups by the independent t-test. Finally, their relationship with BHB levels was examined by the correlation test.
Results: In the studied population, 10 cows presented subclinical ketosis in the postpartum period, and no cases of subclinical ketosis were observed before calving. A comparison of data in apparently healthy cows and those with subclinical ketosis after calving showed that BCS, rectal temperature, and stool scores did not differ between healthy and subclinical ketosis. Blood glucose and serum MDA levels were significantly higher in cows with subclinical ketosis than in healthy cows (p < 0.05). No significant difference was observed in milk quality indicators and serum TAC, SOD, and GPX levels between healthy and subclinical ketosis cows. A significant correlation was found between MDA and BHB (p < 0.05).
Conclusion: The results of this study showed that MDA values as an indicator of oxidative stress increase significantly in subclinical ketosis, and, in addition to other biochemical indicators determining subclinical ketosis, are helpful in diagnosing this disease. Moreover, the lack of correlation between the level of BHB and the antioxidant enzymes GPX and SOD, despite the positive correlation with MDA as an indicator of oxidative stress, indicates the different effects of antioxidants in different degrees of subclinical ketosis.
Background: The transition period is of great importance in the health, production, and profitability of dairy cows due to fundamental changes in nutrition, metabolism, hormonal changes, and immunity. During this period, a negative energy balance occurs due to the increased demand for milk production and the subsequent decrease in blood glucose levels. Subclinical ketosis is a disorder of energy metabolism in high-producing cows that causes a decrease in dairy cow performance without obvious clinical signs. Subclinical ketosis occurs without obvious clinical signs due to a decrease in dry matter intake in early lactation of dairy cows. This disease is diagnosed by ketone body tests, which are usually used for diagnosis from the beta-hydroxybutyrate (BHB) test in blood, serum, and plasma, as well as the acetostat test in urine. Malondialdehyde (MDA) is generally considered one of the best predictors of oxidative damage, which often shows good correlation with other stress parameters. The antioxidant enzymes, e.g., superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT), are considered the first line of intracellular defense against reactive oxygen species. Total antioxidant capacity (TAC) is a sensitive, reliable, and useful index for measuring the cumulative function of all antioxidants present in plasma. The present study aimed to investigate the relationship between subclinical ketosis and biochemical factors indicative of oxidative stress in the postpartum period of dairy cows.
Methods: This clinical study was conducted on 50 Holstein dairy cows in the industrial dairy farm of Shams Abad Dairy Complex, Qom province, Iran, over three months in the summer of 2022. The samples were selected randomly from apparently healthy cows in the last lactation period, present in the dry period. In total, the samples consisted of 17 heifers, 15 cows in the second calving period, six in the third period, and seven in the fourth period. The transition of cows to the close-up period was determined based on the average annual calving in the mentioned dairy farm at 251 days of gestation for heifers and 254 days of gestation for multiparous cows. To investigate subclinical ketosis and the effects of oxidative stress on it, it was decided to prepare and evaluate samples one week before and one week after calving. Accordingly, the initial sampling schedule was determined based on the transition time to the close-up period at 265 days of gestation for heifers and 268 days of gestation for multiparous cows. Then, the day of calving was recorded, and resampling was performed 1 week later. The general condition of the animals was recorded before and after calving. Urine samples were taken before and after calving to examine the amount of ketone bodies, pH, glucose, and specific gravity. Milk samples were taken at the time of calving to study the quality and the average milk record for the first 2 months after calving. Serum MDA, SOD, GPX, and TAC indices were measured by taking blood samples one week before and after calving. Serum antioxidant enzymes and biochemical indices were measured with commercial kits and the spectrophotometric method. Based on the level of BHB, cows were divided into two groups, healthy and those with subclinical ketosis, and the relationship of the obtained data with the level of BHB was examined as an index of subclinical ketosis. The data obtained from all experiments were analyzed by SPSS software, and the mean and standard deviation of the range were determined. Furthermore, their changes before and after calving were examined by the paired t-test, and these factors were compared in healthy and sick groups by the independent t-test. Finally, their relationship with BHB levels was examined by the correlation test.
Results: In the studied population, 10 cows presented subclinical ketosis in the postpartum period, and no cases of subclinical ketosis were observed before calving. A comparison of data in apparently healthy cows and those with subclinical ketosis after calving showed that BCS, rectal temperature, and stool scores did not differ between healthy and subclinical ketosis. Blood glucose and serum MDA levels were significantly higher in cows with subclinical ketosis than in healthy cows (p < 0.05). No significant difference was observed in milk quality indicators and serum TAC, SOD, and GPX levels between healthy and subclinical ketosis cows. A significant correlation was found between MDA and BHB (p < 0.05).
Conclusion: The results of this study showed that MDA values as an indicator of oxidative stress increase significantly in subclinical ketosis, and, in addition to other biochemical indicators determining subclinical ketosis, are helpful in diagnosing this disease. Moreover, the lack of correlation between the level of BHB and the antioxidant enzymes GPX and SOD, despite the positive correlation with MDA as an indicator of oxidative stress, indicates the different effects of antioxidants in different degrees of subclinical ketosis.
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