Effect of selenium supplementation of cows on maternal transfer of selenium to fetal and newborn calves

Impact of maternal serum selenium concentration on postpartal serum concentrations of selenium and immunoglobulins in dairy calves - A field study

Selenium (Se) status is suspected to affect the passive transfer of immunoglobulins (Ig) via colostrum to newborn calves. The objective of this study was to investigate associations between maternal Se serum concentration with those of their newborn calves including colostrum quality. A total of 915 prepartum cows from 113 large dairy herds, were examined 3-1 weeks prepartum, including blood sampling. Colostrum samples collected 1-4 h postpartum were analysed using BRIX refractometry. Blood samples from their calves were taken 1-4 days postpartum. Data on herd-specific management of close-up cows, newborn calves and colostrum supply were collected additionally. A generalised linear mixed effects regression models with hierarchically structured random effects (cow or calve within herd) were fitted to the data. BRIX value was positively associated with the maternal prepartum Se serum concentration as well as with parity and vitamin D administration. Se serum concentration of calves were related to Se serum concentration of their dams and the amount of colostrum administered at first feeding. Ig serum concentration of calves was related to BRIX (p < 0.01) and calves Se serum concentration (p < 0.01) in the same multivariable model. The association identified under field conditions confirmed an adequate Se status of prepartum cows being vital for the passive transfer of Ig both by a higher colostral Ig concentration and a higher serum Se concentration of calves at which both mechanisms acting synergistically. Se status of prepartum cows was proven to be a key factor of passive transfer of Ig to newborn calves.

Effects of Vitamin and Mineral Supplementation During Gestation in Beef Heifers on Immunoglobulin Concentrations in Colostrum and Immune Responses in Naturally and Artificially Reared Calves

Two experiments assessed the effects of providing a vitamin and mineral supplement to gestating beef heifers on concentrations of immunoglobulins (Ig) in colostrum and calf serum 24 h after feeding maternal colostrum (Exp. 1) or a colostrum-replacement product (Exp. 2). Angus-based heifers (n = 31, Exp. 1; n = 14, Exp. 2) were fed a basal diet (CON) or were fed a basal diet plus a vitamin and mineral supplement (VTM) from breeding (Exp. 1) or 60 d pre-breeding (Exp. 2) through calving. Colostrum was collected at calving, and serum was collected from calves 24 h after colostrum consumption to evaluate passive transfer. Serum was collected from calves in Exp. 1 to determine serum titers in response to vaccination at birth, pasture turn out, weaning, and 14 d after vaccination. Concentrations of IgG, IgM, or IgA in colostrum or in calf serum at 24 h were not impacted by dam treatment (p ≥ 0.21); however, concentrations of Ig in calf serum at 24 h were greater (p ≤ 0.01) in calves receiving maternal colostrum than those receiving a colostrum replacer. Calves born to VTM heifers had greater antibody titers at birth, pasture turn out, and weaning for infectious bovine rhinotracheitis (IBR), bovine viral diarrhea virus type 2 (BVD-2), and bovine respiratory syncytial virus (BRSV), respectively. Our results suggest that the programming of immune function in calves via prenatal nutrition appears to extend postnatally in CON and VTM offspring.

Invited review: Limitations to current mineral requirement systems for cattle and potential improvements

The mineral requirements or recommendations generated by various NASEM committees are used by many ration formulation programs. The current NASEM dairy requirement system uses the factorial approach (requirements for maintenance, lactation, gestation, and growth) for most minerals, but when data or equations were not available to estimate factorial requirements the committee used available data to estimate adequate intake values. The current beef NASEM uses the factorial method for Ca and P and recommendations for the other minerals. The factorial method works well for Ca and P because adequate data are available to estimate absorption coefficients (AC) and maintenance requirements. In addition, feeding Ca and P above requirements has few if any positive effects. For many other minerals the factorial method is problematic. Estimating both the maintenance requirement and AC can be extremely difficult and inaccuracies in those values have a major impact on accuracy of total dietary requirements. Some minerals have positive effects on health, production, and reproduction when fed above factorially determined requirements. For those minerals, response models rather than or in addition to requirement models are more appropriate. The AC is in the denominator of the factorial equation and converts absorbed requirements into dietary requirements. The AC for trace minerals is small, often <0.1, and small changes in a low AC can have substantial effects on dietary requirements. Although accurate AC are essential for the factorial method to work, woefully few data are available on the true absorption of trace minerals. Because of antagonism to absorption (e.g., negative effect of S on absorption of Cu, Mn, Se, and Zn) equations will be needed to estimate AC under different dietary conditions, but current data are inaccurate to generate equations. The systems currently used will almost always prevent clinical mineral deficiencies, but because of uncertainties, most nutritionists formulate diets to exceed and often far exceed established recommendations. This leads to increased costs, potential antagonism, and increased manure excretion of environmentally important minerals. More accurate systems for estimating mineral requirements will optimize animal performance and health while keeping costs in check and reducing environmental damage.

Maternal selenium dietary supplementation alters sociability and reinforcement learning deficits induced by in utero exposure to maternal immune activation in mice

Maternal immune activation (MIA) during pregnancy increases the risk for the unborn foetus to develop neurodevelopmental conditions such as autism spectrum disorder and schizophrenia later in life. MIA mouse models recapitulate behavioural and biological phenotypes relevant to both conditions, and are valuable models to test novel treatment approaches. Selenium (Se) has potent anti-inflammatory properties suggesting it may be an effective prophylactic treatment against MIA. The aim of this study was to determine if Se supplementation during pregnancy can prevent adverse effects of MIA on offspring brain and behaviour in a mouse model. Selenium was administered via drinking water (1.5 ppm) to pregnant dams from gestational day (GD) 9 to birth, and MIA was induced at GD17 using polyinosinic:polycytidylic acid (poly-I:C, 20 mg/kg via intraperitoneal injection). Foetal placenta and brain cytokine levels were assessed using a Luminex assay and brain elemental nutrients assessed using inductively coupled plasma- mass spectrometry. Adult offspring were behaviourally assessed using a reinforcement learning paradigm, the three-chamber sociability test and the open field test. MIA elevated placental IL-1β and IL-17, and Se supplementation successfully prevented this elevation. MIA caused an increase in foetal brain calcium, which was prevented by Se supplement. MIA caused in offspring a female-specific reduction in sociability, which was recovered by Se, and a male-specific reduction in social memory, which was not recovered by Se. Exposure to poly-I:C or selenium, but not both, reduced performance in the reinforcement learning task. Computational modelling indicated that this was predominantly due to increased exploratory behaviour, rather than reduced rate of learning the location of the food reward. This study demonstrates that while Se may be beneficial in ameliorating sociability deficits caused by MIA, it may have negative effects in other behavioural domains. Caution in the use of Se supplementation during pregnancy is therefore warranted.

Vitamin and mineral supplementation to beef heifers during gestation: impacts on morphometric measurements of the neonatal calf, vitamin and trace mineral status, blood metabolite and endocrine profiles, and calf organ characteristics at 30 h after birth

To examine the effects of feeding a vitamin and mineral supplement to beef heifers throughout gestation on mineral status and hormone/endocrine profiles in the dam and calf, and morphometric characteristics and organ mass of the calf at 30 h after birth, Angus-based heifers (n = 72, 14 to 15 mo of age, initial body weight [BW] = 380.4 ± 50.56 kg) were estrus synchronized and artificially inseminated (AI) with female-sexed semen. Heifers were blocked by BW and randomly assigned to receive either a basal diet (CON; n = 36) or a basal diet plus a vitamin and mineral supplement (VTM; n = 36) via an individual feeding system beginning at breeding, with both diets targeting BW gains of 0.45 kg heifer-1·d-1. Heifers not pregnant after the first AI (CON, n = 19; VTM, n = 18) were rebred via AI 60 d after treatment initiation, and heifers gestating female fetuses (CON, n = 7; VTM, n = 7) received treatments throughout gestation and were experimental units for this study. Calves were separated from their dams and fed colostrum replacer within 2 h of birth and euthanized 30 h after the first feeding. Calf morphometrics were recorded, and tissues were weighed and sampled. Serum from the dam at calving and serum, liver, and muscle from the calf at 30 h were analyzed for concentrations of minerals. Serum from the dam and calf were analyzed for concentrations of leptin, vitamins A, D, and E, cortisol, growth hormone, and insulin-like growth factor 1. All response variables were analyzed using the MIXED procedure of SAS. Calf body morphometrics and BW of the dam at calving (P ≥ 0.32), calf organ weights (P ≥ 0.21), and calf ovarian follicle counts (P ≥ 0.13) were not affected by maternal treatment. Concentrations of Se and Co in calf serum and Se in calf liver were increased (P ≤ 0.02) in VTM. Serum concentrations of Co and vitamin A in the dam were greater (P ≤ 0.01) in supplemented compared with nonsupplemented dams, and serum concentrations of vitamin D were greater (P ≤ 0.0003) in supplemented dams and calves compared with the nonsupplemented cohort. Maternal supplementation supported vitamin and mineral status in the neonate, yet had no discernable impact on BW, organ mass, or circulating hormones/metabolites in the calf. Evaluating offspring at later postnatal time points is warranted to determine if prenatal vitamin and mineral supplementation affects performance, health, metabolism, and efficiency of energy utilization in key metabolic tissues in the calf.

Selenium and Vitamin E Concentrations in Miranda Jennies and Foals (Equus asinus) in Northeast Portugal

The increase in donkeys treated by practitioners in recent years has led to an increased interest in finding more information on basic biochemical preliminary reference values. The aims of this study were to measure Se and Vit E levels in plasma from Miranda jennies peripartum and postpartum and in their foals to compare blood profiles of the jenny and foal related to the overall foal's health. Twenty-two healthy peripartum and postpartum Miranda donkeys were sampled (12 jennies and 10 foals) in the northeast of Portugal (Atenor and Paradela) from May to November, 2018. Amounts of selenium in soil were significantly correlated (0.97) to concentrations of selenium in jennies (42.412 μg/L in Atenor and 9.612 μg/L in Paradela) and foals (19.378 μg/L in Atenor and 6.430 μg/L in Paradela). Selenium levels were lower in foals than adults and in males than females. Vitamin E was associated with overall foal health. Foals with a mean vitamin E of 3.585-5.307 mg/L showed signs of weakness, but carpal flexural deformities were observed when the average vitamin E was 11.520 mg/L. Low vitamin E levels (5.307 mg/L) in jennies were related to foal mortality. Diets, location, parity, and age affect blood profiles of jennies and, ultimately, foal health.

Effects of inorganic selenium injection on the performance of beef cows and their subsequent calves

Sixty-seven pregnant Angus cows and their subsequent calves were used in a randomized design to evaluate the effect of inorganic Se injection from 80 d of gestation until weaning on cow reproductive parameters, BW and BCS evolution, milk yield and quality, calf growth and calf hematology parameters. The treatments were as follows: 1) Se+: cows were administered Se as sodium selenite at doses of 0.05 mg/Kg of BW at 80, 140, 200, 260 d of gestation and 30, 90, 150 and 240 d of lactation. Calves from Se + cows were Se as sodium selenite subcutaneously injected with a dose of 0.05 mg/Kg of BW at 70, 104, 144 d of age; 2) Control: cows and calves were administered sterile NaCl solution (9 g/l) at the same volume and intervals as Se + treatment. At the start of the experiment, forage Se concentration was 58.6 ppb ± 7.6 ppb, and cow whole blood Se concentration was similar (P > 0.10) between treatments (Se+, 29.3 ± 0.3 ppb; Control, 28.1 ± 0.5 ppb). After Se injection, cow whole blood Se concentration was increased (P < 0.01) in Se + cows in relation to control cows until the end of the experiment. Calf whole blood Se concentration was increased (P < 0.01) at birth and 30 d of age in calves from Se + cows compared to calves from Control cows. However, calf whole blood Se concentration was not different (P > 0.10) between treatments at d 70 after birth. After the first Se injection (70 d of age), calf whole blood Se concentration was increased (P < 0.01) at 104 and 144 d of age in calves from Se + cows compared to calves from Control cows. Cow BW and BCS did not differ (P > 0.10) between treatments throughout the experiment. Ovarian follicle diameter measured by ultrasound 47 d postpartum was greater (P = 0.03) in Se + cows compared to Control cows. Pregnancy rate to fixed time artificial insemination (FTAI), overall pregnancy rate (P > 0.10) and pregnancy loss (P = 0.19) did not differ between groups. Selenium injection did not affect (P > 0.10) milk yield and composition. Calf morphometric parameters, BW at birth and growth rate during lactation were not affected (P > 0.10) by treatments. No significant effect (P > 0.10) was observed between treatments on hematological results of blood samples from calves at weaning. Results of this study shown that inorganic Se injection was an efficient tool to improve Se-status in cow-calf operation under extensive management. Selenium injection increased follicle diameter in postpartum beef cow, however, did not affect the rest of the variables studied.

Selenium biofortified alfalfa hay fed in low quantities improves selenium status and glutathione peroxidase activity in transition dairy cows and their calves

The hypothesis of the study was that feeding a relatively low amount of Se biofortified alfalfa hay during the dry period and early lactation would improve selenium status and glutathione peroxidase activity in dairy cows and their calves. Ten Jersey and 8 Holstein primiparous dairy cows were supplemented with Se biofortified (TRT; n = 9) or non-biofortified (CTR; n = 9) alfalfa hay at a rate of 1 kg/100 kg of BW mixed with the TMR from 40 d prior parturition to 2 weeks post-partum. Se concentration in whole blood, liver, milk, and colostrum, the transfer of Se to calves, and the glutathione peroxidase (GPx) activity were assessed. TRT had 2-fold larger (P < 0.05) Se in blood v. CTR that resulted in larger Se in liver and colostrum but not milk and larger GPx activity in plasma and erythrocytes but not in milk. Compared to CTR, calves from TRT had larger Se in blood but only a numerical (P = 0.09) larger GPx activity in plasma. A positive correlation was detected between Se in the blood and GPx activity in erythrocytes and plasma in cows. Our results demonstrated that feeding pregnant primiparous dairy cows with a relatively low amount of Se-biofortified alfalfa hay is an effective way to increase Se in the blood and liver, leading to greater antioxidant activity via GPx. The same treatment was effective in improving Se concentration in calves but had a modest effect on their GPx activity. Feeding Se biofortified hay increased Se concentration in colostrum but not in milk.

Influence of selenium administration to dry cows on selected biochemical and immune parameters of their offspring

The study was performed on 16 Holstein-Friesian calves divided into two groups of eight animals each. The first group was composed of calves whose mothers did not receive selenium supplements (Se0). The second group consisted of calves whose mothers were administered intramuscular injections of a selenium and vitamin E supplement containing 0.5 of sodium selenite/ml and 50 mg of tocopherol acetate/ml in a single dose of 30 ml (Se30) ml, 10 days before the expected parturition date (10 ± 2 days). The calves were fed 2.5 L of the mother's colostrum administered by stomach tube 2 hr after birth and another 2 L 6 hr after birth. Blood from all calves was collected 7 times from external jugular vein (day 0-before colostrum administration and on the 2nd, 3rd, 4th, 7th, 14th and 21st days of life) for analyses of selenium, ceruloplasmin, transferrin, lactoferrin, immunoglobulin G (IgG) concentrations and gamma-glutamyl transferase (GGT) and lysozyme activity. Selenium concentration was significantly higher in calves whose mothers received selenium supplements than in the offspring of non-supplemented cows until 72 hr after birth (p ≤ .05). Lysozyme and GGTP activity and IgG concentration were significantly higher in the S30 group during the entire experiment (p ≤ .05). Supplementation of selenium to the mothers did not influence the ceruloplasmin, lactoferrin and transferrin levels in calves. A single injection of a selenium supplement administered to cows during late pregnancy increases selenium levels in calves and enhances passive transfer from the mother to the offspring.

Levels of trace elements and potential toxic elements in bovine livers: A trend analysis from 2007 to 2018

Trace elements and potential toxic elements were analyzed in bovine livers submitted for autopsy in the Netherlands during the years 2007 to 2018. The age of each animal was recorded. In total, 1544 livers were analyzed for cadmium, cobalt, chromium, copper, iron, molybdenum, nickel, lead, selenium and zinc. Less than 2% of the liver samples were from veal calves. Young animals had significantly higher concentrations of iron and zinc in their livers compared to animals older than one year, while older animals had significantly higher levels of cadmium and molybdenum in their livers. Animals aged 1 to 2 years had the lowest copper and selenium levels. There was a tendency for lower chromium and nickel levels during the last years of the testing period, while copper showed an increase. Lead intoxication was only seen in the youngest group of cattle, while copper intoxication, defined as a liver copper of more than 1000 mg/kg dry matter, occurred in older animals, mainly in animals of 3 to 4 years old. This trend analysis of trace elements in bovine livers of cattle over time in recent years, and the relation of liver element concentrations with age of the animal, provides insight in the uptake and storage of these elements by cattle in The Netherlands. Possible reasons for observed trends and age-related patterns are discussed.

Health benefits of subcutaneous zinc edetate and diphenyl diselenide in calves during the weaning period

The aims of this study were to investigate whether treatments with zinc edetate (Zn) and diphenyl diselenide ((PhSe)2) enhance performance, immune responses, protein metabolism, and oxidant/antioxidant status in calf serum and muscle. Animals were divided into four groups (n=6 each): control (without supplementation), and groups supplemented on days 50 and 70 of life with (PhSe)2, Zn, and a combination of (PhSe)2 and Zn. Animals treated with (PhSe)2 gained more weight by experimental day 220 than did the control group, but there was no difference by the end of the experiment (day 300). The absolute number of leukocytes and lymphocytes increased in groups Zn and (PhSe)2+Zn on day 20 of experiment, but decreased on day 40 in groups (PhSe)2, and (PhSe)2+Zn. The number of monocytes decreased in all groups compared with control. One of the principal findings was that (PhSe)2+Zn together had beneficial effects on protein metabolism, represented by increases total protein and globulin levels, compared with the control group. The combination of (PhSe)2 and Zn led to low levels of TBARS and ROS in serum and muscle, and stimulated antioxidant enzyme activities. Thus, supplementation with (PhSe)2+Zn may be a compelling approach to augmenting the calf antioxidant system during weaning.

Redox Biology in Transition Periods of Dairy Cattle: Role in the Health of Periparturient and Neonatal Animals

Dairy cows undergo various transition periods throughout their productive life, which are associated with periods of increased metabolic and infectious disease susceptibility. Redox balance plays a key role in ensuring a satisfactory transition. Nevertheless, oxidative stress (OS), a consequence of redox imbalance, has been associated with an increased risk of disease in these animals. In the productive cycle of dairy cows, the periparturient and neonatal periods are times of increased OS and disease susceptibility. This article reviews the relationship of redox status and OS with diseases of cows and calves, and how supplementation with antioxidants can be used to prevent OS in these animals.

Effects of three methods of oral selenium-enriched yeast supplementation on blood components and growth in Holstein dairy calves

The objective of this study was to investigate the effect of three methods of oral selenium-enriched yeast (Se-yeast) supplementation on the blood characteristics and growth of Holstein dairy calves. The three methods were: (1) maternal (dams supplemented with 0.3 mg Se per kg of dietary DM during 3 weeks pre-calving), (2) post-calving (calf starter enriched with 0.3 mg Se per kg of DM), and (3) maternal and post-calving Se-yeast supplementation. These three methods were compared with a control group (no supplementation). Maternal supplementation with Se-yeast successfully increased Se concentration in the colostrum and the serum of calves 24 h after calving (P &lt; 0.05). At day 56, the Se concentration in the blood of calves supplemented with Se-yeast pre- (maternal) or post-calving (via starter) was greater than the control group (P &lt; 0.05), but maternal plus post-calving supplementation was not more effective than either maternal or post-calving supplementation. Globulin and total protein concentration in the blood of calves at day 0 increased and albumins:globulins decreased with maternal supplementation (P &lt; 0.05), but these variables were similar for all treatments at day 56. Immunoglobulins in the blood of calves and colostrum were not affected by maternal Se-yeast supplementation. Maternal supplementation increased the concentration of urea in the blood of calves at 0 days (P &lt; 0.05), but not at 56 days. Calf birthweight was increased with maternal supplementation of Se-yeast (P &lt; 0.01), but growth to day 56 was not affected by the methods of Se supplementation. Maternal supplementation with Se-yeast may improve growth and health characteristics of calves at calving time.

Effect of Organic Selenium Supplementation on Selenium Status, Oxidative Stress, and Antioxidant Status in Selenium-Adequate Dairy Cows During the Periparturient Period

The periparturient period represents a stressful time for dairy cows as they transition from late gestation to early lactation. Oxidation stress occurs during this period owing to the increased metabolic activity. Antioxidants supplementation slightly above the suggested requirements may be beneficial in relieving this kind of stress. The objective of this study was to determine whether supplementing selenium (Se) yeast to diets with adequate Se concentrations affects Se status, oxidative stress, and antioxidant status in dairy cows during the periparturient period. Twenty multiparous Holstein cows were randomly divided into two groups with ten replicates in each group. During the last 4 weeks before calving, cows were fed Se-yeast at 0 (control) or 0.3 mg Se/kg dry matter (Se-yeast supplementation), in addition to Na selenite at 0.3 mg Se/kg dry matter in their rations. The concentrations of Se, reactive oxygen species (ROS), hydrogen peroxide (H₂O₂), hydroxyl radical, malonaldehyde (MDA), α-tocopherol and glutathione (GSH), the activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT), and the total antioxidant capacity (T-AOC) in plasma or erythrocyte of dairy cows were measured at 21 and 7 days prepartum, and at 7 and 21 days postpartum. Cows fed Se-yeast supplement during the last 4 weeks of gestation had higher plasma Se and lower MDA concentrations at 7 days prepartum, and at 7 and 21 days postpartum, and had higher whole blood Se and lower plasma ROS and H₂O₂ concentrations at 7 and 21 days postpartum compared with control cows. Se-yeast supplementation increased plasma and erythrocyte GSH-Px activities and erythrocyte GSH concentration at 7 days postpartum as compared to Se-adequate control cows. Compared with control cows, the enhanced SOD and CAT activities, increased α-tocopherol and GSH concentrations, and improved T-AOC in plasma at 7 and 21 days postpartum in Se-yeast-supplemented cows were also observed in this study. The results indicate that feeding Se-adequate cows a Se-yeast supplement during late gestation increases plasma Se status, improves antioxidant function, and relieves effectively oxidative stress occurred in early lactation.

Effects of selenium biofortification of hayfields on measures of selenium status in cows and calves consuming these forages

Two experiments were conducted to evaluate the Se status of weaned calves (Exp. 1) and pregnant cows and newborn calves (Exp. 2) consuming bermudagrass [ (L.) Pers.] fertilized with Se. Sodium selenate was dissolved into water (8.8 g/L) and sprayed onto hayfields. Selenium-fertilized forage had greater ( ≤ 0.001) Se concentration compared with the control forage without Se fertilization (7.7 ± 1.81 vs. 0.1 ± 0.04 mg Se/kg DM and 10.8 vs. 0.1 mg Se/kg DM for Exp. 1 and Exp. 2, respectively). In Exp. 1, beef calves ( = 32; 176 ± 8.7 kg initial BW) were stratified by BW and randomly assigned to pens (16 pens; 2 calves/pen). Treatments were randomly assigned to pens, including control (no supplemental Se), Se hay, or sodium selenite ( = 2, 7, and 7 pens, respectively). A 42-d pair-feeding design was used, wherein each pen receiving Se hay was paired to a pen receiving sodium selenite. Blood and liver samples were collected on d 0, 21, and 42. Liver Se concentrations were greatest ( ≤ 0.005) on d 42 for calves provided Se hay compared with calves provided sodium selenite or control. This difference was attributed only to paired-feeding groups consuming <3 mg Se daily. In Exp. 2, mature, late-pregnancy cows were randomly assigned to 3 treatments: Se hay ( = 12), sodium selenite ( = 9), or control (no supplemental Se; = 6). Cows assigned to the sodium selenite and Se hay treatments were provided 2.5 mg of supplemental Se daily. Upon enrollment, cows were moved into individual feeding areas at an estimated 30 d prior to calving. Following calving, cotyledon and colostrum samples were collected from cows. Four days later, liver and blood samples were collected from both cows and calves. Selenium-supplemented cows had greater ( ≤ 0.001) liver, cotyledon, plasma, and whole blood Se concentrations compared with cows not receiving supplemental Se. Furthermore, cows provided Se hay tended ( = 0.11) to have greater liver Se concentrations compared with cows provided sodium selenite. Calves born to Se-supplemented cows had greater ( = 0.001) plasma Se concentrations than calves born to cows receiving no supplemental Se. Furthermore, calves born to cows provided Se hay tended ( = 0.06) to have greater plasma Se concentrations compared with calves born to cows provided sodium selenite. These data imply that Se biofortification of hayfields is an effective method to increase Se concentration of forage. Consumption of these forages result in increased Se status of weaned calves, periparturient cows, and their calves.

The Technical and Financial Effects of Parenteral Supplementation with Selenium and Vitamin E during Late Pregnancy and the Early Lactation Period on the Productivity of Dairy Cattle

This study aimed to determine the effects of parenteral selenium (Se) and vitamin E supplementation on economic impact, milk yield, and some reproductive parameters in high-yield dairy cows in the dry period and in those at the beginning of lactation. At the beginning of the dry period, cows (n = 323) were randomly divided into three groups as follows: Treatment 1 (T1), Treatment 2 (T2), and Control (C). Cows in group T1 received this preparation 21 days before calving and on calving day, and cows in group T2 received it only on calving day. The cows in the control group did not receive this preparation. Supplementation with Se increased Se serum levels of cows treated at calving day (p<0.05). Differences in milk yield at all weeks and the electrical conductivity values at the 8th and 12th weeks were significant (p<0.05). Supplementation with Se and Vitamin E decreased the incidence of metritis, the number of services per conception and the service period, but had no effects on the incidence of retained fetal membrane. A partial budgeting analysis indicated that Se supplementation was economically profitable; cows in group T1 averaged 240.6$ per cow, those in group T2 averaged 224.6$ per cow. Supplementation with Se and Vitamin E has been found to increase serum Se levels, milk yield, and has positive effects on udder health by decreasing milk conductivity values and incidence of sub-clinical mastitis.

Effect of supranutritional maternal and colostral selenium supplementation on passive absorption of immunoglobulin G in selenium-replete dairy calves

Selenium (Se) is an essential micronutrient for ruminant animals affecting both performance and immune functions. Adding 3 mg of Se/L (in the form of Na selenite) to colostrum has been shown to improve IgG absorption in Se-deficient newborn dairy calves. The objective of our study was to determine the effect of supranutritional maternal and colostral Se supplementation on IgG status of Se-replete dairy calves. The study design was a 2 × 2 × 2 factorial design. During the last 8 wk before calving, dairy cows at a commercial dairy were fed either 0 (control cows) or 105 mg of Se-yeast once weekly (supranutritional Se-yeast-supplemented cows), in addition to Na selenite at 0.3 mg of Se/kg of DM in their ration. After birth, calves were fed pooled colostrum from control or supranutritional Se-yeast-supplemented cows to which 0 or 3 mg of Se/L (in the form of Na selenite) was added. Concentrations of whole-blood (WB) Se and serum Se measured at birth and at 48 h and 14 d of age, and serum IgG concentrations measured at 48 h and 14 and 60 d of age were determined. Calves born to Se-yeast-supplemented cows had higher WB-Se and serum-Se concentrations for the first 2 wk, and higher IgG absorption efficiency (62% at 48 h), resulting in higher serum-IgG concentrations (43% at 48 h and 65% at 14 d) and higher total serum-IgG content (50% at 48 h and 75% at 14 d), compared with calves born to control cows. Calves that received colostrum with added Na selenite had higher WB-Se concentrations for the first 2 wk, but only at 14 d of age were serum-Se concentrations, serum-IgG concentrations (53% higher), and total serum-IgG content (56% higher) higher, compared with calves that were fed colostrum without added Na selenite. Calves born to Se-yeast-supplemented cows that received colostrum from Se-yeast cows without added Na selenite had a higher IgG absorption efficiency compared with all other treatment groups. Our results support that feeding cows supranutritional Se-yeast supplement during the dry period or spiking colostrum with Na selenite both improve IgG status of Se-replete calves.

Evaluating micronutrient concentrations in liver samples from abortions, stillbirths, and neonatal and postnatal losses in beef calves

The primary objective of the current study was to describe micronutrient concentrations in livers collected during postmortem examination from 501 beef calves and fetuses in western Canada. The most frequently identified deficiencies based on reported ranges for aborted fetuses were magnesium, copper, and vitamin E. For stillborn, neonatal, and postnatal calves, the most common deficiencies were magnesium, vitamin A, and vitamin E. However, for calves that died after 3 days of age, selenium deficiency was also very likely. Concentrations of all micronutrients examined in the study except zinc ( P = 0.85) were different among fetuses, stillbirths, and neonatal and postnatal losses. This included liver selenium, copper, manganese, molybdenum, iron, magnesium, vitamin A, and vitamin E ( P < 0.01). The percentiles of micronutrient concentrations for each age group, empirical prediction intervals for individual calves, and model predicted confidence intervals to compare with average concentrations from groups of calves were summarized for each age group. Information on cow, calf, and herd management attributes were available for 221 samples from 106 herds collected as part of study 1. Cow age, supplementation history, water quality, and herd location were associated with the concentration of iron, zinc, and molybdenum. The current study is unique in the number of samples included from young calves that were submitted as part of routine surveillance and not based on suspicion of either deficiency or toxicity. Most previous studies have been focused on older animals or fetuses and have contained a mix of beef and dairy animals with little or no information on their supplementation history.

Individual intake of free-choice mineral mix by grazing beef cows may be less than typical formulation assumptions and form of selenium in mineral mix affects blood Se concentrations of cows and their suckling calves

The objectives of this study were to determine (1) the individual ad libitum intake of mineral mix by beef cows managed under a year-long, fall-calving, forage-based production regimen and (2) if Se form in the mineral mix affected the blood Se concentrations of cows and suckling calves. Twenty-four late-gestation (6 to 8 months) Angus-cross cows (2.7 ± 0.8 years; body weight [BW] = 585 ± 58 kg) were blocked by BW and randomly assigned (n = 8) to a mineral supplement treatment (TRT) containing 35 ppm Se as either inorganic (ISe; sodium selenite), organic (OSe; Sel-Plex®), or a 1:1 combination of ISe/OSe (MIX). Cows commonly grazed a 10.1-ha predominately tall fescue pasture and had individual ad libitum access to TRT using in-pasture Calan gates. Cows calved from August to November and calves had common ad libitum access to creep feed and a mineral supplement that lacked Se. Cow jugular blood was taken at 28-day intervals (13 periods) and calf blood was taken with cows from birth through weaning. Individual cow mineral mix (mean = 54.0 ± 7.0 g/day, range = 97.3 to 27.9 ± 7.4 g/day) and Se (mean = 1.82 ± 0.25 mg/day, range = 3.31 to 0.95 ± 0.25 mg/day) intakes were affected by period (P < 0.0001), but not by cow Se TRT (P > 0.30). Cow blood Se (0.109 to 0.229 ± 0.01 μg/mL) was affected (P < 0.002) by period, Se form, and their interaction, with ISe < MIX for periods 8 and 11, ISe < OSe for all periods except period 1, and MIX < OSe for periods 2 to 4, 7, 8, 10, and 12. Calf blood Se (in micrograms Se per milliliter) was correlated with cow blood Se and affected (P < 0.0001) by cow Se TRT, with ISe (0.07 to 0.11) < MIX (0.10 to 0.15) = OSe (0.16 to 0.19). These data reveal that (1) mean supplemental ad libitum cow mineral intake was 36% less than the typical formulation intake expectations (85 g/day) and, correspondingly, mean supplemental Se intake was 33% less than that allowed by the FDA and (2) cow Se TRT differentially affected both cow and calf blood Se concentrations, resulting in adequate concentrations for all cows but inadequate concentrations for ISe calves.

Colostrum and milk selenium, antioxidative capacity and immune status of dairy cows fed sodium selenite or selenium yeast

Dietary selenium (Se) can be supplemented from organic or inorganic sources and this may affect Se metabolism and functional outcome such as antioxidative status and immune functions in dairy cows. A feeding trial was performed with 16 Holstein-Friesian dairy cows fed with a total mixed ration (0.18 mg Se/kg dry matter (DM)) either without Se supplement (Control, n = 5), or with Se from sodium selenite (Group SeS, n = 5) or Se yeast (Group SeY, n = 6). In Groups SeS and SeY, the Se supplementation amounted to an additional intake of 4 mg Se and 6 mg Se/d during gestation and lactation, respectively. The effect of both Se sources was characterised by milk Se and antioxidant levels, and the phenotyping and functional assessment of phagocytic activity of milk immune cells. Se yeast has been found to increase (p ≤ 0.001) the milk Se and antioxidant levels markedly compared to the control group. The experimental treatment did not affect the immune parameters of the cows. Lymphocyte subpopulations and phagocytosis activity of neutrophilic granulocytes were affected neither by the Se intake nor by the two different dietary supplements. It can be concluded that sodium selenite and Se yeast differ considerably in their effects on antioxidant status in dairy cows. However, the basal dietary Se concentration of 0.18 mg/kg DM seemed to be high enough for the measured immune variables.

Serum trace mineral variations in Nili-Ravi buffaloes suffering with prepartum vaginal prolapse in two different agro-ecological zones of Punjab, Pakistan

The present study was conducted during 2005 and 2006 on 200 Nili-Ravi buffaloes kept in two agroecological zones (irrigated [zone 1] and rain-fed [zone-2]) of Punjab, Pakistan, with the objective to determine the level of trace minerals (Cu, Fe, Zn, Se) in serum of the buffaloes suffering from vaginal prolapse and to compare them with their healthy counterparts. In each zone 50 buffaloes suffering from prepartum vaginal prolapse during their seventh month of gestation were identified through survey. Vaginal prolapse-affected buffaloes belonging to zone 1 were identified as group VPB1 (N = 50), whereas buffaloes belonging to zone 2 were recognized as VPB2 (N = 50). The buffaloes of control group in zone 1 and zone 2 were identified as NCB1 and NCB2, respectively. The blood samples in all four groups of buffaloes were collected three times, i.e., first when these animals were in the eighth month of gestation, second during the eighth to ninth month of gestation, and finally when these animals were in the ninth or later month of gestation. The mean serum copper concentrations in buffaloes of group VPB1 were significantly lower (P < 0.05) in comparison with NCB1 and NCB2, whereas there were nonsignificant differences (P > 0.05) in copper concentrations between VPB1 and VPB2. There was a significant difference (P < 0.05) of iron concentration in VPB1 compared with NCB1 and NCB2. Similarly, VPB2 also had significantly lower (P < 0.05) iron concentrations compared with NCB1 and NCB2. Serum zinc concentrations were significantly lower (P < 0.05) in animals of the VPB1 group when compared with NCB1 and NCB2. Similarly, lower zinc concentrations were observed in VPB2 in comparison with NCB1 and NCB2. There was significantly lower (P < 0.05) zinc concentration in affected buffaloes (VPB1 and VPB2) from the ninth month of gestation to term when compared with those in the eighth to ninth mo of gestation, and with those not yet in the eighth month of gestation. Serum selenium concentration were significantly higher (P < 0.05) in control group buffaloes (NCB1 and NCB2) in comparison with vaginal prolapse-affected buffaloes (VPB1 and VPB2). During different stages of gestation, mean serum selenium concentrations varied nonsignificantly (P > 0.05) within each group of buffalo. Based on information obtained from this study, it was concluded that the low serum concentration of copper and selenium are linked to increased incidence of vaginal prolapse in buffaloes during the last trimester of gestation.

Effect of prepartum supplementation of selenium and vitamin E on serum Se, IgG concentrations and colostrum of heifers and on hematology, passive immunity and Se status of their offspring

Forty heifers at the late stage of gestation were randomly assigned into five groups. Heifers were balanced for age, weight, and time of calving in each group. Four and 2 weeks before expected time of calving, the heifers were injected with 0 ml (C), 10 ml (T1), 20 ml (T2), 30 ml (T3), and 40 ml (T4) Se and VE supplements, respectively. Each milliliter of the supplement contained of 0.5 mg Se as sodium selenite and 50 IU of dl-alpha-tocopheryl acetate. Blood samples were collected from the heifers 4 weeks before expected calving and at calving day and from the calves at birth and 7 days of age. The serum Se and immunoglobulin G (IgG) concentrations, white blood cell and differential leukocyte counts were measured. The Se concentrations in the sera of the heifers before the injections of Se and VE supplements were the same among the groups (P > 0.05), but after calving were significantly increased in the treated heifers (P < 0.05). Similarly, the serum Se levels of calves of the treated heifers were higher (P < 0.05). The Se concentrations in the colostrums of the heifers were affected by treatments (P < 0.05). Colostrum and daily milk productions at 8-week lactation were increased in treated heifers compared with the controls (P < 0.05). Likewise, the milk somatic cell counts decreased in the treated heifers compared with the controls. The changes of the mean serum IgG levels did not differ among calves (P > 0.05). The white blood cell counts were higher in calves of heifers in groups T3 and T4 compared with the control group at 7 days of age (P < 0.05).

Effect of selenium and vitamin E supplementation during the late pregnancy on reproductive indices and milk production in heifers

A trial was performed to determine the effects of supplementation of selenium (Se) and vitamin E (VE) on reproductive indices and milk production in Holstein heifers. Sixty heifers at the late stage of gestation were randomly assigned into three groups. Heifers were balanced for age, weight and time of calving. Four and 2 weeks before expected calving the heifers were injected 0 ml (C), 20 ml (T1), and 40 ml (T2) Se and VE supplements. Each ml contained 0.5mg Se and 50 IU of D, L-alpha-tocopheryl acetate. Blood samples were collected from heifers 4 weeks before expected calving and at calving day. Se concentrations in serum and colostrums were measured. The reproductive parameters were recorded. The effects of Se and VE supplements on somatic cell count (SCC) and milk yield also were measured. Supplementation of Se increased the level of Se in serum of treated heifers at calving day (P<0.05). Se concentration of colostrums were affected by the treatments (P<0.05). Concerning reproductive performance of treated heifers; gestation length was similar among groups but in comparison with controls, T1 and T2 had no incidence of retained fetal membrane (i.e., beyond 12h.). In addition, open days were fewer in T1 and T2 heifers and the number of services per conception was fewer in T2 compared with controls (P>0.05). Daily milk production at 8 weeks lactation was significantly increased in T2 compared with controls (P<0.05). Likewise, the milk SCC decreased in treated heifers compared with controls (P<0.05).

The selenium levels of mothers and their neonates using hair, breast milk, meconium, and maternal and umbilical cord blood in Van Basin

The objective of the present study is to calculate linear regressions between a mother and her child with respect to their selenium concentration (ng/g) in the following traits: maternal blood and umbilical cord blood, maternal and child hair, maternal milk and child umbilical cord blood, maternal milk and meconium, maternal blood plasma, and child meconium. The data were collected at Research Hospital of the University of Yüzüncü Yil from 30 pairs of mothers and their newborn baby. The mean maternal serum Se level in 30 mothers was 68.52 +/- 3.57 ng/g and cord plasma level was 119.90 +/- 18.08 ng/g. The Se concentration in maternal and neonatal hair was 330.84 +/- 39.03 and 1,124.76 +/- 186.84 ng/g, respectively. The Se concentration of maternal milk at day 14 after delivery was determined as 68.63 +/- 7.78 ng/g (n = 13) and the concentration of Se was 418.90 +/- 45.49 ng/g (n = 22) for meconium of neonatal. There was no significant difference between maternal blood and milk Se levels. However, hair Se concentration was significantly higher than milk and maternal blood Se level. For each trait comparison, the average absolute difference in log(10)-transformed Se concentration was calculated between a mother and her child. The observed average absolute difference was compared with a test distribution of 1,000 resampled bootstrap averages where the number of samples was maintained but the relationship between a mother and her child was randomized among samples (alpha = 0.05).

Effect of selenium source on selenium status, neutrophil function, and response to intramammary endotoxin challenge of dairy cows

The effects of feeding dry and early lactation dairy cows diets with selenate or selenized yeast (Se-yeast) on concentrations of Se in serum, milk, and newborn calves, neutrophil function, and inflammatory response were determined. At 60 d before anticipated calving until approximately 30 d in milk (DIM), cows were fed diets that contained 0.3 mg of supplemental Se/kg of DM from sodium selenate or Se-yeast. Diets also contained 0.2% supplemental S (as sulfate) because it has been shown to reduce absorption of Se by dairy cows. The concentration of Se in serum at calving and 28 DIM was about 1.4 times greater for cows fed Se-yeast than for those fed selenate. Serum concentrations decreased 45 and 23% from dry-off to calving for cows fed selenate or Se-yeast, respectively. Selenium concentrations in serum from newborn calves were also about 1.4 times greater when the dams were fed Se-yeast. Concentrations of Se in colostrum and milk were about 1.8 times greater when cows were fed Se-yeast. Blood neutrophils were isolated from cows at 28 DIM and were used in an in vitro kill assay. Selenium treatment did not affect bacterial kill or the percentage of neutrophils that phagocytized bacteria. At approximately 28 DIM, one quarter from each cow was infused with a solution containing endotoxin. Peak body temperature (40.7 degrees C) occurred 6 h postinfusion, and peak somatic cell count (6.5 log10/mL) occurred at 12 h postinfusion. Neither measure was influenced by Se treatment.

Effect of Se on selenoprotein activity and thyroid hormone metabolism in beef and dairy cows and calves

Although Se is essential for antioxidant and thyroid hormone function, factors influencing its requirement are not well understood. A survey and two experiments were conducted to determine the influence of cattle breed and age on selenoprotein activity and the effect of maternal Se supplementation on cow and calf selenoprotein activity and neonatal thyroid hormone production. In our survey, four cowherds of different ages representing three breeds were bled to determine the influence of breed and age on erythrocyte glutathione peroxidase activity (RBC GPX-1). All females were nonlactating, pregnant, and consumed total mixed diets (Holstein) or grazed pasture (Angus and Hereford). In our survey of beef breeds, yearlings had greater average RBC GPX-1 activity than mature cows. In Exp. 1, neonatal Holstein heifers (n = 8) were bled daily from 0 to 6 d of age to determine thyroid hormone profile. An injection of Se and vitamin E (BO-SE) was given after the initial bleeding. Thyroxine (T4) and triiodothyronine (T3) concentrations were greatest on d 0 and decreased (P < 0.05) continuously until d 5 postpartum (156.13 to 65.88 and 6.69 to 1.95 nmol/L, d 0 to 5 for T4 and T3, respectively). Reverse T3 concentrations were 3.1 nmol/L on d 0 and decreased (P < 0.05) to 0.52 nmol/ L by d 5. In Exp. 2, multiparous Hereford cows were drenched weekly with either a placebo containing 10 mL of double-deionized H2O (n = 14) or 20 mg of Se as sodium selenite (n = 13). After 2 mo of treatment, Se-drenched cows had greater (P < 0.01) plasma concentrations than control cows (84.92 vs. 67.08 ng/mL), and at parturition, they had plasma Se concentrations twofold greater than (P < 0.05) control cows (95.51 vs. 47.14 ng Se/mL). After 4 mo, cows receiving Se had greater (P < 0.05) RBC GPX-1 activity than controls; this trend continued until parturition. Colostrum Se concentration was twofold greater (P < 0.05) in Se-drenched cows than control cows (169.97 vs. 87.00 ng/mL). Calves born to cows drenched with Se had greater (P < 0.05) plasma Se concentration, RBC GPX-1, and plasma glutathione peroxidase activity on d 0 compared with calves born to control cows. By d 7, no differences in plasma glutathione peroxidase activity in calves were observed. Maternal Se supplementation did not influence calf thyroid hormone concentrations. Selenium provided by salt and forages is not adequate for cattle in Se-deficient states.

Transport kinetics of zinc, copper, selenium, and iron in perfused human placental lobule in vitro

Transport characteristics of essential trace elements as zinc, copper, selenium and iron have been studied in maternal-fetal direction in normal pregnancies, using in vitro perfusion of human placental lobules. Solutions of trace elements corresponding to twice the physiological concentrations were injected (100 microl bolus) into the maternal arterial perfusate. Serial perfusate samples were collected every 30 sec from venous outflows for a study period of 5 min. Concentrations of these trace elements and their transport kinetics were determined. Transport fractions (TF) of zinc, copper, selenium and iron averaged 0.21, 0.49, 0.55 and 0.10% of maternal load respectively. Other parameters such as area under the curve, clearance, elimination constant, absorption and elimination rates showed some significant differences between the various elements. Copper and selenium appear to be transported passively in maternal-fetal direction, while for iron and zinc, role of active transport for transfer across the human placental membrane cannot be discounted. We speculate that alterations in copper: zinc TR50 (transport rate for 50% efflux) and TF ratios could serve as useful indicators for assessing placental transport status of these essential elements in complicated pregnancy states.

The role of essential trace elements in embryonic and fetal development in livestock

This review addresses the concept that essential trace minerals play a vital role in many enzymatic and metabolic pathways that are critical for conceptus development during pregnancy in livestock species. The conceptus relies entirely on the maternal system for a sufficient supply of trace minerals and other nutrients needed for normal development. If this supply is inadequate, growth and/or health of the conceptus can be affected adversely, and many of these effects carry over into the neonatal period. Information, accumulated in our laboratory and presented herein, indicates that zinc, copper and manganese are among the trace minerals that have the greatest impact on reproduction. For example, levels of zinc, copper and manganese were several fold greater in the conceptus than in other reproductive tissues, indicating that the conceptus preferentially accumulates these minerals, an action that may be important for conceptus development, growth and survival. Moreover, some recent results indicate that increasing the biological availability of zinc, copper and manganese, by attachment to short peptide chains (i.e., proteinated trace minerals) can enhance reproductive performance of swine. Mineral concentrations in conceptuses from female pigs consuming proteinated trace minerals were greater than those from females that consumed only inorganic mineral salts. Elucidating the mechanisms whereby conceptus development and survival are enhanced by essential trace minerals may lead to development of specific feeding programs to increase the number and health of offspring at parturition, thereby allowing for further improvements in production efficiency in animal agriculture.

Maternal-fetal transport kinetics of copper, selenium, magnesium and iron in perfused human placental lobule: in vitro study

Transport characteristics of certain inorganic elements such as copper, magnesium, selenium and iron have been studied in maternal-fetal direction in normal pregnancies, using in vitro perfusion of isolated placental lobules. Copper, selenium, magnesium and iron salts corresponding to twice physiological concentrations were injected as a 100 microl bolus, into the maternal arterial perfusate. Serial perfusate samples were collected from venous outflows for a study period of 5 min. Concentrations of various inorganic elements and their transport kinetics were determined. Transport fractions of copper, selenium, magnesium and iron averaged 0.14, 0.19, 0.06 and 0.23% of maternal load respectively. The pharmacokinetic parameters such as area under the curve, clearance, elimination constant, and time for maximum response showed some significant differences between the various elements. We speculate that copper and selenium share the same transport pathway along a concentration gradient in maternal-fetal direction, while for iron and magnesium, active transport plays a predominant role for element transfer across the human placental membrane.

Selenium status in Saudi Arabia

Selenium (Se) is a naturally occurring trace element that is essential for animal and human nutrition, but the range between dietary requirements and toxic levels is relatively narrow. In this review, we are interested in the beneficial effects of selenium and we report on a number of studies of the selenium status of different populations in Saudi Arabia. The Status reflects the geographical area inhabited by the populations. Apart from the few available studies reviewed here, no data on the human status of Se in Saudi Arabia has been obtained. A further objective of this paper is throw some the light on the direction of future studies.

Nutrient and immunity transfer from cow to calf pre- and postcalving

Nutritional and management strategies for dairy cattle are designed to prepare the cow for lactation and to minimize the incidence of metabolic diseases around calving. However, strategies initiated during the dry period should also consider the potential effects on the calf prior to and after calving. Fetal requirements for energy and protein are significant, particularly during the last trimester of gestation. Energy requirements increase to 1.3 to 1.5 times maintenance in late pregnancy; therefore, the formulation of rations for dry cows must contain sufficient energy to support fetal growth plus maintenance. Protein requirements during pregnancy increase, particularly during the last 2 mo. Colostrum is a source of immune components and nutrients to the neonate and contains more protein, immunoglobulins (Ig), nonprotein nitrogen, fat, ash, vitamins, and minerals than does milk. Because some vitamins do not cross the placental barrier, colostrum is the primary source of these nutrients for the calf after birth. Colostrum from cows that are not supplemented with vitamin E during the dry period may provide inadequate vitamin E to calves after birth. The Ig concentration in colostrum is not markedly affected by prepartum protein nutrition; diets containing high crude protein (CP) generally increase the nonprotein fraction of colostrum, but low CP diets do not affect the CP or Ig concentration of colostrum. However, data from beef calves suggest that absorption of IgG may be impaired when low protein diets are fed during the dry period. Diets for dry cows may be balanced to reduce the cation to anion ratio, which may reduce the incidence of parturient paresis. Recent research also suggests that these diets might increase the incidence of calves born in respiratory acidosis, which may impair the acquisition of passive immunity.

Effect of anionic salts on selenium metabolism in nonlactating, pregnant dairy cows

The objective of this trial was to determine whether anionic salts in the diets of nonlactating, pregnant cows for 14 to 21 d prepartum affected measures of Se status. One of three dietary treatments (control, anionic salts, and anionic salts plus Se) was administered to 34 nonlactating, pregnant cows using a completely randomized design with repeated measures. The anionic salts were delivered via gelatin capsules that were administered orally in two equal amounts per day, and the Se (3 mg/d) was administered via an intraruminal bolus. The incidence of milk fever among cows was not significantly different across dietary treatments. The severity of hypocalcemia as indicated by concentrations of ionized Ca in serum collected < 2 h postpartum was significantly lessened by dietary anionic salts. Supplementation of anionic salts to the diet did not significantly affect serum Ca concentrations at either 7 d prepartum or 7 d postpartum. Anionic salts did not affect concentrations of Se in blood; however, Se supplementation of the diets of cows significantly increased postpartum concentrations of Se in serum. No treatment effects were detected for concentrations of Se in either serum or whole blood of newborn calves. In conclusion, these data indicate that diets supplemented with anionic salts for 14 to 21 d prepartum and the supplementation of diets with Se had independent effects on concentrations of minerals in blood. Thus, anionic salts administered to prevent milk fever without danger of significantly reducing the transfer of Se from the dam to the calf and without compromising the Se status of the cow when the anionic salts are limited to administration for 14 to 21 d before calving.