Circulating and endometrial cell oxidative stress in dairy cows diagnosed with metritis

Dairy cows diagnosed with metritis may experience a greater degree of oxidative stress (OS) and a deficit in the antioxidative capacity compared to healthy cows. We aimed to assess circulating OS markers and endometrial cell mitochondrial function, intracellular reactive oxygen species (ROS) production, and mean endometrial nuclear cell area in postpartum cows diagnosed with metritis or as healthy. From an initial pool of 121 Holstein cows, we retrospectively selected 34 cows and balanced for metritis (n = 17) or healthy (n = 17). Metritis was defined as an enlarged uterus with red-brown watery or thick off-white purulent discharge occurring within 21 days postpartum. Cows with no signs of clinical disease (including dystocia or retained placenta) were referred to as healthy. Blood samples for serum reactive oxygen metabolites (d-ROM), antioxidants (OXY), and oxidative status index (OSI) tests, evaluated via photometric determination of plasma thiols, were performed at 7, 14, 21, 28, and 35 days postpartum. Furthermore, from the initial pool, a random subset of 5 cows diagnosed with metritis and 6 diagnosed as healthy we collected (at the same time points as for the blood samples) endometrial cytology samples using the cytobrush technique. From the uterine samples, we evaluated the endometrial cell mitochondrial function, intracellular ROS levels, and the endometrial cell nuclear area using MitoTracker Orange, dichlorodihydrofluorescein diacetate, and Hoechst 33258, respectively. Mixed linear regression models, accounting for repeated measurements, were fitted to assess the effect of metritis versus healthy on circulating and endometrial cell OS parameters and endometrial cell size. The effect of days postpartum and its interaction with uterine health status were forced into each model. Serum concentrations of d-ROMs and OSI were greater in metritis at 7, 14, and 35 days postpartum than in healthy cows. Interestingly, the mean endometrial cell nuclear area was lower in metritis than healthy cows at 14 and 21 days postpartum. We found no differences between metritis and healthy for endometrial cell mitochondrial function and intracellular ROS production. In conclusion, cows diagnosed with metritis experienced greater systemic OS levels than healthy cows, but their OS was not higher in the uterine milieu.

Concentration of vitamin E in bovine plasma and erythrocytes

The aim of this study was to determine and compare the plasma and erythrocyte (RBCs) levels of vitamin E in cows of 3 different categories (2–3 weeks antepartum, 1–3 weeks and 2.5–3 months of lactation) and 1-month-old calves on dairy nutrition. We were interested in the degree of correlation of vitamin E in plasma and RBCs within the individual categories. Blood on EDTA was collected from 61 cows and 12 calves. As a part of the haematological examination, we determined haematocrit (HCT) immediately after the collection. We determined vitamin E from plasma and RBCs by a standard HPLC method. We compared the results of vitamin E in plasma and RBCs and correlated them. The concentration of vitamin E in the plasma and RBCs was 6.98 and 3.45 μmol/l, respectively, in cows 2–3 weeks antepartum; 1–3 weeks of lactation it was 4.98 and 3.34; 2.5–3 months of lactation 11.76 and 2.80 μmol/l; and in the case of calves 12.07 and 6.29 μmol/l. Weak correlations were observed between vitamin E in plasma and the RBC concentrations in the antepartum category R2 = 0.2076; 1–3 weeks of lactation R2 = 0.0369; 2.5–3 months of lactation R2 = 0.2403 and calves on dairy nutrition R2 = 0.4628. Vitamin E concentrations in RBCs were shown to be more stable than in plasma, where the concentrations varied. It is possible that vitamin E in RBCs could tell us more about the longer-term reserves of vitamin E in the organism. The highest concentration of vitamin E in plasma and RBCs, as well as a stronger correlation was found in calves.

The influence of haemolysis on the determination of vitamin E in cattle

The study deals with the influence of haemolysis on the results of vitamin E determination in plasma (serum) in cattle. Although nowadays specific High Performance Liquid Chromatography (HPLC) techniques are used almost exclusively for the determination of vitamin E, this indicator is also influenced by haemolysis. This occurs in the pre-analytical phase due to the fact that iron contained in haemoglobin is able to catalyze peroxidation reactions. Subsequently, changes occur mainly in polyunsaturated fatty acids in the lipoprotein components of serum/plasma. The vitamin E present inhibits this process, as a result of which its concentration is reduced. The experiment was performed by preparing model samples with a defined degree of haemolysis by adding haemolysate to the centrifuged plasma in the range of ca 0–12 g/l, i.e. mild to severe haemolysis. After 4 h of incubation at room temperature, the vitamin E concentration was determined by the HPLC method. Haemolysis was found to reduce the test result; mild one (approximately up to 2 g/l) non-significantly, medium and severe haemolysis by up to tens of percent, which warrants repeated sampling. False reductions in results will not endanger the patient’s health, but economic losses may occur due to unnecessary check-ups and increased vitamin E supplementation.

Pest flies on dairy farms affect behaviour and welfare of dairy cows during summer season

Monitoring of changes in the behaviour of dairy cows related to the occurrence of insects in the stable and in the milking parlour was carried out on a selected dairy farm during the summer season. The effect of the number of insects on the occurrence of huddling of dairy cows in the stable was proved. Huddling occurred significantly (P = 0.003) more often when the number of insects captured by fly glue traps exceeded 500 individuals. The occurrence of pest flies affected also the behaviour of dairy cows during milking. With the increasing number of insects captured by glue traps in the milking parlour, the cows more frequently kicked off the milking units (r = 0.944, P < 0.001) and defecated (r = 0.940, P < 0.001) during milking. In addition, the increasing number of captured insects correlated with a significantly lower milk yield in cows (r = -0.709, P < 0.001). The number of insects in the stable also correlated with the incidence of mastitis in dairy cows on the monitored farm (r = 0.681, P < 0.001) during the summer season. The study shows that pest flies affect the behaviour of cows which is further reflected in their health, milk production and thus the overall farm performance.

The effect of parenteral application of vitamin A, vitamin E, and β-carotene to pregnant cows on selected indices in their calves

The aim of the study was to determine the effect of parenteral application of vitamin preparations containing vitamins A, E, and β-carotene to pregnant cows (10–14 days before calving) on vitamin concentrations, haematological indices and the total antioxidant status (TAS) in their calves. Thirty cows were divided into 3 groups – control, the experimental group 1 (vitamins A, E), and experimental group 2 (β-carotene). Blood sampling in calves was performed immediately after birth, 2 h after receiving colostrum, 24 h after birth and 5–7 days after birth. The calves received the first 4 doses of colostrum from their mothers. The highest concentration of vitamin E was observed 5–7 days after birth in group 1 compared to the control (P < 0.05) and group 2 (P < 0.01). The concentration of β-carotene was the highest in group 2 (2 and 24 h after receiving colostrum) compared to group 1 (P < 0.01). The TAS was the highest in group 1 compared to the control (P < 0.05, P < 0.001) and group 2 (P < 0.01). A significant increase in haemoglobin (P < 0.01, P < 0.05) and haematocrit (P < 0.05, P < 0.01) was recorded in group 1 and group 2, respectively, compared to the control, as well as in the red blood cell count (P < 0.05) in group 2 compared to the control. The highest total protein was observed in the control group in all samplings. Parenteral application of vitamins to pregnant cows most likely had an effect on the concentrations of vitamins, TAS and haematological indices in their calves.

Monitoring the redox status in dairy cows by using plasma dROMs, PAT, and OSI biomarkers

The aim of this work was to determine the changes of redox indicators such as reactive oxygen metabolites (dROMs), plasma antioxidant test (PAT) and the oxidative stress index (OSI) in dairy cows at different stages of lactation using a diagnostic equipment which is suitable for in vivo oxidative stress (OS) monitoring procedures. In total, 628 dairy cows were examined in the pre-parturient period (days in milk [DIM]: -21 to -1 day; n = 117), in the calving and maternity period (DIM: 0 to 7; n = 137), in the early lactation period (DIM: 8 to 30; n = 139), and the in the peak lactation (DIM: 31 to 150; n = 235). The dROMs and OSI values were significantly different (P < 0.05) when comparing the 1st and 2nd+ lactation cows in each group. The highest mean value of dROMs was detected at the calving and maternity stage in 1st lactation cows (141 ± 25 U. Carr) and the lowest (103 ± 29 U. Carr) was found in peak lactation. The OSI developed similarly, with the highest value of 5.58 ± 0.94 in the calving and maternity period in the 1st lactation cows and the lowest value of 4.05 ± 1.21 in peak lactation and significant differences were found in many cases. Based on the results, the measurement of dROMs and OSI may be suitable for detecting oxidative stress in different lactation stages.

The impact of the oxidative status on the reproduction of cows and the calves’ health – a review

The profitability of cattle farming is largely determined by ensuring high-quality breeding animals for replacement and longevity in production. The provision of breeding animals requires adequate fertility of the cowherd and then intensive weight gain in the calf rearing period. For ensuring these demands, many management aspects must be considered. Continuous monitoring of the herd’s health status, including redox status, is essential. This review aims to provide a summary of relevant scientific data published in the last few decades regarding the role of oxidative stress (OS) in infertility of dairy cows and developmental diseases in calves, the major predisposing factors, and possible prevention.

Comparison of laparotomic omentopexy vs. laparoscopic abomasopexy treatments of left displaced abomasum in dairy cows under field conditions: biochemical analysis

The objective of this retrospective study was to compare the effects of the two methods (laparoscopic or laparotomic) of LDA (left displaced abomasum) correction under field conditions by means of survival rate and biochemical profile evaluation. Holstein cows from one farm with LDA over a 20-month period were included in the study. Cows underwent laparoscopic abomasopexy (Janowitz’s method, LS) or a laparotomic right flank omentopexy (Dirksen’s method, LT). Blood samples for biochemical analysis were taken just prior to surgery (D1) and on days 10 (D10) and 30 (D30) following surgery. Blood profiles of healthy cows identified from the farm’s routine transition cow monitoring program were used as control (C). Aiming to minimize disruptive effects of quite a long period of data collection, the cows’ biochemical profile was evaluated in three orthogonal comparisons: LS cows vs. control group, LT cows vs. control group, and LS cows vs. LT cows. The rate of animal survival was similar for both methods (loss of about 11% until 30 days after treatment). Most of the blood parameters from LS and LT groups were comparable in all three sampling terms indicating continual organism recovery. At D10 the difference of higher cholesterol concentration and lower haptoglobin concentration were favourable for the LS group (P < 0.05). Total protein, calcium, magnesium and albumin showed more positive dynamics in the LS group too. This proves previous laboratory and clinical indices of expediency of LDA laparoscopy treatment under field conditions.

Traditional Chinese herbal medicine complex supplementation improves reproductive performance, serum biochemical parameters, and anti-oxidative capacity in periparturient dairy cows

This study was conducted to investigate the effects of a traditional Chinese herbal medicine complex (TCHMC) on the productive performance of periparturient dairy cows. Eighteen non-lactating pregnant Holstein dairy cows with similar body conditions with 1 to 2 parity were randomly divided into three groups (n = 6), receiving a basal diet with 0 (CON group), 200 (T-200 group), and 300 (T-300 group) g TCHMC per day from 14 to 9 days prepartum. The results demonstrated that TCHMC treatments decreased the days of gestation, calving to first service, and calving to first visible estrus. Compared with CON at specific time points, TCHMC treatments increased the concentrations of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E₂), whereas progesterone (P₄) and E₂ concentrations decreased. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and creatine kinase (CK) concentrations were downregulated, whereas that of globulin (GLB) and immunoglobulin G (IgG) were upregulated by TCHMC treatments around the time of calving. Compared with CON and T-200 treatments, the T-300 treatment increased the serum concentrations of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT) and total antioxidant capacity (T-AOC) and decreased the malondialdehyde (MDA) concentration from 7 d prepartum to 21 d postpartum when. In addition, although TCHMC treatment had no effect on average birth weight, heart rate, respiratory rate, and body temperature of calves, the T-300 treatment increased serum albumin (ALB) and IgG concentrations in calves from 3 to 14 days postpartum. The addition of TCHMC used in the present study could serve as a potential effective strategy to improve the health and productive performance of periparturient dairy cows, and the optimal dose should be set at 300 g per day.