Search

BackgroundHydroxytryptophan (5-HTP) can regulate the synthesis of 5-Hydroxytryptamine (5-HT) and melatonin (MT). In a previous metabolome analysis, we found that 5-HTP is an effective ingredient in yeast culture for regulating rumen fermentation. However, research on the effect of this microbial product (5-HTP) as a functional feed additive in sheep production is still not well explained. Therefore, this study examined the effects of 5-HTP on sheep rumen function and growth performance using in vitro and in vivo models.MethodsA two-factor in vitro experiment involving different 5-HTP doses and fermentation times was conducted. Then, in the in vivo experiment, 10 sheep were divided into a control group which was fed a basal diet, and a 5-HTP group supplemented with 8 mg/kg 5-HTP for 60 days.ResultsThe results showed that 5-HTP supplementation had a significant effect on in vitro DMD, pH, NH3-N, acetic acid, propionic acid, and TVFA concentrations. 5-HTP altered rumen bacteria composition and diversity indices including Chao1, Shannon, and Simpson. Moreover, the in vivo study on sheep confirmed that supplementing with 8 mg/kg of 5-HTP improved rumen fermentation efficiency and microbial composition. This led to enhanced sheep growth performance and increased involvement in the tryptophan metabolic pathway, suggesting potential benefits.ConclusionDietary 5-HTP (8 mg/kg DM) improves sheep growth performance by enhancing ruminal functions, antioxidant capacity, and tryptophan metabolism. This study can provide a foundation for the development of 5-HTP as a functional feed additive in ruminants’ production.

This research develops a simulation model, aiming to study the breakdown process of the tri-post insulator when exposed to electric field and mechanical loadings. The insulator is subjected to external forces of varying magnitudes and directions, along with an applied 1100 kV AC voltage. Results show that the breakdown process is driven by the electrostatic energy density (Wele) under an AC voltage. As the length of the breakdown channel increases, Wele, also rises, thereby accelerating the extension of the breakdown channel. After applying a straight tension along the insulator post, the tensile stress and the corresponding strain energy density become concentrated near the tips of the lateral branches, thus promoting their expansion and even causing a transverse fracture under the condition of 100 kN. In the case of a small straight compression below 25 kN, the breakdown process can be restrained. But when it comes to 75 kN, the breakdown process is promoted again, and a shear fracture can be caused above 100 kN. Under diagonal tensile or compressive stress, the breakdown channel deviates towards the applied force due to asymmetric strain energy density distribution. The objective of this research is to improve the comprehension and forecasting of breakdown in dielectric materials.

Seasonal heat stress and metabolic disorders during mid-lactation are the main factors limiting production in Holstein cows, and several proteins and molecules involved in metabolic pathways are altered in response to stress. We investigated the effects of heat stress on the milk yield, milk composition, serum oxidative status, and metabolites in Holstein cows during mid-lactation to identify biomarkers associated with heat stress in serum and milk. Holstein cows with similar body condition scores (3.0 ± 0.25), parity (2.5 ± 0.5), and lactation days (115 ± 5 days) were selected in August (heat stress, HS, n = 20) 2017 and March 2018 (non-heat stress, NHS, n = 20). Milk yield was recorded daily and serum was collected on days 1, 31, and 61. Serum and milk metabolites were analysed by gas chromatography-mass spectrometry on day 1. The results showed a significantly lower average daily milk yield in the HS group than in the NHS group (P < 0.05). The milk compositions of fat (%), lactoprotein, lactose yield, and milk solid-not-fat in the HS group were significantly lower than in the NHS group on days 1, 31, and 61 (P < 0.05). The levels of malondialdehyde were higher, whereas those of superoxide dismutase and glutathione peroxidase were lower in the serum of the HS group (P < 0.05) than that of the NHS group. The serum concentrations of d-glucose, 9,12-octadecadienoic acid, and d-lactose were significantly higher in the NHS group than in the HS group (P

IntroductionPeripartal cows are susceptible to a negative energy balance due to inadequate nutrient intake and high energy requirements for lactation. Improving the energy metabolism of perinatal dairy cows is crucial in increasing production in dairy cows.MethodsIn this study, we investigated the impact of rumen-protected branched-chain amino acid (RPBCAA) on the production performance, energy and lipid metabolism, oxidative stress, and immune function of primiparous dairy cows using metabolomics through a single-factor experiment. Twenty healthy primiparous Holstein cows were selected based on body condition scores and expected calving date, and were randomly divided into RPBCAA (n = 10) and control (n = 10) groups. The control group received a basal diet from calving until 21 d in milk, and the RPBCAA group received the basal diet and 44.6 g/d RPLeu, 25.14 g/d RPIle, and 25.43 g/d RPVal.ResultsIn comparison to the control group, the supplementation of RPBCAA had no significant effect on milk yield and milk composition of the dairy cows. Supplementation with RPBCAA significantly increased the concentrations of insulin, insulin growth factor 1, glucagon, and growth hormones, which are indicators of energy metabolism in postpartum cows. The very low density lipoprotein, fatty acid synthase, acetyl coenzyme A carboxylase, and hormone-sensitive lipase contents of the RPBCAA group were significantly greater than that of the control group; these metrics are related to lipid metabolism. In addition, RPBCAA supplementation significantly increased serum glutathione peroxidase and immunoglobulin G concentrations and decreased malondialdehyde concentrations. Liquid chromatography–mass spectrometry (LC-MS) analysis revealed 414 serum and 430 milk metabolic features. Supplementation with RPBCAA primarily increased concentrations of amino acid and lipid metabolism pathways and upregulated the abundance of serotonin, glutamine, and phosphatidylcholines.DiscussionIn summary, adding RPBCAA to the daily ration can influence endocrine function and improve energy metabolism, regulate amino acid and lipid metabolism, mitigate oxidative stress and maintain immune function on primiparous cows in early lactation.

Hemicellulose is an important polysaccharide in ruminant nutrition, but it has not been studied as thoroughly as cellulose. Further research is needed to explore supplements that can improve its digestibility and ruminal buffering effects. Our previous research demonstrated the efficacy of oxalic acid (OA) as an essential nutrient in yeast culture (YC) for improving rumen fermentation performance. Consequently, we conducted in vitro rumen digestion experiments to examine the effects of YC and OA on rumen fermentation and bacterial composition. Two diets containing different levels of hemicellulose were formulated: diet 1 with 10.3% and diet 2 with 17% hemicellulose. Three levels of YC (0.00, 0.625, and 1.25 g/kg) and three doses of OA (0.0, 0.4, and 0.8 g/kg, DM) were added into each diet with a 3 × 3 factorial design. A comprehensive assessment was conducted on a total of 18 experimental treatments at fermentation periods of 0, 6, 12, 24, and 48 h. In the first experiment (diet 1), the supplementation of YC, OA, and their interaction significantly increased in vitro DM disappearance (IVDMD) and NDF disappearance (IVNDFD; p

Abstract Background Even if breed, parity, dietary and environmental management are same, dairy cows still have notable differences in milk yield that may be underpinned by physiologic differences. Objectives This study aimed to investigate the physiological dissimilarities of dairy cows with different milk yields. Methods Thirty cows were sorted into high milk‐yielding cows (group H: 58.93±2.31 kg/day), moderate milk‐yielding cows (group M: 44.99±0.54 kg/day), and low milk‐yielding cows (group L: 24.99±6.83 kg/day) according to milk yield. Blood was collected and serum parameters were assessed. Rumen fluid was collected for the evaluation of rumen fermentation parameters (RFPs) and bacterial community composition (BCC). Results Serum prolactin, growth hormone, glutathione peroxidase, immunoglobulin A and non‐esterified fatty acid had a significantly positive correlation with milk yield (p < 0.05), whereas serum glucagon and total antioxidant capacity had a significantly negative correlation with milk yield (p < 0.05). The concentration of valeric acid and the ratio of acetic acid to propionic acid in the rumen fluid in group H was significantly lower than that in group L (p < 0.05). The concentration of acetic acid and butyric acid in group H was significantly lower than that in groups M and L (p < 0.05). The relative abundances of Ruminococcaceae_NK4A214_group, Prevotella_1, Rikenellaceae_RC9_gut_group, Christensenellaceae_R‐7_group, Muribaculaceae, and Ruminococcus_2 were negatively correlated with milk yield, whereas the relative abundance of Succinivibrionaceae_UCG‐001, Lachnospiraceae_NK3A20_group, Shuttleworthia and Dialister were positively correlated with milk yield (p < 0.05). Conclusions This study indicates that dairy cows with different milk yields have clear divergence in serum indicators, RFPs, BCC and rumen microbial metabolism.

Abstract This paper offers a simulation study on the application of a novel approach to control the electric field around a basin‐type spacer by combining permittivity functionally graded materials (ε‐FGM) and superficially non‐linear conductivity materials (SNCM), namely multi‐dimensional functional materials (MDFM). The permittivity distribution of the ε‐FGM spacer is designed by the iteration optimization algorithm, and the epoxy/SiC composites with 30 and 60 phr doping contents are assigned as the coating materials of two SNCM spacers, namely SNCM30 and SNCM60. The MDFM spacer combines ε‐FGM in its bulk and SNCM60 on its surface. The electric field regulation effect of each functional spacer is investigated under variable conditions, that is, DC steady state (DC‐steady), DC turn‐on state (DC‐on), DC polarity reversal (DC‐PR), and DC superimposed with switching impulse voltage (DC‐SI). Results show that the applicability of ε‐FGM and SNCM is limited to transient and stationary conditions, respectively. The MDFM spacer combines the advantages of ε‐FGM and SNCM for adaptively relaxing the electric field under all the above conditions. It is hoped that this research will be beneficial to the development and application of spacers for the direct current gas‐insulated switchgear (DC‐GIS).

Abstract Background Silage is achieved by anaerobic fermentation of lactic acid bacteria. However, harvest stage and Lactiplantibacillus plantarum (L. plantarum) content affect the changes of microbial community in silage, which play an important role in silage quality and mycotoxin levels. The current study evaluated the effects exerted by the application of L. plantarum on fermentation, mycotoxins and bacterial community of whole-crop corn silage at different harvest stages. The fresh whole plant corn from the same area was harvested during the milk stage and the dough stage, following which from each harvest stage was subjected to four L. plantarum treatments: 0 cfu/g; 1 × 106 cfu/g; 1 × 107 cfu/g; and 1 × 108 cfu/g in a 2 × 4 factorial experimental design. Samples were collected on days 0, 3, 7, 21 and 42. Subsequently, nutrition parameters, fermentation parameters, mycotoxin levels and bacterial community were determined. Results Prolonging the harvest stage resulted in an increase in the levels of starch and dry matter as well as deoxynivalenol in corn silage. Addition of 1 × 107 cfu/g and 1 × 108 cfu/g of L. plantarum applied after 42 d of ensilage reduced dry matter loss, which significantly lowered deoxynivalenol concentration in corn silage at the dough stage (P

The diet structure is very important for the growth and development of calves. This study aimed to investigate the effects of dietary protein-to-starch metabolizable energy ratios (DPSRs) on growth performance, blood index, and gastrointestinal microbiota of calves. Forty-eight Holstein bull calves were fed six dietary DPSRs including A20-35 (20% CP and 35% starch), B20-30, C20-25, D22-35, E22-30, and F22-25 at d 4 to d 60, and then changed to another six dietary DPSRs at d 61 to d 180 (A18-30, B18-27, C18-24, D20-30, E20-27, and F20-24). Twelve calves (d 60) from groups A20-35, C20-25, D22-35, and F22-25 (n = 3) and another twelve calves (d 180) from groups A18-30, C18-24, D20-30, and F20-24 (n = 3) were euthanized. The growth performance parameters were measured. Blood, ruminal fluid, and cecum digesta were collected for further analysis. Results showed heart girth gain of B18-27 was significantly higher than A18-30, C18-24, and heart girth gain (d 180) was significantly affected by protein × starch (DPSRs; p

Abstract Background In highly intensive dairy farms, cows often suffer from metabolic disorders that cause severe oxidative stress. Objectives This study aimed to observe correlations and associations of oxidative stress‐related indicators with milk compositions and metabolites. Methods Twenty‐two multiparous Holstein dairy cows in early lactation were randomly selected from a commercial dairy farm. The morning milk was collected for composition and metabolites analysis. Blood was sampled via the tail vein to analyze oxidative stress‐related indicators (reactive oxygen species, ROS; catalase, CAT; superoxide dismutase, SOD; glutathione peroxidase, GPX; malondialdehyde, MDA) and metabolites. Results Results showed that ROS were positively correlated with CAT, GPX, SOD, and MDA. However, the levels of CAT, GPX, and SOD were negatively related to milk fat (P

The objective of the study was to elucidate the stearoyl-coenzyme A desaturase (SCD1)-dependent gene network of c9, t11-CLA biosynthesis in MAC-T cells from an energy metabolism perspective. The cells were divided into the CAY group (firstly incubated with CAY10566, a chemical inhibitor of SCD1, then incubated with trans-11-octadecenoic acid, (TVA)), the TVA group (only TVA), and the control group (without CAY, TVA). The c9, t11-CLA, and TVA contents were determined by gas chromatography. The mRNA levels of SCD1 and candidate genes were analyzed via real-time PCR. Tandem mass tag (TMT)-based quantitative proteomics, bioinformatic analysis, parallel reaction monitoring (PRM), and small RNA interference were used to explore genes involved in the SCD1-dependent c9, t11-CLA biosynthesis. The results showed that the SCD1 deficiency led by CAY10566 blocked the biosynthesis of c9, t11-CLA. In total, 60 SCD1-related proteins mainly involved in energy metabolism pathways were primarily screened by TMT-based quantitative proteomics analysis. Moreover, 17 proteins were validated using PRM analysis. Then, 11 genes were verified to have negative relationships with SCD1 after the small RNA interference analysis. Based on the above results, we concluded that genes involved in energy metabolism pathways have an impact on the SCD1-dependent molecular mechanism of c9, t11-CLA biosynthesis.

Sarcophaga gracilior Chen, 1975 (Diptera: Sarcophagidae) plays a significant role in epidemiology and medicine. In this study, we first report the complete mitochondrial genome (mitogenome) of S. gracilior. This mitogenome was 15,534 bp in length (GenBank No. MW531675), comprising 13 protein-coding genes (PCGs), two ribosomal RNAs (rRNAs), 22 transfer RNAs (tRNAs), and a non-coding control region. The arrangement of genes was identical to that of ancestral metazoan. Nucleotide composition revealed a strong A + T bias, accounting for 76.7% (A 39.6%, G 9.3%, C 14.0%, T 37.1%). The phylogenetic relationships indicated that the species of S. gracilior emerged as sister to Sarcophaga melanura. This study provides important mitochondrial data for further studying evolutionary relationships and species identification of flesh flies.

Hemicellulose is an important polysaccharide in ruminant nutrition, but it has not been studied as thoroughly as cellulose. Further research is needed to explore supplements that can improve its digestibility and ruminal buffering effects. Our previous research demonstrated the efficacy of oxalic acid (OA) as an essential nutrient in yeast culture (YC) for improving rumen fermentation performance. Consequently, we conducted in vitro rumen digestion experiments to examine the effects of YC and OA on rumen fermentation and bacterial composition. Two diets containing different levels of hemicellulose were formulated: diet 1 with 10.3% and diet 2 with 17% hemicellulose. Three levels of YC (0.00, 0.625, and 1.25 g/kg) and three doses of OA (0.0, 0.4, and 0.8 g/kg, DM) were added into each diet with a 3 x 3 factorial design. A comprehensive assessment was conducted on a total of 18 experimental treatments at fermentation periods of 0, 6, 12, 24, and 48 h. In the first experiment (diet 1), the supplementation of YC, OA, and their interaction significantly increased in vitro DM disappearance (IVDMD) and NDF disappearance (IVNDFD; p < 0.001). In the second experiment (diet 2), the supplementation of OA and the interaction between YC and OA (p < 0.001) increased IVDMD and IVCPD, but had no significant effects on IVNDFD. The interactions of YC and OA significantly increased ammonia nitrogen (p < 0.001). The production of acetic acid, propionic acid, and total volatile fatty acids (TVFA), and pH levels were significantly higher in treatments supplemented with YC and OA (p < 0.001). YC and OA in both diets significantly altered the rumen bacterial community leading to increased Shannon and Simpson diversity indices (p < 0.001). In both diets, OA supplementation significantly increased the relative abundance of the phylum Bacteroidetes and Prevotella genus. The result also showed a positive correlation between the Prevotella and Selenomonas genera with IVDMD, IVNDFD, propionic acid, and TVFA production, suggesting that these dominant bacteria enhanced nutrient disappearance in the rumen. In conclusion, adding YC and OA resulted in modifications to the bacterial community's composition and diversity, and improved nutrient disappearance. These changes indicate improved rumen fermentation efficiency, which is promising for future in vivo studies. [ABSTRACT FROM AUTHOR]

We have used an infrared laser for desorption of material and ionization by interaction with electrosprayed solvent. Infrared laser-assisted desorption electrospray ionization (IR LADESI) mass spectrometry was used for the direct analysis of water-containing samples under ambient conditions. An ion trap mass spectrometer was modified to include a pulsed Er:YAG laser at 2.94 µm wavelength coupled into a germanium oxide optical fiber for desorption at atmospheric pressure and a nanoelectrospray source for ionization. Analytes in aqueous solution were placed on a stainless steel target and irradiated with the pulsed IR laser. Material desorbed and ablated from the target was ionized by a continuous stream of charged droplets from the electrosprayed solvent. Peptide and protein samples analyzed using this method yield mass spectra similar to those obtained by conventional electrospray. Blood and urine were analyzed without sample pretreatment to demonstrate the capability of IR LADESI for direct analysis of biological fluids. Pharmaceutical products were also directly analyzed. Finally, the role of water as a matrix in the IR LADESI process is discussed. [ABSTRACT FROM AUTHOR]