Metabolic and oxidative status of Saanen goats of different parity during the peripartum period

Effect of parity on non-esterified fatty acid, oxidant/antioxidant status, and zinc and copper levels around periparturient period in Beetal goats of Himalayan Region

The study was conducted to evaluate the effect of parity and physiological status on non-esterified fatty acid (NEFA), oxidative stress, and zinc and copper levels among the Beetal breed of goat. Thirty dual-purpose Beetal goats reared under the semi-intensive system were selected and based on parity were divided into three groups with 10 animals each viz. Early parity (EP; ≤2 parity), mid parity (MP; 3-6 parity), and late parity (LP; ≥7 parity). Blood samples were collected 3 weeks and 1 week pre-kidding followed by 1, 2, 4, and 8 weeks post-kidding for the estimation of NEFA, oxidant (malondialdehyde [MDA], antioxidant (superoxide dismutase [SOD], catalase [CAT], glutathione [GSH], glutathione peroxidase [GSH-Px], and glutathione S-transferase [GST]), and zinc and copper levels. Significant (p < 0.01) increase was observed in NEFA and MDA levels as the goats approached kidding and continued till 2 weeks post-kidding in MP and LP and 1 week post-kidding in EP goats. Significant decrease in SOD (p < 0.05), CAT (p < 0.05), GSH-Px (p < 0.01), GSH (p < 0.01), and GST (p < 0.05) activities were observed as goats approached kidding and continued to decrease up to 2 weeks post-kidding. Zinc and copper levels showed a significant decline from 3 weeks pre-kidding to 2 weeks post-kidding in MP and LP and 1 week post-kidding in EP goats. A significant effect of parity was observed on MDA (p < 0.05), GSH (p < 0.05), and GSH-Px (p < 0.05) activities only; however, parity × sampling time interaction was observed in all the parameters. Findings highlight a different metabolic, trace mineral (zinc and copper), and oxidative response around the periparturient period in Beetal goats, with the EP goats, responding first to increased metabolic and oxidative stress and also first to recover from oxidant/antioxidant imbalance.

Changes in plasma fatty acids profile in hyperketonemic ewes during early lactation: a preliminary study

The transition from late pregnancy to early lactation is characterized by marked changes in energy balance of dairy ruminants. The mobilization of adipose tissue led to an increase in plasma non-esterified fatty acids (NEFA) and β-hydroxybutyrate (BHB). The aim of this study was to analyze the total plasma fatty acids of healthy and hyperketonemic dairy ewes in early lactation through gas chromatography (GC) to evaluate metabolic alterations. An observational study was used with a cross-sectional experimental design. Forty-six Sarda dairy ewes were enrolled in the immediate post-partum (7 ± 3 days in milk) and divided into two groups according to serum BHB concentration: non-hyperketonemic group (n = 28; BHB < 0.86 mmol/L) and hyperketonemic group (n = 18; BHB ≥ 0.86 mmol/L). A two-way ANOVA included the effect of group and parity was used to evaluate differences in fatty acids (FA) concentrations. A total of 34 plasma FA was assessed using GC. 12 out of 34 FA showed a significant different between groups and 3 out of 34 were tended to significance. Only NEFA concentration and stearic acid were influenced by parity. The results may suggest possible links with lipid metabolism, inflammatory and immune responses in hyperketonemic group. In conclusion, GC represents a useful tool in the study of hyperketonemia and primiparous dairy ewes might show a greater risk to develop this condition.

Dietary Moringa oleifera Alters Periparturient Plasma and Milk Biochemical Indicators and Promotes Productive Performance in Goats

The purpose of the current study was to explore the supplementing effects of Moringa oleifera leaf powder (MOLP) on plasma and milk biochemical indices and productive/reproductive performance of goats. A total of 30 healthy pregnant goats were randomly distributed (n = 10) into three experimental groups: control (M₀) group (basal diet without MOLP), M_2% group (basal diet + 2% MOLP), and M_3.5% group (basal diet + 3.5% MOLP). The experiment started 2 months before parturition and continued till the first month of lactation. The plasma flavonoids were significantly increased in the M_3.5% group during the entire experiment, whereas the total phenolic contents were enhanced only during the lactation period depending on the supplementation percentage. The amount of vitamin C increased significantly in M_2% and M_3.5% groups as compared to the M₀ group. Supplementation of MOLP improved the plasma total antioxidant capacity by declining malondialdehyde concentration and total oxidant status values. The activities of superoxide dismutase and peroxidase enzymes were modified in M_2% and M_3.5% supplemented groups throughout the experiment, while the catalase activity was significantly influenced only during the lactation stage. The protein and lycopene contents in plasma were significantly improved in the M_3.5% group, whereas the total sugars and carotenoid level was increased in both M_2% and M_3.5% groups. Dietary supplementation with 3.5% MOLP more effectively enhanced protease and amylase activities as compared to 2% supplementation. MOLP also improved the biochemical indices and antioxidant status of colostrum and milk. The milk yield, weight gain of the kids, and reproductive performance were high in M_2% and M_3.5% groups in comparison to the M₀ group. These findings disclose that supplementing the diet with 3.5% MOLP improves antioxidant status, milk yield, and reproductive performance in goats.

Differences of the Plasma Total Lipid Fraction from Pre-Foaling to Post-Foaling Period in Donkeys

Simple Summary

An association between increased metabolic demands and reduced dry matter intake is observed from late gestation to early lactation in donkeys. Furthermore, little is known about the nutritional and energy requirements of this period in animals. Changes in energy metabolism make donkeys more susceptible to metabolic diseases such as hyperlipemia, which is characterized by the mobilization of fatty acids from adipose tissue. A better knowledge of this period could improve animal husbandry, well-being, and health. The aim of this study was to analyze the plasma total lipid fraction, to highlight metabolic changes from the pre-foaling to post-foaling periods, using the gas chromatography technique. Our findings reveal a greater risk of metabolic disease in late gestation to early lactation in donkeys.

Abstract

The period from late gestation to early lactation is characterized by changes in energy metabolism. The aim of the current study was to analyze the plasma total lipid fraction using gas chromatography (GC) analysis, in order to highlight metabolic changes from the pre-foaling to post-foaling periods. Eleven pluriparous dairy jennies (mean age of 11.88 ± 3.79 years) belonging to the Amiata donkey breed were enrolled. Blood sampling was performed at 15 days before foaling (T0), and 15 (T1), 30 (T2), 60 (T3), and 90 (T4) days after foaling, for biochemical and GC analysis. A total of 37 fatty acids were identified in plasma samples: 4 medium chain (MCFA), 24 long chain (LCFA), and 9 very-long chain (VLCFA) fatty acids. Among them, 20 fatty acids changed significantly, and two fatty acid showed a trend toward significance. Furthermore, the LCFA, saturated, unsaturated, monounsaturated, and polyunsaturated ω-3 fatty acids changed significantly during the study period. The main alterations were between T0 and the other time points and appeared to be related to lipid metabolism, cellular structure and function, and inflammatory and immune responses. Our findings reveal greater energy requirements at the end of gestation compared to early lactation in donkeys.

Pre- and Post-partum Berberine Supplementation in Dairy Goats as a Novel Strategy to Mitigate Oxidative Stress and Inflammation

As in dairy cattle, goats during the transition period face risk factors, in particular negative energy balance (NEB), inflammation, and impairment of the antioxidant response. The current study determined the effects of pre- and post-partum berberine (BBR) supplementation on antioxidant status and inflammation response during the transition period in dairy goats. Twenty-four primiparous Saanen goats were randomly divided into four groups: control (CON, without BBR) and supplemented with 1 g/day BBR (BBR1), 2 g/day BBR (BBR2), or 4 g/day BBR (BBR4). The blood samples were collected weekly from 21 days pre-partum to 21 days post-partum. Compared with CON, supplementation with either BBR2 or BBR4 decreased (P ≤ 0.05) the levels of plasma non-esterified fatty acids (NEFA) at kidding and thereafter an increased (P ≤ 0.05) the plasma levels of glucose and insulin. Following BBR ingestion, blood antioxidant status elevated throughout the transition period, so that total antioxidant capacity (TAC), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase activity were increased (P ≤ 0.05) and plasma malondialdehyde (MDA) was decreased (P ≤ 0.05). Likewise, paraoxonase (PON) was reduced (P ≤ 0.05) in goats fed BBR2 and BBR4. The levels of haptoglobin, ceruloplasmin, and bilirubin were reduced (P ≤ 0.05) by BBR2 and BBR4 immediately before kidding and thereafter. The results demonstrated that supplementation of either 2 or 4 g/day BBR enhanced antioxidant capacity and immune function of transition goats and improved post-partum performance showing its beneficial effect to mitigate oxidative stress and inflammation during the transition period in dairy goats.

Perspectives for Buck Kids in Dairy Goat Farming

To start milk production, dairy goats need to give birth at least once. While most female kids are reared to become the next generation of dairy goats, only a small proportion of male kids (buck kids) are reared with reproduction aims. The market for buck kid meat, especially within Northern European countries, is currently relatively small compared to the number of bucks born. Therefore, the purposes for buck kids are limited and a substantial proportion of buck kid meat is used for pet food. Due to the limited economic value of buck kids, farmers are faced with a dilemma. Although raising bucks costs more money than it yields, the birth of kids is a prerequisite for production of milk and should be seen as an investment for business-wise healthy dairy goat farming. In that perspective, dairy goat farmers have an ethical responsibility toward buck kids, as well. In this paper, we compare various scenarios of dealing with the issue of surplus male animals. We provide recommendations for the rearing of buck kids based on the sector‘s experience and current practice in the Netherlands. Reducing the number of surplus (male) offspring, e.g., by an optimized prolonged lactation management and/or by artificial insemination with sex-sorted semen, could alleviate the issue of low value buck kids. Killing surplus animals before or directly after birth, on the other hand, is met with increasing societal scrutiny. Initiatives to propagate a market for buck kid meat for human consumption are important to enable a suitable and sustainable production system. To maintain the health and welfare of goat kids, amongst other factors, sufficient and good quality colostrum, milk, and an appropriate diet as they grow older, needs to be provided. One option to assure the safeguarding of health and welfare of all goat kids are quality assurance schemes for milk production. These schemes make dairy farmers accountable for the health and welfare of all kids in the rearing period, including the provision of colostrum and adequate care for newborn buck kids. We conclude that the combination of reducing the number of surplus kids, increasing the demand for goat products, and quality assurance schemes that may help to safeguard the welfare of buck kids.

Changes in ghrelin, microminerals, antioxidants and vitamins A, E and C levels during different physiological status in high yielding Saanen goats subjected to heat stress

The aim of this study was to evaluate the changes of ghrelin, microminerals, antioxidants, and vitamins A, E and C levels during different metabolic periods in high yielding Saanen goats subjected to heat stress. Twenty clinically and paraclinically healthy, high yielding and multiparous goats with an average age of 3 ± 0.5 years and pregnant with a single fetus were included in this study. Sampling was performed at three different physiologic periods: non-pregnancy non-lactation (P₁), four-month gestation (P₂), and first month of lactation (P₃). In this study, the ambient temperature ranged from 19 to 42 °C and relative humidity ranged from 14 to 19% during the hot months. Serum concentrations of ghrelin, glucose (Glu), superoxide dismutase (SOD), glutathione peroxidase (GPx), vitamins (A, E and C) and microminerals (selenium, manganese, cobalt, iron, copper and zinc) were measured. Mean raw milk yield of the goats per day at the first month of lactation was 2.34 ± 0.2 kg. Concentration of ghrelin at P₁ was significantly lower than P₂ and P₃ (P < 0.05). Glucose levels were significantly lower at P₃ compared with P₁ and P₂ (P < 0.05). There were no significant correlations between ghrelin and Glu at different periods. Concentrations of selenium and manganese were significantly higher at P3 compared with P2 and were significantly higher at P2 compared with P1. Values of copper at P2 were significantly higher than P1 and P3 (P < 0.05). Zinc levels were significantly higher at P₁ compared with P₂ and P₃ (P < 0.05). Values of antioxidants and vitamins were significantly lower at P3 compared with P2. It is concluded that high yielding Saanen goats may suffer from hormonal and metabolic disturbances, oxidative stress and micromineral deficiencies during late gestation and the first month of lactation especially when they are subjected to heat stress.

Circulating oxidative stress status in Bedouin she-camels (Camelus dromedarius) during the peripartum period

This study aimed to assess the oxidative stress status in blood plasma of nomadic she-camels (Camelus dromedarius) during transition from late pregnancy to early lactation. From 12 late pregnant she-camels, blood was sampled weekly as they progressed from the third week prepartum up to the third week postpartum. Levels of albumin, uric acid, and malondialdehyde (a biomarker of lipid peroxidation) concentrations were fairly constant (P > 0.05) throughout the sampling times. Compared to the initial time (third week prepartum), values of the superoxide anion, total peroxides, and protein carbonyl (a biomarker of protein peroxidation) increased (P < 0.05) by more than 67%, 43%, and 23%, respectively, at parturition and this increase extended to the first week postpartum. Ascorbic acid concentration lost more than 20% (P < 0.05) of its value at parturition. Bilirubin value increased as camels progressed from the first week pre- up to the first week postpartum, and reached its maximum value (~ 2.5 fold) at parturition. Superoxide dismutase activity increased (P < 0.05) by 71.7% at the first week pretpartum and by 57% at parturition. Total antioxidant capacity level increased (P < 0.05) by ~ 25% at the first week prepartum and remained at this high level up to the second week postpartum. It seems that periparturient camels experience a substantial oxidative stress particularly at parturition and the week after calving as indicated by the increased peroxidative by-products of proteins in parallel to the enhanced production of pro-oxidants.

Oxidative status in dairy goats: periparturient variation and changes in subclinical hyperketonemia and hypocalcemia

BACKGROUND

A better comprehension of the redox status during the periparturient period may facilitate the development of management and nutritional solutions to prevent subclinical hyperketonemia (SCHK) and subclinical hypocalcemia (SCHC) in dairy goats. We aimed to evaluate the variation in the redox status of dairy goats with SCHK and SCHC during their periparturient periods. Guanzhong dairy goats (n = 30) were assigned to SCHK (n = 10), SCHC (n = 10), and healthy (HEAL, n = 10) groups based on their blood β-hydroxybutyrate (BHBA) and calcium (Ca) concentrations. Blood were withdrawn from goats every week from 3 weeks before the expected parturition date to 3 weeks post-kidding. On the same day, the body condition scores (BCS) were evaluated, and the milk yield was recorded for each goat. The metabolic profile parameters and the indicators of oxidative status were determined by using the standard biochemical techniques.

RESULTS

In comparison with the HEAL goats, SCHK and SCHC goats presented with a more dramatic decline of BCS post-kidding and a significant decrease in the milk yield at 2- and 3-weeks postpartum, ignoring the obvious increase at 1-week postpartum. The levels of non-esterified fatty acids (NEFA) peaked at parturition, exhibiting significantly higher levels from 1-week prepartum to the parturition day in the SCHK and SCHC groups. The malondialdehyde (MDA) concentration was increased in the SCHK goats from 1-week antepartum until 3-weeks postpartum, with its concentration being significantly higher in the SCHC goats at parturition. The hydrogen peroxide (H2O2) concentration was significantly lower in the SCHK and SCHC goats from 2-weeks antepartum to 1-week post-kidding. The total antioxidant capacity (T-AOC) and the superoxide dismutase (SOD) level were decreased at 1-week antepartum in the SCHK and SCHC goats, respectively. The glutathione peroxidase (GSH-Px) level was increased in the SCHK and SCHC goats during the early lactation period.

CONCLUSIONS

The SCHK and SCHC goats exerted more efforts to maintain their redox homeostasis and to ensure the production performance than the HEAL goats during their periparturient period, probably owing to more intense fat mobilization and lipid peroxidation in the former.

Metabolic and behavior changings during the transition period as predictors of calving proximity and welfare of dairy goats

This Research aimed to evaluate the metabolic status and behavior changes during the transition period in dairy goats from three breeds, under tropical conditions. Thirty multiparous female goats were kept in pens, distributed randomly by breeds. Infrared cameras were fitted in the pens to monitor the animals, and its activities were recorded. Goats displayed varied idle, standing, walking, and feeding behaviors at kidding day (P < 0.10) when compared with the days after and before. Agnostic interactions prevailed between 3.33 and 7.98% of the time on the day of kidding. There was a day effect for the exploratory activities (P < 0.10), where the most exploratory activities were observed on the day of kidding. The milk production and fat content differed according to breed and lactation week. Collective pens for lactating goats, kept in a tropical environment, do not compromise the social behavior and welfare.

The effect of maternal high-fat-diet mediated oxidative stress on ovarian function in mice offspring

A maternal high-fat diet (HFD) has been shown to exert deleterious effects on fetal programming by impairing embryo growth, and exerts a long-term effect on the health of offspring. The present study aimed to evaluate the effect of a maternal HFD on the ovaries of offspring from the perspective of oxidative stress. Female C57BL/6J mice were randomly assigned to four groups fed various HFDs during the preconception (4 weeks) and gestation-lactation periods. Offspring were fed a normal diet after weaning, and serum and ovaries were collected at 10 weeks of age. The developmental status of follicles was observed using hematoxylin and eosin staining. The serum oxidative stress levels and insulin resistance were detected using ELISA test kits. The expression of phosphorylated form of H2AX histone variant (γH2AX), forkhead box protein O3a (FOXO3a), Bcl-2-like protein 11 (Bim)and insulin-like growth factor (IGF)-1 in ovarian tissue was analyzed using reverse transcription-quantitative PCR and western blot analyses to further explore the pathogenic mechanism. Prenatal exposure to a maternal HFD resulted in a reduced number of primordial and preantral follicles in the ovaries of offspring. Exposure to an HFD in the preconception period exerted a greater effect on the offspring compared with exposure to an HFD in the gestation-lactation period. A reduction in fat intake during the preconception, gestation and lactation periods significantly reduced the associated adverse outcomes. The expression of genes (FOXO3a, IGF-1, γH2AX and Bim) involved in oxidative stress showed a decreasing trend (high-fat/high-fat>high-fat/control>control/high-fat >control/control) in the ovaries of offspring. Overall, HFD exposure during the preconception period exerted a greater effect on offspring compared with HFD exposure during the gestation-lactation period. The long-term effect on follicular growth and development may be associated with increased oxidative stress and the activation of the insulin/PI3K/Akt pathway.

Short communication: Associations between nonesterified fatty acids, β-hydroxybutyrate, and glucose in periparturient dairy goats

The objective of the present study was to use longitudinal data to examine the relationships between blood concentrations of nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHB), and glucose during the transition period in dairy goats. Weekly blood samples were collected from Saanen goats from a commercial herd in Australia [1-7 yr; body weight 70 ± 16.0 kg; body condition score 2.5 ± 0.3; and daily milk yield 2.4 ± 0.73 L/d; all mean ± standard deviation (SD)]. The weekly prevalence of goats above hyperketonemic levels (BHB ≥0.8 mmol/L) was approximately 6 times greater postpartum than antepartum. As well, of the 935 goats sampled antepartum, 50 (5%) had at least 1 hyperketonemic event, and 823 (88%) had at least 1 event of NEFA above the threshold (≥0.3 mmol/L). Of 847 goats tested postpartum, 258 (30%) had at least 1 hyperketonemic event, and 690 goats (81%) had at least 1 event of NEFA above the threshold (≥ 0.7 mmol/L). Substantial variation was found when analyzing the mean days of maximum NEFA and maximum BHB concentrations antepartum (-11 ± 6.6 and -14 ± 7.2 d, respectively, mean ± SD) and postpartum (14 ± 6.6 and 9 ± 6.8 d, respectively, mean ± SD). We observed moderate to strong relationships between NEFA and BHB concentrations (r = 0.66) and between NEFA and glucose concentrations (r = -0.46) throughout the transition period. Our results suggested that 3 to 16 d in milk is the best sampling window for monitoring hyperketonemia in dairy goats, and that results from simultaneous BHB and glucose tests provide an improved indication of the fat mobilization and energy status of the herd when measured close to this timeframe.

Endocrine and metabolic status of commercial dairy goats during the transition period

The aim of this study was to evaluate temporal variations in circulating levels of selected hormones and metabolites in commercial dairy goats during the transition period. Blood samples from 940 goats were collected weekly, from -3 to 3 wk relative to delivery, to measure the effects of level of milk production, parity number, and litter size on concentrations of glucose, β-hydroxybutyrate (BHB), fatty acids, and plasma urea nitrogen (PUN). A subset of 80 goats [40 low-yielding (LY, < 1.8 L/d) and 40 high-yielding goats (HY, > 3.7 L/d)] were selected from the study population to measure the effects of level of milk production on plasma concentration of insulin, prolactin, and growth hormone. Average (±SD) milk yield (from 3 to 30 d in milk), body weight, and body condition score for the study population were 2.4 ± 0.78 L/d, 70 ± 16.0 kg, and 2.5 ± 0.28 units, respectively. Milk yield was moderately correlated with parity number (r = 0.49) but had weak correlation with litter size (r = 0.14). In multiparous but not in primiparous goats, antepartum concentrations of fatty acids and BHB increased with increasing litter size. Concentrations of fatty acids, BHB, and PUN were consistently lower in primiparous goats compared with those in second or greater parity. Postpartum, HY goats had higher ratios of glucose, fatty acids, and BHB to insulin than did LY goats, which might explain the greater mobilization of body tissues and enhanced milk production observed in this group. Collectively, our results indicate that increased milk yield has the most significant influence on the magnitude of body tissue mobilization. Our results also show that goats of higher parity display higher levels of lipid mobilization, and that both pregnancy and lactation are less able to elicit lipomobilization in primiparous compared with multiparous goats.

Oxidative Status of Goats with Different CSN1S1 Genotypes Fed ad Libitum with Fresh and Dry Forages

Forty late-lactation Girgentana goats were used to study the effect of diets fed ad libitum and αS1-casein (CSN1S1) genotype on redox balance. The goats genotyped at CSN1S1 locus (A/A, A/F) were subjected to four feeding treatments different for percentage inclusion of dry and fresh forage: DAF100 (98% of Dry Alfalfa Forage), DAF65 (65% of Dry Alfalfa Forage), FSF100 (100% of Fresh Sulla Forage) and FSF65 (65% of Fresh Sulla Forage). Blood samples were analyzed for superoxide dismutase (SOD) and glutathione peroxidase (GPX) activity, reactive oxygen metabolites (ROMs), biological antioxidant potential (BAP) and non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHBA), albumin, glucose and cholesterol contents. The oxidative stress index (OSI) was calculated as percentage ratio of ROMs to BAP. Redox balance was improved by Sulla inclusion, as reflected in the lower OSI values found in FSF100 and FSF65 groups. DAF100 group displayed the highest GPX activity, while other groups exhibited the highest SOD activity. Fresh forage diets increased albumin concentration while no effect of tested factors was noted on glucose, NEFA, BHBA and cholesterol contents. The interaction diet × genotype was significant only for GPX activity. GPX and albumin were negatively correlated and were correlated positively and negatively with ROMs, respectively. Diet rather than genotype affects redox balance in dairy goats and a possible role of forage polyphenol compounds on oxidative status needs to be tested in future studies.

Hepatic Sirt3 expression declines postpartum in dairy goats

The experiments reported in this research communication aimed to plot the expression pattern of Sirt3, a master regulator of energy metabolism and antioxidation defence, in the liver of dairy goats during perinatal period. Ten healthy dairy goats in late pregnancy were chosen, and needle biopsy was applied to collect liver samples at 1-week intervals. Protein levels of hepatic Sirt3 were analysed by western-blotting. Serum enzyme activities of manganese superoxide dismutase (Mn-SOD) and non-esterified fatty acids (NEFA) levels were measured, and their correlation with Sirt3 mRNA levels was also estimated. Compared with >3-week before parturition (BP), Sirt3 proteins were significantly reduced at 1-week after parturition (AP) and 2-week AP (P < 0·05), but increased on the day of parturition (P < 0·01). Correlation analysis revealed a positive association between hepatic Sirt3 mRNA levels and serum enzyme activity of Mn-SOD (r = 0·46), but a negative association between that and serum NEFA levels (r = -0·41). These data indicate that the decreased hepatic expression of Sirt3 might be one of the reasons that dairy goats undergo oxidative stress after parturition.

The effect of conjugated linoleic acid supplements on oxidative and antioxidative status of dairy cows

Dairy cows develop frequently negative energy balance around parturition and in early lactation, resulting in excessive mobilization of body fat and subsequently in increased risk of ketosis and other diseases. Dietary conjugated linoleic acid (CLA) supplements are used in dairy cows mainly for their depressing effect on milk fat content, but are also proposed to have antioxidative properties. As negative energy balance is associated with oxidative stress, which is also assumed to contribute to disease development, the present study was conducted to examine effects of CLA on oxidative and antioxidative status of lactating dairy cows. German Holstein cows (primiparous n=13, multiparous n=32) were divided into 3 dietary treatment groups receiving 100g/d of control fat supplement, containing 87% stearic acid (CON; n=14), 50g/d of control fat supplement and 50g/d of CLA supplement (CLA 50; n=15), or 100g/d of CLA supplement (CLA 100; n=16). The CLA supplement was lipid-encapsulated and contained 12% of trans-10,cis-12 CLA and cis-9,trans-11 CLA each. Supplementation took place between d1 and 182 postpartum; d 182 until 252 postpartum served as a depletion period. Blood was sampled at d -21, 1, 21, 70, 105, 140, 182, 224, and 252 relative to calving. The antioxidative status was determined using the ferric-reducing ability of plasma, α-tocopherol, α-tocopherol-to-cholesterol mass ratio, and retinol. For determination of oxidative status concentrations of hydroperoxides, thiobarbituric acid-reactive substances (TBARS), N'-formylkynurenine, and bityrosine were measured. Mixed models of fixed and random effects with repeated measures were used to evaluate period 1 (d -21 to 140) and 2 (d182-252) separately. Cows showed increased oxidative stress and lipid peroxidation during the periparturient period in terms of increased serum concentrations of hydroperoxides and TBARS, which decreased throughout lactation. During period 1, the supplemented cows had lower TBARS concentrations, which was not detectable in period 2. The other determined parameters were not affected by CLA supplementation. The obtained results show that dietary CLA supplementation in the chosen dosage, formulation, and application period had a marginal antioxidative effect in terms of lipid peroxidation in lactating dairy cows.