Pharmacokinetics of Enrofloxacin in Plasma, Urine, and Feces of Donkey (Equus asinus) after a Single Intragastric Administration.

Enrofloxacin is a broad-spectrum antimicrobial agent, but the study of its pharmacokinetics/pharmacodynamics (PKs/PDs) in donkeys is rarely reported. The present study aimed to investigate the pharmacokinetics of enrofloxacin administered intragastrically, and to study the pharmacokinetics of enrofloxacin and its metabolite ciprofloxacin in plasma, urine, and feces, and the PK/PD parameters were investigated to provide a rationale for enrofloxacin treatment in donkeys. A total of five healthy donkeys were selected for intragastric administration of 7.5 mg·kg-1 BW of enrofloxacin by gavage, and blood, urine, and fecal samples were collected. The results showed that the elimination half-life of plasma enrofloxacin was 11.40 ± 6.40 h, Tmax was 0.55 ± 0.12 h, Cmax was 2.46 ± 0.14 mg·L-1, AUC0-∞ was 10.30 ± 3.37 mg·L-1·h, and mean residence time (MRT) was 7.88 ± 1.26 h. The Tmax of plasma ciprofloxacin was 0.52 ± 0.08 h, Cmax was 0.14 ± 0.03 mg·L-1, and AUC0-∞ was 0.24 ± 0.16 mg·L-1·h. Urinary Cmax was 38.18 ± 8.56 mg·L-1 for enrofloxacin and 15.94 ± 4.15 mg·L-1 for ciprofloxacin. The total enrofloxacin and ciprofloxacin recovered amount in urine was 7.09 ± 2.55% of the dose for 144 h after dosing. The total enrofloxacin and ciprofloxacin recovered amount in feces was 25.73 ± 10.34% of the dose for 144 h after dosing. PK/PD parameters were also examined in this study, based on published MICs. In conclusion, 7.5 mg/kg BW of enrofloxacin administered intragastrically to donkeys was rapidly absorbed, widely distributed, and slowly eliminated in their bodies, and was predicted to be effective against bacteria with MICs < 0.25 mg·L-1.

Toxicokinetics of Deoxynivalenol in Dezhou Male Donkeys after Oral Administration.

Deoxynivalenol (DON) is detected in different types of foods and feeds, inducing toxicity in humans and animals. After entering the organism, DON first appears in the plasma; then, it is rapidly absorbed and distributed in various organs and tends to accumulate in the body to exert its toxic effects. This study was performed to investigate the toxicokinetics of DON on Dezhou male donkeys after a single oral dose of 500 µg/kg·BW (body weight). The plasma of donkeys was collected at 0, 5, 10, 15, 20, 30, 45 min, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 6, 9, 12, 24, 48, 72, 96 and 120 h after administration, and the feces and urine were collected at 0 h and at 6 h intervals up to 24 h, followed by 4 h intervals up to 120 h. The concentrations of DON in plasma, urine and feces were determined by HPLC. The peak concentration of DON in plasma was 174.30 µg/L, which occurred at 1.07 h after oral gavage. The recovery of unchanged DON in urine and feces amounted to 19.98% and 6.74%, respectively. Overall, DON was rapidly absorbed and slowly eliminated in donkeys within 120 h following a single oral dose, which can lead to DON accumulation in the body if ingested for a long time.

Analysis of lncRNA and mRNA expression profiling in immature and mature DeZhou donkey (equine Taurus) testes.

Testicular development and spermatogenesis are tightly regulated by the number of genes and noncoding genes, and mRNAs and lncRNAs play vital roles in regulating posttranscriptional gene expression. However, mRNAs and lncRNAs have not been systematically identified in the testes of donkeys. In this study, mRNA and lncRNA expression profiles in the testes of DeZhou donkeys between 2 months and 2 years of age were comprehensively analysed by RNA sequencing. We identified 56,605 lncRNAs and 61,857 mRNAs by gene expression analysis, and 21,845 lncRNAs (p < .05) and 14,109 mRNAs (p < .05) were differentially expressed in the immature (2-month-old, n = 3, noADGW) and mature (2-year-old, n = 3, ADGW) stages. In addition, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses revealed that the predicted target genes were enriched in the adherens junction, cell cycle, propanoate metabolism and cell adhesion molecule pathways. This study identified and analysed a comprehensive catalogue of lncRNAs and mRNAs in donkey testes, which provides a useful resource for further investigation of biological function in donkey lncRNAs.

TMT-based comparative proteomic analysis of Dezhou donkey spermatozoa related to freezability.

The freezability difference between donkey ejaculates is a limiting factor of sperm cryopreservation. Our recent study shows that the freezability of donkey semen is related to the seminal plasma proteome. In this study, we aimed to identify the different abundance sperm proteins in good freezability ejaculates (GFEs) and poor freezability ejaculates (PFEs) using a Tandem Mass Tag (TMT) peptide labeling coupled with LC-MS/MS approach. A total of 2682 proteins were identified, among which 58 were significantly up-regulated in GFEs and 16 were down-regulated compared with PFEs. Bioinformatic analysis results revealed that the majority of different abundance proteins (DAPs) participated in copper and calcium binding, regulation of RNA biosynthetic process, positive regulation of innate immune response, and negative regulation of programmed cell death. KEGG pathway enrichment analysis showed the up-regulated proteins in GF group were mainly involved in N-Glycan biosynthesis and protein processing in endoplasmic reticulum. Our study was the first to analyze the proteome of sperm from donkey ejaculates with different freezabilities. The identified candidate proteins might be used to explore the molecular mechanism related to donkey sperm cryotolerance and might improve the screening of jacks with good sperm freezability. SIGNIFICANCE: Cryopreserved semen has been widely used in assisted reproductive technology. However, semen cryopreservation is a damaging process, which can cause oxidative stress, reduce sperm motility and motility. There are differences in sperm freezability reported to exist between or within breeds, and even between fractions coming from the same ejaculate. The freezability difference between donkey ejaculates is a limiting factor of sperm cryopreservation. The mechanisms that affect the freezing difference in sperm quality remain to be investigated, and freezability differences was found to be related to protein composition of spermatozoa. Some protein markers that can indicate good freezability or poor freezability semen have been identified in mammals. Until now, there is no information about the relationship between donkey spermatozoa proteome and freezability. Additional novel biomarkers of semen freezability in donkey spermatozoa are also needed. The identified candidate proteins might be used to explore the molecular mechanism related to donkey sperm cryotolerance and might improve the screening of jacks with good sperm freezability.

Identification of Dezhou donkey muscle development-related genes and long non-coding RNA based on differential expression analysis.

Long non-coding RNAs (lncRNAs) play a critical role in the development of muscles. However, the role of lncRNAs in regulating skeletal muscle development has not been studied systematically in the donkey. In this study, we performed the RNA sequencing for different stages of muscles in donkeys, and investigate their expression profile, which showed that 3215 mRNAs (p-adjust <0.05) and 471 lncRNAs (p-value <0.05) were significantly differently expressed (DE) verified by RT-qPCR. GO and KEGG enrichment analysis indicated that DE genes and target genes of DE lncRNAs were associated with muscle development in the donkey. We also found these four target genes (DCN, ITM2A, MUSTN1, ARRDC2) involved in skeletal muscle growth and development. Combined with transcriptome data, network, and RT-qPCR results showed that four co-expression networks of DCN and lnc-008278, ITM2A and lnc_017247, MUSTN1 and lnc_030153, and ARRDC2 and lnc_033914, which may play an important role in the formation and development of muscle in the donkey.

Proteomic analysis of donkey sperm reveals changes in acrosome enzymes and redox regulation during cryopreservation.

Sperm cryoinjuries caused by cryopreservation restrict the application of donkey frozen semen in artificial insemination (AI). Identification of differentially represented proteins in fresh and frozen-thawed spermatozoa is of great significance to optimize the cryopreservation process and modify the component of cryopreservation extender. In this study, protein samples prepared from fresh (F) and frozen-thawed (FT) donkey spermatozoa were compared. 2682 proteins were quantitatively identified by tandem mass spectrometry (TMT) polypeptide labeling technique and LC-MS/MS method, of which 28 were more abundant in thawed samples and 147 in fresh spermatozoa. The differential abundant proteins (DAPs) were analyzed by bioinformatics. Most of the DAPs in intensive bioinformatic analysis were involved in the process of regulation of biological process and metabolism. Functional protein analysis showed that DAPs process mainly protein hydrolase activity and oxidoreductase activity. Cellular Component analysis showed that DAPs were related to vesicle transport and membrane system. This is the first analysis and study on differential proteomics of donkey sperm proteins before and after cryopreservation, which has a certain guiding significance for studying the mechanism of sperm damage caused by cryopreservation and improving the freezing and thawing procedure. SIGNIFICANCE: In recent years, the commercial value of donkey products has been discovered. Improving the breeding efficiency of donkeys can save the stock of donkeys which is decreasing rapidly, and allow people to continuously benefit from the nutritional value brought by donkey milk. Sperm cryopreservation technology has laid the foundation for encouraging the spread of artificial insemination in donkey reproduction, but the freezing and thawing process causes damage to sperm, which dramatically reducing the viability of frozen sperm and leading to low fertility. At present, the mechanism of damage to donkey sperm caused by cryopreservation is still unclear, and studying this mechanism can provide a direction for improving the quality of frozen semen. Protein is a potential key factor affecting sperm cryopreservation activity. Studying changes in the sperm proteome during cryopreservation can provide promising evidence for revealing sperm cryopreservation damage, which is of great significance for optimizing the cryopreservation process, improving the composition of cryopreservation extender, and seeking directions for improving the quality of frozen semen.

Comparative Whey Proteome Profiling of Donkey Milk With Human and Cow Milk.

Donkey milk (DM), similar to human milk (HM) in chemical composition, has been suggested as the best potential hypoallergenic replacement diet for babies suffering from Cow milk (CM) protein allergy. In order to better understand DM protein, many studies based on proteomic have been performed. In this study, the label-free quantitative proteomic approach was conducted to quantitatively identify the differentially expressed whey proteins (DEPs) in DM vs. HM group and DM vs. CM group. In total, 241 and 365 DEPs were found in these two groups, respectively. Bioinformatics analysis of DEPs showed that the majority of DEPs participated in the lipoprotein metabolic process, regulation of cytokine production, chemical homeostasis, and catabolic process. The Kyoto Encyclopedia of Gene and Genomes (KEGG) pathways analysis found that these DEPs mainly participated in an antigen processing, complement, and coagulation cascades. These results may provide valuable information in the composition of milk whey proteins in DM, HM, and CM, especially for low abundant components, and expand our knowledge of different biological functions between DM and HM or CM.

Metabolomic profiling of Dezhou donkey seminal plasma related to freezability.

Donkeys are indispensable livestock in China because they have transport function and medicinal value. With the popularization of artificial insemination on donkeys, semen cryopreservation technology has gradually become a research hotspot. Seminal plasma is a necessary medium for transporting sperm and provides energy and nutrition for sperm. Seminal plasma metabolites play an important role in the process of sperm freezing, and also have an important impact on sperm motility and fertilization rate after freezing and thawing. In this study, liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis was used to compare the metabolic characteristics of seminal plasma of high freezability (HF) and low freezability (LF) male donkeys. We identified 672 metabolites from donkey seminal plasma, of which 33 metabolites were significantly different between the two groups. Metabolites were identified and categorized according to their major chemical classes, including homogeneous non-metal compounds, nucleosides, nucleotides, and analogues, organosulphur compounds, phenylpropanoids and polyketide, organoheterocyclic compounds, organic oxygen compounds, benzenoids, organic acids and derivatives, lipids and lipid-like molecules, organooxygen compounds, alkaloids and derivatives, organic nitrogen compounds. The results showed that the contents of phosphatidylcholine, piceatannol and enkephalin in donkey semen of HF group were significantly higher than those of LF group (p < .05), while the contents of taurocholic and lysophosphatidic acid were significantly lower than those of LF group (p < .05). The different metabolites were mainly related to sperm biological pathway response and oxidative stress. These metabolites may be considered as candidate biomarkers for different fertility in jacks.

Metabolomic profiling of Dezhou donkey sperm associated with freezability.

The cryopreservation technology of sperm has promoted the popularization of artificial insemination in the reproductive process of donkeys to a certain extent, but the freezing-thawing process would bring damage to the sperm, and the vitality of the sperm would be greatly reduced after freezing. Sperm metabolites play an important role in the process of sperm freezing, and also have an important impact on the vitality and fertilization rate of sperm after freezing-thawing. In this study, the LC-MS/MS analysis method was used to compare the metabolic profiles of high freezability (HF) and low freezability (LF) male donkey sperm after freezing-thawing. We identified 1323 metabolites in total, of which 17 metabolites are significantly different between the two groups. Most of these metabolites belong to fatty acids and phospholipids, including phosphatidylcholine, stearic acid and so on. These different metabolites are mostly related to the plasma membrane fatty acids of sperm and oxidative stress. Our results illustrate several metabolites related to sperm freezability and provide corresponding biomarkers.

Quantitative Label-Free Proteomic Analysis of Milk Fat Globule Membrane in Donkey and Human Milk.

Previous studies have found donkey milk (DM) has the similar compositions with human milk (HM) and could be used as a potential hypoallergenic replacement diet for babies suffering from cow's milk allergy. Milk fat globule membrane (MFGM) proteins are involved in many biological functions, behaving as important indicators of the nutritional quality of milk. In this study, we used label-free proteomics to quantify the differentially expressed MFGM proteins (DEP) between DM (in 4-5 months of lactation) and HM (in 6-8 months of lactation). In total, 293 DEP were found in these two groups. Gene Ontology (GO) enrichment analysis revealed that the majority of DEP participated in regulation of immune system process, membrane invagination and lymphocyte activation. Several significant Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were determined for the DEP, such as lysosome, galactose metabolism and peroxisome proliferator-activated receptor (PPAR) signaling pathway. Our study may provide valuable information in the composition of MFGM proteins in DM and HM, and expand our knowledge of different biological functions between DM and HM.

Transport stress affects the fecal microbiota in healthy donkeys.

BACKGROUND: With the development of large-scale donkey farming in China, long-distance transportation has become common practice, and the incidence of intestinal diseases after transportation has increased. The intestinal microbiota is important in health and disease, and whether or not transportation disturbs the intestinal microbiota in donkeys has not been investigated. OBJECTIVES: To determine the effects of transportation on the fecal microbiota of healthy donkeys using 16S rRNA sequencing. ANIMALS: Fecal and blood samples were collected from 12 Dezhou donkeys before and after transportation. METHODS: Prospective controlled study. Cortisol, ACTH, and heat-shock protein 90 (HSP90) concentrations were measured. Sequencing of 16S rRNA was used to assess the microbial composition. Alpha diversity and beta diversity were assessed. RESULTS: Results showed significant (P < .05) increases in cortisol (58.1 ± 14.6 to 71.1 ± 9.60 ng/mL), ACTH (163.8 ± 31.9 to 315.8 ± 27.9 pg/mL), and HSP90 (10.8 ± 1.67 to 14.6 ± 1.75 ng/mL) on the day of arrival. A significantly lower (P = .04) level of bacterial richness was found in fecal samples after transportation, compared with that before transportation without distinct changes in diversity. Most notably, donkeys had significant decreases in Atopostipes, Eubacterium, Streptococcus, and Coriobacteriaceae. CONCLUSIONS AND CLINICAL IMPORTANCE: Transportation can induce stress in healthy donkeys and have some effect on the composition of the in fecal microbiota. Additional studies are required to understand the potential effect of these microbiota changes, especially significantly decreased bacteria, on the development intestinal diseases in donkeys during recovery from transportation.

Comparative proteomic analysis of seminal plasma proteins in relation to freezability of Dezhou donkey semen.

Variation in donkey sperm freezability (capacity to withstand freeze-thawing) between ejaculates is a limitation for sperm cryopreservation. Seminal plasma proteins are essential for sperm function and also related to individual differences in sperm freezability. A Tandem Mass Tag (TMT) peptide labeling combine with a LC-MS/MS approach was conducted to quantitatively identify the seminal plasma proteins differentially abundant in ejaculates with optimal freezability characteristics (GFE) compared with those with suboptimal freezability characteristics (PFE). A total of 866 proteins were identified, and 99 ejaculates were in larger abundance in GFE samples. Differentially abundant proteins (DAPs) were subjected to intensive bioinformatic analysis. The majority of DAPs were involved in metabolic processes, oxidation-reduction processes and biological regulation. Results from functional protein analysis suggested that proteins functioned in oxidoreductase activity and acid phosphatase activity. This is the first report where there were analyses of the proteome of seminal plasma from donkey ejaculates with different freezability and to identify candidate proteins that could be used to explore the molecular mechanism related to donkey sperm cryotolerance. In this study, there also was elucidation of biomarkers for the early identification and selection of donkeys with optimal semen freezability.

Daily Sperm Output, Spermatogenic Efficiency, and Sexual Behavior of Dezhou Donkey Jacks Mounting Jennies in Estrus.

This study aimed to assess the sexual behavior of jacks mounting jennies in estrus and determine the daily sperm output (DSO) and spermatogenic efficiency using two equations to calculate testicular volume (TV). Eight sexually rested mature jacks, aging 5 to 10 years old, had semen collected once a day for 10 consecutive days using jennies in good standing estrus for mounting. Sexual behavior and semen parameters were assessed during each collection. Testicular measurements of height, width, and length were taken immediately before the first semen collection, and these measurements were used to calculate TV. After that, the TV was used to predict the DSO. The average total sperm number (TSN) obtained on days 8 to 10 was deemed the actual DSO. Differences in the predicted vs. the actual DSO were used to calculate the spermatogenic efficiency. In addition, the actual DSO was also used to calculate the number of inseminating doses a jack could produce for both on- and off-site breeding. Jack's sexual behavior and sperm motility did not vary across collection days. Sperm concentration and TSN reduced over time (P < .05). The actual DSO was 9.1 ± 4.1 billion, and the predicted DSO varied from 4.7 to 18 billion. Spermatogenic efficiency varied from 50 to 150% based on jack and the equation used to calculate TV. The number of inseminating doses ranged from 15 to 47 at 300-500 million progressively motile sperm (pms)/dose for on-site breeding. In contrast, the number of breeding doses with cooled-shipped semen (1 billion pms/dose) varied from 4 to 14 doses across donkeys. In conclusion, sexual behavior was not affected by daily semen collections. Sexual rest did not affect sperm motility. The predicted DSO varied with the equation used to determine TV. Clinically normal donkeys have high spermatogenic efficiency, which confirms previous histology reports.

Multivariate models for estimating jackass semen production and quality.

The purpose of this study was to analyse the effects of season, age, gonad and accessory sex glands on semen characteristics of jackass and to construct multivariate regression models to predict semen quality. In autumn, spring and summer, semen characteristics of 30 sexually mature donkeys (1,014 ejaculations) were analysed to investigate the effect of seasons on semen quality, and gonad and accessory sex gland parameters of 12 jackasses were measured immediately after ejaculation by ultrasonography to investigate the effect of seasons on reproductive organ size. Semen (598 ejaculates), gonad and accessory sex gland parameters of 40 jackasses aged between 3 and 7 years were analysed in autumn to investigate the effects of age and reproductive organ size on semen quality and to construct multivariate models. To verify the accuracy of the models, semen (476 ejaculates), gonad and accessory sex gland parameters of 20 jackasses were measured from March to June. Results revealed that semen, gonad and accessory sex gland parameters were not affected by season and age. Progressive motility (PM) was positively correlated with long axis of the spermatic cord (LASC) and negatively correlated with percentages of sperm abnormality (PSA). Total sperm count (TSC) was positively correlated with testis circumferences (TC) and cross-sectional area of cauda epididymis (CSACE). TC, CSACE, LASC and PSA were included into multivariate models to predict PM, TSC and functional sperm count (FSC) in 20 jackasses (PM = 72.332 + 0.428 LASC - 0.441 PSA; TSC = -169.929 + 8.728 TC + 0.253 CSACE; FSC = -206.645 + 8.788 TC + 0.258 CSACE). The predicted and observed values corresponded well. In conclusion, the tested models can be used for predicting semen quality of donkey.

Practical protocols for timed artificial insemination of jennies using cooled or frozen donkey semen.

BACKGROUND: With the expansion of the donkey industry, timed artificial insemination (TAI) is becoming increasingly important in the reproductive management of jennies, however, TAI has not been widely investigated in donkeys. OBJECTIVES: To develop efficient TAI protocols for cooled or frozen semen in jennies, based around ovulation induction with a GnRH analogue. STUDY DESIGN: Experimental exploratory study. METHODS AND RESULTS: In experiment 1, the effects of different GnRH analogue (deslorelin) doses, follicle diameter (FD) at induction, repeated use of a GnRH analogue, and the influence of season on induction efficiency, as well as distribution of ovulations over time after induction were investigated. Induction efficiency was sufficient with 2.2 mg deslorelin (≥90% ovulation within 48 hours of treatment). Ovulation rate between 24 and 48 hours was highest when the FD at treatment was 31-35 mm, as compared to 25-30 mm or 36-40 mm. Repeated use of deslorelin or treatment during different seasons had no effect on induction efficiency. About 70% of ovulations occurred between 32 and 48 hours, and highest incidence of ovulation was at 36-38 hours after induction. In experiment 2, TAI using cooled semen (1 × 109 motile sperm in a 10 mL volume) was performed once at 8 hours after induction (n = 59). Pregnancy rate after TAI with cooled semen was 49.2% (29/59). In experiment 3, jennies were inseminated twice with 10 (n = 23), 5 (n = 31), 3 (n = 32), 2 (n = 82) and 1 (n = 66) straws (more than 50 × 106 motile spermatozoa in each 0.5 mL straw) of frozen semen at 34 and 42 hours after induction. The pregnancy rates were 30.4%, 35.5%, 34.4%, 29.3% and 28.8%, respectively (P > 0.05). MAIN LIMITATIONS: In the frozen semen trial, 22.5% (68/302) jennies were excluded after failure to ovulate during the appropriate time interval. In addition, there were no control groups for the AI trials. CONCLUSION: When FD reaches 31-35 mm, a donkey jenny can be inseminated once using cooled semen at 8 hours or twice using frozen semen at 34 and 42 hours after deslorelin treatment. The frozen semen TAI protocol resulted in acceptable pregnancy rates using 1 × 108 motile spermatozoa per cycle.

Timed Artificial Insemination by Combining Estrous Behavior Observation With Deslorelin Treatment in Jennies.

The purpose of this study was to determine the optimal time for ovulation induction and artificial insemination (AI) based on the relationship between estrous behavior and ovulation in jennies. Thirty-two jennies were teased by one jackass for 1 hour per day during 46 days and estrous behaviors were recorded, while the follicular development and ovulation was examined by ultrasound. Furthermore, another 31 jennies were teased by one jackass as the teasing group (group T), which were injected with Deslorelin at 2 and 4 days after the onset of estrus, and AI was performed at 8 hours after each injection. Moreover, Ultrasound was performed on the follicle development of 23 jennies as the ultrasonography group (group U). Injection with Deslorelin when the follicle diameter ≥ 30 mm, and AI was performed at 8 hours later. The results showed that mouth clapping was the specific estrous behavior of jennies and indicated the beginning of estrus. The mean time for jennies to develop dominant follicles (≥30 mm) after the onset of estrus was 3.5 ± 1.3 days, and the mean time between the onset of estrus and ovulation was 5.1 ± 1.5 days. Estrous behaviors ended 0.5 ± 1.2 days after ovulation. After AI, there were no significant differences in ovulation (96.8% vs. 91.3%) and conception rates (40.0% vs. 38.1%) between group T and U. The optimal breeding time of jennies can be determined by jackass teasing and hastening ovulation by Deslorelin injection.

Donkey genomes provide new insights into domestication and selection for coat color.

Current knowledge about the evolutionary history of donkeys is still incomplete due to the lack of archeological and whole-genome diversity data. To fill this gap, we have de novo assembled a chromosome-level reference genome of one male Dezhou donkey and analyzed the genomes of 126 domestic donkeys and seven wild asses. Population genomics analyses indicate that donkeys were domesticated in Africa and conclusively show reduced levels of Y chromosome variability and discordant paternal and maternal histories, possibly reflecting the consequences of reproductive management. We also investigate the genetic basis of coat color. While wild asses show diluted gray pigmentation (Dun phenotype), domestic donkeys display non-diluted black or chestnut coat colors (non-Dun) that were probably established during domestication. Here, we show that the non-Dun phenotype is caused by a 1 bp deletion downstream of the TBX3 gene, which decreases the expression of this gene and its inhibitory effect on pigment deposition.

Effects of long-distance transportation on blood constituents and composition of the nasal microbiota in healthy donkeys.

BACKGROUND: This study aims to determine the effects of transportation on the nasal microbiota of healthy donkeys using 16S rRNA sequencing. RESULTS: Deep nasal swabs and blood were sampled from 14 donkeys before and after 21 hours' long-distance transportation. The values of the plasma hormone (cortisol (Cor), adrenocorticotrophic hormone (ACTH)), biochemical indicators (total protein (TP), albumin (ALB), creatinine (CREA), lactic dehydrogenase (LDH), aspartate transaminase (AST), creatine kinase (CK), blood urea (UREA), plasma glucose (GLU)) and blood routine indices (white blood cell (WBC), lymphocyte (LYM), neutrophil (NEU), red blood cell (RBC), hemoglobin (HGB)) were measured. 16S rRNA sequencing was used to assess the nasal microbiota, including alpha diversity, beta diversity, and phylogenetic structures. Results showed that levels of Cor, ACTH, and heat-shock protein 90 (HSP90) were significantly increased (p < 0.05) after long-distance transportation. Several biochemical indicators (AST, CK) and blood routine indices (Neu, RBC, and HGB) increased markedly (p < 0.05), but the LYM decreased significantly (p < 0.05). Nine families and eight genera had a mean relative abundance over 1%. The predominant phyla in nasal microbiota after and before transportation were Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes. Transportation stress induced significant changes in terms of nasal microbiota structure compared with those before transportation based on principal coordinate analysis (PCoA) coupled with analysis of similarities (ANOSIM) (p < 0.05). Among these changes, a notably gain in Proteobacteria and loss in Firmicutes at the phylum level was observed. CONCLUSIONS: These results suggest transportation can cause stress to donkeys and change the richness and diversity of nasal microbiota. Further studies are required to understand the potential effect of these microbiota changes on the development of donkey respiratory diseases.

Label-free based comparative proteomic analysis of whey proteins between different milk yields of Dezhou donkey.

Donkey milk, similar to human milk in compositions, has been suggested as the best potential hypoallergenic replacement diet for babies suffering from cow milk protein allergens and a promising nutraceutical for aged people. In this study, label-free mass spectrometry analysis was conducted to quantitatively identify the whey proteins differentially expressed in high-milk-yield samples compared with low-milk-yield samples. A total of 216 whey proteins were identified, and 19 of them showed significant differences in high-milk-yield samples. Of these proteins, 16 were upregulated and 3 were downregulated. Differentially expressed proteins (DEPs) were subjected to intensive bioinformatic analysis. Results revealed that the majority of DEPs participated in protein processing in endoplasmic reticulum, estrogen signaling pathway, progesterone-mediated oocyte maturation, and PI3K-Akt signaling pathway. Functional protein analysis suggested that proteins functioned in binding, catalytic activity, molecular function regulation, structural molecule activity, and transporter activity. Our study was the first to analyze the whey protein profile of different samples of donkey milk and to identify candidate proteins that could be used to explore the molecular mechanism related to the yield traits of Dezhou donkey milk. This study provided the biomarkers for the selection of high-milk-yielding donkey and obtained valuable information for future studies.