Beef bull selection is the core of beef cattle breeding. Traditional breeding of beef bulls requires progeny testing, which has the advantages of high accuracy, however, it has the problems of long cycle for breeding, difficult to collect the slaughter and meat quality traits, and high cost, resulting in low selection efficiency. Since the concept of genomic selection was put forward in 2001, it has quickly become a hot spot in animal and plant breeding. When genomic selection was used to select the beef bulls, it can select individuals at early age, greatly shorten the generation interval, improve the prediction accuracy of low heritability traits such as reproduction traits, accelerate the genetic progress, and greatly reduce the breeding cost. In 2014, the American Angus Association began to apply the genomic selection technology, and other developed countries in Europe and the United States also successively used it. Beef cattle breeding entered the genomic era. Since 2017, China began to use the genomic selection technology to select young beef bulls. In 2020, this technology was implemented for national beef cattle genomic evaluation. The current situation of genetic evaluation in China and abroad was summarized in this article, which was respected to provide references for beef cattle breeding in China.

The spine is the backbone of the mammalian body which has high heritability and important impact on carcass length. Its number varies among species, even within the same species, such as pigs and sheep. The number of vertebra is affected by the number of somites during the embryo development. In order to further explore the regulation mechanism of spine formation and quantity variation, this article reviews the embryonic development process of the spine, the formation and regulation of important intermediate structural somites. The aim of this review is to clarify the regulation mechanism of spine formation and development and provide theoretical basis and ideas for number of vertebrae breeding in economic animals.

Freemartinism is the phenomenon that female born with co-male of heterosexual twin or multiple pregnancy is sterile, and becomes the most common type of congenital infertility in cattle. It is practically needed to develop a method of diagnosing freemartin quickly and accurately at early age, avoiding losses from rearing freemartin or eliminating fertile heterosexual twin female. In fact, freemartin itself is a potential animal model for heterochimeric symbiosis. This review summarized the diagnostic methods of freemartin via technologies of clinical examination, immunoreaction, hormone detection, cytological classification and molecular detection, emphasizing the elevation effects in accuracy and timeliness benefiting from cytomolecular technique. In the meantime, the applied production of heterosexual twin female as breeding stock and fattening resource was generalized, and its potential as animal model for solid organ transplantation, gonad development and twin-twin transfusion syndrome were also discussed. Finally, three potential ideas of heterosexual twin female, namely associations among reproductive hormone, chimerism and masculinization, the essence of chimerism from the perspective of types of chimeric tissue and chimeric time with cellular molecular and endocrinology, and taking fertile heterosexual twin female as the animal model for studying immune tolerance, were provided to promote the efficient utilization of heterosexual twin female and explore the scientific value behind them.

Corneal disease is one of the most common ophthalmic diseases in animals. Serious consequences such as vision loss, blindness and even enucleation will be caused with inappropriate diagnosis and treatment, which bring great pain and living obstacles to animals. With development for many years, veterinary ocular surface transplantation has become an effective method to treat corneal injury, save eyeball and even restore vision in animals. Different surgical methods and transplantation materials have great significance and influence on corneal healing, immune rejection, optical properties and ocular morphology. In this paper, the research progress of various ocular surface transplantation techniques and graft materials in animal corneal diseases, including indications, application characteristics and prognosis are reviewed. The purpose of this study is to provide meaningful guidance for the clinical treatment of veterinary ophthalmic.

Duck Tembusu virus disease is an emerging viral infection caused by duck Tembusu virus (DTMUV), an infectious disease characterized by a severe decrease in egg production of laying ducks and neurological symptoms in ducklings or breeding ducks. Since its outbreak in 2010, DTMUV has brought huge economic losses to the duck breeding industry in China. In this paper, we review DTMUV in terms of pathogenesis, epidemiology, innate immune response, diagnosis and prevention and control of the virus to provide a scientific basis for the diagnosis and prevention of the disease in the future.

Royal jelly is a traditional health-care product with complex chemical composition. It is secreted from the mandibular glands and hypopharyngeal glands of nurse worker bees. Royal jelly has been demonstrated to have a variety of biological functions and has been used in the field of traditional medicine, health care products and cosmetics. In this review, we reported the studies for the essential biological functions of royal jelly such as antibacterial, anti-inflammatory, anti-tumor and antioxidant, as well as its regulatory effects on immunity, blood pressure, cholesterol, blood glucose homeostasis and nerves of human beings. By summarizing the relevant researches over the last decade, we aim to provide insights into the biological functions and pharmacological activities and to provide reference to comprehensively evaluate the health care and medicinal value of royal jelly.

The purpose of this study was to analyze the sequence of chicken tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6) and TNF receptor associated factor(TRAF)-interacting proteins with a forkhead-associated(FHA) domain (TIFA), and verify their interaction. In this study, the reverse transcription products of total RNA extracted from chicken embryo fibroblasts were used as templates to amplify the CDS region of chicken TRAF6 and TIFA genes. The obtained fragments were then inserted into the plasmids pCMV-HA and pEGFP-C1 to construct the recombinant eukaryotic expression vectors pCMV-HA-TRAF6 and pEGFP-C1-TIFA, respectively. The bioinformatics software ProtParam, SOPMA, SWISS-MODEL, MegAlign and PSORTⅡ were employed to analyze the physicochemical properties, secondary and tertiary structures, amino acid homology, functional domain conservation and subcellular localization of chicken TRAF6 and TIFA proteins. The fluorescence co-localization and co-immunoprecipitation (Co-IP) assays were performed to verify the interaction between chicken TRAF6 and TIFA. The chicken TRAF6 and TIFA genes were amplified, and the recombinant plasmids pCMV-HA-TRAF6 and pEGFP-C1-TIFA were successfully constructed. Sequence analysis results showed that the CDS regions of chicken TRAF6 and TIFA genes were 1 638 and 564 bp in length, respectively, which encoded 545 and 187 amino acids with molecular weights of about 62 and 22 ku. The results of secondary and tertiary structure analysis revealed that both chicken TRAF6 and TIFA proteins were mainly composed of irregular coil and alpha helix. The amino acid homology analysis showed that the homologies of TRAF6 and TIFA proteins between chicken and human, other mammals were 76.4%-80.3% and 49.7%-53.3%, respectively, while those with Xenopus laevis were 69.4% and 49.7%, respectively. In addition, multiple amino acid site variations existed in the functional structural domains of chicken TRAF6 and TIFA proteins. Subcellular localization analysis indicated that both chicken TRAF6 and TIFA proteins were localized in the nucleus. Further fluorescence co-localization and Co-IP assays demonstrated that chicken TRAF6 protein interacted with TIFA protein in the nucleus. This study confirmed that although the low homology and conservation were presented in the TRAF6 and TIFA proteins of chicken, human, other mammals and Xenopus laevis, chicken TRAF6 protein could interact with TIFA protein in the nucleus, which lay a foundation for further studying the role of chicken TRAF6 and TIFA proteins interaction in regulating the replication of chicken related viruses.

The aim of this study was to investigate the genetic diversity and haplotype characteristics of the mitochondrial control region (mtDNA D-loop region) in different hybrid combinations of chickens. A total of 387 individual's mtDNA D-loop regions from 6 populations of Gushi chickens, Recessive White feather chickens and their reciprocal cross F1 generations, Tibetan chickens and F2 generations were sequenced to analyze their genetic laws and haplotype characteristics. Their maternal origins were analyzed by clustering with different red jungle fowl subspecies. The results showed that the full sequence of the D-loop region of the 6 populations was 1 231 bp, and a total of 28 polymorphic sites and one C-base deletion mutation were detected, constituting 19 haplotypes which were divided into 4 haplotype groups, A, B, C and E. Among them, the Gushi chicken and the reverse cross F1 generation were mainly A and C haplotypes, the proportions of A and C haplotypes in Gushi chicken were 53.42% and 46.58%, respectively, and the proportions of A and C haplotypes in reverse cross F1 generation were 50.75% and 49.25%, respectively. The dominant haplotype of Recessive White feather chicken, orthogonal F1 generation and F2 generation was E, accounting for 48.89%, 48.84% and 50.00%, respectively. The haplotype diversity (Hd) of the 6 chicken populations ranged from 0.496 to 0.729, and the nucleotide diversity (Pi) ranged from 0.003 40 to 0.005 41. The largest Hd and Pi values were detected in the orthogonal F1 generation, followed by the Recessive White feather chicken and the F2 generation, and the genetic diversities of the Gushi chicken and the reverse cross F1 generation populations were close to each other. Cluster analysis showed that the haplotype group A, B and Gallus gallus spadiceus were clustered in one group; haplotype group E and Gallus gallus murghi were clustered in another group; haplotype group C was clustered with 4 subspecies of red jungle fowl, including Gallus gallus murghi, Gallus gallus spadiceus, Gallus gallus gallus and Gallus gallus bankiva. The present study demonstrated that the mtDNA D-loop region followed strict matrilineal inheritance, and the genetic diversity and haplotype ratio of the progeny were basically the same as those of their female parent; the local chicken breeds in China had multiple maternal lineages, and mainly originated from Gallus gallus spadiceus.

The aim of this study was to develop SSR markers, and lay the foundation for the applications in genetic diversity analysis, relationship identification, and marker assisted selection in the pig production. The previous RNA-seq results of longissimus dorsi of 6-month-old Large White pig and Mashen pig were used to predict SSR markers. A total of 154 SSRs were selected randomly based on the chromosome locations, base types, repeat numbers of SSR markers, and the amplification primers of the selected SSRs were designed and synthesized. The polymorphic SSR markers were developed by PCR, PAGE analysis and cloning sequencing verification, and used to investigate the genetic diversity of 6-month-old Mashen pig, Large White pig, Jinfen White pig, and Shanxi Black pig(30 individuals from each breed) for assessing the practicability of the developed SSR markers. The result showed that a total of 10 488 SSRs were identified from 36 693 Unigene of transcriptome sequences. There were 9 424 homozygous SSRs and 1 064 compound SSRs, which distributed in 6 953 Unigene sequences. A total of 4 727 Unigene contained the single SSR, and 2 226 Unigene contained two or more SSRs. The occurrence and appearance frequency of SSR were 18.95% and 28.58%, respectively. The dominant SSR repeats were mononucleotide, trinucleotide and dinucleotide, and the largest number of repeats mainly ranged from 5 to 22 times. The most repeated primitive sequences were A/T, AC/GT and GCC/GGC. The dominant repeat motif length type was 10-20 bp. A total of 154 sites were randomly screened for verification, and 124 pairs of SSR primers could amplify the bright and specific bands, the amplification efficiency was 80.52%, among them, 25 pairs of SSR primers were polymorphic, accounting for 16.23%. The polymorphism of 120 pigs from Mashen pig, Large White pig, Jinfen White pig and Shanxi Black pig was analyzed using 25 pairs of SSR primers. A total of 131 alleles were identified, and the range of allele number was 2-7, the average allele number and effective allele number was 5.24 and 3.487 1, respectively. The average PIC value was 0.646 7, which indicated the sites were highly polymorphic, and the genetic diversity of the tested populations was high. This study results indicated that it was feasible to develop SSR markers based on RNA-seq result in pig, and the developed SSR marker enriched the pig SSR database. The developed SSR markers in this study were reliable and highly polymorphic, and could be used to investigate pig genetic diversity.

Based on the results of genome genetic evaluation and dairy herd improvement (DHI) data of Holstein cows in China, this study aimed to validate the effects of genomic selection of Holstein bulls in China. Based on the genomic evaluation results of 1 686 bulls calculated in December 2019 and their daughters' phenotypic values of milk production and type traits, by using R software and Excel, the correlation between genomic estimated breeding values (GEBVs) and progeny testing results was analyzed, and the daughters' phenotypic values among the different groups for GEBVs was compared. The correlation analysis results showed that the genomic China performance index (GCPI) values of Holstein young bulls were positively correlated with the China performance index (CPI) values of progeny (r_s>0.3). Highly positive correlations (0.4 < r_s < 0.8) between the GEBVs and EBVs for milk yield and somatic cell score (SCS) were observed. Analysis of the daughter's phenotype data showed that the trends of daughters' phenotypic values in milk yield, milk protein percentage, milk fat percentage and feet and legs score were consistent with the GEBVs grouping of bulls, the phenotypic values of daughters of the most traits were significantly different among the GEBV groups of bulls (P<0.01). The trends between GEBV grouping of bulls and phenotypic values of daughter for milk yield, SCS and feet and legs score in Beijing and Shanghai regions were more consistent than that in other provinces, the differences between the highest and lowest GEBV groups in Beijing and Shanghai regions were higher than those in other regions. Based on the genomic selection results of 1 686 Holstein bulls and the phenotypic data of their daughters, it was found that the genomic selection of Holstein young bulls in China was effective, in which the phenotypic data of milk yield, milk protein percentage, SCS and feet and legs score better presented the effects of genomic selection. The data from Beijing and Shanghai regions can better reflect the effects of genomic selection than that from other provinces, likely due to their better performance testing data.

The purpose of this study was to accelerate the genetic progress of Chinese Simmental beef cattle and realize nationwide joint breeding. The birth weight traits of 3 991 Chinese Simmental beef cattle born from 2000 to 2019 at 38 beef breeding farms and bull stations in China was used to calculate the connectedness rate between farms by DMU software. And the predicted accuracy of estimated breeding value(EBV) and heritability was compared between single-farm and connectedness group. This study found that the national average connectedness rate of Chinese Simmental beef cattle was 1.91%, there was a low connectedness rate between the most farms. According to the connectedness rate, two connectedness groups were divided, which included 6 and 8 farms, respectively. The average connectedness rates within the two groups were 11.23% and 12.54%, respectively. The range of heritability for birth weight in single-farm evaluation was 0.32-0.44. The heritability of joint evaluation group-1 and group-2 were 0.47 and 0.43, respectively. The average accuracy of estimated breeding value in the single-farm evaluation of group 1 and group 2 was 0.47 and 0.45, respectively. The average accuracy of estimated breeding value in the joint evaluation of group 1 and group 2 was 0.61 and 0.56, respectively. The accuracy of estimated breeding value in joint evaluation was obviously higher than that in single-farm evaluation. Dividing the joint evaluation groups according to the connectedness rate for joint breeding is beneficial to speed up the breeding process of Chinese Simmental beef cattle. In order to promote the breeding process of Chinese Simmental beef cattle, regional joint breeding should be formed first, and then genetic association should be gradually strengthened to form a nationwide genetic association system.

The aim of this study was to explore whether miR-148a-3p could target PPARγ to regulate the production of steroid hormone in granulosa cells of goose. In the present study, 12 healthy and high-laying maternal Tianfu meat female geese were used for sample collection and culture of granulosa cells in vitro. Quantitative polymerase chain reaction (qPCR) was used to detect the expression profile of miR-148a-3p at different stages of granulosa layers in follicles of goose. MEGA 7 software was used to identify the conservation of miR-148a-3p in different species. Target genes of miR-148a-3p were predicted and validated via double luciferase report system. miR-148a-3p mimics and inhibitor were transfected into goose granulosa cells, and the expression levels of target gene and downstream genes were examined by qPCR. Meanwhile, ELISA was used to measure the changes of hormone levels. The results showed that miR-148a-3p was highly conserved in different species. The expression level of miR-148a-3p firstly increased and then decreased during the follicles development of goose. In the culture of goose granulosa cells in vitro, the expression level of 3β-HSD and the progesterone production significantly decreased after the transfection of miR-148a-3p mimics(P<0.05), while the above indicators increased after the transfection of miR-148a-3p inhibitor (P<0.05). Bioinformatic analysis and double luciferase report system demonstrated that PPARγ was the target gene of miR-148a-3p. The expression level of PPARγ significantly decreased after transfection of miR-148a-3p mimics in granulosa cells(P<0.05), while that increased after transfection of miR-148a-3p inhibitor(P<0.05). After interfering PPARγ, the expression level of 3β-HSD significantly decreased(P<0.05), and the progesterone production also decreased. These results demonstrated that miR-148a-3p could target PPARγ to inhibit the expression of 3β-HSD and decrease the progesterone production in granulosa cells of goose.

The objective of this study is to investigate the effects of prostaglandins (PGs) D₂ and F_2α on the corpus luteum tissue morphology, reproductive hormones and the expression of key genes and receptors in female sheep. Meanwhile, the interrelationship and mechanism of the above factors in the degradation of the corpus luteum are analyzed, which can provide a new theoretical basis for ensuring the continuous breeding of female animals. Sixteen Kazakh sheep were randomly divided into 4 groups, and were injected intramuscularly in uterus with PGD₂, PGF_2α, PGD₂+PGF_2α and normal saline (control group) during the luteal phase of the estrus cycle, respectively. HE staining combined with physical photographs were used to compare the morphological changes of the corpus luteum before and after the treatment. ELISA method was used to detect the changes in the concentration of P₄, E₂, PGD₂ and PGF_2αin the peripheral serum; qRT-PCR and Western blot were used to detect the key synthase genes HPGDS, PGFS and their receptors (DP1, CRTH2, FP) mRNA and protein expression levels. Results showed that, compared with the control group, the corpus luteum degeneration effect was the most obvious in the PGD₂+PGF_2α group, followed by the PGF_2α group and PGD₂ group. ELISA results showed that with the passage of time after treatment, P₄ concentration in different experimental treatment groups showed a significant downward trend (P<0.05), and the change trend was the most significant in the PGD₂+PGF_2α group (P<0.05). However, the concentrations of E₂, PGD₂ and PGF_2α showed different differences in different groups. Among them, the PGD₂ and PGF_2α concentrations in the PGD₂+PGF_2α group were significantly decreased (P<0.05); the E₂ concentration was significantly increased (P<0.05), and the PGD₂ concentration was significantly decreased (P<0.05) in the PGF_2α group; the E₂ concentration was significantly decreased (P<0.05), and the PGD₂ concentration was significantly increased (P<0.05) in the PGD₂ group. Results of qRT-PCR and Western blot showed that, compared with the control group, HPGDS mRNA and protein expression were significantly down-regulated (P<0.05), but PGFS, CRTH2 and FP mRNA and protein expression were significantly up-regulated (P<0.05) in PGD₂+PGF_2α group; In the PGF_2αgroup, HPGDS mRNA and protein expression were significantly down-regulated (P<0.05), and the mRNA and protein expression levels of other genes were significantly up-regulated (P<0.05); In the PGD₂ group, the expressions of HPGDS, DP1, PGFS and FP mRNA and protein were significantly up-regulated (P<0.05). Meanwhile, in the detection of gene expression of different receptors, it was found that the expression of DP1 receptor was significantly higher than that of the CRTH2 receptor in the PGD₂ group (P<0.05), while the expression of CRTH2 was significantly higher than that of DP1 in the PGF_2α group (P<0.05). In summary, the above results showed that whether PGD₂ was used alone or in combination with PGF_2α, it could promote the degradation of CL, especially when the two were combined, which had an obvious synergistic effect to promote dissolution of CL. This mechanism may be related to the hormones level, the expression of key synthetases and receptor types in vivo, which lays a foundation for a comprehensive understanding of the regulatory mechanism of CL degradation in mammals, and provides a new idea for further optimization of efficient reproductive technology (especially PGs scheme).

In order to improve in vivo embryo production efficiency and optimize the screening criteria for donor Holstein cows, this study analyzed the correlation between the peripheral blood AMH concentration with embryo production efficiency in Holstein young cows during the process of superovulation of donor cattle. In this experiment, 96 Holstein young cows were selected, after superovulation, peripheral blood was collected from caudal roots on the day of CIDR implantation, artificial insemination and embryo recovery to detect AMH concentration, and divided into 3 groups according to high (25% of the highest concentration distribution), medium (25%-75% of the middle concentration distribution) and low (25% of the lowest concentration distribution) AMH concentration. The difference in the average embryos number per donor, average usable embryos number per donor, average degenerated embryos number per donor and average unfertilized oocytes number per donor among 3 groups were compared and analyzed. The results showed that:1) The detection results of AMH concentration in peripheral blood showed that the concentration of AMH decreased from CIDR implantation to embryo recovery. 2) On the day of CIDR implantation, the average embryos number per donor in AMH high-concentration group (9.38±1.24) was significantly higher than that in AMH medium-concentration group(6.47±0.56, P<0.05), indicating that donor cattle with high AMH concentration on the day of CIDR implantation had better superovulation effect and more embryos recovered; However, the average unfertilized oocytes number per donor in AMH high-concentration group was significantly higher than that in other two groups (P<0.05); It means that some oocytes failed to be fertilized, which might be due to the fact that more follicles of cows in the high-concentration group dominated, and the prolonged ovulation cycle caused some oocytes to fail to complete normal fertilization. 3) The results of AMH data analysis on the day of artificial insemination and embryo recovery showed that there were no significant differences in various embryo production indicators among the 3 groups (P>0.05). 4) The effect of body weight of donor cattle on the in vivo embryo production efficiency was investigated, the results showed that the difference in embryo production efficiency among individuals with different body weight was not significant (P>0.05), the number of available embryos and the number of retrieved embryos of cows in moderate body condition group were higher than that in other two groups, especially higher than that in the over-weight group. Therefore, the concentration of AMH in peripheral blood on the day of CIDR implantation can be used as one of the screening criteria for donor cattle, and the donor heifer should own appropriate body condition score.

The purpose of this study was to establish the protocol of isolation, culture and identification of sertoli cells from yak and cattle-yak, and to compare the biological characteristics of sertoli cells between yak and cattle-yak. Testis tissues were collected from 3 healthy male yaks and 3 F1 cattle-yaks aged 24 months to constitute 2 sample groups with 3 biological replicates in each group. The sertoli cells from yak and cattle-yak were separated by mixed enzyme digestion, differential adhesion and starvation treatment. DMEM high glucose and DMEM/F12 medium were used to culture sertoli cells to select an optimum culture system. Alkaline phosphatase staining, Oil red O staining and immunofluorescence staining were employed to identify the phenotypic characteristics of sertoli cells. CCK8 and RT-qPCR methods were used to detect proliferative activity and functional gene expression of sertoli cells. The sertoli cells from yak and cattle-yak were further treated with different concentrations of mitomycin C to evaluate the tolerance of sertoli cells and their potential as feeder cells. The sertoli cells from yak and cattle-yak were successfully isolated, and a long-term in vitro culture program for testicular sertoli cells was successfully established. DMEM high glucose medium was more suitable for the proliferation of sertoli cells. There were no significant differences between two types of sertoli cells, which presented the clear cellular profile and a polygonal or long spindle morphology. The proliferation capacity and viability of sertoli cells of yak were better than that of cattle-yak. The expressions of GDNF, CXCL12, TGF-β1 genes related to spermatogonial proliferation and differentiation were significantly changed in sertoli cells of yak and cattle-yak. The expression of GDNF and TGF-β1 were down-regulated with 3.4 and 2.9 folds in the cattle-yak sertoli cells (P<0.05), the expression of and CXCL12 was up-regulated by 3.6 folds (P<0.05). The expressions of SOX9 and WT1 genes related to testicular development and sertoli cell markers were down-regulated by 25.9 (P<0.01) and 38.7 folds (P<0.01) in the cattle-yak sertoli cells, respectively. Compared with yak, cattle-yak sertoli cells possessed poorer tolerance to mitomycin C treatment and the cultured cells presented unclear boundaries between cytoplasm and nucleus, severe cytoplasmic vacuolation and more dead cells. This study successfully established the protocol of isolation, culture and identification of sertoli cells from yak and cattle-yak. Compared with yak, the cattle-yak sertoli cells have defects in proliferation activity, testicular development and functional gene expressions for spermatogonial differentiation, which may be one of the reasons for sterility of cattle-yak.

This study aimed to explore the effect of piceatannol (PIC) on the oxidative damage, mucosal morphology, and barrier function in the jejunum of weaned piglets challenged with diquat (DQ). Fifty-four male piglets (Duroc×[Landrace×Yorkshire]) in good health with an average body weight (BW) of (8.13±0.41)kg were selected and randomly divided into 3 groups (each treatment group contained 6 replicates with 3 piglets per replicate). Piglets in the CON and DQ-CON groups were orally administered with a vehicle solution contained 0.5% carboxymethylcellulose sodium, while piglets in the DQ-PIC group were orally administered with 0.5% carboxymethylcellulose sodium solution supplemented with PIC at a dosage of 80 mg·kg^-1. Piglets in DQ-CON and DQ-PIC groups were challenged with DQ at a dosage of 10 mg·kg^-124 h before slaughter, while the piglets in CON group were treated with an equal sterile saline. This treatment protocol trial lasted for 8 days. The damage of jejunum, the activity of antioxidant enzymes and the expression of genes were determined after slaughter at 36-day-old. The results showed that:1) Compared with the CON group, plasma diamine oxidase (DAO) contents of piglets in the DQ-CON group significantly increased (P<0.05), and the expression of jejunal tight junction (OCLN) gene significantly decreased (P<0.05); Compared with the DQ-CON group, plasma DAO contents of piglets in the DQ-PIC group significantly decreased (P<0.05), and the expression of OCLN gene significantly increased (P<0.05). 2) Compared with the CON group, the total superoxide dismutase (T-SOD) activity, catalase (CAT) activity and the relative expression of superoxide dismutase 1 (SOD1) significantly decreased (P<0.05), and the content of malondialdehyde (MDA) significantly increased (P<0.05). Compared with the DQ-CON group, the jejunal mucosal T-SOD activity, CAT activity, SOD1 gene and HO1 gene relative expression levels of piglets in the DQ-PIC group significantly increased (P<0.05), while the MDA content significantly decreased (P<0.05). Therefore, piceatannol can alleviate the oxidative stress damage of the piglet's jejunum induced by diquat and improve the antioxidant capacity of the jejunum and promote the restoration of intestinal morphology and barrier function.

This experiment was conducted to study the effects of 15 mg·m^-3 H₂S exposure for different duration on the growth performance, blood physiological and biochemical indicators and the health of the main respiratory, circulatory, metabolic and immune organs in weaned piglets. Twelve healthy 35-day-old weaned piglets with an average body weight of (11.25±0.69) kg were randomly divided into 2 groups with 6 replicates per group and half males and half females in each group. The piglets were fed in 2 sealed environment controlled chambers, respectively. The concentration of hydrogen sulfide in the control group was 0 mg·m^-3, the concentration of hydrogen sulfide in the experimental group was 15 mg·m^-3. The experiment lasted for 28 days. The growth performance, blood physiology and biochemistry indicators, organ indexes and histopathological observation were measured. The results showed as follows:1) The results of growth performance:Compared with the control group, there were no significant changes in ADFI, ADG and F/G in experimental group (P>0.05). 2) The results of blood routine indexes:In the experimental group, MCV, PCT, MPV and PDW were significantly increased (P<0.05) and MCHC were significantly decreased (P<0.05) after 2 days of H₂S exposure; LYM% and MCH were significantly increased (P<0.05) and RBC were significantly decreased (P<0.05) after 14 days of H₂S exposure. GRA%, HGB, MCH and PDW were significantly increased (P<0.05) after 28 days of H₂S exposure, while PLT and PCT were significantly decreased (P<0.05). 3) The results of the serum biochemical indexes related to liver, heart and kidney functions:Serum TP, ALT, TBIL and CK in experimental group were significantly increased (P<0.05) after 2 days of H₂S exposure. There were no significant differences in biochemical indexes related to liver, heart and kidney functions after 14 and 28 days of H₂S exposure (P>0.05), respectively. 4) The results of serum immune-related indicators:In the experimental group, IgA was significantly increased (P<0.05) after 2 days of H₂S exposure, and there were no significant differences in all indicators after 14 days of H₂S exposure (P>0.05); IgA, IgM and CRP were significantly increased (P<0.05) within 28 days of H₂S exposure. 5) The results of organ indexes and histopathology:There were no significant changes in the organ indexes of lung, liver, heart, kidney, spleen and thymus (P>0.05) within 28 days of H₂S exposure. Histopathological observation revealed that slight inflammatory damage was found only in the lung, while no pathological damage was observed in the other organs. The above results showed that for the weaned piglets under different exposure times at the concentration of 15 mg·m^-3 H₂S, a short period of exposure may cause immune response as well as liver and heart injury. Then with the time accumulation of exposure, each organ proceeded compensatory repair by itself and enhanced the adaptability. But long time exposure induced slight inflammatory injury in lung, ultimately not conducive to the growth and health of weaned piglets.

The objective of this study was to investigate the effects of grazing in nature pasture and fattening in house on meat quality, nutritional components of yaks in cold season. Theoretical data has been provided for evaluating the quality of yak meat nutritional regulation of short-term fattening in cold season. A total of 12 5-year-old healthy and no disease male yaks with similar body weight ((270±10) kg) were selected. The yaks were randomly divided into 2 groups:grazing and barn feeding fattening groups, 6 replicates in each group. At the same time, the animals were grazed in nature pasture and fattened in house with total mixed rations (TMR), respectively, the test period was 120 days. At the end of the fattening trial, the two groups of yaks were slaughtered and 500 g of longissimus dorsi (LD), biceps brachii (BB) and biceps femoris (BF) were collected, respectively, for the determination of meat quality (processing quality and edible quality) and nutritional components. The results showed that:1) After barn feeding fattening, the meat color luminance values(L^*) of the 3 parts significantly improved (P<0.05), however, the redness values (a^*) were significantly decreased(P<0.05); The water loss rate of LD was significantly decreased(P<0.05), and the water loss rate of BB and BF were extremely significantly decreased(P<0.01);The cooking loss and shear force of LD were extremely significantly decreased(P<0.01); The cooking loss and shear force of BB and BF were significantly decreased(P<0.05). 2) The effect of fattening in house on contents of moisture, protein, fat, calcium and phosphorus in different parts of yak muscle were extremely significant (P<0.01); However, the ash content was only significantly affected in LD (P<0.01). 3) The contents of essential amino acids (EAA) and non-essential amino acids (NEAA) in LD were significantly affected by fattening in house(P<0.05), while the contents of essential amino acids (EAA) and non-essential amino acids (NEAA) in other two parts of muscle had no significant change(P>0.05); In the three parts of muscle, the main fatty acids were C_16:0, C_18:0, C_18:1N₉C, C_18:2N₆C and C_20:4N₆; The content of polyunsaturated fatty acids (PUFA) in each part of muscle was extremely significantly decreased (P<0.01), the content of monounsaturated fatty acids (MUFA) was extremely significantly increased (P<0.01), and the ratio of n-6/n-3 was decreased in each part of muscle. The results indicated that, compared with natural grazing, the luminance and the redness of yak meat were affected by fattening in house, the processing quality of yak meat was improved, the cooking loss was reduced, at the same time, the general nutritional components of yak meat were higher than that of grazing yak. The amino acids composition and protein quality in longissimus dorsi of fattening yaks were better than that of grazing yaks. Fattening in house sacrifices some rich, healthy fatty acids in muscle, but the fat content increased, which can greatly improve the edible quality and tenderness of yak meat.

The previous research data showed that the expression level of cathepsin S (CTSS) in sow colostrum was significantly higher than that of mature milk and CTSS has the effect of inhibiting virus replication. This study aims to explore the effect of pig-derived CTSS on the replication of foot-and-mouth disease virus serotype O (FMDV-O) and the production of antiviral cytokines induced by FMDV-O.PK-15 cells were infected with FMDV-O. The effect of FMDV-O infection on the expression of endogenous CTSS was investigated by RT-qPCR and Western blot at the transcriptional and translational level, respectively, and the effect of FMDV-O infection on the enzyme activity of CTSS in vitro was determined by CTSS activity detection kit. According to the CTSS gene sequence (XM_021089893.1) published by GenBank, the eukaryotic expression plasmid of CTSS was constructed and transfected into PK-15 cells by liposome. The expression of CTSS was detected by Western blot. On this basis, the effect of overexpressed CTSS on FMDV-O replication and the level of antiviral cytokine mRNA induced by FMDV-O was detected by Western blot and RT-qPCR, and three pairs of siRNA specific to CTSS were designed and synthesized. Western blot and RT-qPCR were used to detect the changes of CTSS and FMDV-O. The results showed that PK-15 cells infected with FMDV-O could significantly up-regulate the expression of porcine CTSS and enhance the activity of CTSS enzyme; overexpression of CTSS could inhibit the replication of FMDV-O in PK-15 cells, which may be through promoting the production of antiviral cytokines induced by FMDV-O; the interference sequence siRNA-2947 down-regulated the expression of endogenous CTSS and promoted the replication of FMDV-O. Porcine CTSS promoting the production of host antiviral cytokines may be one of the reasons for inhibiting FMDV-O replication. This study provides a basis for further exploring the role and mechanism of host CTSS in anti-FMDV innate immune response.

Growth arrest and DNA damage 45β (GADD45β) is involved in various cellular signaling pathways and plays an important role in viral infection, but there are few studies on avian leukosis virus (ALV) infection. In this study, we used RT-qPCR and Western blot to detect the expression level of GADD45β in DF-1 cells infected with ALV-J. To investigate the effect of GADD45β on the replication of ALV-J, immunofluorescence, Western blot and ELISA were used to detect the effect of overexpression of GADD45β and interference of GADD45β on ALV-J replication. The results showed that the protein level of ALV-J was decreased after overexpression of GADD45β. However, when interfering the expression of GADD45β, the replication of ALV-J showed the opposite effect, indicating that GADD45β inhibited the replication of ALV-J. This study found for the first time that GADD45β has the effect of inhibiting the replication of ALV-J, which is of great significance and value for ALV-J-related research.

To understand the genetic variation of a strain (GD-1) of canine distemper virus (CDV) from captive red panda, the H and F genes of the CDV were cloned by RT-PCR, then were sequenced and analyzed. The results showed that the H gene sequence of this isolate had the highest nucleotide similarity (96%) with the CDV strain (accession number:GU266280) reported from Denmark in GenBank, and the F gene sequence had the highest nucleotide similarity with the CDV strain (accession number:KY057355) reported from Brazil. The sequences of CDV representative strains were downloaded for genetic evolution, amino acid sequence alignment and molecular characterization analysis. The results showed that there were 8 potential N-glycation sites in H protein, which were located at sites 19, 149, 309, 391, 422, 456, 587 and 603, respectively. The amino acid sequence of the SLAM receptor binding site of H protein was the same as that of Eurasian wild type virulent strain. Compared with the vaccine strains, the amino acid sequences at positions 530, 549 were different. Compared with other CDV reference strains, there were significant variations in H protein at 24 and 41 sites. The amino acid homology between H protein and standard virulent strain A75/17 was 95.2%. The amino acid sequence similarity with five vaccine strains such as Onderstepoort and Convac was 88.2%-89.3%. There were six N-glycosylation sites in F protein, which were located at 62, 108, 141, 173, 179 and 517 sites, respectively. The amino acid similarity between F protein and other vaccine strains ranged from 89.1% to 89.7%. Compared with other reference strains, there were eleven amino acid mutations in 115, 130 and so on. The genetic evolution tree based on H and F genes was constructed. The results showed that the strain was located in a small evolutionary branch of Asia-4 type, which was different from the current epidemic strains mainly located in Asia-1 type in China. In this study, the Asia-4 genotype CDV wild strain from red panda was reported for the first time, and the H and F genes of the strain were sequenced, which is of great significance for the study of genetic variation, epidemiological investigation, disease prevention and control and vaccine development of CDV epidemic strains in China.

Taking Escherichia coli (E. coli) K1 strain DE058 as a host, a virulent phage PNJ1809-36 was isolated from chicken feces. The biological characteristics and genome analysis of this phage were studied. Phage PNJ1809-36 was isolated and purified, whereafter, the biological characteristics of the phage were studied by analyzing the morphology, optimal MOI, one-step growth curve, temperature and acid-base tolerance, and lysis curve in vitro. Moreover, the whole genome of the phage was sequenced and analyzed. The results showed that phage PNJ1809-36 formed transparent plaque with a clear boundary. Under microscopy, phage PNJ1809-36 presented a contractile tail, indicating that it belongs to Myoviridae. The result of host range test showed that phage PNJ1809-36 specifically targeted E. coli with K1 capsule. The optimal MOI of phage PNJ1809-36 was 0.01. One-step growth curve showed that the latent and explosive period was 10 min and 40 min, respectively. Phage was stable at 40 and 50℃, while lost activity at 60℃ for 30 min. Phage PNJ1809-36 could maintain activity under conditions of pH 3-11, with the optimal pH 6; The lysis curve showed that the phage could continuously inhibit the growth of host bacteria for 6 h. Genomic analysis showed that it had low sequence identity with early reported E. coli K1-specific phage, such as K1F and K1E, but presented over 90% sequence homology with newly discovered E. coli K1-specific phage at nucleic acid level, such as nepoznato, PVP-SE1, and phAPEC8. PNJ1809-36, a lytic phage targeting E. coli K1, belongs to a new phylogenetic branch of Myoviridae. Due to the specificity to E.coli K1, phage PNJ1809-36 has the potential to identify and control the diseases caused by E. coli K1.

This study aimed to explore the immunogenicity and protective effects of CbpB protein of Erysipelothrix rhusiopathiae, and to provide new ideas and technical reserves for the further development of ER genetic engineering subunit vaccine. Mice were immunized with the expressed ER recombinant proteins CbpB, SpaA, CbpB+SpaA, ER inactivated whole cell (V-AEr21), commercial attenuated vaccine, and commercial inactivated vaccine, respectively. Indirect ELISA was used to detect the level of IgG antibodies. The challenge test was selected to determine the immune protection rate. Tissue bacteria count test was conducted to determine ER colonization. Mouse tissue organs (spleen, lung, liver, and kidney) were collected to prepare slices and observe pathological changes. Compared with the commercial attenuated vaccine with the strongest immunogenicity, the IgG antibody produced by CbpB and SpaA was only 1:6 400, but the bactericidal efficacy of serum was high. The immune challenge protection rate of mice was the same as that of commercial attenuated vaccine, which was 100%, and there was no bacterial colonization in spleen, lung, liver and kidney, and there was no significant difference between histopathological observation and blank control. There was no difference between CbpB and SpaA. CbpB recombinant protein has good immunogenicity and protective efficacy, can stimulate the body to produce humoral immunity and cellular immunity, and can be used as a candidate antigen for swine erysipelas genetic engineering subunit vaccine.

This experiment was conducted to investigate infection of Bartonella and spotted fever group rickettsiae in Melophagus ovinus in Shiqu County, Sichuan Province. M. ovinus collected from Tibetan sheep were classified by morphological identification. Total DNA of all M. ovinus were extracted and partial sequences of gltA and rpoB genes of Bartonella, and OmpA and OmpB genes of Rickettsia were amplified by PCR, respectively. The positive products were sequenced and compared through the NCBI database and phylogenetic trees were constructed based on gltA, rpoB, OmpA and OmpB for determination of Bartonella and Rickettsia, respectively. A total of 407 adult M. ovinus were collected in four villages in Shiqu County. Bartonella melophagi was detected in all four villages, with a total infection rate of 14.0% (57/407). Rickettsia raoultii was detected in Arizha, Gayi and Changxgma, with a total infection rate of 11.1% (45/407). The infection rate in Changxgma was significantly higher than that in Arizha and Gayi (P<0.05). Rickettsia sp. was only detected in Xinrong, with a total infection rate of 6.6% (8/121). No co-infection was observed in this study. In Shiqu, Tibetan sheep is the biological vector of Bartonella and Rickettsia. In this study, B. melophagi, R. raoultii and Rickettsia sp. were first detected in M. ovinus in Shiqu County.

This study aimed to investigate the relationship between the expression level of porcine m⁶A methylases WTAP and resistance to E. coli infection. In this study, the small intestine tissues of 35-day-old Sutai piglets (Sus scrofa) were collected from 4 individuals of E. coli resistant-and sensitive-type. RT-qPCR was used to detect the expression level of WTAP in the duodenum, jejunum of E. coli resistant-and sensitive-individuals. The mRNA expression level of the WTAP gene in intestinal epithelial cells (IPEC-J2) was detected respectively after Escherichia coli F18ab and F18ac stimulation and lipopolysaccharide (LPS) induction. At the same time, the interference vectors of the WTAP gene were constructed and transfected into IPEC-J2 cells, and the effect of gene silencing on the adhesion ability of E. coli was detected by pili protein detection, colony count and indirect immunofluorescence assay. Results showed that the expression level of the WTAP gene in duodenum and jejunum of resistant individuals were significantly higher than that of sensitive individuals (P<0.01). After F18ab and F18ac stimulation, the expression level of the WTAP gene was significantly decreased, which was consistent with the results after 6 h LPS induction (P<0.01). Meanwhile silencing the WTAP gene could significantly increase the adhesion ability of E. coli (P<0.01). This study verified that the high expression level of m⁶A methyltransferase WTAP may improve the ability of piglets to resist E. coli infection and laid a foundation for further RNA methylation investigation of the regulatory mechanism of E. coli infection in piglets.

This experiment aimed to study the effects of fine particulate matter (PM_2.5) from pig house on the arginine metabolism, expression of inflammatory cytokines and macrophage polarization markers in primary porcine alveolar macrophages (PAMs). Bronchoalveolar lavage was conducted to isolate PAMs. After PAMs were purified, Diff-quik staining were used to identify PAMs and F4/80 labeling were used to identity PAMs, and cell viability of PAMs was determined. The PAMs were further divided into the control and the PM_2.5 (50 μg·mL^-1) groups, continuing cultured for 4, 8, or 12 h to determine cell viability, the cellular supernatant was collected to detect the concentration of nitric oxide (NO), PAMs were lysed to detect the activity of arginase, and RT-PCR was used to detect the relative expression of cytokines IL-1β, TNF-α and IL-10, and the relative expression of M1 and M2 markers CD80 and CD206 in PAMs. The results showed that PAMs were successfully isolated by bronchoalveolar lavage and purified, the cell viability of PAMs gradually decreased when the culture time was increased (P<0.05). After PM_2.5 treatment, the concentration of NO in the cellular supernatant was significantly increased (P<0.05) and the activity of arginase significantly decreased (P<0.01). The mRNA expression of inflammatory cytokines IL-1β and TNF-α were significantly increased (P<0.01), and the mRNA expression of IL-10 was decreased (P<0.05). In the early stage of PM_2.5 treatment, the mRNA expression of CD80 was significantly increased (P<0.01), and the mRNA expression level of CD206 was significantly decreased in the later stage (P<0.01). These results suggested that PM_2.5 from pig house promotes PAMs to the M1 polarization and promotes the development of inflammation.

This experiment was conducted to study the CT and MRI features of cerebral coenurosis in sheep. Three Xinjiang fine-wool sheep with typical symptoms of cerebral coenurosis were selected, then neurological examination, blood routine, and serum biochemical examination were performed. CT and MRI examinations were performed on two sheep's heads, and the pathological autopsy was performed on all the sheep after the CT and MRI scan to observe the changes. Results were as follows:1) Neurological examination results showed that all animals had nystagmus, bilateral palpebral reflexes, and corneal reflexes of the animals were weakened, and the animals' righting reactions and bilateral wheelbarrowing reactions were abnormal, and no obvious abnormalities in blood routine and serum biochemical examination were found. 2) In the CT images of the sheep, varying amounts of intracranial cystic hypoattenuating structures with a clear margin can be observed, in which CT values were similar to cerebrospinal fluid (CSF). Mass effect correlated with the hypoattenuating structures can be observed as well, and a large number of punctate isoattenuating or hyperattenuating structures invaginated in clusters on the cyst wall can be seen, which were found to be protoscolices. No obvious abnormal attenuating images in the rest of the brain tissue were found; In the MRI images of the sheep, varying amounts of intracranial cystic lesions can be observed, the cystic lesions were characterized by a high signal on T2WI and low signal on T1WI, being accord with CSF signal. Punctate protoscolices embedded in the cyst wall were iso-signal on T1WI and low signal on T2WI, no perilesional abnormal signal was found. 3) Pathological autopsy revealed parasitic cysts filled with clear cystic fluid, which contained varying numbers of protoscolices, the location of the parasitic cysts was consistent with the imaging findings. These results indicated that sheep cerebral coenurosis has characteristic CT and MRI features. Combing two imaging diagnostic methods can accurately locate the parasitic cysts and show the involvement of the surrounding tissues, which is helpful for veterinarians to make surgery treatment plans.

To explore the oxidative stress response of adipose-derived mesenchymal stem cells-conditioned medium (ADSCs-CM) on liver injury in miniature pigs. In this experiment, 24 healthy miniature pigs were selected and randomly divided into four groups, namely model group (IRI), DMEM control group (DMEM), ADSCs-CM treatment group (CM) and ADSCs treatment Groups (ADSCs), six pigs each group. All four groups, laparoscopic techniques were used to establish the liver injury model of miniature pigs with ischemia reperfusion (IR) combined with partial hepatectomy. The pigs in the IRI group were transplanted with normal saline, the pigs in the DMEM group were transplanted with concentrated basal medium, and the pigs in the CM group were transplanted with concentrated adipose-derived stem cell culture medium, the pigs in the ADSCs group were transplanted with adipose stem cells. Blood and liver tissue samples were collected in each group before the operation, 1 day, 3 days and 7 days after the operation. Use liver function test kit to detect total bilirubin (T-BIL), lactate dehydrogenase (LDH), and total protein (TP) in sera; use oxidation reaction kit to detect malondialdehyde (MDA), intramedullary peroxidase (MPO), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase in liver tissue (GSH-Px) for detection. Results were as follows:1 day and 3 days after operation, the model group and the control group had severe liver function damage, with obvious oxidative stress. The CM and ADSCs treatment groups significantly promoted the recovery of liver function, and the expression of oxidative stress related indicators decreased significantly compared with the model group and the control group. After 7 days, each group basically recovered to the preoperative level. The results showed that laparoscopic liver ischemia-reperfusion combined with partial hepatectomy injury can cause oxidative stress in miniature pigs. Adipose-derived mesenchymal stem cells and their condition medium can improve oxidative stress after liver injury.

The aim of this study was to establish a chemiluminescence detection method for antibody against classical swine fever virus (CSFV), CSFV E2 protein was employed as the antigen, which was probed and bound by goat anti-pig IgG-HRP antibody. The signal was quantified by adding Luminol as the substrate solution. Compared to the commercial CSFV antibody detection kit, this method is characterized by fast detection (20 min at room temperature), equivalent sensitivity and great specificity, as evidenced by no cross-reaction with positive serum samples of A and O serotype of foot-and-mouth disease virus, porcine reproductive and respiratory syndrome virus, senecavirus A and African swine fever virus. Meanwhile, this method demonstrated high repeatability with low intraassay coefficient of variation (CV) (1.80%-6.88%) and interassay CV (1.11%-9.18%). The Kappa value of 152 pig serum samples collected from the field was 0.929, which was highly consistent with the results of the commercial CSFV antibody detection kit. In conclusion, the CSFV chemiluminescence antibody detection method established in this study displayed strong specificity, high sensitivity and repeatability, which can be applied to the clinical detection of CSFV serum antibody.

This experiment was conducted to establish a droplet digital PCR (ddPCR) method for detection of Brucella. A ddPCR method was developed, the primers and probes were designed based on the conservative regions of BCSP31 gene of Brucella. The concentration of primer and probe, the annealing temperature were optimized. The sensitivity, specificity and reproducibility of ddPCR method were evaluated. In results, the optimal primer concentration and the probe concentration were 900 nmol·L^-1 and 250 nmol·L^-1, the optimum annealing temperature was 58℃. The detection limit of ddPCR method was 1.12 copies·μL^-1 with a good linear response, it had no cross reaction with E. coli O:157 and other four bacterium, both the intra-batch reproducibility and the inter-batch reproducibility were good. All the results showed that Brucella ddPCR was sensitive and specific, it was suitable for quantitative detection of clinical samples infected with Brucella.

A study was undertaken to construct a virus-like particle that uses hepatitis B core antigen (HBcAg) as a carrier to present PEDV S1 epitope. In this work, the 270 bp gene containing the B cell epitope in the PEDV S1 protein was inserted into the main immunodominant region (MIR) of the HBcAg to construct the recombinant plasmid pET-32a(+)-HBcAg-PEDV S1 and transform it into competent cell BL21 (DE3), the expression was induced by IPTG, and the expressed protein was purified with Ni column. The purified recombinant protein was identified by SDS-PAGE, and its morphology was detected by transmission electron microscope. The recombinant plasmid pET-32a(+)-HBcAg-PEDV S1 was successfully constructed and expressed as inclusion bodies in BL21(DE3). The purified and renatured recombinant protein, virus-like particle structure was detected by transmission electron microscope after 2% phosphotungstic acid negative staining. HBcAg-PEDV S1 recombinant protein can spontaneously form a virus-like particle structure. In prokaryotic expression, HBcAg can be used as a carrier to present PEDV S1 epitope, which provides ideas for future research on new PED vaccines.

To reveal the distribution and expression characteristics of the pulmonary ionocyte-related factor ATP6V0D2 in the lungs of yaks of different ages and to explore the structural formation and possible regulation of ATP6V0D2 in the yak lung for adaptation to high-altitude hypoxia. The localization and expression of ATP6V0D2 in the lungs of newborn, juvenile, adult, and elderly yaks were studied using immunohistochemistry, quantitative reverse transcription PCR (qRT-PCR), and Western blot. The results of immunohistochemistry showed that ATP6V0D2 was mainly localized in the ciliated cells and club cells of the epithelial mucosal layer of the bronchus and its branches in the lungs, and it was strongly expressed in the adult group and elderly. Expression of ATP6V0D2 in the yak lungs varied according to age. The ATP6V0D2 expression was the highest in the newborn group and was significantly different from the other three groups (P<0.05). The ATP6V0D2 protein expression of the adult group was significantly higher than the other three groups (P<0.05), and the pairwise comparisons between the newborn, juvenile, and elderly groups showed significant differences (P<0.05). ATP6V0D2 was expressed in bronchiolar epithelial cells in the lungs of yaks at different ages, and the expression levels significantly varied among different age groups(P<0.05). This study showed that ciliated cells and club cells were related to the pulmonary ionocytes in yaks. The differences in pulmonary ionocyte-related factors ATP6V0D2 was related to adaptations of yak lungs to high altitude hypoxia, through prevention of airway damage.