Study of metabolomics in selenium deprived Przewalski's Gazelle (Procapra przewalskii)

Multi-omics reveals the hepatic metabolic mechanism of neurological symptoms caused by selenium exposure in Przewalski's gazelle (Procapra przewalskii)

Neurological symptoms resulting from selenium(Se) exposure significantly impact the health and conservation of Przewalski's gazelle. In this study, we performed proteomic and metabolomic analyses of the liver in Przewalski's gazelle for the first time, aiming to reveal the hepatic metabolic mechanisms underlying the neurological symptoms caused by Se exposure. We identified 89 differentially expressed proteins and 30 metabolites with altered regulation. Using multi-omics integrated analysis, we identified a neurofunctional regulation network composed of three metabolic pathways, with (S)-3-amino-2-methylpropionate transaminase being the key enzyme in the regulatory network. Molecular docking revealed that the binding of selenocysteine to (S)-3-amino-2-methylpropionate transaminase may act as a key factor in activating this regulatory network. Consequently, these findings provide important insights into the molecular mechanisms of neurological symptoms caused by Se exposure and have significant implications for the conservation in Przewalski's gazelle.

Omics insights into the responses to dietary selenium

Selenium is a well-known health-relevant element related with cancer chemoprevention, neuroprotective roles, beneficial in diabetes, and in several infectious diseases, among others. It is naturally present in some foods, but deficiency in people led to the production of nutraceuticals, supplements, and functional food enriched in this element. There is a U-shaped link between selenium levels and health and a narrow range between toxic and essential levels, and thus, supplementation should be performed carefully. Omics methodologies have become valuable approaches to delve into the responses of dietary selenium in mammals that allowed a deeper knowledge about the metabolism of this element as well as its biological role. In this review, we discuss omics approaches from the workflows to their applications that has been previously used to deep insight into the metabolism of dietary selenium. There is a special focus on selenoproteins, metabolomics responses in blood and tissues (e.g., brain, reproductive organs, etc.) as well as the impact on gut microbiota and its metabolites profile. Thus, we mainly reviewed heteroatom-tagged proteomics, metallomics, metabolomics, and metataxonomics, usually combined with transcriptomics, genomics, and other molecular methods.

Effects of Organic Chromium Yeast on Performance, Meat Quality, and Serum Parameters of Grow-Finish Pigs

Trivalent chromium (Cr) is an essential trace element for humans and animals. This study was conducted to investigate the effects of chromium(III) yeast (CrYst) on growth performance, carcass characteristics, meat traits, antioxidant status, immune traits, and serum biochemical parameters of grow-finish pigs. A total of 72 commercial hybrid barrows (Duroc × Landrace × Large White) of approximately 50 kg body weight were allocated into two dietary treatments randomly, which received a corn-soybean meal basal diet or a basal diet supplemented with 100 mg CrYst/kg. The trial duration was 11 weeks divided into three periods from body weights of 50-75 kg, 75-100 kg, and 100-110 kg, respectively. The results revealed that supplemental CrYst did not affect growth performance. Organic CrYst supplementation significantly decreased the backfat depth and increased the meat tenderness score and juiciness score values in pigs (P < 0.05), while other carcass traits and meat traits indexes were unaffected. CrYst addition significantly decreased serum malondialdehyde (MDA) content of pigs in the whole growth phase; significantly increased the serum levels of immunoglobulin G (IgG), total antioxidant capacity (T-AOC), glutathione peroxidase (GSH-Px), and reduced glutathione (GSH) in growing pigs; and also increased the serum IgG, IgM, and GSH concentrations in pigs during the finishing phase (P < 0.05). Additionally, diets supplemented with CrYst significantly decreased the serum high-density lipoprotein cholesterol (HDL-C) content in growing pigs and significantly increased the serum LDL-C level at the fattening period (P < 0.05), whereas no significant differences were observed for the other serum biochemical indexes compared to the control pigs. In conclusion, CrYst supplementation could reduce lipid peroxidation and backfat thickness and improve the meat tenderness and juiciness, immune traits, and antioxidant status of pigs.

Effect of Foliage Dressing in Nano-Potassium Molybdate on Daily Gain and Antioxidant Function in Grazing the Chinese Merino Sheep

The study was implemented for exploring influences of nano-K₂MoO₄ on the daily gain and antioxidant function of Chinese merino sheep in the native pasture, Xinjiang Uygur Autonomous Region, Northwest of China. Eighty of the sheep, weight of (45.56 ± 2.35) kg, were randomly distributed to the tested areas for 90 days, 20 sheep/group. The findings showed that the contents of Mo and N in the forage of applying nano-K₂MoO₄ were extremely higher than those in the control pastures (P <0.01). The daily gain in the fertilized groups were remarkably lower than that in the control group (P <0.01). The harvest of forage in the fertilized pastures were significantly higher than those in control (P <0.01). The contents of Mo in blood and liver in grazing the Chinese merino sheep were extremely higher than those from the control group (P <0.01). The contents of Cu in blood and liver in grazing the Chinese merino sheep were extremely lower than those in the unfertilized pastures (P <0.01). The levels of hemoglobin (Hb), blood platelet (PLT), and erythrocyte count (RBC) in animals from the fertilized pastures were extremely lower than those in the control pastures (P < 0.01). The activities of SOD, GSH-Px, and CAT in serum were significantly lower than those in group C. The serum MDA levels were significantly higher than those in the control group (P < 0.01). In conclusion, the application of nano-K₂MoO₄ in pastures can greatly improve the yield of forage, but strikingly decreased the daily gain and antioxidant function in grazing the Chinese merino sheep.

Effects of Molybdenosis on Antioxidant Capacity in Endangered Przewalski's Gazelles in the Qinghai Lake National Nature Reserve in the Northwestern China

The purpose of this study is to investigate the effects of molybdenosis on antioxidant capacity in endangered Przewalski's gazelles (Procapra przewalskii) in the animal rescue center in the Qinghai Lake National Nature Reserve in Northwestern China. Ten P. przewalskii in molybdenosis were selected and treated orally with copper sulfate (CuSO₄) at a dose of 20 g/animal/5 days for 20 days. Ten healthy P. przewalskii were also selected and allocated to healthy pastures for 20 days. Samples of soil, forage, and animal tissue were collected. The values of mineral and hematological parameters were measured. Results showed levels of molybdenum (Mo) in soil and forage were significantly higher than those in healthy ranches (P < 0.01). The Mo content of blood and hair in gazelles from the rescue center was also significantly higher than those in the healthy ranches animals (P < 0.01). The copper (Cu) contents in blood and hair from the rescue center were significantly lower than those from the healthy pasture (P < 0.01). Hemoglobin (Hb) and red cell volume (PCV) in the gazelles from the animal rescue center were significantly lower than those from animals in healthy ranches (P < 0.01). Aspartate aminotransferase (AST), lactate dehydrogenase (LDH), phosphocreatine kinase (CPK), and alkaline phosphatase (ALP) were significantly higher than those from gazelles in healthy ranches (P < 0.01). The antioxidant capacity in gazelles from the animal rescue center was significantly lower than that of gazelles in healthy ranches. Supplementing CuSO₄ significantly decreased the Mo content of blood and cured molybdenosis in gazelles. In summary, the Mo content of soil and forage was very excessive for gazelles in the animal rescue center. The antioxidant capacity of P. przewalskii has been seriously affected by molybdenosis.

Effects of the Seleno-Chitosan on Daily Gain, Wool Yield, and Blood Parameter in the Chinese Merino Sheep

To study the effects of the seleno-chitosan on daily gain, wool yield, and blood parameters in the Chinese merino sheep in the selenium (Se)-deficient pastures. The samples of soils, forages, and tissues had been collected in the Southern Xinjiang of Northwest China. Our findings indicated that the Se contents in soils and forages from affected pastures were remarkably lower than those unaffected by the pastures (P < 0.01). The Se contents in the blood and the wool from affected Chinese merino sheep were extremely lower than those from healthy sheep. Meanwhile, the values of Hb, PCV, and PLT in affected sheep were significantly decreased (P < 0.01). The yield of wool and the growth rate in affected sheep were also remarkably reduced (P < 0.01). The affected Chinese merino sheep were orally treated by seleno-chitosan for 150 days; the Se contents in blood were remarkably increased and reached the healthy range on day 5. The blood parameters soon recovered to a healthy range on day 10. The growth rate of sheep in the treated group was remarkably higher than that in the control animals. The yield of the wool was also significantly increased in the treated group. Consequently, the Se-deprived environment caused a threat to daily gain, wool yield, and blood parameters in the Chinese merino sheep. The seleno-chitosan could not only markedly increase the Se contents blood contents, but also significantly increase the production performance (daily gain and wool yield), and release the symptoms of anemia in the Se-deprived animal.

Effect of Nano-potassium Molybdate on the Copper Metabolism in Grazing the Pishan Red Sheep

The aims of this study were to investigate the impact of different levels of nano-potassium molybdate (nano-K₂MoO₄) fertilization on the copper (Cu) metabolism in grazing the Pishan red sheep in the natural pasture. The fertilization and grazing experiments were conducted on the Pishan farm in Southern Xinjiang, China. The natural pastures of 16 hm² were randomly divided into four groups (4 hm²/group), consisting of group C (no fertilized), group I, group II, and group III. The fertilizing amount of Mo from nano-K₂MoO₄ was 0, 7, 8, and 9 kg/hm² for group C, group I, group II, and group III, respectively. The 40 Pishan red sheep were randomly distributed to the tested pastures for 90 days, and the 10 sheep/group. The results showed that the contents of Mo and N in forage from the fertilized pastures were extremely increased (P < 0.01). The yield and dry matter digestibility of forage in fertilized pastures were significantly higher than those in no fertilized pasture (P < 0.01). The values of crude protein (CP) and crude fat (EE) in forage from fertilized pastures were significantly increased (P < 0.01). The Mo contents in the blood and liver in the Pishan red sheep from fertilized pastures were greatly increased (P < 0.01). The Cu contents in the blood and liver in the Pishan red sheep from the fertilized pastures were greatly decreased (P < 0.01). The activities of serum superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and total antioxidant capacity (T-AOC) in group I, group II, and group III were extremely lower than those in group C (P < 0.01), and the contents of serum malondialdehyde (MDA) in group I, group II, and group III were greatly higher than those from group C (P < 0.01). In summary, the application of nano-K₂MoO₄ improved the nutritive values and the yield of forage, but overuse will remarkably reduce the Cu contents of blood and greatly interfere with the Cu metabolism, leading to the Cu deficiency and low antioxidant capacity in grazing the ruminants.

Metabolomic Analysis Reveals the Adaptation in the P. przewalskii to Se-Deprived Environment

The Procapra przewalskii inhabits in a selenium (Se)-deprived environment in long-term, but they have no pathological manifestations due to the Se deprivation. This study aimed to reveal the underlying adaptation induced by Se deprivation. In the analysis, a total of 93 significantly changed metabolites were identified in positive and negative ion modes, including 46 upregulated and 47 downregulated compounds in the Se-deprived group. The differential metabolites were annotated as the major molecules in bile acid biosynthesis, biosynthesis of unsaturated fatty acids, and pyrimidine metabolism, respectively. This study systematically analyzed the serum metabolomics characteristics of P. przewalskii under Se-deprived conditions for the first time, providing a basis for further understanding of the metabolic mechanism of P. przewalskii in the Se-deprived environment.

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.

Effects of Nano-copper Oxide on Antioxidant Function of Copper-Deficient Kazakh Sheep

Kazakh sheep are vital to the production system of the Barkol prairie. The purpose of this study was to determine the effect of nano-copper oxide (Nano-Cu₂O) on the antioxidant system of Cu-deficient Kazakh sheep in the Barkol prairie in Xinjiang, China. We analyzed mineral contents in soil, forage, and animal tissues. Blood parameters were also measured at the same time. The results showed that compared with healthy grassland, the Cu content in the soil and forage in Cu-deficient pastures was significantly lower than that in healthy grassland (P < 0.01). The Cu content in the blood, wool, and liver of Cu-deficient Kazakh sheep was significantly lower than that of healthy animals (P < 0.01). After Kazakh sheep were supplemented with Nano-Cu₂O or CuSO₄, the blood Cu concentration increased significantly (P < 0.01). From the 5th day, the Cu content of the Nano-Cu₂O group was significantly higher than that of the CuSO₄ group. The levels of hemoglobin (Hb), erythrocyte count (RBC), and packed cell volume (PCV) in the two experimental groups were significantly higher than those in Cu-deficient Kazakh sheep (P < 0.01). Compared with Cu-deficient Kazakh sheep, the serum ceruloplasmin (Cp) level of the two experimental groups increased significantly (P < 0.01), while the serum lactate dehydrogenase (LDH), alkaline phosphatase (AKP), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) decreased significantly (P < 0.01). Compared with Cu-deficient Kazakh sheep, the activities of serum superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and total antioxidant capacity (T-AOC) in Nano-Cu₂O and CuSO₄ groups increased significantly (P < 0.01), while the level of serum malondialdehyde (MDA) decreased significantly (P < 0.01). Therefore, Nano-Cu₂O could not only significantly increase the Cu content in the blood of Cu-deficient Kazakh sheep, but also greatly improve the antioxidant capacity.