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

Trace Mineral Supplementation of Beef Cattle in Pasture Environments

The United States Department of Agriculture defines pastureland as "A land cover/use category of land managed primarily for the production of introduced forage plants for livestock grazing." The purpose of this article is to review trace mineral supplementation for beef cattle in this environment. Supplementation of trace minerals in these environments is accomplished with the use of a trace mineralized salt or a complete mineral-vitamin product that contains macrominerals, trace minerals, and vitamins. The form of the supplement may influence uptake and utilization. Supplementation may be augmented with pulse dosing with injectables or oral products.

Effects of probiotic and yeast extract supplementation on oxidative stress, inflammatory response, and growth in weaning Saanen kids

This study aimed to investigate the effects of probiotic and yeast extract supplementation on the metabolic, immune, and oxidative status of Sannen goat kids during the weaning challenge. Forty goat kids were randomly assigned to four groups: a probiotic group (Pr) (basal diet + mixture of Bacillus subtilis, Bacillus lechiniformis, Streptococcus Thermophilis, and Enterococcus faecium), a yeast cell wall extract group (YC) (basal diet + Saccharomyces cerevisiae), a probiotic and yeast cell wall extract group (Pr + YC) (basal diet + mixture of probiotic and yeast cell wall extract), and a control group (basal diet). Treatments were administered 21 days prior to weaning (80 ± 2 days of life) until 21 days post-weaning except for the control group. Blood samples were collected at four different time points, including 21 days before weaning, 2 days post-weaning (weaning time), 7 days post-weaning, and 21 days post-weaning. Average levels of triiodothyronine, thyroxine, total protein (TP), albumin, globulin, blood urea nitrogen (BUN), total antioxidant capacity (TAC), serum adenosine deaminase (ADA), nitric oxide (NO), ferritin, glucose, cortisol, triglyceride, non-esterified fatty acid (NEFA), Β-hydroxybutyric acid (BHBA), and body weight were measured. The average levels of cortisol tended to be higher in the Pr group in comparison to the control group (P = 0.07) and the Pr + YC group (P = 0.10). NEFA was found to be higher and tended to be higher in the control group compared to the Pr + YC group (P > 0.001) and Pr group (P = 0.10), respectively. Additionally, the BHBA concentration was higher in the control group compared to the Pr group (P > 0.001). No differences were observed in the concentration of other measured parameters among the treatments. The concentration of cortisol tended to be higher (P = 0.10) at the weaning time as compared to the third sampling time. Furthermore, the concentration of TAC was observed to be higher (P > 0.01) at the weaning time in comparison to the third and fourth sampling times. The concentration of NO was higher (P > 0.01) at the third sampling time when compared to the first sampling time. A reduction in NEFA and BHBA levels may suggest an improvement in the metabolic status of the supplemented animals during the weaning challenge. However, supplementation with probiotics and yeast cell wall extract did not appear to have an effect on the oxidative status of the animals. The increase in TAC and NO levels observed during the weaning time may indicate an increase in oxidative stress during this period.

Different dietary sources of selenium alter meat quality, shelf life, selenium deposition, and antioxidant status in Hu lambs

Thirty-two male Hu lambs (32.31 ± 3.31 kg; 4-months-old) were randomly assigned to four treatments: (1) control (CON), (2) selenium-enriched yeast (SeY, 0.8 mg/kg), (3) selenized glucose (SeGlu, 0.8 mg/kg), and (4) sodium selenite (SS, 0.8 mg/kg) to evaluate their effects on Hu lamb production and slaughter performance, antioxidant capacity, hematological parameters, meat quality and shelf-life. The production and slaughter performances were not different (P > 0.05) among treatments. SeGlu and SeY increased (P < 0.05) the total antioxidant capacity in serum and muscle selenium content while decreasing (P < 0.05) the malondialdehyde (MDA) contents both in serum and muscle. SeGlu extended muscle shelf-life by 7.7 h compared with CON and decreased (P < 0.05) yellowness (b*) and lightness (L*) in meat stored for 24 h. In summary, the effects of SeGlu were similar to those of SeY and better than those of SS in improving serum and muscle antioxidant status, prolonging muscle shelf-life, and increasing selenium deposition in muscle.

Trace Minerals Supplementation with Great Impact on Beef Cattle Immunity and Health

Simple Summary

Supplementation with trace minerals (TM) is a husbandry strategy to improve cattle health. There is solid evidence of the beneficial effects of TM supplementation on the immune system. The concentration of TM in the soil is variable across the USA, with several regions having deficient levels in forages. Therefore, TM supplementation is highly recommended especially in areas where forages do not supply the mineral requirements. Before starting TM supplementation, it is important to evaluate the herd’s mineral profile, and the amount of TM the animals are consuming. Oral free-choice TM may not be sufficient to satisfy the requirements in certain situations, and could lead to TM deficiencies. This is due to a high variability in TM composition and intake, binding to undigested feed particles, reduced absorption, and antagonisms. Single, oral pulse-dose supplementation provides a controlled and homogeneous amount of TM intended to remove such a variation. However, this strategy does not efficiently increase circulating and hepatic TM levels. Parenteral TM supplementation has resulted in a more efficient increase in TM concentration. The strategic supplementation combining injectable TM during critical times of cattle management (e.g., vaccination) in conjunction with oral free-choice supplements has shown significant benefits for the immune response and protection against respiratory disease in beef cattle, reducing morbidity and treatment costs.

Abstract

Trace minerals (TM) play an important role in cattle immunity, health and performance. Although TM are needed in small quantities, they are fundamental for enzymes involved in antioxidant protection against cellular damage and several pathways of the immune response. Cattle TM status results from the balance between TM dietary intake and their requirements. Free-choice oral TM supplementation is a common practice in beef cattle production systems. However, there is a high variation in TM intake and thus TM status and bioavailability in animals receiving free-choice oral TM supplements. Strategic pulse-dose supplementation during critical points of beef cattle management provides a controlled amount of TM intended to remove such a variation. Adequate TM supplementation should not only satisfy the basal requirements but also provide a source of TM when there is a higher demand of the antioxidant systems or during the development of the immune response. This paper reviews the research-based evidence of the effects of TM supplementation on immunity and its impact on beef cattle health. This review highlights the benefits of a novel approach of strategic administration of injectable trace minerals (Se, Zn, Cu and Mn) during critical episodes of cattle management (e.g., around weaning or at vaccination) in combination with free-choice oral supplementation to maintain adequate TM and oxidative status, enhanced immunity and overall cattle health. This strategy has proven to decrease morbidity, which would positively impact the productivity of the beef cattle systems.

The Effect of Maternal Dietary Selenium Supplementation on Blood Antioxidant and Metabolic Status of Ewes and Their Lambs

This study investigated the effect of dietary selenium supplementation (organic and inorganic) of late-gestation ewes on blood selenium concentrations and metabolic and antioxidant status indicators in ewes and their lambs. In addition, the efficacy of selenium transfer from ewes to lambs during the suckling period was determined. The study was conducted on 30 Merinolandschaf ewes and their lambs and lasted four months. The feed mixture of the control group (group I) contained no added selenium, while the feed mixture of group II was enriched with 0.3 mg/kg of organic selenium sources and the third group with 0.3 mg/kg of inorganic selenium sources. In ewes and their lambs, selenium supplementation significantly (p < 0.01; p < 0.05) increased selenium concentration, glutathione peroxidase, and superoxide dismutase activity and decreased malondialdehyde concentration compared to the control group. Selenium supplementation had a positive effect on metabolism and hematological indicators in lambs. A positive correlation was found between antioxidant indicators in the whole blood of ewes and lambs. The good transfer of selenium from ewes to lambs was complemented by higher correlation coefficients when the feed mixture was supplemented with organic compared to inorganic selenium.

Physiological Indicators and Production Performance of Dairy Cows With Tongue Rolling Stereotyped Behavior

Non-nutritive oral behaviors, especially tongue rolling, are prevalent in the stabled cow population. These behaviors mean that the environment or management process might not suit the cows, suggesting low welfare. However, few researches have reported the physiological indicators or production performance of dairy cows with the stereotyped behavior. This study aimed to determine physical conditions, daily activity, rumen fermentation, and milk production of cows with tongue-rolling behavior. Three hundred and fifty nine Holstein cows in the same barn and lactation stage were subjected to scan sampling behavior observations 126 times for 7 days. Ten cows with high-frequency tongue-rolling behavior (TON) and 10 cows without abnormal oral behavior (CON) were selected for further study. Serum sample, ruminal fluid, milk sample, and behavior record video of TON and CON cows were collected. TON cows had more drinking behavior and more stable lying behavior than the CON cows during the daytime. The body condition score of the TON cows decreased, while the milk yield, yield of milk fat, protein, and lactose in the study period increased. The TON cows had lower ruminal fluid pH, acetate/propionate ratio, and total volatile acid. The bacterial diversity in the ruminal fluid was not different between the two groups. Compared to CON cows, the TON cows had a higher level of serum stress indicators, such as cortisol, thyroid hormone, and norepinephrine, which positively correlated to the frequency of tongue-rolling behavior. Meanwhile, the TON cows had a higher level of lactate dehydrogenase, serum glucose, total triglyceride, total cholesterol, and Interleukin 6. Overall, it means they suffer from higher levels of stress and have higher energy metabolism for a long time when cows show tongue-rolling behavior. TON cows had suffered a higher stress level and had higher energy metabolic status for a long time. The TON cows might have better heat tolerance to the thermal environment by more lying and drinking time. Our data revealed the changes in milk production, physiological stress indicators of dairy cows with high-frequency tongue rolling behavior, which will provide essential knowledge for the in-depth understanding of tongue rolling behavior in dairy cows.

Genome-wide association study for meat tenderness in beef cattle identifies patterns of the genetic contribution in different post-mortem stages

The beef tenderization process during the post-mortem period is one of the most important sensorial attributes and it is well-established. The aim of this study was to identify the genetic contribution pattern to meat tenderness at 7-(LMD7), 14-(LMD14), and 21-(LMD21) days post-mortem. The heritabilities for LMD7 (0.194), LMD14 (0.142) and LMD21 (0.048) are well established in the population evaluated here. However, its genetic contribution in terms of genomic candidate regions is still poorly understood. Tenderness was measured in the Longissiums thoracis using Warner-Bratzler shear force in the three post-mortem periods. A total of 4323 crossbred beef cattle were phenotyped and genotyped using the Illumina BovineSNP50K. The percentage of the total genetic variance was estimated using the weighted single-step genomic best linear unbiased prediction method. The main candidate windows for LMD7 were associated with proteolysis of myofibrillar structures and the weakening endomysium and perimysium. Candidate windows for LMD14 and LMD21 were mapped in bovine QTLs for body composition, height and growth. Results presented herein highlight, the largest contribution of proteolysis related processes before 14-days post-mortem and body composition characteristics in later stages for meat tenderness.

Age-related changes in thyroid hormones, some serum oxidative biomarkers and trace elements and their relationships in healthy Saanen goat kids during the first three month of age

BACKGROUND

Early-life diseases in dairy animals are main causes of economic loss in livestock production. Oxidative stress (OS) and thyroid hormones are important inter-related components in the normal physiology of this critical period of life. However, limited information regarding their physiology in goat kids is available. This study was conducted to investigate the age-related changes of thyroid hormones, some serum oxidative biomarkers and trace elements in healthy Saanen goat kids.

METHODS

Nineteen newborn healthy Saanen goat kids (14 females and five males) were studied longitudinally from birth until three months of age. Blood sampling was performed 24-48 h after birth and was repeated on 10 ± 2, 28 ± 2, 56 ± 2 and 84 ± 2 days of age. The serum levels of thyroid hormones, malondialdehyde (MDA), reduced glutathione (GSH), total antioxidant capacity (TAC), selenium (Se), manganese (Mn) and molybdenum (Mo) were measured.

RESULTS

Age-related changes were observed for all measured variables except for MDA (p < 0.05). A decreasing trend was detected throughout the study in thyroid hormones, T3: T4 ratio and Mn (p < 0.01). Some factors decreased from birth to day 10 (Se) or day 28 (TAC and GSH) and followed by an increasing trend that extended to day 84 (p < 0.01). There were significant correlations between thyroid hormones and TAC, as well as Mn levels (p < 0.05).

CONCLUSIONS

These results imply that specific age-related reference values are essential for proper interpretation of the serum level of thyroid hormones and Mn in Saanen goat kids during the first three months of life. In addition, given the high level of thyroid hormones particularly during the first days of life, and their relationship with oxidative biomarkers and trace elements, improving the antioxidant system in this critical period is essential.

Revisiting the Effects of Different Dietary Sources of Selenium on the Health and Performance of Dairy Animals: a Review

Selenium (Se) is one of the most important essential trace elements in livestock production. It is a structural component in at least 25 selenoproteins such as the iodothyronine deiodinases and thioredoxin reductases as selenocysteine at critical positions in the active sites of these enzymes. It is also involved in the synthesis of the thyroid hormone and influences overall body metabolism. Selenium being a component of the glutathione peroxidase enzyme also plays a key role in the antioxidant defense system of animals. Dietary requirements of Se in dairy animals depend on physiological status, endogenous Se content, Se source, and route of administration. Most of the dietary Se is absorbed through the duodenum in ruminants and also some portion through the rumen wall. Inorganic Se salts such as Na-selenate and Na-selenite have shown lower bioavailability than organic and nano-Se. Selenium deficiency has been associated with reproductive disorders such as retained placenta, abortion, early embryonic death, and infertility, together with muscular diseases (like white muscle disease and skeletal and cardiac muscle necrosis). The deficiency of Se can also affect the udder health particularly favoring clinical and subclinical mastitis, along with an increase of milk somatic cell counts in dairy animals. However, excessive Se supplementation (5 to 8 mg/kg DM) can lead to acute toxicity including chronic and acute selenosis. Se is the most vital trace element for the optimum performance of dairy animals. This review focuses to provide insights into the comparative efficacy of different forms of dietary Se (inorganic, organic, and nano-Se) on the health and production of dairy animals and milk Se content.

Advances in Research on the Toxicological Effects of Selenium

Selenium is a trace element necessary for the growth of organisms. Moreover, selenium supplementation can improve the immunity and fertility of the body, as well as its ability to resist oxidation, tumors, heavy metals, and pathogenic microorganisms. However, owing to the duality of selenium, excessive selenium supplementation can cause certain toxic effects on the growth and development of the body and may even result in death in severe cases. At present, increasing attention is being paid to the development and utilization of selenium as a micronutrient, but its potential toxicity tends to be neglected. This study systematically reviews recent research on the toxicological effects of selenium, aiming to provide theoretical references for selenium toxicology-related research and theoretical support for the development of selenium-containing drugs, selenium-enriched dietary supplements, and selenium-enriched foods.

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.

Studies of Selenium Deficiency in the Wumeng Semi-Fine Wool Sheep

Wumeng semi-fine wool sheep are affected by a disease, characterized by emaciation, stiffness and trembling of the limbs, weakness and inability to stand, and sudden death. The objective of the study was to determine possible relationships between the disease and mineral deficiencies. Samples of wool, blood, and liver were collected from affected and healthy sheep. Samples of soil and forage were collected from affected and unaffected areas. The samples were used for hematological and biochemical analyses and mineral nutrient measurements. Results showed that selenium concentrations in forage and soil samples from affected areas were significantly lower than those from unaffected areas (P < 0.01). Meanwhile, selenium concentrations of wool, blood, and liver from the affected sheep were also significantly lower than those from the healthy sheep (P < 0.01). The mean concentration of hemoglobin (Hb), packed cell volume (PCV), and mean corpuscular hemoglobin (MCH) from the affected sheep were significantly lower than those from the healthy sheep (P < 0.01). Serum glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT) activity in the affected sheep were significantly lower than those in the healthy sheep (P < 0.01). Serum creatine phosphokinase (CPK), lactate dehydrogenase (LDH), glutamate pyruvate transaminase (GPT), glutamic oxaloacetic transaminase (GOT), alkaline phosphatase (ALP), and malondialdehyde (MDA) values in the affected sheep were significantly higher than those in the healthy sheep (P < 0.01). Serum concentrations of free triiodothyronine (FT₃) and triiodothyronine (TT₃) in the affected sheep were significantly lower than those in the healthy sheep; serum concentrations of free tetraiodothyronine (FT₄) and tetraiodothyronine (TT₄) in the affected sheep were significantly higher than those in the healthy sheep (P < 0.01). But the administration of selenium and vitamin E by hypodermic injection prevented and cured the disease. The injection contains 0.1% and 5% of sodium selenite and vitamin E, respectively. A single dose is 6, 6, and 2 mL for mature ewe, mature ram, and lamb, respectively, repeated only once 15 days later. This study demonstrated that the disorder of Wumeng semi-fine wool sheep was mainly caused by the selenium deficiency in soil and forage.

Bioefficacy of hydroxy-selenomethionine as a selenium supplement in pregnant dairy heifers and on the selenium status of their calves

This study aimed to determine the effects of supplementing pregnant heifers with the organic selenium (Se) source 2-hydroxy-4-methylselenobutanoic acid (HMSeBA) during the last 8 wk of pregnancy on dam and calf Se status. A total of 42 in-calf heifers were recruited to the study and randomly allocated to 1 of 3 treatments; a negative control (Con), sodium selenite (NaSe), or HMSeBA. Animals were blocked by body weight, body condition score, and expected calving date before treatment allocation. Following enrollment, all animals underwent a 7-wk wash-out period, after which they received their respective supplements, top-dressed daily onto a basal diet for the last 8 wk of pregnancy. Heifer blood samples were taken at weekly intervals from enrollment until 2 wk before expected calving date and as soon as possible after calving for determination of whole-blood glutathione peroxidase activity (GSH-Px) and plasma Se and malondialdehyde (MDA) concentrations. Selenized AA were determined in plasma samples taken at 3 wk precalving. A colostrum sample was taken as close to parturition as possible for determination of colostrum total Se, selenized AA, and IgG concentration. Calves were blood sampled as close to birth as possible for determination of whole-blood GSH-Px activity and plasma Se and MDA concentrations. Differences in whole-blood GSH-Px activity did not become apparent until calving; GSH-Px activity was lowest in Con heifers but similar between NaSe and HMSeBA heifers. Plasma Se was lowest in unsupplemented heifers and greatest in those supplemented with HMSeBA; this was attributable to greater selenomethionine concentrations in the plasma of HMSeBA heifers. Colostrum Se was lowest in Con heifers and greatest in HMSeBA heifers. The greater Se concentration of HMSeBA heifers was attributable to a greater proportion of total Se comprising selenocysteine; the reason for this is not known. There was no effect of supplementation on colostrum IgG concentration. Plasma Se was lowest in calves born to Con heifers and greatest in those born to HMSeBA heifers. There were no effects of treatment on calf whole-blood GSH-Px activity or plasma MDA concentration. The enhanced Se status associated with HMSeBA supplementation is likely a consequence of selenomethionine supply and may confer benefits to both the dam and her calf postpartum.

Selenium and copper interaction at supra-nutritional level affecting blood parameters including immune response against P. multocida antigen in Murrah buffalo (Bubalus bubalis) calves

Minerals play important role in the diet of an animal. Bio-availability of minerals largely gets affected by absolute as well as the relative amount of each mineral present in the diet of an animal. Copper and selenium are two such an essential elements affect utilization of each other in the gastrointestinal tract. The present study elucidates the utilization of copper and selenium at supra-nutritional levels (higher than nutritional requirements). Male Murrah buffalo (Bubalus bubalis) calves (n = 10, 8-9 months, 111.7 ± 12.55 kg body weight) were divided equally into two groups and fed either a standard (Control) diet or the same diet supplemented with 0.3 ppm selenium (Se) and 10 ppm copper (Cu) (Treatment). Supplementation was made using liquid solutions of two inorganic mineral sources after mixing in the concentrate mixture and study lasts for a period of 80 days. Blood samples were collected just before starting supplementation (designated as 0 day of study) and at day 40 and 80 after starting supplementation. Blood samples were subjected to haematological parameters, plasma minerals and various oxidative stress-related parameters were determined with the cell-mediated and humoral immune response against antigen P. multocida (P₅₂ strain). Supra-nutritional Se with Cu had higher blood monocytes (P < 0.05) and plasma selenium (P < 0.01) levels, while other hematological parameters and plasma minerals (except zinc, which was lower (P = 0.025) at day 80 in the treatment group) remained unaffected. Among markers for oxidative stress in blood, levels of lipid peroxidation were lesser (P < 0.01), at day 80 and overall mean values of the enzyme glutathione peroxidase and catalase were higher (P < 0.05) in the supra-nutritional group against control values. The overall mean activity of other oxidative stress markers including reduced glutathione, ceruloplasmin as well as the concentration of α tocopherol, retinol, and β carotene remained unaffected due to supra-nutritional Se and Cu. Although cell-mediated immune response remained comparable (P > 0.05) between groups, higher (P < 0.05) overall mean antibody titer values, as well as the values at day 80, was reported in supra-nutritional Se + Cu group. The study concluded that supra-nutritional Se with Cu in the ration of growing Murrah buffalo calves was helpful to reduce the oxidative stress and to enhance the humoral immune response. Simultaneously, higher plasma Se level and number of monocytes in blood highlighted the additional role of selenium and copper in a ration of growing buffalo calves as compared to its normal recommended dose.

A prophylactic protocol to stimulate the immune response also controls infectious disease and, consequently, minimizes diarrhea in newborn heifers

The immunostimulatory and immunomodulatory properties of selenium (Se), an essential trace element for animals, has increase its use because may prevent/or reduce the occurrence of infectious diseases. Thus, the aim of this study was to verify whether Se and vitamins (A and E) applied via subcutaneous associated with secnidazole via oral exert positive effects in the antioxidant and immune systems, as well as whether prevent infections caused by protozoan and bacteria, and consequently, reduce the number of cases of diarrhea in heifers. Thirty-two newborn Holstein heifers were divided into two groups with sixteen animals each: the control group and the treated group that received sodium selenite (0.2 mg/kg) and vitamins A (35 mg/kg) and E (1 mg/kg) with one day of life, and a second application associated with secnidazole (400 mg/animal) on day 10 of life. Sample collection (blood and feces) were performed on days 1, 15, 30, 45 and 60 of life. Heifers from the treated group showed higher hematocrit values compared to the control group on day 60 of life, while total serum protein levels were higher on days 15 and 30. The ceruloplasmin (days 15, 30 and 60), IgG of heavy chain (days 15, 30, 45 and 60), IgG of light chain (days 45 and 60) and haptoglobin (days 15, 30, 45 and 60) were higher in the treated group compared to the control group. Serum levels of glucose decreased in treated animals on day 60 of life, while serum levels of albumin, triglycerides, urea, cholesterol, thiobarbituric acid reactive substances, reactive oxygen species and glutathione S-transferase activity did not differ between groups. Secnidazole was able to prevent infections caused by Giardia duodenalis in the first few days of life, but no difference was observed between groups. Moreover, there was no difference on total bacteria count and the incidence of diarrhea between groups. No difference on weight gain was observed on day 60 of life, but on day 210 of life treated animals had higher weight gain compared to the control group. Based on these evidences, we concluded that the injectable application of Se and vitamins (A and E) associated to secnidazole can improve the immunological system, and consequently, favor animal's performance.

Effect of Low-Selenium/High-Fat Diet on Pig Peripheral Blood Lymphocytes: Perspectives from Selenoproteins, Heat Shock Proteins, and Cytokines

The aim of the present study was to clarify the effect of low selenium (Se)/high fat on the mRNA expression of selenoproteins, heat shock proteins (HSPs) and cytokines in pig peripheral blood lymphocytes. Forty crossbred boar piglets with healthy lean body weights of 10 kg were randomly divided into four treatment groups (group C, group L-Se, group H-fat, and group L-Se-H-fat) (n = 10/group) and fed with the corresponding diet for 16 weeks. The pig peripheral blood lymphocytes were extracted, and the mRNA expression of selenoproteins, HSPs, and cytokines was measured. Most mRNA levels for selenoproteins decreased in group L-Se, group H-fat, and group L-Se-H-fat, except Gpx1, Gpx2, Selt, and Selm, which were elevated in group H-fat. At the same time, low-Se/high-fat diet increased the expression of HSPs (HSP40, HSP60, HSP70, and HSP90) and inflammatory cytokines (IL-1α, IL-1β, IL-6, IL-8, IL-9, iNOS, COX-2, NF-κB, and TNF-α) in group L-Se, group H-fat, and group L-Se-H-fat, and genes in group L-Se-H-fat showed greater increases. Also, low-Se/high-fat diet inhibits the expression of TGF-β1 and IFN-γ. In summary, a low-Se/high-fat diet can cause relevant selenoprotein expression changes and promote the expression of pro-inflammatory factors and HSPs, and low Se enhances the expression of HSPs and inflammation factors induced by high fat. This information is helpful for understanding the effects of low-Se and high-fat diet on pig peripheral blood lymphocytes.

Selenium nanoparticles-loaded chitosan/citrate complex and its protection against oxidative stress in D-galactose-induced aging mice

BACKGROUND

Selenium (Se) is an indispensable trace element required for animals and humans, and extra Se-supplement is necessary, especially for those having Se deficiency. Recently, selenium nanoparticles (SeNPs), as a special form of Se supplement, have attracted worldwide attention due to their distinguished properties and excellent bioactivities. In this present study, an eco-friendly and economic way to prepare stable SeNPs was introduced. SeNPs were synthesized in the presence of chitosan (CTS) and then embedded into chitosan/citrate gel, generating selenium nanoparticles-loaded chitosan/citrate complex (SeNPs-C/C). Additionally, the clinical potential of SeNPs-C/C was evaluated by using D-galactose (D-gal)-induced aging mice model.

RESULTS

SeNPs in high uniform with an average diameter of around 50 nm were synthesized in the presence of chitosan, and reversible ionic gelation between chitosan and citrate was utilized to load SeNPs. Subsphaeroidal SeNPs-C/C microspheres of 1-30 μm were obtained by spay-drying. Single SeNPs were physically separated and embedded inside SeNPs-C/C microparticles, with excellent stability and acceptable release. Acute fetal test showed SeNPs-C/C was safer than selenite, with a median lethal dose (LD₅₀) of approximately 4-fold to 11-fold of that of selenite. Oral administration of SeNPs-C/C remarkably retarded the oxidative stress of D-gal in Kunming mice by enhancing the activity of antioxidase, as evidenced by its significant protection of the growth, liver, Se retention and antioxidant bio-markers of mice against D-gal.

CONCLUSIONS

The design of SeNPs-C/C opens a new path for oral delivery of SeNPs with excellent stability, energy-conservation and environment-friendliness. SeNPs-C/C, as a novel supplement of Se, could be further developed to defend the aging process induced by D-gal.

A Summary of New Findings on the Biological Effects of Selenium in Selected Animal Species-A Critical Review

Selenium is an essential trace element important for many physiological processes, especially for the functions of immune and reproductive systems, metabolism of thyroid hormones, as well as antioxidant defense. Selenium deficiency is usually manifested by an increased incidence of retention of placenta, metritis, mastitis, aborts, lowering fertility and increased susceptibility to infections. In calves, lambs and kids, the selenium deficiency demonstrates by WMD (white muscle disease), in foals and donkey foals, it is associated with incidence of WMD and yellow fat disease, and in pigs it causes VESD (vitamin E/selenium deficiency) syndrome. The prevention of these health disorders can be achieved by an adequate selenium supplementation to the diet. The review summarizes the survey of knowledge on selenium, its biological significance in the organism, the impact of its deficiency in mammalian livestock (comparison of ruminants vs. non-ruminants, herbivore vs. omnivore) and possibilities of its peroral administration. The databases employed were as follows: Web of Science, PubMed, MEDLINE and Google Scholar.

Hydroxy-selenomethionine: A novel organic selenium source that improves antioxidant status and selenium concentrations in milk and plasma of mid-lactation dairy cows

This study aimed to evaluate the effect of hydroxy-selenomethionine (HMSeBA), a novel organic selenium (Se) source, on milk performance, antioxidative status, and Se concentrations in the milk and plasma of mid-lactation dairy cows compared with that of sodium selenite (SS). Fifty mid-lactation dairy cows with similar days in milk, milk yield, and parity received the same basal diet containing 0.06 mg of Se/kg of DM. They were assigned to 1 of 5 treatments according to a randomized complete block design: negative control (without Se supplementation), SS supplementation (0.3 mg of Se/kg of DM; SS-0.3) or HMSeBA supplementation (0.1, 0.3, or 0.5 mg of Se/kg of DM: SO-0.1, SO-0.3, and SO-0.5, respectively). The experiment lasted for 10 wk, including a pretrial period of 2 wk. The results indicated that neither Se supplementation nor Se source affected dry matter intake, milk yield, milk composition, or blood biochemical parameters, except for milk fat percentage. Simultaneously, milk fat percentage and milk fat yield increased linearly as the quantity of HMSeBA supplementation was increased. Production of 4% FCM and ECM was elevated linearly as dietary HMSeBA increased. The SO-0.3 group showed higher serum activity of glutathione peroxidase, total antioxidant capacity, and superoxide dismutase than the SS-0.3 group, but malondialdehyde content was not affected by Se source. Furthermore, HMSeBA supplementation linearly increased the activities of serum glutathione peroxidase and superoxide dismutase, but decreased malondialdehyde content. Compared with the SS-0.3 group, the SO-0.3 group showed augmented concentrations of total Se in milk and plasma, and total Se milk-to-plasma concentration ratio. In addition, increasing doses of HMSeBA linearly increased the concentrations of total Se in the milk and plasma. This study demonstrates that HMSeBA improves antioxidant status and increases milk and plasma Se concentrations more effectively than SS, indicating that HMSeBA could replace SS as an effective organic Se source for lactating dairy cows.

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.

Selenium in Cattle: A Review

This review article examines the role of selenium (Se) and the effects of Se supplementation especially in the bovine species. Selenium is an important trace element in cattle. Some of its roles include the participation in the antioxidant defense the cattle farms. The nutritional requirements of Se in cattle are estimated at 100 μg/kg DM (dry matter) for beef cattle and at 300 μg/kg DM for dairy cows. The rations high in fermentable carbohydrates, nitrates, sulfates, calcium or hydrogen cyanide negatively influence the organism's use of the selenium contained in the diet. The Se supplementation may reduce the incidence of metritis and ovarian cysts during the postpartum period. The increase in fertility when adding Se is attributed to the reduction of the embryonic death during the first month of gestation. A use of organic Se in feed would provide a better transfer of Se in calves relative to mineral Se supplementation. The addition of Se yeasts in the foodstuffs of cows significantly increases the Se content and the percentage of polyunsaturated fatty acids (PUFA) in milk compared to the addition of sodium selenite. The enzyme 5-iodothyronine deiodinase is a seleno-dependent selenoprotein. It is one of the last proteins to be affected in the event of Se deficiency. This delay in response could explain the fact that several studies did not show the effect of Se supplementation on growth and weight gain of calves. Enrichment of Se in the diet did not significantly affect the slaughter weight and carcass yield of bulls. The impact and results of Se supplementation in cattle depend on physiological stage, Se status of animals, type and content of Se and types of Se administration. Further studies in Se supplementation should investigate the speciation of Se in food and yeasts, as well as understanding their metabolism and absorption. This constitute a path to exploit in order to explain certain different effects of Se.

Selenium-fertilized forage as a way to supplement lactating dairy cows

Fertilization with Se improves forage organic Se concentration, but comparisons with other forms of Se supplementation in feeding lactating dairy cows are scarce. Our objective was to compare the effect of Se-enriched forages to dietary sources of inorganic and organic Se. Digestibility, retention, and balance were assessed by measuring Se concentrations in feces, urine, milk, and blood. The resulting effect on antioxidant status and lactation performance of dairy cows was also determined. High-Se silages [1.72 mg of Se/kg of dry matter (DM)] were produced following a spring application of 2.5 kg/ha of Selcote Ultra, whereas low-Se silages (0.05 mg of Se/kg of DM) were produced in the Se-unfertilized portion of the same fields. After a 77±17 d period of Se depletion, 33 late-lactation primiparous Holstein cows were blocked and randomly assigned for 43 d to 1 of 4 experimental total mixed rations fed for ad libitum intake in an unbalanced randomized block design. Treatments consisted of 4 diets: control with low-Se silages, without Se supplement (0.12±0.04 mg of Se/kg of DM); ISe with low-Se silages and inorganic Se (0.80±0.14 mg of Se/kg of DM); YSe with low-Se silages and organic Se from yeast (0.70±0.11 mg of Se/kg of DM); and FSe with high-Se silages, without Se supplement (0.79±0.14 mg of Se/kg of DM). Organic Se, either as YSe or FSe, was more available and more effective to increase blood and milk Se concentrations than ISe. Moreover, FSe was more available than YSe, as cows fed FSe excreted 16 and 22% less Se (as percentage of intake) in feces and urine, respectively, had higher Se apparent absorption (17%), retention (37%), and balance (45%), and had greater concentration of Se in serum (16%) and milk (11%) than cows fed YSe. Antioxidant status (whole blood and plasma glutathione peroxidase, and milk thioredoxin reductase and malondialdehyde) was not affected by treatments. Dry matter intake, yield of actual, energy-corrected, and fat-corrected milk, as well as milk fat and lactose concentrations, were not affected by the dietary treatments. Cows fed ISe had lower milk protein concentration (3.44%) than cows fed YSe (3.58%) or FSe (3.51%). Cows fed Se-supplemented diets had a lower milk somatic cell count than cows fed the control diet. Results from the current study showed that the production of Se-enriched forages is an effective method to supplement dairy cows in Se as it was more available than YSe, and did not alter antioxidant status and performances of lactating dairy cows.

The Relationship between Selenium and T3 in Selenium Supplemented and Nonsupplemented Ewes and Their Lambs

Twenty pregnant ewes were selected and classified into two groups. The first group received subcutaneous selenium supplementation (0.1 mg of sodium selenite/kg BW) at the 8th and 5th weeks before birth and 1st week after birth while the other was control group without selenium injection. Maternal plasma and serum samples were collected weekly from the 8th week before birth until the 8th week after birth and milk samples were taken from ewes weekly, while plasma and serum samples were collected at 48 hours, 1st, 2nd, 3rd, 5th, and 8th weeks after birth from the newborn lambs. Results demonstrated significant positive relationship between maternal plasma selenium and serum T3 in supplemented and control ewes (r = 0.69 to 0.72, P < 0.05). There was significant (P < 0.001) increase in T3 in supplemented ewes and their lambs until the 8th week after birth. There was positive relationship between milk, selenium concentration, and serum T3 in the newborn lambs of the supplemented group (r = 0.84, P < 0.01), while the relationship was negative in the control one (r = −0.89, P < 0.01). Muscular and thyroid pathological changes were independent of selenium supplementation. Selenium supplementation was important for maintaining T3 in ewes and newborn lambs until the 8th week after birth.

Effects of dietary iodine and selenium on nutrient digestibility, serum thyroid hormones, and antioxidant status of Liaoning cashmere goats

Forty-eight 2-year-old Liaoning Cashmere goats (body weight = 38.0 ± 2.94 kg) were used to investigate the effects of dietary iodine (I) and selenium (Se) supplementation on nutrient digestibility, serum thyroid hormones, and antioxidant status during the cashmere telogen period to learn more about the effects of dietary I and Se on nutrition or health status of Cashmere goats. The goats were equally divided into six groups of eight animals each that were treated with 0, 2, or 4 mg of supplemental I/kg dry matter (DM) and 0 or 1 mg of supplemental Se/kg DM in a 2 × 3 factorial arrangement of treatments. The six treatments were I(0)Se(0), I(2)Se(0), I(4)Se(0), I(0)Se(1), I(2)Se(1), and I(4)Se(1). The concentrations of I and Se in the basal diet were 0.67 and 0.09 mg/kg DM, respectively. The study started in March and proceeded for 45 days. Supplemental I or Se alone had no effect on nutrient digestibility and nitrogen metabolism. However, the interaction between I and Se was significant regarding the digestibility of acid detergent fiber (ADF; P < 0.05), and compared with group I(4)Se(1), the digestibility of ADF was significantly increased in group I(4)Se(0) (P < 0.05). Selenium supplementation did not affect serum triiodothyronine (T(3)) or thyroxine (T(4)) concentrations. However, the concentration of serum T(4) but not that of T(3) was significantly increased with I supplementation (P < 0.05). In addition, serum superoxide dismutase (SOD) activity was not affected (P > 0.05), but serum glutathione peroxidase (GSH-Px) activity was significantly decreased by I supplementation (P < 0.05). The antioxidant status was improved by Se supplementation, and the activities of SOD and GSH-Px were significantly increased (P < 0.05).

Selenomethionine: an effective selenium source for sow to improve Se distribution, antioxidant status, and growth performance of pig offspring

The present study was to investigate the efficiency of maternal selenomethionine intake on growth performance, Se distribution, and antioxidant status of pig offspring by comparing with sodium selenite. A total of 12 sows (Landrace × Yorkshire) with same pregnancy were randomly divided into two groups; each group was replicated six times. These two groups received the same basal gestation and lactation diets containing 0.04 mg Se/kg, supplemented with 0.3 mg Se/kg sodium selenite and selenomethionine (i.e., seneno-DL: -methylseleno), respectively. The feeding trial lasted for 60 days, with 32 and 28 days for gestation and lactation period, respectively. Compared with sodium selenite, maternal selenomethionine intake significantly (p < 0.05) increased the daily weight gain of piglet from birth to weaning. The Se concentration in the colostrum and milk and tissue Se content of piglets were significantly higher (p < 0.05) in the selenomethionine-treated group. The antioxidant status was greatly improved in piglets of selenomethionine-treated group and was illuminated by the increased total antioxidant capability, glutathione peroxidase, superoxide dismutase, and glutathione, and decreased the malondialdehyde level in the organs of piglets. The increased (p < 0.05) triiodothyronine (T(3)) and decreased (p < 0.05) thyroxine (T(4)) concentration indicated the improved protein synthesis and energy production in the selenomethionine-treated group. The increased (p < 0.05) pancreatic digestive enzymes of protease, amylase, and lipase activities indicated that maternal selenomethionine intake may have a positive effect on the degradation and absorption of nutrients in its piglets. In summary, we concluded that maternal selenomethionine intake increased Se deposition, antioxidant status, and nutrient use efficiency, thus providing an effective way to improve the growth performance of piglets from birth to weaning.