The importance of selenium and the effects of its deficiency in animal health

Studies of a Naturally Occurring Selenium-Induced Microcytic Anemia in the Przewalski's Gazelle

Due to the fencing of the Przewalski's gazelle (Procapra przewalskii), the microcytic anemia incidence rate continues to increase. The primary pathological symptoms include emaciation, anemia, pica, inappetence, and dyskinesia. To investigate the cause of microcytic anemia ailment in the Przewalski's gazelle, the Upper Buha River Area with an excessive incidence was chosen as the experimental pasture, and the Bird Island Area without microcytic anemia disease was chosen as the control field. Then, the mineral contents in the soil, forage, blood, and liver, as well as the blood routine parameters and biochemical indexes were measured. The findings showed that the experimental pasture had much lower Se content in the soil and forage than the control field (p < 0.01), while the impacted pasture had significantly higher S content in the forage. The damaged gazelles had considerably lower Se and Cu contents and higher S content in the blood and liver than the healthy gazelles (p < 0.01). The presences of Hb, HCT, MCV, and MCH were significantly decreased compared to those in healthy gazelles (p < 0.01). The experimental group had a significantly lower level of GSH-Px activity in their serums compared to the control group (p < 0.01). In the treatment experiment, ten gazelles from the affected pasture were orally administered CuSO4, 6 g/animal once every 10 days for two consecutive times, and all gazelles were successfully cured. Therefore, it is possible that low Se content in the soil induced an increase in the absorption of S content by forage, leading to the deficiency of secondary Cu in the Przewalski's gazelles, resulting in microcytic anemia.

The effect of selenium on the proliferation of bovine endometrial epithelial cells in a lipopolysaccharide-induced damage model

BACKGROUND

Endometritis is a common bovine postpartum disease. Rapid endometrial repair is beneficial for forming natural defense barriers and lets cows enter the next breeding cycle as soon as possible. Selenium (Se) is an essential trace element closely related to growth and development in animals. This study aims to observe the effect of Se on the proliferation of bovine endometrial epithelial cells (BEECs) induced by lipopolysaccharide (LPS) and to elucidate the possible underlying mechanism.

RESULTS

In this study, we developed a BEECs damage model using LPS. Flow cytometry, cell scratch test and EdU proliferation assay were used to evaluate the cell cycle, migration and proliferation. The mRNA transcriptions of growth factors were detected by quantitative reverse transcription-polymerase chain reaction. The activation of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) and Wnt/β-catenin pathways were detected by Western blotting and immunofluorescence. The results showed that the cell viability and BCL-2/BAX protein ratio were significantly decreased, and the cell apoptosis rate was significantly increased in the LPS group. Compared with the LPS group, Se promoted cell cycle progression, increased cell migration and proliferation, and significantly increased the gene expressions of TGFB1, TGFB3 and VEGFA. Se decreased the BCL-2/BAX protein ratio, promoted β-catenin translocation from the cytoplasm to the nucleus and activated the Wnt/β-catenin and PI3K/AKT signaling pathways inhibited by LPS.

CONCLUSIONS

In conclusion, Se can attenuate LPS-induced damage to BEECs and promote cell proliferation and migration in vitro by enhancing growth factors gene expression and activating the PI3K/AKT and Wnt/β-catenin signaling pathways.

Effects of sodium selenite, cysteamine, bacterially synthesized Se-NPs, and cysteamine loaded on Se-NPs on ram sperm cryopreservation

During the cryopreservation of sperm, the production of highly reactive oxygen species (ROS) can reduce their viability and fertility. However, the addition of antioxidants can help reduce the harmful effects of ROS. One such antioxidant is selenium, which is a co-factor of the glutathione peroxidase enzyme that is effective in scavenging ROS. Cysteamine can also take part in the structure of this enzyme. The use of nanoparticles can be less toxic to cells than their salt form. To this end, researchers synthesized Se-NPs using the streptococcus bacteria and loaded cysteamine onto the synthesized Se-NPs. The biosynthesis of Se-NPs and cysteamine loaded on Se-NPs was confirmed by UV-visible spectroscopy, X-ray diffraction (EDX), Fourier transforms infrared (FTIR) spectroscopy, and Field Emission Scanning Electron Microscope (FE-SEM). For cryopreservation, ram semen samples were diluted, and different concentrations (0, 1, 5, 25, and 125 µg/mL) of cysteamine, Se-NPs, cysteamine loaded on Se-NPs, and sodium selenite were added. An extender containing no supplement was considered as control group. After cooling the semen samples, they were frozen and stored in liquid nitrogen for evaluation. The samples were thawed and analyzed for mobility, viability, membrane and DNA integrity, and sperm abnormalities, as well as malondialdehyde level (MDA) and superoxide dismutase (SOD). The data was processed using SPSS, and a significance level of p < 0.05 was considered. The results of this experiment showed that adding 1 μg/mL of cysteamine loaded on Se-NPs to the diluent significantly increased the motility, viability, and membrane integrity and SOD of spermatozoa compared to the other treatment groups and control group, and reduced the abnormality, apoptosis, and MDA level of spermatozoa in comparison with the other treatment groups and control group (p < 0.05). In conclusion, the addition of cysteamine loaded on Se-NPs was found to improve the quality of ram sperm after cryopreservation.

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.

Accidental monensin poisoning in goats

Sodium monensin is the most frequently used ionophore as a growth promoter in ruminant diets. It has numerous benefits; however its toxic effects have also been observed in several animal species. Naturally occurring cases have not yet been reported in goats. This study describes an outbreak of accidental poisoning, characterizing its clinical, laboratory and pathological findings. Thirty-seven of 40 Anglo Nubian goat kids became intoxicated after receiving a diet that was erroneously supplemented with sodium monensin. They ingested an estimated toxic dose between 25 and 39 mg/kg BW. Clinical evolution was monitored (n = 27), followed by serum creatine kinase (CK) and aspartate aminotransferase (AST) activities measurements, and blood gas analysis. Postmortem examinations were performed between 1 and 8 days of evolution (n = 14). Clinical signs began 5 h after ingestion and included reticuloruminal hypomotility, lethargy, anorexia, tachycardia, cardiac arrhythmia, wet cough, pulmonary and tracheal crackles, and serous nasal discharge. The morbidity and lethality rates were 92.5 and 62.1%, respectively. CK and AST activities increased, reaching median values of 10,860 and 1596 U/L, respectively; the hyperchloremic metabolic acidosis was mild. The lesions were characterized by degeneration and necrosis of the cardiac and skeletal muscles, pulmonary congestion and edema, and passive liver congestion. The kids essentially developed cardiomyopathy with left and right congestive heart failures. Unlike in other ruminant species, skeletal muscle functional disability was infrequent. It can be concluded that monensin is toxic to goats and should be used with caution in their diet.

Systematic Analysis of Genes Related to Selenium Bioaccumulation in Microalgae: A Review

Se is one of the essential nutrients for human health and animal growth; it participates in various physiological functions, such as antioxidant and immune response and metabolism. Se deficiency is related in the animal industry to poor production performance and the appearance of health problems in humans. Therefore, interest has arisen in producing fortified foods, nutritional supplements, and animal feed products enriched with Se. A sustainable strategy for bio-based products enriched with Se is microalgae. These are characterized by the ability to bioaccumulate inorganic Se and metabolize it into organic Se for product formulations of industrial interest. Although there are some reports on Se bioaccumulation, further exploration is needed to understand the effects of Se bioaccumulation in microalgae. Therefore, this article presents a systematic review of the genes or groups of genes that trigger biological responses associated with the metabolization of Se in microalgae. A total of 54,541 genes related to Se metabolization distributed in 160 different classes were found. Similarly, trends were identified through bibliometric networks on strains of greatest interest, bioproducts, and scientific production.

Copper chloride and copper sulphate in combination with nitroxynil against gastrointestinal nematodes of ruminants: A possible hitchhiking synergic effect at low concentrations

Infections caused by Haemonchus spp. and Trichostrongylus spp. are major health problems for sheep and cattle. The objective of this study was to determine the efficacy of copper chloride (CuCl₂), and copper sulphate (CuSO₄) at 2.0, 7.0, 30.0, 125.0, 500.0, and 2000.0 µM formulations, and nitroxynil 34% (NTX) at 0.235 mM against gastrointestinal nematodes (GINs) of ruminants. Hence, the in vitro egg hatch test (EHT), the larval development test (LDT), and the larval migration inhibition test (LMIT) were used. Haemonchus spp. (52%) and Trichostrongylus spp. (38%) were the most frequently found parasites. The data fitted a concentration-dependent shape with the highest efficacies of CuCl₂ and CuSO₄ at 95.2 and 97.3% for parasites collected from sheep, and 95.8 and 93.4% from cattle, respectively. The combination of the 50% inhibitory concentration (IC₅₀) of CuCl₂ and CuSO₄ and the IC₁₀ of NTX showed up to a 52% increase in efficacy above the expected additive results, demonstrating a synergic/drug enhancer interaction. NTX may retain Cu-II ions by complexation, in a hitchhiking mechanism carrying the salts across the parasite cell wall, causing oxidative stress as a consequence of free radical production and cell damage. Synergy data between NTX and CuCl₂, and CuSO₄ represent a viable opportunity to develop new formulations for combating parasites of ruminants (i.e., Fasciola hepatica, Haemonchus spp., and Oesophagostomum spp.).

The uptake of selenium by perennial ryegrass in soils of different organic matter contents receiving sheep excreta

Background and aims

The intake of selenium, an essential element for animals and humans, in ruminants is largely determined by selenium concentration in ingested forages, which take up selenium mainly from soil. Ruminant excreta is a common source of organic fertilizer, which provides both nutrients and organic matter. This study aims to unentangle the unclear effect of applying different types of ruminant excreta in soils of different organic matter contents on selenium uptake by forage.

Methods

Perennial ryegrass (Lolium perenne) was grown in soils of different organic matter contents. Urine and/or feces collected from sheep fed with organic or inorganic mineral supplements, including selenium, were applied to the soils. The selenium in the collected samples were analyzed using ICP-MS. The associated biogeochemical reactions were scrutinized by wet chemistry.

Results

The application of urine and/or feces resulted in either the same or lower selenium concentrations in perennial ryegrass. The excreta type did not affect total selenium accumulation in grass grown in low organic matter soil, whereas in high organic matter soil, feces resulted in significantly lower total selenium accumulation than urine, which was attributed to a possible interaction of selenium sorption in soil and microbial reduction of Se.

Conclusion

This one-time excreta application did not increase, but further decrease in some treatments, selenium concentration and accumulation in the perennial ryegrass. Consequently, to increase ruminant selenium intake, supplementing selenium directly to animals is more recommended than applying animal manure to soil, which might drive selenium reduction and decrease selenium uptake by grass.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11104-023-05898-8.

Relationship between selenium status, selenoproteins and COVID-19 and other inflammatory diseases: A critical review

The antioxidant effects of selenium as a component of selenoproteins has been thought to modulate host immunity and viral pathogenesis. Accordingly, the association of low dietary selenium status with inflammatory and immunodeficiency has been reported in the literature; however, the causal role of selenium deficiency in chronic inflammatory diseases and viral infection is still undefined. The COVID-19, characterized by acute respiratory syndrome and caused by the novel coronavirus 2, SARS-CoV-2, has infected millions of individuals worldwide since late 2019. The severity and mortality from COVID-19 have been associated with several factor, including age, sex and selenium deficiency. However, available data on selenium status and COVID-19 are limited, and a possible causative role for selenium deficiency in COVID-19 severity has yet to be fully addressed. In this context, we review the relationship between selenium, selenoproteins, COVID-19, immune and inflammatory responses, viral infection, and aging. Regardless of the role of selenium in immune and inflammatory responses, we emphasize that selenium supplementation should be indicated after a selenium deficiency be detected, particularly, in view of the critical role played by selenoproteins in human health. In addition, the levels of selenium should be monitored after the start of supplementation and discontinued as soon as normal levels are reached. Periodic assessment of selenium levels after supplementation is a critical issue to avoid over production of toxic metabolites of selenide because under normal conditions, selenoproteins attain saturated expression levels that limits their potential deleterious metabolic effects.

Effects of organic and inorganic selenium on selenium bioavailability, growth performance, antioxidant status and meat quality of a local beef cattle in China

Selenium (Se) is an essential nutrient with multiple health benefits to humans and animals. Cattle generally require dietary Se supplementation to meet their daily requirements. The two main forms of dietary Se in cattle are organic Se and inorganic Se. Data comparing the health and productivity effects of organic Se and inorganic Se on cattle are still insufficient, and it is necessary to conduct more research to evaluate the bioavailability, nutritional value, deposition, and body functions of Se sources in different breeds and physiological stages of cattle raised in areas with different Se levels. The objectives of this study were to determine the effects of organic and inorganic sources of Se on plasma biochemical indices, Se bioavailability, deposition in body tissues and organs, growth performance, antioxidant capacity and meat quality of beef cattle raised in Se-deficient areas. Fifteen Chinese Xiangzhong Black beef cattle with an average weight of 254.5 ± 8.85 kg were assigned to three dietary groups. The three groups were fed the same basal ration and supplemented with either an inorganic [sodium selenite (SS)] or organic [selenomethionine (SM) or Se-enriched yeast (SY)] source of Se (0.1 mg/kg dry matter) for 60 days. At the end of the experiment, three cattle from each group were randomly selected and slaughtered, and samples were collected from tissues and organs for analysis. The results revealed that growth performance, slaughter performance, Se content of tissues and organs, meat quality characteristics including chemical composition, pH_45min, pH_24h, drip loss, and cooking losses did not differ (p > 0.05) due to supplementation of the different organic and inorganic sources of Se. SM and SY were more effective in increasing (p < 0.05) immunoglobulin M (IgM) concentrations in the blood and reducing (p < 0.05) malondialdehyde (MDA) content in the longissimus dorsi than SS. In conclusion, organic Se is more effective than inorganic Se in improving the immune and antioxidant capacity of Chinese Xiangzhong Black beef cattle.

Plasma and Colostrum Selenium Statuses of Properly Supplemented Belgian Blue Cows on Commercial Farms and Their Relationship with Sources of Dietary Selenium and Blood Biomarkers

Selenium (Se) is an essential trace element for the health and immunity of cattle. Double-muscled Belgian Blue cows are well known to be prone to nutritional deficiencies. Colostrum Se level is also a key factor to promote immunoglobulin intake in young calves. The main objectives of this study were to assess (1) the plasma and colostrum Se statuses of properly supplemented Belgian Blue cows on commercial farms and (2) the relationship between Se concentrations in plasma and colostrum. The secondary objectives were to assess relationships between plasma or colostrum Se concentrations and dietary Se supplementation as well as blood biomarkers. Blood and colostrum samples were collected from 49 Belgian Blue cows on five commercial farms in Belgium. They received five different rations with Se supplementation ranging from 0.5 to 2 ppm, including 20% to 83% in organic form. Results showed that the average Se concentration was 90 ± 15 µg/L in plasma and 79 ± 26 µg/L in colostrum, consistent with previous studies on well-supplemented cows. No relationship was observed between Se concentrations in plasma and colostrum, suggesting that colostrum Se testing would be a complementary indicator for improving calf Se supplementation. Relationships between plasma or colostrum Se concentrations and dietary Se or blood biomarkers emphasized the complexity of Se metabolism in observational studies under field conditions.

The importance and status of the micronutrient selenium in South Africa: a review

Selenium (Se) is a vital micronutrient with widespread biological action but leads to toxicity when taken in excessive amounts. The biological benefits of Se are mainly derived from its presence in active sites of selenoproteins such as glutathione peroxidase (GPx). An enzyme whose role is to protect tissues against oxidative stress by catalysing the reduction of peroxidase responsible for various forms of cellular damage. The benefits of Se can be harvested when proper regulations of its intake are used. In South Africa, Se distribution in people's diets and animals are low with socio-economic factors and heterogeneous spread of Se in soil throughout the country playing a significant role. The possible causes of low Se in soils may be influenced by underlying geological material, climatic conditions, and anthropogenic activities. Sedimentary rock formations show higher Se concentrations compared to igneous and metamorphic rock formations. Higher Se concentrations in soils dominates in humid and sub-humid areas of South Africa. Furthermore, atmospheric acid deposition dramatically influences the availability of Se to plants. The studies reviewed in this article have shown that atomic absorption spectroscopy (AAS) is the most utilised analytical technique for total Se concentration determination in environmental samples and there is a lack of speciation data for Se concentrations. Shortcomings in Se studies have been identified, and the future research directions of Se in South Africa have been discussed.

Supplemental dietary Selenohomolanthionine affects growth and rumen bacterial population of Shaanbei white cashmere wether goats

Selenium (Se) is an important trace element for all livestock growth. However, little is known about the dietary supplementation of Selenohomolanthionine (SeHLan) effect on growth and rumen microbiota of cashmere goats. In this study, thirty-two growing Shaanbei white cashmere wether goats with mean body weight (26.18 ± 2.71) kg were randomly assigned into 4 treatments, each with 8 replicates. The goats in 4 experimental groups were fed the basal diet (0.016 mg/kg Se) added with organic Se in the form of SeHLan, namely, control group (CG, added 0 mg/kg Se), low Se group (LSE, added 0.3 mg/kg Se), medium Se group (MSE, added 0.6 mg/kg Se), and high Se group (HSE, added 1.2 mg/kg Se). The feed experiment lasted for 70 days including 10-day adaptation, followed by 11 days digestibility trial including 7-day adaptation and 4-day collection period. On the last day of feeding experiment, rumen fluid was collected for microbial community analysis. The feed, orts, and fecal samples were collected for chemical analysis during digestibility trial. The results showed that average daily feed intake (ADFI) and the apparent digestibility of crude protein (CP) were both quadratic ally increased with increased SeHLan supply (P_quadratic < 0.05), while average daily gain (ADG) and feed conversion ratio (FCR) showed a linear response (P_linear < 0.05). The ADFI and ADG were all highest in the MSE group, which also had the lowest FCR (P < 0.05). Alpha diversity indices of the microbial community did not differ among four treatments. While principal coordinates analysis (PCoA) showed that rumen bacterial population differed among four groups. Taxonomic analysis revealed that Bacteroidetes, Firmicutes, and Euryarchaeota were the dominant phyla. The dominant families were Prevotellaceae, Selenomonadaceae, Methanobacteriaceae, and Bifidobacteriaceae. The significantly different rumen bacterial genera were found to be Methanobrevibacter, Quinella, Christensenellaceae_R-7_group, Veillonellaceae_UCG-001, and Succinivibrionaceae_UCG-002 (P < 0.05). In addition, Tax4fun analysis revealed that SeHLan supplemented groups enhanced the enrichment of genes related to energy metabolism, amino acid metabolism, carbohydrate metabolism, and enzymes. Twenty-eight pathways showed significant differences among four treatment groups (P < 0.05). In conclusion, dietary supplementation of medium SeHLan significantly affects rumen bacterial composition and ultimately promotes Shaanbei white cashmere wether goats nutrient digestibility and growth.

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.

Effect of Supplementation with the Combination of Se-Enriched Lentinula edodes Mycelium, Exogenous Enzymes, Acidifiers, Sodium Butyrate and Silicon Dioxide Nanoparticle Feed Additives on Selected Parameters in Calves

During the initial months of calves’ lives, the young animals are exposed to bacterial and viral infections, and during this period, crucial physiological changes take place in their organisms. Offering calves feed additives that will have a beneficial influence on their organisms and improve their growth while reducing the morbidity rate is the optimal task of feeding. This is the first study to investigate the effect of experimental supplementation for calves with the combination of two feed additives—one containing Lentinula edodes enriched with selenium (Se), and the second containing pancreatic-like enzymes, fat-coated organic acids, sodium butyrate, and silicon dioxide nanoparticles—on the serum Se concentration, selected immune parameters, and the average daily gains in the calves. During the study, the serum Se concentration was examined by means of inductively coupled plasma mass spectrometry, and the immunoglobulin and cytokine concentrations with ELISA assays. The white blood cell (WBC) count with leukocyte differentiation was examined with the use of a hematological analyzer, and the percentages of subpopulations of T lymphocytes and monocytes, phagocytic activity, and oxidative burst of monocytes and granulocytes with the use of a flow cytometer. The average daily gains of the calves were also evaluated. In summary, the supplementation of the experimental calves with the combination of two feed additives resulted in significantly higher serum Se concentrations, and the immune systems of the calves were not suppressed while the examined feed additives were being delivered. Although not statistically significant, some positive effects on the calves were seen: a tendency towards the improvement of some of the immune parameters evaluated, and a tendency for higher average daily gains in the calves.

Effects of Se-Enriched Malt on the Immune and Antioxidant Function in the Se-Deprived Reclamation Merino Sheep in Southern Xinjiang

We have found that the Reclamation merino sheep in Southern Xinjiang, China, showed emaciation, stiff limbs, instability, and sudden death, which is related to the impairment of immune function and antioxidant capacity caused by selenium (Se) deficiency. The experiments were to study the effects of Se-enriched malt on the immune and antioxidant function in Se-deprived Reclamation merino sheep in Southern Xinjiang, China. The samples of soil and forage had been collected from tested pastures, and animal tissues were also collected in tested animals. The mineral content of soil, forage, and animal tissues was measured in the collected samples. Hematological indexes and biochemical values were also examined. The findings showed that the Se contents were extremely lower in affected soil and forage than those from healthy soil and forage (P < 0.01). The Se contents in affected blood and wool were also extremely lower than those from healthy blood and wool (P < 0.01). The values in glutathione peroxidase and total antioxidant capacity in affected serum samples were also extremely lower than those from healthy serum samples, and levels of malondialdehyde, total nitric oxide synthase, and lipid peroxide were extremely higher in affected serum samples than those from healthy serum samples (P < 0.01). Meanwhile, the values of hemoglobin, packed cell volume, and platelet count from affected blood were extremely lower than those from healthy blood (P < 0.01). The levels of interleukin (IL)-1β, IL-2, tumor necrosis factor-alpha, immunoglobulin A, and immunoglobulin G in serum were extremely decreased in the affected Reclamation merino sheep (P < 0.01). The levels of IL-6 and immunoglobulin M in serum were extremely reduced in the affected Reclamation merino sheep compared to healthy animals (P < 0.01). The animals in affected pastures were orally treated with Se-enriched malt, and the Se contents in blood were extremely increased (P < 0.01). The immune function and antioxidant indicator returned to within the healthy range. Consequently, our findings were indicated that the disorder of the Reclamation merino sheep was mainly caused by the Se deficiency in soil and forage. The Se-enriched malt could not only markedly increase the Se content in blood but also much improve the immune function and the antioxidant capacity in the Se-deprived Reclamation merino sheep.

The use of artemia for aquaculture industry: An updated overview

The increasing global population tends many sectors to overcome the food security issue; sustainable aquaculture is one of the systems that reveal the food problem in the world. The aquaculture industry is drastically increasing to offer the growing demand for this food type. The high mortalities threaten this sector during the first larval stages because of the low supplies of suitable feed for the fish larva. Artemia is vital for the aquaculture industry as it is the primary feed source for fish larvae; it is distinguished by its small size, food carrier characteristic, and off-the-shelf food feature. However, the principal source of artemia cysts has been affected by climate change, ultimately affecting artemia cyst production. Consequently, many areas worldwide try to produce artemia locally to satisfy the aquaculture rearing requirements. As a feed transmitter, artemia can be enriched with essential elements to feed the fish larvae; this method increases survivability, growth performance, and other growth indicators for many fish species. This review aimed to update the academia and stakeholders involved in artemia production in relation to the aquaculture industry. An updated overview of artemia production is also presented in the current review.

The health benefits of selenium in food animals: a review

Selenium is an essential trace mineral important for the maintenance of homeostasis in animals and humans. It evinces a strong antioxidant, anti-inflammatory and potential antimicrobial capacity. Selenium biological function is primarily achieved by its presence in selenoproteins as a form of selenocysteine. Selenium deficiency may result in an array of health disorders, affecting many organs and systems; to prevent this, dietary supplementation, mainly in the forms of organic (i.e., selenomethionine and selenocysteine) inorganic (i.e., selenate and selenite) sources is used. In pigs as well as other food animals, dietary selenium supplementation has been used for improving growth performance, immune function, and meat quality. A substantial body of knowledge demonstrates that dietary selenium supplementation is positively associated with overall animal health especially due to its immunomodulatory activity and protection from oxidative damage. Selenium also possesses potential antiviral activity and this is achieved by protecting immune cells against oxidative damage and decreasing viral replication. In this review we endeavor to combine established and novel knowledge on the beneficial effects of dietary selenium supplementation, its antioxidant and immunomodulatory actions, and the putative antimicrobial effect thereof. Furthermore, our review demonstrates the gaps in knowledge pertaining to the use of selenium as an antiviral, underscoring the need for further in vivo and in vitro studies, particularly in pigs.

Heat Stress: Effects on Rumen Microbes and Host Physiology, and Strategies to Alleviate the Negative Impacts on Lactating Dairy Cows

Heat stress (HS) in dairy cows causes considerable losses in the dairy industry worldwide due to reduced animal performance, increased cases of metabolic disorders, altered rumen microbiome, and other health problems. Cows subjected to HS showed decreased ruminal pH and acetate concentration and an increased concentration of ruminal lactate. Heat-stressed cows have an increased abundance of lactate-producing bacteria such as Streptococcus and unclassified Enterobacteriaceae, and soluble carbohydrate utilizers such as Ruminobacter, Treponema, and unclassified Bacteroidaceae. Cellulolytic bacteria, especially Fibrobacteres, increase during HS due to a high heat resistance. Actinobacteria and Acetobacter, both acetate-producing bacteria, decreased under HS conditions. Rumen fermentation functions, blood parameters, and metabolites are also affected by the physiological responses of the animal during HS. Isoleucine, methionine, myo-inositol, lactate, tryptophan, tyrosine, 1,5-anhydro-D-sorbitol, 3-phenylpropionic acid, urea, and valine decreased under these conditions. These responses affect feed consumption and production efficiency in milk yield, growth rate, and reproduction. At the cellular level, activation of heat shock transcription factor (HSF) (located throughout the nucleus and the cytoplasm) and increased expression of heat shock proteins (HSPs) are the usual responses to cope with homeostasis. HSP70 is the most abundant HSP family responsible for the environmental stress response, while HSF1 is essential for increasing cell temperature. The expression of bovine lymphocyte antigen and histocompatibility complex class II (DRB3) is downregulated during HS, while HSP90 beta I and HSP70 1A are upregulated. HS increases the expression of the cytosolic arginine sensor for mTORC1 subunits 1 and 2, phosphorylation of mammalian target of rapamycin and decreases the phosphorylation of Janus kinase-2 (a signal transducer and activator of transcription factor-5). These changes in physiology, metabolism, and microbiomes in heat-stressed dairy cows require urgent alleviation strategies. Establishing control measures to combat HS can be facilitated by elucidating mechanisms, including proper HS assessment, access to cooling facilities, special feeding and care, efficient water systems, and supplementation with vitamins, minerals, plant extracts, and probiotics. Understanding the relationship between HS and the rumen microbiome could contribute to the development of manipulation strategies to alleviate the influence of HS. This review comprehensively elaborates on the impact of HS in dairy cows and introduces different alleviation strategies to minimize HS.

Gastrointestinal nematodes and mineral deficiencies in yearling cattle in Santiago del Estero, northern Argentina

The aims were to study the epidemiology and the effect of gastrointestinal nematodes (GINs) on yearling cattle in a semiarid region in Argentina and to evaluate the mineral serum levels. Ten- to twelve-month-old calves were monitored between November and April 2019. Animals were divided into three groups: untreated control (CONG; n = 20); group treated with moxidectin (MXD, 200 µg/kg) every 30-40 days (MXDG; n = 20); group equally MXD treated and mineral supplementation administered in November and January (MMG; n = 20). Individual GIN egg counts (epg) and fecal cultures were made every 30-40 days. Animal live weight gain was determined. On 7-11-18, 25-1-19, and 3-4-19, serum levels of Se, Cu, Zn, Mg, and Ca were determined by atom absorption spectrophotometry. At the start of the trial, epg values were low (x̄ = 5.5), which increased only in CONG towards the end of the assay (x̄ = 229). In both GMXD and MMG, epg remained very low (x̄ = 4.1). Cooperia spp. (81%) prevailed over Haemonchus spp. (9%) and Oesophagostomum spp. (9%). Deficiency of Se ranged between marginal and important, except for MMG, although mean values were always below normal. Cu was marginally deficient in CONG and MXDG on the first two sampling dates, whereas MMG had normal values after treatment. Mg had low values in the three groups (x̄ = 1.5 mg/dl), whereas Ca and Zn exhibited normal values. Live weight gain (LWG) was higher in MMG than in MXDG, with significant differences (p < 0.05) by mid-January and then, when epg increased, dewormed groups showed higher LWG (p < 0.034) than CONG. A negative effect of GINs on LWG was observed, as well as low to marginal levels of Se, Cu, and Mg.

Effects of dietary supplementation with organic selenium-enriched yeast on growth performance, carcass characteristics, and meat quality of finishing lambs

This study was aimed to assess the impact-enriched Saccharomyces cerevisiae with organic selenium addition in finishing lambs on fatty acid composition and physicochemical meat characteristics. Eighteen five-month-old Pelibuey female lambs were fed the same diet for 60 days. Animals were assigned a completely random design of three treatments, control (Se0) without the addition of selenium-yeast or supplemented with 0.35 ppm of selenium-yeast (Se35) and with 0.60 ppm of selenium-yeast (Se60). Lambs were slaughtered at an average weight of 39.5 ± 4.41 kg. Feed intake and meat water holding capacity were decreased (P = 0.001) in Se35 lambs, whereas meat moisture and fat were decreased (P = 0.002) in Se60 lambs. However, meat carbohydrates were increased (P = 0.001) in Se60 lambs. It is concluded that consumption of selenium-yeast in lambs did not alter the productive variables nor the fatty acid composition, though, the fat content is lower, and the carbohydrates are higher in physicochemical meat characteristics.

Calcium overload and reactive oxygen species accumulation induced by selenium deficiency promote autophagy in swine small intestine

Selenium (Se) deficiency can seriously affect the small intestine of swine, and cause diarrhea in swine. However, the specific mechanism of Se deficiency-induced swine diarrhea has rarely been reported. Here, to explore the damage of Se deficiency on the calcium homeostasis and autophagy mechanism of swine, in vivo and in vitro models of swine intestinal Se deficiency were established. Twenty-four pure line castrated male Yorkshire pigs (45 d old, 12.50 ± 1.32 kg, 12 full-sibling pairs) were divided into 2 equal groups and fed Se-deficient diet (0.007 mg Se/kg) as the Se-deficiency group, or fed Se-adequate diet (0.3 mg Se/kg) as the control group for 16 weeks. The intestinal porcine enterocyte cell line (IPEC-J2) was divided into 2 groups, and cultured by Se-deficient medium as the Se-deficient group, or cultured by normal medium as the control group. Morphological observations showed that compared with the control group, intestinal cells in the Se-deficiency group were significantly damaged, and autophagosomes increased. Autophagy staining and cytoplasmic calcium staining results showed that in the Se-deficiency group, autophagy increased and calcium homeostasis was destroyed. According to the reactive oxygen species (ROS) staining results, the percentage of ROS in the Se-deficiency group was higher than that in the control group in the in vitro model. Compared with the control group, the protein and mRNA expressions of autophagy-calcium-related genes including Beclin 1, microtubule-associated proteins 1A (LC3-1), microtubule-associated proteins 1B (LC3-2), autophagy-related protein 5 (ATG5), autophagy-related protein 12 (ATG12), autophagy-related protein 16 (ATG16), mammalian target of rapamycin (mTOR), calmodulin-dependent protein kinase kinase β (CAMKK-β), adenosine 5′-monophosphate-activated protein kinase (AMPK), sarco(endo)plasmic reticulum Ca²⁺-ATPase (SERCA), and calpain in the Se-deficiency group were significantly increased which was consistent in vivo and in vitro (P < 0.05). Altogether, our results indicated that Se deficiency could destroy the calcium homeostasis of the swine small intestine to trigger cell autophagy and oxidative stress, which was helpful to explain the mechanism of Se deficiency-induced diarrhea in swine.

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.

Biogenic Selenium Nanoparticles: Potential Solution to Oxidative Stress Mediated Inflammation in Rheumatoid Arthritis and Associated Complications

Rheumatoid arthritis (RA) is a common chronic inflammation-mediated disorder having systematic complications. RA triggers a self-directed inflammatory and immunological cascade that culminates in joint destruction. Though a range of treatment options are available, none of them are without adverse effects and this has led researchers to search for alternative solutions. Nanomedicine has emerged as a powerful therapeutic alternative, and selenium (Se) is an essential micronutrient trace element that has a crucial role in human health and disease. Selenium nanoparticles (SeNPs) derived from biological sources, such as plants, bacteria, fungi, and proteins, have exhibited remarkable candidate properties and toxicological profiles, and hence have shown potential to be used as antirheumatic agents. The potential of SeNPs can be attributed to the effect of functional groups bound to them, concentration, and most importantly to their nano range size. The antirheumatic effect of SeNPs is considerable due to its potential in amelioration of oxidative stress-mediated inflammation via downregulation of radical and nonradical species, markers of inflammation, and upregulation of inherent antioxidant defenses. The size and concentration impact of SeNPs has been shown in the subsequent antioxidant and anti-inflammatory properties. Moreover, the article emphasizes the role of these biogenic SeNPs as a notable option in the nanomedicine arena that needs to be further studied as a prospective remedial alternative to cure RA and medication-related adverse events.

Impacts of heat stress on immune responses and oxidative stress in farm animals and nutritional strategies for amelioration

Heat stress is one of the greatest challenges for the global livestock industries as increased environmental temperature and humidity compromises animal production during summer leading to devastating economic consequences. Over the last 30 years, significant developments have been achieved in cooling and provision of shade and shelter to mitigate heat stress reducing some of the losses associated with heat stress in farm animals. However, the recent increase in the incidence of heat waves which are also becoming more severe and lasting longer, due to climate change, further accentuates the problem of heat stress. Economic losses associated with heat stress are both direct due to loss in production and animal life, and indirect due to poorer quality products as a result of poor animal health and welfare. Animal health is affected due to impaired immune responses and increased reactive oxygen species production and/or deficiency of antioxidants during heat stress leading to an imbalance between oxidant and antioxidants and resultant oxidative stress. Research over the last 20 years has achieved partial success in understanding the intricacies of heat stress impacts on oxidative stress and immune responses and developing interventions to ameliorate impacts of heat stress, improving immune responses and farm animal health. This paper reviews the body of knowledge on heat stress impacts on immune response in farm animals. The impacts of heat stress on both cell-mediated and humoral immune responses have been discussed identifying the shift in immune response from cell-mediated towards humoral response, thereby weakening the immune status of the animal. Both species and breed differences have been identified as influencing how heat stress impacts the immune status of farm animals. In addition, crosstalk signaling between the immune system and oxidative stress has been considered and the role of antioxidants as potential nutritional strategies to mitigate heat stress has been discussed.

Uptake Dynamics of Ionic and Elemental Selenium Forms and Their Metabolism in Multiple-Harvested Alfalfa (Medicago sativa L.)

A pot experiment, under greenhouse conditions, was carried out aiming at investigating the agronomic biofortification of alfalfa (Medicago sativa L.) with Se and monitoring the Se uptake and accumulation dynamics within four consecutive harvests within the same growing season. Two ionic Se forms, i.e., sodium selenate (Se (VI)) and sodium selenite (Se (IV)), were applied once at a rate of 1, 10, and 50 mg kg−1 (added on Se basis), while 10 and 50 mg L−1 of a red elemental Se (red Se0) were used; all Se treatments were added as soil application. Application of Se (VI) at the rate of 50 mg kg−1 was toxic to alfalfa plants. The effect of Se forms on Se accumulation in alfalfa tissues, regardless of the applied Se concentration, follows: Se (VI) > Se (IV) > red Se0. The leaf, in general, possessed higher total Se content than the stem in all the treatments. The accumulation of Se in stem and leaf tissues showed a gradual decline between the harvests, especially for plants treated with either Se (VI) or Se (IV); however, the chemically synthesized red Se0 showed different results. The treatment of 10 mg kg−1 Se (VI) resulted in the highest total Se content in stem (202.5 and 98.0 µg g−1) and leaf (643.4 and 284.5 µg g−1) in the 1st and 2nd harvests, respectively. Similar tendency is reported for the Se (IV)-treated plants. Otherwise, the application of red Se0 resulted in a lower Se uptake; however, less fluctuation in total Se content between the four harvests was noticed compared to the ionic Se forms. The Se forms in stem and leaf of alfalfa extracted by water and subsequently by protease XIV enzyme were measured by strong anion exchange (SAX) HPLC-ICP-MS. The major Se forms in our samples were selenomethionine (SeMet) and Se (VI), while neither selenocysteine (SeCys) nor Se (IV) was detected. In water extract, however, Se (VI) was the major Se form, while SeMet was the predominant form in the enzyme extract. Yet, Se (VI) and SeMet contents declined within the harvests, except in stem of plants treated with 50 mg L−1 red Se0. The highest stem or leaf SeMet yield %, in all harvests, corresponded to the treatment of 50 mg L−1 red Se0. For instance, 63.6% (in stem) and 38.0% (in leaf) were calculated for SeMet yield % in the 4th harvest of plants treated with 50 mg L−1 red Se0. Our results provide information about uptake and accumulation dynamics of different ionic Se forms in case of multiple-harvested alfalfa, which, besides being a good model plant, is an important target plant species in green biorefining.

Effect of Selenium Sources on Laying Performance, Egg Quality Characteristics, Intestinal Morphology, Microbial Population and Digesta Volatile Fatty Acids in Laying Hens

The use of toxic and less bioavailable inorganic selenium can now be supplemented with an alternative organic source from bacterial species in nutrition for human and animal benefit. This study investigated the effects of selenium sources on laying performance, egg quality characteristics, intestinal morphology, caecum microbial population, and digesta volatile fatty acids in laying hens. One hundred and forty-four Lohman Brown Classic laying hens, at 23 weeks of age, were divided into four experimental groups (36 hens in each), differing in form of Se supplementation: no Se supplementation (Con), 0.3 mg/kg of inorganic Se in the form of sodium selenite (Na2SeO3), 0.3 mg/kg of organic Se from selenium yeast (Se-Yeast), and 0.3 mg/kg of organic Se from Stenotrophomonas maltophilia (bacterial organic Se, ADS18). The results showed that different dietary Se sources significantly affected laying rate, average egg weight, daily egg mass, feed conversion ratio (FCR), and live bodyweight (LBW) (p < 0.05). However, average daily feed intake and shell-less and broken eggs were unaffected (p > 0.05) among the treatment groups. The findings revealed that selenium sources had no (p > 0.05) effect on egg quality (external and internal) parameters. However, eggshell breaking strength and Haugh unit were significantly (p < 0.05) improved with organic (ADS18 or Se-yeast) Se-fed hens compared to the control group. In addition, egg yolk and breast tissue Se concentrations were higher (p < 0.05) in the dietary Se supplemented group compared to the control. Intestinal histomorphology revealed that hens fed ADS18 or Se-Yeast groups had significantly (p < 0.05) higher villi height in the duodenum and jejunum compared to those fed Na2SeO3 or a basal diet. However, when compared to organic Se fed (ADS18 or Se-Yeast) hens, the ileum villus height was higher (p < 0.05) in the basal diet group; with the lowest in the SS among the treatment groups. A significant increase (p < 0.05) of Lactobacilli spp. and Bifidobacteria spp., and a decrease of Escherichia coli and Salmonella spp. population were observed in the organic (ADS18 or Se-yeast) compared to inorganic supplemented and control hens. The individual digesta volatile fatty acid (VFA) was significantly different, but with no total VFA differences. Thus, bacterial selenoprotein or Se-yeast improved the performance index, egg quality characteristics, egg yolk and tissue Se contents, and intestinal villus height in laying hens. Moreover, caecum beneficial microbes increased with a decrease in the harmful microbe population and affected individual cecal volatile fatty acids without affecting the total VFA of the laying hens digesta.

Effect of Intense Exercise on Plasma Macrominerals and Trace Elements in Lidia Bulls

Minerals are inorganic substances present in all body tissues and fluids that directly or indirectly influence the maintenance of multiple metabolic processes and, therefore, are essential for the development of various biological functions. The Lidia bull breed may be considered an athlete, as during a bull fight it displays considerable physical effort of great intensity and short duration in a highly stressful situation. The objective of this study was to assess plasma minerals concentration (macro- and microminerals) in Lidia bulls after intense physical exercise during a bull fight. Plasma Ca, Mg, P, K, Na, Fe, Cr, Co, Ni, Cu, Zn, Se and Mo concentrations were measured in 438 male Lidia bulls. Ca, P and Mg were measured using a Cobas Integra autoanalyzer, while Na and K were determined by ICP-AES, and Fe, Cr, Co, Ni, Cu, Zn, Se and Mo were measured by ICP-MS. All macrominerals, (Ca: 2.96 ± 0.31, Mg: 1.27 ± 0.17, P: 3.78 ± 0.65, K: 7.50 ± 1.58, Na: 150.15 ± 19.59 in mmol/L), and Cr (1.24 ± 0.58), Ni (0.249 ± 1.07), Cu (22.63 ± 4.84) and Zn (24.14 ± 5.59, in μmol/L) showed greater mean values than the reported reference values in the published literature, while Co (0.041 ± 0.07), Se (0.886 ± 0.21) and Mo (0.111 ± 0.08, in μmol/L) values were lower than those reported for other bovine breeds. These increased concentrations could be justified mainly by muscle cell metabolism, hepatic need to provide energy, and intense dehydration and hemoconcentration by losses through sweat glands or urination.

Effects of canola oil and antioxidants on performance, serum parameters, carcass traits, and rumen fermentation patterns of Nellore cattle

Several nutritional strategies have been used in beef cattle production in order to increase animal performance and profitability. However, in the past two decades, the increase of consumer preference for functional foods has driven the investigation for improving food via adding functional substances to animal diets. We evaluated the effect of canola oil supplementation associated with vitamin E and selenium on performance, rumen metabolism, carcass traits, meat tenderness, and serum, liver, and meat status of antioxidants in finishing Nellore males. Animals were fed for 106 days in a feedlot and were randomly distributed in a 2 × 2 factorial arrangement: two levels of oil in the diet (no inclusion and 3% canola oil, defined as diet without oil inclusion (NO) and effect of oil (OIL), respectively) and two levels of antioxidants in the diet (no inclusion and 2.5 mg of Se/kg of DM + 500 UI of vitamin E/kg of DM, defined as diet without antioxidant inclusion (NA) and effect of the antioxidants (ANT), respectively). DM intake (kg/day) was evaluated daily; performance and serum were analysed at the beginning of the feedlot and every 28 days. Animals were slaughtered and hot carcass weight (kg) was recorded; ruminal fluid and liver samples were collected. At 24 h postmortem, carcass pH was recorded and the Longissimus thoracis was sampled. There was no significant effect of the OIL*ANT interaction (P > 0.05) for any trait evaluated. Bulls fed OIL presented greater final BW (P < 0.01), average daily gain (kg/day; P < 0.01), feed efficiency (P < 0.01), rump fat thickness (P8RF; P < 0.05), and greater tenderness; the ANT diet increased P8RF (P < 0.05). The levels of selenium and vitamin E in serum, liver, and meat were increased (P < 0.01) with the inclusion of ANT. ANT did not change triiodothyronine (T3, ng/mL) and thyroxine (T4, µg/gL) serum concentrations but decreased serum glucose levels. The treatments did not affect (P > 0.05) ruminal parameters or the protozoa population. Our results showed that the inclusion of 3% canola oil in the diet DM increased performance, feed efficiency, carcass fat deposition, and tenderness, with no effect on rumen fermentation and protozoa population of Nellore cattle in a feedlot system. The inclusion of ANT in the cattle diet did not affect performance or rumen parameters. However, the levels of ANT were increased in the serum, liver, and meat, enriching the final product with these compounds.

Malnutrition as the cause of recumbency in suckler cows associated with Trypanosoma theileri infection

BACKGROUND

Recumbent cows are a diagnostic challenge because of a wide range of differential diagnoses, which include trauma, neurological and metabolic disorders, malnutrition and mineral deficiencies. This case report describes recumbent suckler cows that presented as a herd problem. In addition to weakness due to inanition, Cu and Se deficiencies were considered as possible aetiologies of the recumbency. Furthermore, Trypanosoma (T.) theileri, a blood parasite of unknown importance in Germany, was detected in the blood of some cows.

CASE PRESENTATION

Three recumbent cows were referred to the Clinic for Ruminants and Swine, Faculty of Veterinary Medicine of the University of Leipzig. They were unable to rise and had low body condition scores and rough hair coats. Haematological and serum biochemical analyses showed neutrophilia, electrolyte imbalances, increased activities of muscle and liver enzymes and decreased concentrations of trace elements, especially Copper (Cu) and Selenium (Se). T. theileri was detected in a routine blood smear from one cow. The cows did not respond to an intensive care protocol, which included intravenous fluids and electrolytes, mineral substitution, non-steroidal anti-inflammatories and antibiotics, and were therefore euthanized or died. Postmortem examination showed cachexia, subcutaneous and scleral oedema and muscular dystrophy, especially in the hind limbs. Follow-up examination of the herd of origin produced similar findings including the detection of T. theileri in a large proportion of the herd. Ration analysis revealed considerable undersupply of several nutrients.

CONCLUSIONS

Based on all findings, an aetiological diagnosis of trace mineral and nutrient deficiency with possible involvement of T. theileri was made.

Sodium Selenite Improves In Vitro Maturation of Bos primigenius taurus Oocytes

Selenium (Se) is an essential trace element with important functions in animals and whose deficiency is associated with reproductive failures. The aim of this study was to investigate the effect of Se concentrations during in vitro maturation (IVM) of Bos taurus oocyte within the reference ranges for Se status in cattle. For this purpose, Aberdeen Angus cumulus-oocyte complexes (COCs) were matured in IVM medium supplemented with 0, 10, 50, and 100 ng/mL Se (control, deficient, marginal, and adequate, respectively). The results demonstrated that marginal and adequate Se concentrations added during IVM increased viability and non-apoptotic cumulus cells (CC). Moreover, the addition of Se to culture media decreased malondialdehyde level in COC with all studied concentrations and increased total glutathione content in CC and oocytes with 10 ng/mL Se. On the other hand, total antioxidant capacity of COC, nuclear maturation, and the developmental capacity of oocytes were not modified by Se supplementation. However, 10 ng/mL Se increased hatching rate. In conclusion, supplementation with 10 ng/mL Se during in vitro maturation of Bos primigenius taurus oocytes should be considered to improve embryo quality.

Safety and efficacy of sodium selenate as feed additive for ruminants

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of sodium selenate as a nutritional feed additive for ruminants, when used via an intraruminal bolus in ruminants. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) Panel concludes that based on (i) the estimation of the release of selenium from the bolus, (ii) the similarities in bioavailability with sodium selenite, (iii) the experience with the use of boluses in ruminant nutrition and (iv) the wide margin of safety compared with the maximum tolerable levels of selenium in ruminants, the additive is safe for ruminants. The use of sodium selenate by bolus administration providing a selenium intake not exceeding that resulting from the maximum authorised EU level of total selenium in feed presents no concerns for consumer safety. The additive does not pose a risk to users by inhalation and is considered as non‐corrosive but irritant for the skin and the eyes. The FEEDAP Panel considers the additive as a skin sensitiser and respiratory sensitiser. The additive under assessment, in its intended use as complementary feed for ruminants in the form of boluses, is a substitute for other authorised selenium additives and will not further increase the environmental burden of selenium. Based on two studies submitted in cattle and sheep and studies from the literature, the FEEDAP Panel concludes that sodium selenate delivered by a bolus to ruminants is an efficacious source of selenium in meeting the animals’ requirements. The Panel posed some recommendations regarding the use of the bolus, especially in small size ruminants. The Panel also posed a remark, concerning the zinc content of the bolus from which the additive is delivered.

Effect of Slow-Release Pellets of Selenium and Iodine on Performance and Some Blood Metabolites of Pregnant Moghani Ewes and Their Lambs

The need for minerals during pregnancy in mammals increases by progress of gestation due to embryo development. Therefore, the supply of trace minerals for pregnant ewes in late pregnancy may be of vital importance. The present study was carried out to evaluate the effect of selenium and iodine release slowly on the performance and some blood parameters of pregnant ewes and their lambs. Experiments were performed on 40 pregnant ewes from 3 to 4 years old in the last month of pregnancy with a weighing average of 52 ± 5 kg and a factorial experiment (2 × 2) in a completely randomized design with 4 treatments and 10 replicates used for 120 days (30 days before and 90 days after parturition of ewes). Experimental treatments were containing the following: (1) control, (2) ewe receiving bolus containing iodine, (3) ewe receiving bolus containing iodine and selenium, and (4) ewe receiving bolus containing selenium. One month before the expected birth date, the pellets will be fed to each of the livestock by bolus gun. During the test period, ewes will not receive any other mineral supplements and will be kept in a group in a herd. Ewes were blood sampled at 10 days prepartum and 30 and 60 days postpartum. The results showed that body weight on birth and weaning of lambs and average daily gain of lambs were highest in bloused animals that were related to the slow-release selenium tablet lambs (P < 0.05). Lambs born to mothers receiving 0.3 mg day^-1 of selenium per day had a keratin phosphokinase concentration of T₄ concentration and T₄ to T₃ lower than that of zero selenium (P < 0.05). Daily gain, glutathione peroxidase activity, and T₄ concentration at iodine 0.4 mg day^-1 were significantly higher than iodine level (P < 0.05). The adding of slow- release pellets of iodine and selenium improved the immune system.

Incidence risk of bronchopneumonia in newborn calves associated with intrauterine diselementosis

Background and Aim

Macro- and micro-elements are required to ensure the normal course of biochemical processes in the development of an animal's body. Any excess, deficiency, or imbalance in chemical elements in an animal's body can cause the development of various latent or clinically expressed pathological conditions. Diselementosis in pregnant cows may lead to impaired embryo and fetal development, as well as reduced neonatal viability. The aim of this study was to analyze the content of macroelements and microelements in the blood serum of both calving cows and their calves to evaluate the relationship between indicators of mineral metabolism in the mother and newborn and to establish what role separate chemical elements play in making newborn calves more prone to bronchopneumonia.

Materials and Methods

The content of potassium (K), sodium (Na), iron (Fe), Copper (Cu), Zinc (Zn), Strontium (Sr), arsenic (As), nickel (Ni), cobalt (Co), chromium (Cr), molybdenum (Mo), and selenium (Se) in the blood serum of 33 pregnant cows between 239 and 262 days of gestation and their 33 1-day old calves was determined using the Shimadzu AA6300 (Japan) atomic adsorption spectrophotometer. Calcium (Ca) and magnesium (Mg) content was determined using ion-selective electrodes from the Olympus-400 analyzer (Beckman Coulter, USA). During the 1^st month of life, all calves in the sample set had some sort of respiratory diseases and seven of the calves had bronchopneumonia. Retrospectively, the samples of adult and newborn animals were divided into two groups each: Dams I - cows whose calves had uncomplicated bronchitis (n=26); Dams II - cows whose calves got bronchopneumonia (n=7); and Newborns I - calves with uncomplicated bronchitis (n=26); Newborns II - calves with bronchopneumonia (n=7).

Results

The content of Ca, Mg, K, Na, Mo, and Se in dams in both groups of cows was within the reference range; the concentrations of Fe and Ni were higher than the reference range; and the concentrations of Cu, Zn, As, Co, and Cr were lower than the reference range. There were no significant differences in elemental status between the Dams I and Dams II groups. In newborn calves, the concentration of Ca and Mo corresponded to the reference range; the concentrations of Mg, Fe, Co, and Ni in both groups exceeded the reference range; and the concentrations of Cu, Zn, As, Cr, and Se were lower than the reference range. Results highlighted that there was a tendency to decrease concentration of Fe, Mo, and Se and a significant increase in the Ni concentration in calves of the Newborns II group compared with calves of the Newborns I group. It was also found that Zn, Co, Cr, and Mo actively accumulated in the body of newborn animals while the transplacental transfer of Cu, As, and Sr was limited; and transfer of Se and Ni was regulated by concentration ratios in the blood of the mother and the fetus. The excessive concentrations of Ni and Fe in the blood serum of cows and calves and the imbalance in the ratio of elements Fe-Cu-Zn, Fe-Cu-Co negatively affected erythropoiesis, formation of the immune system, and antioxidant status of the fetus and newborn. These changes were considered to be risk factors for the development of bronchopneumonia in calves.

Conclusion

An excess of serum Fe and Ni and deficiency of Cu, Zn, As, Co, and Cr in cows during the gestation period can lead to similar impairments of the mineral status in newborn calves. At the systemic level, dyslementosis in combination with the influence of other adverse factors, can lead to an increased load on the respiratory and hematopoietic systems of calves during postnatal adaptation and can subsequently cause a decrease in the natural resistance of calves and development of bronchopneumonia.

Preliminary study on Se-enriched Lentinula edodes mycelium as a proposal of new feed additive in selenium deficiency

The presence of selenium in European soil is low and this causes its deficiency in livestock and, in consequence, in humans. This study aimed to obtain Lentinula (L.) edodes mycelium with the maximum content of selenium. This species was used for experiment based on its documented medicinal properties. Calves were fed with selenium-enriched L. edodes mycelium, and serum selenium concentration, average daily weight gains and selected immune parameters were estimated. The selenium-enriched mushroom was found to be safe based on cytotoxicity tests (MTT and LDH tests) and for this reason it was used for further experiments. The mean quantity of selenium in the serum of calves fed with selenium-enriched L. edodes mycelium was significantly higher than that of control calves. Additionally, the calves fed with selenium-enriched L. edodes mycelium had higher body weight gains than those of control calves. White blood cell counts and subpopulations of lymphocytes in the experimental and control calves were within the reference range. The administration of L. edodes enriched with selenium had a beneficial effect on state of health of the calves.

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.

Effect of Selenium Source and Level on Performance, Egg Quality, Egg Selenium Content, and Serum Biochemical Parameters in Laying Hens

The objective of this study was to compare the effect of sodium selenite (SS) and selenium yeast (SY) on performance, egg quality, and selenium concentration in eggs and serum biochemical indices in laying hens. Seven hundred twenty healthy Roman laying hens (21 weeks old, 18 weeks in lay) with a similar laying rate (90.27% ± 1.05%) were randomly divided into 5 groups with 6 replicates of 24 hens each. Five diets were prepared as a 1+2×2 factorial arrangement with control and two sources of Se at two levels. Control diet (control) was prepared without adding exogenous selenium (analyzed basal Se content of 0.178 mg/kg). The other four diets were prepared with the control diet supplemented with SY or SS at 0.3 mg/kg (low; L) or 0.5 mg/kg (high; H) to give 5 diets designated as control, SY-L, SY-H, SS-L, and SS-H. The analyzed selenium content in the SY-L, SY-H, SS-L, and SS-H diets were 0.362, 0.572, 0.323, and 0.533 mg/kg respectively. The pre-trial period lasted 7 d, and the experimental period lasted 56 d (30 weeks old), during which the egg production, egg quality, and hen serum parameters were measured. Results showed that selenium source and level had no effect (P > 0.05) on average daily egg weight and feed conversion ratio (FCR). However, the laying rate was different at the L and H levels of supplementation, regardless of source, such that hens that were supplemented had a higher performance than that of the control, and the H level of supplementation lead to a higher laying rate than that of the L level (P < 0.05). There was a difference in average daily feed intake (ADFI) with an interaction in selenium source and level (P < 0.05), such that SS-L was higher than other selenium supplemented treatment or control. There were no significant differences in egg quality (P > 0.05); at the high level, SY had higher egg yolk selenium compared with SS. However, within SY, adding 0.5 mg/kg selenium led to higher egg yolk selenium than 0.3 mg/kg selenium (P < 0.05). Moreover, adding 0.3 mg/kg SY, 0.3 mg/kg, or 0.5 mg/kg SS to the basal diet had no significant effect on the selenium content in the egg (P > 0.05). There were no significant differences in serum biochemical indices among the five groups (P > 0.05). In conclusion, adding a high level of selenium in the diet of laying hens significantly increased egg production, and addition of a high level of selenium in the form of SY led to a higher deposition of selenium in the yolk than that of SS. These results indicate that adding 0.5 mg/kg of SY in the diet of laying hens would result in Se-enriched eggs.

Effect of Dietary Selenium Supplementation on Growth and Reproduction of Silkworm Bombyx mori L

The effects of selenium (Se) on the growth and reproduction of the Lepidoptera insect, the silkworm, Bombyx mori L were investigated. Initially, the silkworms were divided into eight groups (150 larvae/group) on the basis of feeding with mulberry leaves saturated with different concentrations of Se (25, 50, 100, 125, 150, 175, and 200 μM) and control from the first day of the fourth instar larvae. After feeding, growth and reproductive performance of B. mori L. were investigated with standard techniques used in sericulture. After the data analysis, 50 μM of Se was recognized as the optimal level which positively influenced the growth and production, with prolonged stage of larvae, increased larval, cocoon, and pupal weights, and enhanced number of eggs laid by the female moth as compared to the control group. On the contrary, 200 μM of Se treatment displayed toxic to silkworm and induced significant decrease in the growth, cocoon production, and reproduction. The weight of the cocoon shell, the cocoon shell ratio, number of eggs produced, and fertilization ratio in all the Se-treated groups were lower than the control group. The present study indicated that lower levels of (50 μM) of Se can promote the larval and pupal growth of the B. mori L. resulting in the higher yield of cocoon crop and significantly influencing the fecundity, while high concentration was toxic to silkworm. Our data supply the novel application of Se which could be highly beneficial to sericulture farmers.

An evaluation of dietary selenium nanoparticles for red sea bream (Pagrus major) aquaculture: growth, tissue bioaccumulation, and antioxidative responses

Selenium nanoparticles (Se-NPs) were added at 0, 0.5, 1, and 2 mg per kg diet to assess its effects on the performance, Se bioaccumulation, blood health, and antioxidant status of red sea bream. After 45 days, Se-NPs positively impacted the growth and feed efficiency of red sea bream especially by 1 mg per kg diet. No significant (P > 0.05) changes in survival and somatic indices were noticed among groups. Dietary Se-NPs significantly (P < 0.05) increased the protein, lipid, and Se contents in the whole body, muscle, and liver tissues, whereas decreasing the whole-body moisture content of treated groups compared with the Se-NP-free group. Using of Se-NPs at 2 mg per kg diet resulted in the highest Se content in the complete body, muscle, and liver. Significantly enhanced intestine protease activity and hematocrit levels accompanied with low cholesterol and triglyceride were observed in fish fed Se-NP-enriched diets. Fish fed on Se-NPs at 0.5, 1, and 2 mg Se-NPs per kg diet exhibited significantly higher values of biological antioxidant potential than the control group (P < 0.05). Therefore, the obtained results recommends adding 1 mg Se-NPs per kg diet to improve the growth, feed efficiency, blood health, and antioxidant defense system of red sea bream.

Genomic analysis of perinatal sucking reflex in German Brown Swiss calves

A healthy sucking reflex is essential for newborn calves to ensure sufficient colostrum intake in the first few hours postpartum. In recent decades, European Brown Swiss breeders have repeatedly reported that some calves lack the ability to consume colostrum directly after birth due to an absent sucking reflex. In this study, we collected the phenotypes of more than 5,500 German Brown Swiss calves and performed variance component estimation with sire threshold models using Markov chain Monte Carlo algorithms. The 50K (777K) genotypes of nearly 2,000 (200) calves were collected, and an imputation was performed for all 50K genotypes up to 777K. Genome-wide association studies (GWAS) for the trait sucking reflex were conducted for all 777K genotypes. Depending on the trait coding, a low heritability was estimated to range from 0.08 to 0.11. The GWAS results identified 34 trait-associated SNP on 6 different chromosomes. Post-GWAS analyses showed significant overrepresentation of Gene Ontologies for central nervous development and several regulative processes. Functional annotation clustering and pathway analysis revealed relations to lipid metabolism, immune and endocrine systems, and signal transduction. The results of this study suggest that breeding for an improved sucking reflex is possible but requires large data sets for the estimation of reliable breeding values (either large progeny testing groups or a large reference genome in a genomic selection program).

Fate of selenium in soil: A case study in a maize (Zea mays L.) field under two irrigation regimes and fertilized with sodium selenite

Selenium (Se) is a trace element necessary for both human and livestock nutrition. To increase Se human intake, soil Se fertilizations were performed but the fate of the added Se remains unclear. The present research aims to: (1) determine the influence of Se fertilization on the fractionation of Se in soil; (2) assess the influence of water availability on the distribution of soil Se chemical fractions; and (3) monitor the Se content in soil, leachates and plants. To reach these goals, 200 g Se ha^-1 was applied to soil as sodium selenite in maize crops under two irrigation regimes, and the Se content in plant, soil chemical fractions and leachates were analyzed. Se application increased the total Se content of the soil, specifically it increased the Se content of the soluble, exchangeable and organic fractions with more pronounced effect in the soils with higher water availability. These differences disappeared over time likely due to the Se loss through volatilization. The hypothesis of Se volatilization is confirmed by the absence of both leachates during the maize growing season and differences among the treatments of Se content in sub-soil samples. Also, although the Se treated plants showed higher Se content than the untreated ones, overall <1% of the added Se was assimilated by plants. Hence, this study demonstrated that the addition of selenite to the soil increased the Se contents of the plants, but the Se does not accumulate in the soil because it is likely lost via volatilization. Further, leaching of Se into groundwater is avoided due to its association with both the soil organic matter and positively charged binding sites of soil, and due to its loss via volatilization. Therefore, soil Se fertilization could increase the nutritional value of plants without consequences on the environment.

Multiple injections of vitamin E and selenium improved the reproductive performance of estrus-synchronized Awassi ewes

The aim of the current study was to investigate the effects of injecting estrus-synchronized ewes with vitamin E and selenium (Se) on their reproductive performance. Awassi ewes (n = 74) were randomly assigned into one of two groups. Group one (control, n = 36) did not receive vitamin E/Se injections, and group two (vitamin E/Se, n = 38) received 13.6-mg/kg BW of vitamin E plus 0.045-mg/kg BW of Se. Concurrent with estrus-synchronization program, vitamin E/Se injections were given at the time of insertion, withdrawal, and 19 days after withdrawal of intravaginal sponges. At all injection times, serum samples were collected (20 ewes per group) to measure Se contents. Pregnancy rates were evaluated by progesterone assay and by ultrasonography, respectively, at days 19 and 40 after sponge removal. Lambing rate, singles and twins%, sex ratio (M:F), and birth weight were recorded at lambing. Vitamin E/Se injections did not affect (P > 0.25) BW at lambing or BW change of ewes from breeding to lambing. Vitamin E/Se injections tended (P = 0.08) to decrease total pregnancy losses from 44.8 to 24.3%, subsequently, injections positively improved (P < 0.05) pregnancy rates determined by progesterone assay (from 80.6 to 97.4%) and ultrasonography (from 63.9 to 86.8%). Although overall fertility was not affected, vitamin E/Se injections markedly increased the percentage of ewes that lambed after only one service from 64.0 to 93.3%. Singles and twins%, lamb sex ratio, and birth weight of lambs were not affected (P > 0.20) by vitamin E/Se injections. Under conditions of our study, multiple injections of vitamin E/Se improved the reproductive performance of estrus-synchronized ewes.

Selenium and hazardous elements distribution in plant-soil-water system and human health risk assessment of Lower Cambrian, Southern Shaanxi, China

The natural selenium poisoning due to toxic Se levels in food chain had been observed in humans and animals in Lower Cambrian outcrop areas in Southern Shaanxi, China. To find out the distribution pattern of selenium and other hazardous elements in the plant, soil and water of Lower Cambrian in Southern Shaanxi, China, and their possible potential health risk, a total of 30 elements were analyzed and the health risk assessment of 18 elements was calculated. Results showed that the soil, plant and natural water of Lower Cambrian all had relatively high Se levels. In Lower Cambrian, the soil was enriched with Se, As, Ba, Cu, Mo, Ni, Zn, Ga, Cd and Cr (1.68 < I_geo < 4.48, I_geo; geo-accumulation index). In same plants, the contents of Se, Cd and Zn (except Cd in corn and rice, Zn in potato and corn) of Lower Cambrian were higher than that of the other strata. Ba and Ga in natural water were higher than that of the other strata, while K and Cs were opposite. The health risk assessment results showed that the people living in outcrop areas of Lower Cambrian had both high total non-carcinogenic risk of 18 elements (HI = 16.12, acceptable range: < 1) and carcinogenic risk of As (3.98E-04, acceptable range: 10^-6-10^-4). High contents of Se, As, Mo and Tl of Lower Cambrian may pose a health risk to local people, and food intake was the major pathway. For minimizing potential health risk, the local inhabitants should use the mix-imported food with local growing foods.