Influence of Body Condition Score on Relationships Between Metabolic Status and Oxidative Stress in Periparturient Dairy Cows

Analysis of chromosome damage by sister chromatid exchange (SCE) and redox homeostasis characterization on sheep flocks from Sardinian pasturelands

Over the last decades, an increase of pollutants of diverse origin (industrial, military, mining, etc.) was recorded in several areas of Sardinia Island. We report the results of a multidisciplinary and complementary study based on cytogenetic and physiological analyses. The data obtained show the effects of the environmental impact on six sheep flocks (Sardinian breed) grazing on natural pasturelands next to possible polluted areas and compared to three herds grazing in different areas far from those potentially contaminated and used as control. Sister chromatid exchange (SCE) test was used as cytogenetic test to analyze chromosomal damages and it was performed on peripheral blood samples collected from 129 adult sheep (age > 4 years) randomly selected from polluted (92 animals) and control (37 animals) areas. Two types of cell cultures were performed: without (normal cultures) and with the addition of 5-BrdU. SCE-mean values estimated over 35 cells counted for each animal were 8.65 ± 3.40, 8.10 ± 3.50, 8.05 ± 3.08, 7.42 ± 3.34, 9.28 ± 3.56 and 8.38 ± 3.29 in the exposed areas, whereas the average values were 7.86 ± 3.31 in the control group. Significant increases (P < 0.01) of SCEs were found in three investigated areas of Southern Sardinia. Furthermore, sheep of the same flocks were characterized for blood redox homeostasis in order to define the potential targets of oxidative damage and to identify biomarkers of the extent of animal exposure to environmental contaminants. The plasma levels of Asc, Toc and Ret were found to be significantly lower (P < 0.001) in exposed sheep (I, II, IV and V) than in the control group. TAC as well as GPx and SOD activities were higher in control than in the exposed groups (P < 0.001). Finally, plasma levels of N-Tyr, PC, and LPO were significantly lower (P < 0.001) in the control group than in the exposed groups.

The etiology of oxidative stress in the various species of animals, a review

Oxidative stress is the consequence of an imbalance of pro-oxidants and antioxidants leading to cell damage and tissue injury. The exhaustion of antioxidant systems is one of the reasons for the occurrence of oxidative stress, which results in avalanche production of reactive oxygen species (ROS) or free radicals. High oxidative stress is common in organs and tissues with high metabolic and energy demands, including skeletal and heart muscle, liver and blood cells. Stress arises in animals in response to unavoidable or adverse environmental conditions. In the external environment, which affects the body of the cow, there are four main groups of stressors: physical, chemical, biological and psychological. Physical stressors include fluctuations in ambient temperature as well as mechanical injuries. High ambient temperature is one of the factors affecting the productivity of cows. Biological stressors are conditioned by errors and irregularities in habits. Both of these phenomena have an adverse impact on both the resistance of animals and fertility and are the etiological agent of oxidative stress. Various mechanisms may be responsible for metal-induced oxidative stress: direct or indirect generation of ROS, depletion of glutathione and inhibition of antioxidant enzymes are well known for all redox-active and redox-inactive metals.

The Role of TCA Cycle Anaplerosis in Ketosis and Fatty Liver in Periparturient Dairy Cows

The transition to lactation period in dairy cattle is characterized by metabolic challenges, negative energy balance, and adipose tissue mobilization. Metabolism of mobilized adipose tissue is part of the adaptive response to negative energy balance in dairy cattle; however, the capacity of the liver to completely oxidize nonesterified fatty acids may be limited and is reflective of oxaloacetate pool, the carbon carrier of the tricarboxylic acid cycle. Alternative metabolic fates of acetyl-CoA from nonesterified fatty acids include esterification to triacylglycerides and ketogenesis, and when excessive, these pathways lead to fatty liver and ketosis. Examination of the anaplerotic and cataplerotic pull of oxaloacetate by the tricarboxylic acid cycle and gluconeogenesis may provide insight into the balance of oxidation and esterification of acetyl-CoA within the liver of periparturient dairy cows.

Short communication: Characterizing metabolic and oxidant status of pastured dairy cows postpartum in an automatic milking system

The periparturient period represents a stressful time for dairy cows as they transition from late gestation to early lactation. Undesirable fluctuations in metabolites and impaired immune defense mechanisms near parturition can severely affect cow health and have residual effects on performance and longevity. Metabolic and oxidative stress profiles of multiparous and primiparous dairy cows in traditional parlor and feeding systems are well characterized, but status of these profiles in alternative management systems, such as grazing cows managed with an automatic milking system (AMS), are poorly characterized. Therefore, the objective of this case study was to characterize the metabolic and oxidant status of pastured cows milked with an AMS. It was hypothesized that primiparous and multiparous cows milked with an AMS would experience changes in oxidative and metabolic status after parturition; however, these changes would not impair cow health or production. Blood was collected from 14 multiparous and 8 primiparous Friesian-cross dairy cows at 1, 7, 14, and 21 d relative to calving for concentrations of insulin, glucose, nonesterified fatty acids (NEFA), β-hydroxybutyrate, reduced glutathione, oxidized glutathione, and antioxidant potential. Milk production and milking frequency data were collected postpartum. Milk production differed on d 7 and 14 between primiparous and multiparous cows and frequency was not affected by parity. Primiparous cows had higher levels of glucose than multiparous cows. No differences in insulin, NEFA, or β-hydroxybutyrate concentrations were noted between multiparous and primiparous cows postpartum, though days relative to calving significantly affected insulin and NEFA. Primiparous cows also had higher antioxidant potential than multiparous cows during the postpartum period. Results from this study show that, although responses were within expected ranges, periparturient multiparous cows responded differently than periparturient primiparous cows with respect to metabolic and oxidative measures during the postpartum period at this pastured-AMS dairy, suggesting different management strategies may need to be considered with primiparous and multiparous cows.

Conjugated linoleic acid isomers strongly improve the redox status of bovine mammary epithelial cells (BME-UV1)

Some studies have shown the protective effects of conjugated linoleic acid (CLA) isomers against oxidative stress and lipid peroxidation in animal models, but no information is available about CLA and changes in oxidative status of the bovine mammary gland. The objectives of the study were to assess in vitro the effect of CLA on the cellular antioxidant response of bovine mammary cells, to examine whether CLA isomers could play a role in cell protection against the oxidative stress, and to study the molecular mechanism involved. For the study, BME-UV1 cells, a bovine mammary epithelial cell line, were used as the experimental model. The BME-UV1 cells were treated with complete medium containing 50 µM cis-9,trans-11 CLA (c9,t11 CLA), trans-10,cis-12 CLA (t10,c12 CLA), and CLA mixture (1:1, cis-9,trans-11: trans-10,cis-12 CLA). To monitor cellular uptake of CLA isomers, cells and culture medium were collected at 0, 3, and 48 h from CLA addition for lipid extraction and fatty acid analyses. To assess the cellular antioxidant response, glutathione (GSH/GSSH), NADPH, and γ-glutamyl-cysteine ligase activity was measured after 48 h from addition of CLA. Cytoplasmic superoxide dismutase, glutathione peroxidase, glutathione S-transferase, and glutathione reductase activities and mRNA were also determined. Intracellular reactive oxygen species and thiobarbituric acid reactive substance production were assessed in cells supplemented with CLA isomers. Cell viability after 3h to H2O2 exposure was assessed to evaluate and to compare the potential protection of different CLA isomers against H2O2-induced oxidative stress. Mammary cells readily picked up all CLA isomers, their accumulation was time dependent, and main metabolites at 48 h are two 18:3 isomers. The CLA treatment induced an intracellular GSH increase, matched by high concentration of NADPH, and an increase of γ-glutamyl-cysteine ligase activity mainly in cells treated with the t10,c12 CLA isomer. The CLA isomer treatment of bovine mammary cells increased superoxide dismutase, glutathione peroxidase, and glutathione S-transferase activity and decreased glutathione reductase activity, but no changes in gene expression of these antioxidant enzymes were observed. Cells supplemented with CLA isomers showed a reduction in intracellular reactive oxygen species and thiobarbituric acid reactive substance levels. All CLA isomers were able to enhance cell resistance against H2O2-induced oxidative stress. These suggest an antioxidant role of CLA, in particular of t10,c12 CLA, by developing a significantly high redox status in cells.

Invited review: Inflammation during the transition to lactation: New adventures with an old flame

For dairy cattle, the first several weeks of lactation represent the highest-risk period in their lives after their own neonatal period. Although more than 50% of cows during this period are estimated to suffer from at least one subclinical disorder, the complicated admixture of normal adaptations to lactation, infectious challenges, and metabolic disorders has made it difficult to determine which physiological processes are adaptive and which are pathological during this time. Subacute inflammation, a condition that has been well documented in obesity, has been a subject of great interest among dairy cattle physiologists in the past decade. Many studies have now clearly shown that essentially all cows experience some degree of systemic inflammation in the several days after parturition. The magnitude and likely persistence of the inflammatory state varies widely among cows, and several studies have linked the degree of postpartum inflammation to increased disease risk and decreased whole-lactation milk production. In addition to these associations, enhancing postpartum inflammation with repeated subacute administration of cytokines has impaired productivity and markers of health, whereas targeted use of nonsteroidal anti-inflammatory drugs during this window of time has enhanced whole-lactation productivity in several studies. Despite these findings, many questions remain about postpartum inflammation, including which organs are key initiators of this state and what signaling molecules are responsible for systemic and tissue-specific inflammatory states. Continued in vivo work should help clarify the degree to which mild postpartum inflammation is adaptive and whether the targeted use of anti-inflammatory drugs or nutrients can improve the health and productivity of dairy cows.

Oxidative stress and antioxidant status in dairy cows during prepartal and postpartal periods

The aim of the present study was to evaluate the indicators of oxidative stress (malondialdehyde [MDA]) and antioxidant status (ferric reducing ability of plasma [FRAP]; superoxide dismutase [SOD]; glutathione peroxidase [GSH-Px]; selenium [Se]; vitamin E) in dairy cows of the Slovak Pied cattle from 3 weeks before parturition to 9 weeks after parturition. The mean MDA concentration was significantly (P < 0.001) higher in the cows 1 week after calving compared to the cows 3, 6, and 9 weeks after calving. The lowest mean FRAP value was found in the cows 3 weeks after parturition. The SOD activities were increased during the whole monitored time (ANOVA, P < 0.001). A significant (P < 0.05) decrease of GSH-Px activities was recorded in the cows 1 week after calving compared to the weeks 6 and 9 after calving. Statistical multiple comparison test showed no significant changes in Se between the examined groups. The lowest mean vitamin E concentration was found in the first week after parturition. Significantly positive correlations (P < 0.05) were recorded between Se and vitamin E (r = 0.897), SOD and GSH-Px (r = 0.903), while Se and GSH-Px had no significantly positive correlation (r = 0.520). Significant changes between MDA and indicators of oxidative stress (SOD, GSH-Px, vitamin E) confirm that during parturition and onset of lactation, oxidative stress occurs in dairy cows. Exposure of peripartal cows to oxidative stress may cause an increased incidence of metabolic diseases.

Hormonal profile and body condition scoring in dairy cows during pre partum and post partum periods

The aim of this study was to evaluate the dynamics of selected indicators of energy, hormonal profile, body condition score (BCS) and their relationships in dairy cows of the Slovak Pied Cattle from 3 weeks before parturition to 9 weeks after. Significant differences were found in the mean values of non-esterified fatty acids (NEFA) (P < 0.001) and β-hydroxybutyrate (BHB) (P < 0.05). According to BCS results, the dry cows were overweight (4.42 ± 0.75 points). After calving the cows lost weight significantly, as the BCS was 3.25 ± 0.30 points at 9 weeks post partum (P < 0.001). The highest concentration of leptin was recorded before calving (26.80 ± 11.47 ng/ml). The concentrations of insulin and ghrelin did not change significantly (an increase in insulin concentrations from 580.8 ± 66.30 IU/ml to 625.50 ± 174.90 IU/ml and a decrease in ghrelin concentrations from 29.25 ± 4.82 pg/ml to 26.57 ± 5.35 pg/ml were found comparing 3 weeks to 1 week before parturition, respectively). Relationships between the hormones showed positive correlation between insulin and leptin (r = 0.220, P < 0.05), BCS and leptin (r = 0.360, P < 0.001), BCS and insulin (r = 0.232, P < 0.05) and negative correlation between leptin and ghrelin (r = -0.235, P < 0.05), BCS and ghrelin (r = -0.257, P < 0.05). These data provide evidence that the variations in the concentrations of leptin, ghrelin, and insulin are related to variations in the BCS. Negative correlation between leptin and ghrelin contributes to the argument that leptin negatively regulates ghrelin.

Silymarin and lycopene administration in periparturient dairy cows: effects on milk production and oxidative status

AIMS

To establish during late gestation and early lactation the effects of supplementing silymarin, a natural hepatoprotective substance, combined with a powerful antioxidant, lycopene, on milk production and on serum biomarkers of oxidative status.

METHODS

Italian Friesian dairy cows were given individually a supplement containing a mixture of silymarin (7.77 g/day/cow) and lycopene (1.27 g/day/cow) (n=10) or no supplement (control; n=10). Treatment was administered from 7 days before the expected calving date to the first 14 days in milk. At 7 days before the expected calving date, at calving, and 7 days postpartum, body condition score (BCS) and concentrations in serum of reactive oxygen metabolites (ROM), total antioxidant capacity (OXY) and thiobarbituric acid reactive substances (TBARS) were evaluated. Bodyweight, milk production, and somatic cell count (SCC) were determined at 7, 14 and 21 days postpartum.

RESULTS

The mean time of treatment prior to calving was 6.3 (min 4, max 11) days. Compared with control cows, treatment increased energy corrected milk yield (33.3 vs. 37.8 (SEM 1.10) kg/day; p=0.006) and milk fat yield (1.14 vs. 1.32 (SEM 0.06) kg/day; p=0.05) over the first 21 days of lactation. Treated cows had lower mean log10 SCC compared to control cows (4.9 vs. 5.24 (SEM 0.11) log10 cells/mL) and had lower overall concentration of TBARS (1.47 vs. 1.59 (SEM 0.016) nM/mL; p<0.001), but similar concentrations of ROM and OXY in serum. However there was a treatment by time interaction (p=0.09) for OXY, and at calving mean OXY was higher in treated cows compared with pre-calving values (p<0.001).

CONCLUSIONS

Despite the acknowledged limitation of the study, i.e. the small number of animals, our results suggest that silymarin and lycopene, as health-beneficial feed supplements, may help dairy cows in metabolic adaptation during the first stages of lactation.

CLINICAL RELEVANCE

During the peripartum period dairy cows suffer moderate-to-severe fatty liver and from an overproduction of free radicals. The supplementation of a mixture of silymarin and lycopene during these stressful days may be useful to mitigate these metabolic disorders with beneficial effects on the subsequent lactation.

A Pilot Study to Compare Oxidative Status between Organically and Conventionally Managed Dairy Cattle During the Transition Period

The aim of this study was to assess the redox balance of organically managed dairy cattle (OMC; n = 40) during the transition period and to compare this with conventionally managed cattle (CMC; n = 22). Serum samples of dairy cows from two organic and one conventional farm were taken. Markers of oxidants production [reactive oxygen species] and total serum antioxidant capacity were measured in four different production stages: (i) far-off dry (2 to 1 months before calving; 44 samples in CMC and 48 in OMC); (ii) close-up dry (1 month until 3 days before calving; 44 CMC; 54 OMC); (iii) fresh (3 days to +1 month after calving; 44 CMC; 49 OMC); and (iv) peak of lactation (+1 to +3 months; 71 CMC; 78 OMC). Values were compared between production stages and against a metabolic baseline status (4th-5th month of pregnancy; 40 CMC; 30 OMC). Our results indicated that throughout the periparturient period, OMC had lower concentrations of reactive oxygen species, but also a lower antioxidant capacity than CMC. Indeed, when the two components of the redox balance were assessed together through the Oxidative Stress index, the values of this parameter were higher for OMC than for CMC, thereby implying a higher risk of oxidative stress. Therefore, further larger studies are needed to confirm the current observations, as organically reared animals might be exposed to a lack of antioxidants supply.

Body condition score and its correlation with ultrasonographic back fat thickness in transition crossbred cows

Aim:

The aim was to study the effect of the transition to body condition score (BCS) and ultrasonographic back fat thickness (USG BFT) in crossbred cows.

Materials and Methods:

A total of 101 multiparous crossbred cows in advanced pregnancy from organized dairy farm were taken up for study. The cows were grouped according to transition stage, i.e. far off dry (FOD), close up dry (CUD) and fresh (F). BCS was estimated by using the five point visual BCS technique with 0.5 increments. The USG BFT was measured by real-time ultrasound using a portable Sonosite instrument.

Results:

In cows with BCS 2-2.5, the BFT of F period was significantly lower than FOD period. In cows with BCS 3-3.5, the mean BFT at F period was significantly reduced as compared to FOD and CUD period. The overall correlation coefficient between BCS and BFT for different transition stages was 84%, 79% and 75% for FOD, CUD and F period, respectively.

Conclusion:

The USG BFT gives an accurate measure of fat reserves in cows. The cows with BCS of ≥3.5 entering the transition period are more prone to lose body condition and hence require better and robust management during the transition period.

Effect of additional chromium supplementation on health status, metabolic responses, and performance traits in periparturient Murrah Buffaloes (Bubalus bubalis)

This study was conducted to determine the effects of inorganic chromium (Cr) on body condition, metabolic responses, lactation performance, and reproductive parameters in periparturient Murrah buffaloes. Twenty-four multiparous advanced pregnant Murrah buffaloes were randomly assigned to four treatment diets. Feeding regimen was the same in all the groups, except that the animals in the four respective groups were additionally supplemented with 0.0, 0.5, 1.0, and 1.5 mg of Cr/kg dry matter (DM) from day 60 prepartum to 150 days postpartum. Dry matter intake (DMI) and milk production were recorded every day, while body condition score (BCS) and whole blood samples were collected at days -60, -45, -30, -15, -7, -3, 0, 3, 7, 15, 30, 45, 60, 90, 120, and 150 relative to actual calving. As the days to calving advanced, DMI, plasma glucose, insulin, leptin, and Cr levels decreased (P < 0.05), and the levels were minimum on the day of calving. In contrast, the concentration of nonesterified fatty acid (NEFA) increased (P < 0.05) and was found to be highest at parturition. No change in DMI as well as BCS was observed due to dietary treatments. Supplementation of Cr improved plasma concentration of glucose, leptin, and Cr levels. However, the concentration of insulin decreased (P < 0.05) with the increased level of supplemental Cr. Milk yield (kg/day) was improved significantly (P < 0.05) in groups supplemented with 1.0 or 1.5 mg Cr/DM; however, only a small change was recorded in the group fed 0.5 mg Cr/kg DM. Fat-corrected milk and energy-corrected milk were 28.78 and 42.32 % and 28.76 and 41.68 % higher in the 1.0 and 1.5 mg Cr/DM groups, respectively. Dietary Cr supplementation during the peripartum period had beneficial effects on the reproductive performance of buffaloes. These results could be interpreted as an improvement in the body condition, metabolic response, milk yield, efficiency of milk production and nutrient utilization, and reproductive performance of peripartum Murrah buffaloes.

NEFAs activate the oxidative stress-mediated NF-κB signaling pathway to induce inflammatory response in calf hepatocytes

Non-esterified fatty acids (NEFAs) are important induction factors of inflammatory responses in some metabolic diseases. High plasma levels of NEFAs and oxidative stress exist in the dairy cows with ketosis. The aim of this study was to investigate whether high levels of NEFAs can induce inflammatory response and the specific molecular mechanism in the hepatocytes of dairy cow. In vitro, primary cultured bovine hepatocytes were treated with different concentrations of NEFAs, PDTC (an NF-κB inhibitor) and NAC (an antioxidant). NEFAs significantly activated NF-κB pathway. Activated NF-κB upregulated the release of pro-inflammatory cytokines, thereby inducing inflammatory response in bovine hepatocytes. When PDTC was added, activation of NF-κB-mediated inflammatory response induced by NEFAs was inhibited. NEFAs treatment results in the overproduction of the markers of oxidative stress, reactive oxygen species (ROS) and malondialdehyde (MDA), which were ameliorated by NAC treatment. These increased ROS and MDA were caused by decreasing activity of antioxidant system, including glutathione peroxidase, superoxide dismutase and catalase, in bovine hepatocytes treated with NEFAs. NAC also ameliorated NEFAs-mediated NF-κB activation and the release of pro-inflammatory cytokines. These results indicate that high concentrations of NEFAs can induce cattle hepatocytes inflammatory response through activating the oxidative stress-mediated NF-κB signaling pathway.

Effect of supranutritional organic selenium supplementation on postpartum blood micronutrients, antioxidants, metabolites, and inflammation biomarkers in selenium-replete dairy cows

Dairy cows have increased nutritional requirements for antioxidants postpartum. Supranutritional organic Se supplementation may be beneficial because selenoproteins are involved in regulating oxidative stress and inflammation. Our objective was to determine whether feeding Se-yeast above requirements to Se-replete dairy cows during late gestation affects blood micronutrients, antioxidants, metabolites, and inflammation biomarkers postpartum. During the last 8-weeks before calving, dairy cows at a commercial farm were fed either 0 (control) or 105 mg Se-yeast once weekly (supranutritional Se-yeast), in addition to Na selenite at 0.3 mg Se/kg dry matter in their rations. Concentrations of whole-blood (WB) Se and serum Se, erythrocyte glutathione (GSH), and serum albumin, cholesterol, α-tocopherol, haptoglobin, serum amyloid A (SAA), calcium, magnesium, phosphorus, non-esterified fatty acids, and β-hydroxybutyrate were measured directly after calving, at 48 h, and 14 days of lactation in 10 cows of each group. Supranutritional Se-yeast supplementation affected indicators of antioxidant status and inflammation. Cows fed a supranutritional Se-yeast supplement during the last 8-weeks of gestation had higher Se concentrations in WB (overall 52 % higher) and serum (overall 36 % higher) at all-time points, had higher SAA concentrations at 48 h (98 % higher), had higher erythrocyte GSH (38 % higher) and serum albumin concentrations (6.6 % higher) at 14 days, and had lower serum cholesterol concentrations and higher α-tocopherol/cholesterol ratios at calving and at 48 h compared with control cows. In conclusion, feeding Se-replete cows during late gestation a supranutritional Se-yeast supplement improves antioxidant status and immune responses after calving without negatively impacting other micronutrients and energy status.

Inactivation of the LOX-1 pathway promotes the Golgi apparatus during cell differentiation of mural granulosa cells

In female mammals, granulosa cells of the ovarian follicle differentiate into the corpus luteum after ovulation of the pregnable oocyte into the fallopian tube. During these differentiation processes several morphological alterations have to occur and the molecular basis is not fully understood. As an endpoint estradiol production from granulosa cells has to switch off in favor for progesterone production from the proceeding corpus luteum to sustain the developing embryo. Previously, we demonstrated that the multiligand receptor LOX-1 plays a critical role in steroid hormone synthesis of granulosa cells via intracellular calcium release from endoplasmic (ER)-dependent and ER-independent calcium pools. In the present study, we show that inhibition of LOX-1 leads to a rearrangement of ceramide from the basal membrane toward the Golgi apparatus. This activity is accomplished by a calcium-dependent phosphorylation of aromatase, the key step in estradiol production. Phosphorylated aromatase increased estradiol production in a dose-dependent manner. Our data indicate that the ceramide cascade is essential for proper granulosa cell function and ceramide redistribution serves as a first step in order to proceed with the prosperous differentiation into a corpus luteum.

Transition cow nutrition and feeding management for disease prevention

In this article, an overview is presented of nutrient modeling to define energy and protein requirements of the late pregnant cow, and metabolic relationships between fetus and cow as they relate to nutrient utilization and risk for postparturient disease are discussed. Recommendations for formulating dry cow diets are provided, with emphasis on opportunities to minimize variation and risk for postparturient disease events.

Immunohistochemical evaluation of superoxide dismutase (Cu/Zn SOD) concentrations in erythrocytes of dairy cattle and farm-raised deer by a computer-assisted analysis of microscopic images

The effectiveness of the immunohistochemical method in determining Cu/Zn SOD concentrations in red blood cells of dairy cattle and farm-raised deer was evaluated by a computer-assisted analysis of microscopic images and scanning technique. Superoxide dismutase (Cu/Zn SOD) concentrations in erythrocytes were determined in smears of whole blood samples collected from 16 Polish Holstein-Friesian cows and 22 farm-raised deer in spring. Mouse anti-bovine SOD (Cu-Zn) monoclonal antibodies (2F5, Serotec) were used in 1:50 dilution. The degree of immunostaining for SOD in red blood cells was determined with the use of the MIDI 3DHistech Panoramic Scanner (Hungary) and 3DHistech Panoramic Viewer, NuclearQuant and MembraneQuant software. Our findings indicate that the immunohistochemical method is a useful technique for evaluating Cu/Zn SOD concentrations in red blood cells of cattle and deer.

Antioxidants and human diseases

Oxidative stress plays a pivotal role in the development of human diseases. Reactive oxygen species (ROS) that includes hydrogen peroxide, hyphochlorus acid, superoxide anion, singlet oxygen, lipid peroxides, hypochlorite and hydroxyl radical are involved in growth, differentiation, progression and death of the cell. They can react with membrane lipids, nucleic acids, proteins, enzymes and other small molecules. Low concentrations of ROS has an indispensable role in intracellular signalling and defence against pathogens, while, higher amounts of ROS play a role in number of human diseases, including arthritis, cancer, diabetes, atherosclerosis, ischemia, failures in immunity and endocrine functions. Antioxidants presumably act as safeguard against the accumulation of ROS and their elimination from the system. The aim of this review is to highlight advances in understanding of the ROS and also to summarize the detailed impact and involvement of antioxidants in selected human diseases.

Energy metabolites, lipid variables and lactation performance of periparturient Murrah buffaloes (Bubalus bubalis) fed on diet supplemented with inorganic chromium

The aim of this study was to elucidate the effects of chromium (Cr) supplementation as inorganic Cr (CrCl3·6H2O) on energy balance, lipid peroxidation, and lactation performance in periparturient Murrah buffaloes. Twenty-four multiparous Murrah buffaloes according to lactation, parity, body mass, and expected calving date were divided equally. Experimental buffaloes were randomly assigned to four treatment diets: a control diet and three diets with an inorganic Cr supplementation at 0.5, 1.0, and 1.5 mg of Cr/kg dry matter (DM), respectively from 60 days before expected calving date until 60 days of lactation. Milk productions of buffaloes were recorded every day until 60 days in milk. Blood samples were collected at days -60, -45, -30,-21, -15, -7, -3, 0, 7, 15, 21, 30, 45, and 60 days relative to actual calving for determination of plasma glucose, nonesterified fatty acid (NEFA), thiobarbituric acid reactive substance (TBARS), total cholesterol, total protein, albumin, blood urea nitrogen (BUN), and minerals. Adding inorganic Cr to the diet of Murrah buffaloes increased milk yield. Percentage of fat and total solid yield increased significantly through the experiment in the Cr-supplemented group. At the day of calving, buffaloes showed a decrease in dry matter intake (DMI), plasma glucose, and zinc (Zn) and Cr concentrations. In contrast, plasma NEFA, TBARS, and copper (Cu) levels were found highest at the day of calving among all groups. Cr supplementation increased peripheral blood glucose concentration while decreased level of NEFA and TBARS was recorded in Cr-fed buffaloes. Supplemental Cr had no effect on plasma cholesterol, total protein, albumin, and BUN in periparturient period. Dietary Cr supplementation had positive effect on plasma Cr concentration, but the plasma concentration of Cu, Zn, and iron (Fe) was not affected by different dietary Cr level supplementation. The results suggest that dietary inorganic Cr supplementation improved milk yield by reducing negative energy balance and lipid peroxidation in buffaloes during periparturient period.

Serum paraoxonase-1 activity of dairy Holstein-Fresian cows in different lactation stages--preliminary study

The objective of this study was to investigate paraoxonase-1 (PON-1) activity in different lactation stages. The study was conducted on Holstein--Friesian dairy cows in 2nd and 3rd lactation. A significant decrease in paraoxonase activity was found in the postpartum period and during peak of lactation. Serum triglyceride and cholesterol concentration were also markedly reduced during postpartum period. The concentrations of uric acid in serum was 23% higher during lactation peak in comparison with dry and postpartum period. The results indicate that lower serum paraoxonase activity and higher concentration of uric acid are associated with oxidative character of transition period and lipid functional antioxidative protection during intensive milk production.

Bovine mammary stem cells: new perspective for dairy science

Mammary stem cells provide opportunities for the cyclic remodelling of the bovine mammary gland. Therefore, understanding the character and regulation of mammary stem cells is important for increasing animal health and productivity. The exciting possibility that stem cell expansion can influence milk production is currently being investigated by several researchers. In fact, appropriate regulation of mammary stem cells could hopefully benefit milk yield, persistency of lactation, dry period management and tissue repair. Accordingly, we and others have attempted to characterize and regulate the function of bovine mammary stem cells. However, research on mammary stem cells requires tissue biopsies, which represents a limitation for the management of animal welfare. Interestingly, different studies recently reported the identification of putative mammary stem cells in human breast milk. The possible identification of primitive cell types within cow's milk may provide a non-invasive source of relevant mammary cells for a wide range of applications. In this review, we have summarized the main achievements in this field for dairy cow science and described the interesting perspectives open to manipulate milk persistency during lactation and to cope with oxidative stress during the transition period by regulating mammary stem cells.

Effects of prepartal body condition score and peripartal energy supply of dairy cows on postpartal lipolysis, energy balance and ketogenesis: an animal model to investigate subclinical ketosis

Subclinical ketosis is a metabolic disorder which often goes undiagnosed and leads to constricted performance and an impairment of general condition. In the current study subclinical ketosis was characterised by a β-hydroxybutyrate (BHB) concentration of >1·2 mmol/l in blood serum. To generate this metabolic situation, an animal model was created. The model, based on group-specific interaction of dietary energy supply and body condition, is appropriate for testing the medical effectiveness of treating this kind of ketosis and its concomitants. During the trial, 18 dairy cows (primiparous and pluriparous) were assigned, according to their body condition score (BCS) 6 weeks before expected parturition, to a normal [6·78 MJ net energy for lactation (NEL)/kg dry matter; 20% concentrate] or to a high-energy feeding group (7·71 MJ NEL/kg dry matter; 60% concentrate). Therefore cows with the highest BCS were allocated to the high-energy group to enhance the contrast with the control group. Statistical analysis was done using the MIXED procedure of SAS. Effects were declared significant when P-values were ⩽0·05. Owing to the higher energy concentration and dry matter intake, the energy intake and balance was significantly higher in the high-energy feeding group, with strong effects on lipid metabolism and health in blood and liver post partum. Within the first 2 weeks after calving, 8 out of 9 cows (89%) of the high-energy group had BHB values indicative of subclinical ketosis. These cows also had significantly higher values of non-esterified fatty acids (NEFA), aspartate transaminase (AST) and glutamate dehydrogenase (GLDH) post partum, as well as a raised total lipid content of the liver. RQUICKI, a calculated parameter which is based on serum concentrations of glucose, insulin and NEFA to assess the insulin sensitivity, was not affected by treatment. Therefore, RQUICKI does not seem to be the right parameter for diagnosing decreased insulin sensitivity in cows affected by subclinical ketosis. The milk fat and the fat:protein ratio of the high-energy group was also higher, even though there was no decrease in milk yield for cows with subclinical BHB values.

Longitudinal profiling of the tissue-specific expression of genes related with insulin sensitivity in dairy cows during lactation focusing on different fat depots

In dairy cows the milk associated energy output in early lactation exceeds the input via voluntary feed intake. To spare glucose for mammary lactose synthesis, peripheral insulin sensitivity (IS) is reduced and fat mobilization is stimulated. For these processes a link between IS and the endocrine functions of adipose tissue (AT) is likely; we thus aimed to characterise the mRNA expression from bovine AT derived proteins and receptors that are related to IS according to the literature in metabolically active tissues plus systemic IS throughout lactation. Conjugated linoleic acids (CLA) reduce milk fat thus decreasing the milk drain of energy and potentially dampening lipolysis, but may also affect IS. Subcutaneous (s.c.) AT and liver from pluriparous cows receiving either control fat or CLA supplement (100 g/day from 1 to 182 days in milk each) were biopsied covering week -3 to 36 relative to parturition. In an additional trial with primiparous cows treated analogously and slaughtered on days in milk 1, 42 or 105, samples from liver, udder, skeletal muscle and 3 visceral and 3 s.c. AT were obtained and assayed for mRNA abundance of adiponectin, its receptors, leptin, leptin receptor, PPARγ, PPARγ2, IL-6, and TNF-α. In pluriparous animals, the mRNA abundance of most of the target genes decreased after parturition in s.c. AT but increased in liver. In primiparous cows, AT depot specific differences were mostly related to retroperitoneal AT; adiponectin receptor 1 and TNF-α were affected predominantly. CLA effects in primiparous cows were largely limited to decreased PPARγ2 mRNA abundance in udder tissue. In pluriparous cows, insulin secretion was increased by CLA resulting in decreased systemic IS but without consistent changes in tissue target mRNA abundance. The temporal gene expression profiles from the adipokines and related receptors support their coactive function in adapting to the needs of lactation.

Hepatic purinergic signaling gene network expression and its relationship with inflammation and oxidative stress biomarkers in blood from peripartal dairy cattle

The liver plays a central role in allowing dairy cattle to make a successful transition into lactation. In liver, as in other tissues, extracellular nucleotides and nucleosides trigger cellular responses through adenosine and ATP receptors. Adenosine triphosphate and certain nucleotides serve as signals that can heighten purinergic receptor activation in several pathologic processes. We evaluated the mRNA expression of genes associated with the purinergic signaling network in liver tissue during the peripartal period. Seven multiparous Holstein cows were dried off at d -50 relative to expected parturition and fed a controlled-energy diet (net energy for lactation=1.24 Mcal/kg of DM) for ad libitum intake during the entire dry period. After calving, all cows were fed a common lactation diet (net energy for lactation=1.65 Mcal/kg of DM) until 30 DIM. Biopsies of liver were harvested at d -10, 7, and 21 for mRNA expression of 9 purinergic receptors, 7 ATP and adenosine transport channels, and 10 enzymes associated with ATP hydrolysis. Blood collected at d -21, -10, 7, 14, and 21 was used to measure concentrations of inflammation and oxidative stress biomarkers. The expression of type 1 purinergic receptors (ADORA2A and ADORA3), several nucleoside hydrolases [ectonucleoside triphosphate diphosphohydrolase 7 (ENTPD7), ectonucleotide pyrophosphatase/phosphodiesterase 2 (ENPP2), ENPP3, and adenosine deaminase (ADA)], and a type 2 purinergic receptor (P2RX7) was downregulated after calving. In contrast, the expression of type 2 purinergic receptors (P2RX4 and PR2Y11), an ATP release channel (gap junction hemichannel GJB1), and an adenosine uptake protein (SLC29A1) followed the opposite response, increasing after calving and remaining elevated through 21 d. Haptoglobin, ceruloplasmin, and reactive oxygen metabolite concentrations increased gradually from d -21 d through at least d 7. The opposite response was observed for albumin, paraoxonase, α-tocopherol, and nitric oxide, which decreased gradually to a nadir at 7 and 14 d. Our results suggest that alterations after calving of the expression of hepatic purinergic signaling genes could be functionally important because in nonruminants, they play roles in bile formation, glucose metabolism, cholesterol uptake, inflammation, and steatosis. The correlation analysis provided evidence of a link between purinergic signaling genes and biomarkers of inflammation and oxidative stress.

Practical applications of trace minerals for dairy cattle

Trace minerals have critical roles in the key interrelated systems of immune function, oxidative metabolism, and energy metabolism in ruminants. To date, the primary trace elements of interest in diets for dairy cattle have included Zn, Cu, Mn, and Se although data also support potentially important roles of Cr, Co, and Fe in diets. Trace minerals such as Zn, Cu, Mn, and Se are essential with classically defined roles as components of key antioxidant enzymes and proteins. Available evidence indicates that these trace minerals can modulate aspects of oxidative metabolism and immune function in dairy cattle, particularly during the transition period and early lactation. Chromium has been shown to influence both immune function and energy metabolism of cattle; dairy cows fed Cr during the transition period and early lactation have evidence of improved immune function, increased milk production, and decreased cytological endometritis. Factors that complicate trace mineral nutrition at the farm level include the existence of a large number of antagonisms affecting bioavailability of individual trace minerals and uncertainty in terms of requirements under all physiological and management conditions; therefore, determining the optimum level and source of trace minerals under each specific situation continues to be a challenge. Typical factorial approaches to determine requirements for dairy cattle do not account for nuances in biological function observed with supplementation with various forms and amounts of trace minerals. Trace mineral nutrition modulates production, health, and reproduction in cattle although both formal meta-analysis and informal survey of the literature reveal substantial heterogeneity of response in these outcome variables. The industry has largely moved away from oxide-based programs toward sulfate-based programs; however, some evidence favors shifting supplementation strategies further toward more bioavailable forms of inorganic and organic trace minerals. Furthermore, opportunities for specific modulation of aspects of health, milk production, and reproduction through supplementation strategies for diets of transition dairy cows are attractive because of the known dynamics of energy metabolism, immune function, and oxidative metabolism during this timeframe.

mRNA Expression of lipogenic enzymes in mammary tissue and fatty acid profile in milk of dairy cows fed flax hulls and infused with flax oil in the abomasum

In the present study, the effect of flax hulls with or without flax oil bypassing the rumen on the expression of lipogenic genes in the mammary tissue of dairy cows was investigated. A total of eight dairy cows were used in a replicated 4 × 4 Latin square design. There were four periods of 21 d each and four treatments: control diet with no flax hulls (CONT); diet with 9·88 % flax hulls in the DM (HULL); control diet with 500 g flax oil/d infused in the abomasum (COFO); diet with 9·88 % flax hulls in the DM and 500 g flax oil/d infused in the abomasum (HUFO). A higher mRNA abundance of sterol regulatory element binding transcription factor, fatty acid (FA) synthase, lipoprotein lipase (LPL), PPARγ1, stearoyl-CoA desaturase (SCD) and acetyl-coenzyme A carboxylase-α was observed in cows fed HULL than in those fed CONT, and HUFO had the opposite effect. Compared with CONT, COFO and HUFO lowered the mRNA abundance of SCD, which may explain the lower proportions of MUFA in milk fat with flax oil infusion. The mRNA abundance of LPL in mammary tissue and proportions of long-chain FA in milk fat were higher in cows fed COFO than in those fed CONT. The highest proportions of trans FA were observed when cows were fed HULL. The present study demonstrates that flax hulls with or without flax oil infusion in the abomasum can affect the expression of lipogenic genes in the mammary tissue of dairy cows, which may contribute to the improvement of milk FA profile.

Effects of Different Amounts of Supplemental Selenium and Vitamin E on the Incidence of Retained Placenta, Selenium, Malondialdehyde, and Thyronines Status in Cows Treated with Prostaglandin F2α for the Induction of Parturition

The incidence of retained placenta (RP) in cows increases in cases of parturition induced by prostaglandin F2α . We analyzed the effects of different doses of supplemental selenium and vitamin E on the incidence of RP, blood selenium, plasma thyronines, and malondialdehyde concentration. Thirty-three clinically healthy, multiparous Holstein-Frisian cows were assigned to 3 groups and supplemented with a single intramuscular injection of sodium selenite (SS) and tocopherol acetate (TAc) between days 250 to 255 of gestation: control-unsupplemented; group A-10 mg SS + 400 mg TAc; group B-20 mg SS + 800 mg TAc. Parturition was induced using PGF2α not before day 275 of gestation. The RP incidence was reduced from 66.7% in the control to 38.2 and 30.8% in groups A and B, respectively. Blood selenium and glutathione peroxidase activity in treated groups were significantly higher compared to control, with no significant difference between groups A and B. Plasma malondialdehyde in group B was significantly lower than that in control and group A, while thyronines levels were not affected. Comparison of RP and non-RP cows, independently of supplement treatment, revealed higher blood selenium and glutathione peroxidase activity and lower MDA and thyroxine in non-RP animals, while triiodothyronine level did not differ.

Effect of vitamin e and zinc supplementation on energy metabolites, lipid peroxidation, and milk production in peripartum sahiwal cows

The study was conducted to evaluate the effect of vitamin E and zinc supplementation on energy metabolites, lipid peroxidation, and milk production in peripartum Sahiwal cows. For this, thirty-two pregnant dry Sahiwal cows were selected at sixty days prepartum and divided into four groups viz control, T1, T2, and T3 of eight each. Group T1 were supplemented with zinc at 60 ppm/d/cow, group T2 were supplemented with vitamin E at 1,000 IU/d/cow and group T3 were supplemented with combination of vitamin E at 1,000 IU/d/cow and zinc at 60 ppm/d/cow during d 60 prepartum to d 90 postpartum. Blood samples were collected on d -60, -45, -30, -15, -7, -3, 0, 3, 7, 15, 30, 45, 60, 90, and 120 with respect to day of parturition and analysed for glucose, non esterified fatty acid, and thiobarbituric acid reactive substance. Body condition score was maintained significantly better (p<0.05) in T3 than in the control, T1 and T2 groups. Overall glucose level was higher (p<0.05) in T3 than control, T1, and T2 groups. Levels of nonesterified fatty acid, and thiobarbituric acid reactive substance were lower (p<0.05) in T3 than control, T1, and T2 groups. Milk yield was higher (p<0.05) in T3 than control, T1, and T2 groups. In conclusion, the present study indicated that the supplementation of vitamin E and zinc in peripartum Sahiwal cows enhanced milk production by reducing negative energy balance.

Effects of grain, fructose, and histidine feeding on endotoxin and oxidative stress measures in dairy heifers

Ruminal endotoxin and plasma oxidative stress biomarker concentrations were studied in dairy heifers challenged with grain, fructose, and histidine in a partial factorial study. Holstein-Friesian heifers [n=30; average body weight (BW) of 359.3±47.3 kg] were randomly allocated to 5 treatment groups: (1) control (no grain); (2) grain [crushed triticale at 1.2% of BW dry matter intake (DMI)]; (3) grain (0.8% of BW DMI) + fructose (0.4% of BW DMI); (4) grain (1.2% of BW DMI) + histidine (6g/head); and (5) grain (0.8% of BW DMI) + fructose (0.4% of BW DMI) + histidine (6 g/head). Rumen samples were collected by stomach tube 5, 65, 115, 165, and 215 min after diet consumption and blood samples at 5 and 215 min after consumption. Rumen fluid was analyzed for endotoxin concentrations. Plasma was analyzed for concentrations of the following oxidative stress biomarkers: reactive oxygen metabolites (dROM), biological antioxidant potential (BAP), advanced oxidation protein products, and ceruloplasmin, and activity of glutathione peroxidase. Dietary treatment had no effect on concentrations of endotoxin or oxidative stress biomarkers. We observed no interactions of treatment by time. Ruminal concentrations of endotoxin decreased during the sampling period from 1.12×10(5) ± 0.06 to 0.92×10(5) endotoxin units/mL ± 0.05 (5 and 215 min after diet consumption, respectively). Concentrations of dROM and the oxidative stress index (dROM/BAP × 100) increased over the sampling period, from 108.7 to 123.5 Carratelli units (Carr U), and from 4.1 to 4.8, respectively. Ceruloplasmin concentrations markedly declined 5 min after the consumption of diets, from 190 to 90 mg/L over the 215-min sampling period. Overall, a single feeding challenge for dairy cattle with grain, fructose, and histidine, and combinations thereof, may not be sufficient to induce marked changes in endotoxin or oxidative stress biomarker concentrations.