[Objective] This study aimed to characterize the changes in whole transcriptome expression profile of breast muscles during the growth process in Xichuan black-bone chicken before and after hatching. [Method] Breast muscle samples were collected from the Xichuan black-bone chicken embryos incubated for 14 d （marked as X-14 d） and the chicks freshly hatched for 1 d （marked as X-1 d）, respectively. Eukaryotic whole transcriptome sequencing analysis were performed around coding RNA （messenger RNA, mRNA） and non-coding RNA （lncRNA, circRNA and miRNA）. [Result] During the growth process of breast muscles in Xichuan black-bone chicken, the transcriptome levels of a large number of genes had significant changes. Compared with the chicken embryos incubated for 14 d, the chicks freshly hatched for 1 d （X-14 d vs X-1 d） had a total of 3 858 differentially expressed mRNA, including 1 054 upregulated genes and 2 804 downregulated genes. There were 371 differentially expressed lncRNA, including 222 upregulated genes and 149 downregulated genes; there were 316 differentially expressed circRNA, including 148 upregulated genes and 168 downregulated genes; there were 377 differentially expressed miRNA, including 159 upregulated genes and 218 downregulated genes. GO enrichment analysis showed that differentially expressed mRNA was involved in multiple biological processes, such as biological process regulation, stimulus response, localization, positive/negative regulation of biological processes, growth processes, immune system processes, etc. The KEGG pathway enrichment analysis of differentially expressed mRNA demonstrated that multiple signaling pathways were enriched, including adhesion junction, actin cytoskeleton regulation, amino acid biosynthesis, oxidative phosphorylation, carbon metabolism, citric acid cycle （TCA cycle）, tight junction, gap junction, metabolic pathway, focal adhesion, glycolysis/gluconeogenesis, pyruvic acid metabolism, melanogenesis, Notch signaling pathway, etc. The significantly differentially expressed genes were mainly related to multiple biological traits of Xichuan black-bone chickens such as growth trait, meat quality trait, lipid trait, melanogenesis trait, and immune system. [Conclusion] As important components of the transcriptome, mRNA, lncRNA, circRNA, and miRNA played crucial roles in the growth and development of Xichuan black-bone chicken. Our results provided references for analyzing the genetic regulation mechanism in the growth and development process of breast muscles in Xichuan black-bone chicken.

[Objective] This study was conducted to assess the effect of Bacillus subtilis culture supernatant on sheep β-defesin-1 （SBD-1） expression in ovine ruminal epithelial cells （ORECs）. [Method] The corresponding supernatants of Bacillus subtilis cultures that had no obvious toxic effects on ORECs were screened using the cell counting kit-8 （CCK-8） assay to determine the ranges of proper stimulating concentration and time. After stimulating ORECs with the different concentrations of Bacillus subtilis culture supernatants that had no obvious toxic effects for 8 h, the optimal stimulating concentration for inducing SBD-1 expression was determined by using qPCR and ELISA assays. In addition, this concentration of Bacillus subtilis culture supernatant was subsequently used to stimulate ORECs for various durations, and the optimal stimulating time for inducing SBD-1 expression was determined by using qPCR and ELISA assays. [Result] ①The corresponding supernatants of Bacillus subtilis cultures at concentrations ranging from 10⁷ to 10¹¹ CFU/mL exhibited no obvious toxic effects on ORECs, and the range of proper stimulating time was 2-24 h. ②The best performance in inducing SBD-1 expression was observed in the corresponding supernatant of Bacillus subtilis cultures at a concentration of 10¹¹ CFU/mL. ③After treatment with the screened optimal stimulating concentration of Bacillus subtilis culture supernatant, the optimal stimulating time for inducing SBD-1 expression was determined as 24 h. [Conclusion] Bacillus subtilis culture supernatant could induce the SBD-1 expression in ORECs.

[Objective] This study was conducted to investigate the effects of testosterone on the expression of a disintegrin and metalloprotease with thrombospondin motifs 16 （Adamts16） gene in sertoli cells and spermatogonia of neonatal rats, and to assess the relationship between the Adamts16 gene and rat cryptorchidism. [Method] RT-qPCR assay was used to detect the relative mRNA expression levels of Adamts16 gene in sertoli cells and spermatogonia of rats cultured with different concentrations of testosterone （10^-6, 10^-7, 10^-8 and 10^-9 mol/L） for 6, 12 and 24 h, respectively. The optimal concentration and time for testosterone to induce the expression of Adamts16 gene in mRNA level in sertoli cells and spermatogonia was determined. The testicular position of wild type and Adamts16 gene knockout rats 2, 4 and 8 days after birth was observed using HE staining. [Result] The highest relative mRNA expression level of Adamts16 gene in sertoli cells of rats was observed when induced with 10^-6 mol/L testosterone for 6 h, and that in spermatogonia was found when induced with 10^-7 mol/L testosterone for 24 h. Compared with the wild type rats, Adamts16 gene knockout rats had slower orchiocatabasis. [Conclusion] Testosterone could promote the mRNA expression of Adamts16 gene in sertoli cells and spermatogonia of neonatal rats. The deletion of Adamts16 gene could cause cryptorchidism in rats.

Constant body temperature is crucial for maintaining life activities. Homeostatic animals require endogenous heat sources. The direct consequence of hypothermia in animals under cold conditions is the inhibition of protein synthesis at the overall cellular level, while the expressions of cold-inducible RNA binding protein （CIRP）, RNA-binding motif protein 3 （RBM3）, uncoupling protein （UCP）, heat shock proteins （HSPs） and a few cytokines are elevated, which ensures the homeostasis and survival of cells in cold environments. This paper summarizes the recent research progress on cold-inducible proteins and related molecules in animals, in hoping to provide insights into the in-depth research of cold-inducible proteins.

With the development of medical laboratory technology, people have gained deeper understanding of respiratory tract micro-ecology and begun to explore the relationship between microbiome and respiratory diseases. More and more evidence suggested that the respiratory tract microbiota is associated with the stability of the pulmonary environment and the occurrence of pulmonary diseases. The current research focused on exploring the causality and potential mechanisms between dysbiosis of respiratory tract microbiota and respiratory diseases such as chronic obstructive pulmonary disease, asthma, and lung cancer. Phlegm, as the preferred sample for respiratory tract micro-ecology research, contains rich micro-ecological information and is easily accessible. This paper summarizes the detection methods of respiratory tract bacterial flora, reviews the research progress of respiratory tract micro-ecology in recent years, and explores the relationship between respiratory tract micro-ecology and the occurrence and progression of respiratory diseases, in hoping to provide new ideas for the specific diagnosis and treatment of respiratory diseases.

[Objective] The purpose of this study was to determine the optimal harvesting height for hybrid Broussonetia papyrifera and the processing parameters for preparation of hybrid Broussonetia papyrifera silage fermented with microbial agents. [Method] The optimal harvesting height was determined by analyzing the nutritional component and biological yield of hybrid Broussonetia papyrifera at different growth heights. Using hybrid Broussonetia papyrifera at the optimal growth height as raw materials, and Lactobacillus plantarum, Pediococcus acidilactici, and Lactobacillus buchneri as fermentative strains, the silage processing parameters such as combinative ratio of bacterial strains, molasses addition amount, cellulase addition amount, and fermentation duration were screened by orthogonal experimental design. The optimal combination of processing parameters for preparation of hybrid Broussonetia papyrifera silage were determined based on indicators of sensory evaluation, chemical composition, aerobic stability, and nutritional component. [Result] The highest biological yield and nutritional value of hybrid Broussonetia papyrifera were obtained when harvested at the height of 1.2 meters. The optimal processing parameters for preparation of hybrid Broussonetia papyrifera silage obtained through orthogonal experimental design were as follows: the ratio of Lactobacillus plantarum, Pediococcus acidilactici, and Lactobacillus buchneri was 4∶1∶1, the molasses addition amount was 3%, the cellulase addition amount was 9×10³ U/kg, and the silage duration was 60 d. [Conclusion] This study determines the optimal harvesting height and the processing parameters for preparation of hybrid Broussonetia papyrifera silage, providing references for the feed utilization of Broussonetia papyrifera.

[Objective] The purpose of this study was to screen the candidate lactic acid bacterial strains for preparing forage silage, so as to improve the fermentation quality of forage silage. [Method] Lactic acid bacterial strains were isolated from the leaves of 8 varieties of gramineous forages, including Pennisetum sinese, Eleusine indica, Imperata cylindrica and so on. On the basis of traditional microbiological identification techniques, molecular biological identification methods and 16S rDNA sequence diversity analysis were used to identify the suspected lactic acid bacterial strains isolated. The performance in growth, acid production and salt tolerance of the lactic acid bacterial strains was characterized. Their growth tolerance under pH value of 3.0, 3.5 and 4.0, as well as NaCl concentrations of 0.02, 0.04, 0.06, 0.08 and 0.10 mg/mL was assessed. Furthermore, their inhibitory effects against Candida, Staphylococcus aureus and Salmonella typhimurium were evaluated. [Result] A total of 30 suspected lactic acid bacterial strains were isolated from the surface of forage leaves. Following phenotypic identification and molecular biological identification, 10 strains of lactic acid bacteria were identified as belonging to the genera of Weissella, Pediococcus and Levilactobacillus, including 3 strains of L. brevis, 2 strains of P. pentosaceus, 2 strains of L. plantarum, 1 strain of W. cibaria, 1 strain of L. pentosus and 1 strain of L. coryniformis. The performance in growth rate and acid production varied among different strains. There were strain-specific salt and acid resistance as well as antibacterial property as well. By comprehensively comparing the biological characteristics of the 10 strains, L. plantarum Lab7 had better performance in salt and acid resistance, while L. brevis Lab1 and L. coryniformis Lab10 had good performance in growth rate, acid production ability, salt and acid resistance, and antibacterial property. [Conclusion] The naturally isolated lactic acid bacterial strains of forage origin, L. plantarum Lab7, L. brevis Lab1 and L. coryniformis Lab10 were screened as candidate strains for lactic acid bacterial preparation used in fermentation of forage silage, and had the potential for further development.

[Objective] This study was conducted to measure and compare the electrical resistance of vaginal mucus （ERVM） of beef cows in different reproductive physiological periods and with different types of reproductive disorders, and to provide references for the assistant detection of estrus and gestation as well as the diagnosis of reproductive disorders in cows based on the obtained relevant basal data. Meanwhile, it also aimed to assess the applicability of animal estrus and ovulation tester, and to render technical support for improving the reproductive efficiency in cows. [Method] A total of 297 reproductive beef cows were selected from 21 cattle farms or households. According to the reproductive records and rectal examination results, the cows were subjected to reproductive physiological periods （anestrous period, estrus period, gestation period) determination or reproductive disorders diagnosis. Based on the above records and results, the 297 cows were assigned into the following four groups: an anestrous period group （n=76）, an estrus period group （n=48）, a gestation period group （n=106）, and a reproductive disorders group （n=67）. The 106 heads in the gestation period group were further classified based on the gestation days: 44 heads with ≤60 days of gestation, 24 heads with 61-120 days of gestation, 31 heads with 121-180 days of gestation, and 7 heads with >180 days of gestation. In accordance with the reproductive physiological processes, 42 heads at the luteal phase, 13 heads at the follicular phase and 24 heads at the gestation phase were selected from the cows in the anestrous, estrus, and gestation periods, respectively. The 67 heads in the reproductive disorders group were further divided based on the types of reproductive disorders: 8 heads with ovarian cysts, 57 heads with persistent corpus luteum, and 2 heads with freemartinism. The ERVM of the cows in different reproductive physiological periods and with different types of reproductive disorders was measured using a fully automated animal estrus and ovulation tester, and was statistically compared and analyzed. [Result] The lowest ERVM was observed in the cows in the estrus period, which was 17.91% （P<0.01） and 28.38% （P<0.01） lower than that in those in the anestrous and gestation periods, respectively; the ERVM in the anestrous period was 12.76% （P<0.01） lower than that in the gestation period. The highest ERVM was observed in the cows with ≤ 60 days of gestation, followed by those with 61-120 days of gestation; both were extremely significantly （P<0.01） higher than those with >180 days of gestation; the ERVM in the cows with 121-180 days of gestation was significantly （P<0.05） higher than that in those with >180 days of gestation. The ERVM in the cows at the follicular phase decreased by 35.85% and 37.05% compared with that in those at the luteal and gestation phases, respectively, reaching extremely significant （P<0.01） levels; the ERVM at the luteal phase was similar to that at the gestation phase （P>0.05）. The ERVM in the cows with freemartinism was the highest, and was 36.12% higher （P<0.01） than that in those with ovarian cysts; the ERVM of the cows with persistent corpus luteum was 22.42% higher than that in those with ovarian cysts （P>0.05）. [Conclusion] The variations in the ERVM of beef cows in different reproductive physiological periods and with different types of reproductive disorders were characterized. The average ERVM of the cow populations evidently varied among the anestrous, estrous and gestation periods as well as the different types of reproductive disorders, and also exhibited apparent individual differences. Moreover, there was partial overlap in the ERVM of cows under different reproductive physiological conditions. A ERVM less than 180 Ω was indicative for the determination of estrous period. Additional diagnostic techniques, such as rectal examination and verification of reproductive records, were necessary when using ERVM to identify gestation and anestrous periods and to diagnose reproductive disorders in cows.

Canada is one of the earliest nations to carry out the conservation of livestock and poultry genetic resources, and has a high level of conservation and utilization of these resources. Through systematic analysis of the current status of livestock and poultry genetic resources, gene bank construction, conservation subjects, and relevant laws and regulations in Canada, it was discovered that the high level of conservation and utilization of these resources were largely due to the established livestock and poultry pedigree registration systems, animal heritage resource information systems, advanced livestock and poultry resource preservation technology, and sound legal systems. By comparing the relevant practices and systems in China, five rationalization suggestions were proposed, including establishing pedigree registration systems and optimizing the preservation technology of livestock and poultry resources, in hoping to provide useful references for improving the conservation and utilization level of livestock and poultry genetic resources in China.

The hypothalamic-pituitary-gonadal axis is the primary endocrine system that regulates the secretion of sex hormones in animals. In-depth research on this system is crucial for improving livestock reproductive performance and treating reproductive diseases. The hypothalamus regulates the secretion of gonadotropin-releasing hormone （GnRH）, which in turn regulates the anterior pituitary, promoting its secretion of follicle stimulating hormone （FSH） and luteinizing hormone （LH）. Establishing an in vitro culture system for anterior pituitary cells can provide a methodological basis for unveiling the mechanism of anterior pituitary hormone secretion. This article introduces the anatomic location of anterior pituitary in brain ventricle as well as the types of anterior pituitary cells and the primary hormones secreted by them, reviews the isolation, culture and identification methods of anterior pituitary cells, as well as the research progress in the effects of exogenous substances on the secretion of gonadotropin （Gn） by anterior pituitary cells in vitro, in hoping to better understand the function and mechanism of the hypothalamic-pituitary-ovarian axis, optimize and improve the in vitro culture system of anterior pituitary cells, and provide references for screening Gn secretion regulating drugs.

Giant Juncao （Cenchrus fungigraminus） has been widely used in cultivation as high-quality herbage and ecological management material due to its advantages such as fast growth, large biomass, strong stress resistance and wide adaptability. In particular, good results have been achieved in the restoration of the ecologically fragile areas and the heavy metal pollution areas. However, due to its late introduction into China, few studies have been conducted on molecular aspects. In this paper, we review the molecular research progress of Giant Juncao in the aspects of genetic molecular markers, transcriptomics, stress resistance and so on, as well as its application in ecological restoration and management, in hoping to provide references for deep exploration of the feeding value and ecological restoration value of Giant Juncao.

[Objective] This study was conducted to characterize the changes in whey protein profile during the fermentation process of traditional koumiss from Inner Mongolia. [Method] Traditional koumiss was prepared using mare milk collected from Xianghuang Banner, Xilin Gol League, Inner Mongolia, with fermentation temperature at （22±2） ℃, and manual mixing 5 times per day, 300 beats each time. The koumiss samples were taken every 12 h during the 0-96 h fermentation process, and whey protein was collected by centrifugation. Variations in Koumiss whey protein profile during the fermentation process were analyzed by the optimized SDS-PAGE. [Result] The optimized SDS-PAGE conditions were as follows: the concentrations of separation gel and spacer gel were 12% and 5%, respectively; the electrophoresis voltage for separation gel was 180 V, and the electrophoresis time was 300 min; the sample loading amount and concentration were 16 μL and 0.5 μg/μL samples, respectively; the gel was stained with modified Coomassie brilliant blue for 12 h and then decolorized for 12 h. Within 0-12 h of fermentation, the koumiss whey protein contents increased and peaked （5.12 μg/μL） at 12 h, and then fell with the extension of fermentation time, decreasing to 3.92 μg/μL at 96 h of fermentation. SDS-PAGE analysis showed that a total of 13 effective bands of whey protein within the molecular weight range of 10-70 kDa were observed. During the fermentation process, the contents of 3 types of whey protein, β-lactoglobulin, lysozyme C, and α-lactalbumin, fluctuated to varying degrees. The sum of their contents peaked at 72 h of fermentation, accounting for 85.73% of the total whey protein contents and maintained high levels during the fermentation process. It was indicated that they were the main components of whey protein in traditional koumiss within the fermentation process of 96 h. Among them, the content of β-lactoglobulin was the highest, accounting for an average of 38.92% of the total whey protein contents. The content of casein with the molecular weight range of 20-40 kDa began to decrease after 24 h of fermentation, and the corresponding bands disappeared till 60 h. The protein with a molecular weight of 10.33 kDa was depleted within 12 h of fermentation and reappeared at 60 h, and its content gradually increased with the extension of fermentation time and peaked at 84 h, accounting for 9.84% of the total whey protein contents. The protein with a molecular weight of 49.80 kDa began to appear after 72 h of fermentation, and its content reached 4.11% of the total whey protein contents at 96 h. Compared to the other whey protein components, the content of β-lactoglobulin and immunoglobulin had minor changes during the fermentation process. [Conclusion] The whey protein contents with the molecular weight range of 10-70 kDa in traditional koumiss from Inner Mongolia had regular increase and decrease within 96 h of fermentation. The main protein that was digested and decomposed was casein. There were some differences in the composition and content of whey protein in different fermentation stages of koumiss, while the original main components β-lactoglobulin, lysozyme C, and α-lactalbumin maintained higher levels. From the middle stage of fermentation, the proportion of peptides with relatively small molecular weight （10.33 kDa） in the whey protein of koumiss gradually increased. Our results showed that the traditional koumiss not only retained the original nutritional value of whey protein in mare milk, but also added some easily absorbed small molecular weight proteins through fermentation.

[Objective] This study was conducted to compare and analyze the fatty acid composition and content in fresh dairy milk from different regions. [Method] From May 2019 to March 2020, one large-scale dairy farm each from Henan Province, Hebei Province, and Shanxi Province was selected. A total of 36 fresh milk samples from healthy dairy cows were collected over the four seasons, with 12 samples coming from each of the three regions. Fatty acids were extracted and methylated using GC-MS method. The fatty acid composition and content were analyzed using CP-WAX 52 CB capillary chromatography column and gas chromatography-mass spectrometry analyzer. By comparing the retention time of 37 mixed standard substances of fatty acid methyl esters and searching in the NIST05 spectrum library, the fatty acid composition was qualitatively analyzed. The fatty acid content was calculated using area normalization method. [Result] A total of 28 fatty acids were detected in the fresh milk collected from Henan Province, among which 15 were saturated fatty acids. The contents of 5 saturated fatty acid methyl ester, including methyl decanoate, methyl laurate, methyl myristate, methyl stearate, and methyl palmitate, were relatively high, accounting for 57.03% of the total detected fatty acid content. Thirteen unsaturated fatty acid were detected, among which most had low levels, with only oleic acid/elaidic acid methyl ester having higher levels, accounting for 32.26% of the total detected fatty acid content. Thirty fatty acids were detected in the fresh milk collected from both Hebei Province and Shanxi Province, while the compositions were slightly different. The characterization of fatty acid content in the fresh milk collected from the two provinces were similar to that collected from Henan Province, with saturated fatty acid content accounting for around 60% of the total detected fatty acid content. The content of oleic acid/elaidic acid in the fresh milk collected from Hebei Province was 39.80%, which was the highest among the three regions. No linolelaidic acid methyl ester, γ-linolenic acid methyl ester, cis-15-carboenoic acid methyl ester, erucic acid methyl ester, and cis-4,7,10,13,16,19-docosahexaenoic acid methyl ester were detected in the fresh milk from all three regions. [Conclusion] The fatty acid content in the fresh dairy milk collected from the three regions were relatively rich, with saturated fatty acid as the main component. Oleic acid/elaidic acid had the highest contents among all the detected fatty acids, while there were also some regional variations in fatty acid composition and content.

[Objective] This study aimed to evaluate the detection capability of the group laboratories by conducting an inter laboratory comparison analysis on the detection of lead, chromium, mercury, and arsenic contents in milk powder. [Method] Using the self-developed quality control samples of milk powder matrix containing lead, chromium, mercury, and arsenic as the experimental materials, following uniformity and stability verification, the laboratory detection capability of lead, chromium, mercury, and arsenic contents in milk powder were evaluated using Robust statistical method algorithm A. [Result] The uniformity and stability test results of the quality control samples met the requirements of the inter laboratory comparison plan. The satisfaction rates for the detection of lead, chromium, mercury, and arsenic contents in milk powder were 98.4%, 98.4%, 96.7%, and 95.2%, respectively. There were no unsatisfactory results, and the overall detection capability of the participating laboratories was good. [Conclusion] By conducting technical comparison analysis on the detection of heavy metal element contents in milk powder, a solid foundation has been laid for improving the detection capability and quality control level of the group laboratories.

[Objective] The aims of the present study were to fully exploit the application potential of cattle manure as organic fertilizer and to avoid potential heavy metal hazards to soil-crop ecosystem from excessive application of cattle manure. [Method] Five treatments were set up according to the different application ratios of cattle manure organic fertilizer and chemical fertilizer: a blank control （CK）, the single application of cattle manure organic fertilizer （CD）, the single application of chemical fertilizer （CF）, the combined application of cattle manure organic fertilizer with chemical fertilizer （DF1） at the ratio of 1∶1, and the combined application of cattle manure organic fertilizer with chemical fertilizer （DF2） at the ratio of 2∶1. Pot experiments were conducted using soil and silage maize as research subjects. The mass fractions of various forms of heavy metals of copper （Cu） and zinc （Zn） in soil under different fertilization treatments were measured and calculated. The correlations between the distribution rate of available Cu and Zn and soil pH value, organic carbon mass fraction were analyzed. The Cu and Zn contents in different parts of silage maize were compared. [Result] Combined application of cattle manure organic fertilizer with chemical fertilizer had significant （P<0.05） impacts on the total mass fractions and mass fractions of different forms of Cu and Zn in the soil. The application of cattle manure organic fertilizer promoted the transformation of residual form Cu to exchangeable form. The distribution rates of exchangeable Cu in CD and DF1 treatments increased from 15.86% in CK to 28.12% and 28.13%, respectively. Compared with CK, DF2 treatment had the largest increase in distribution rate of exchangeable Cu at 42.02%. The distribution rates of residual Zn in CD and DF1 treatments decreased from 53.40% in CK to 39.27% and 38.40%, respectively. In comparison with CK, the distribution rate of residual Zn in DF2 treatment decreased to 24.33%, which had the biggest change range. After the combined application of cattle manure organic fertilizer with chemical fertilizer, the soil pH value and organic carbon mass fraction had an upward trend. Among them, the soil organic carbon mass fraction had positive correlation with the distribution rates of available Cu and Zn in the soil, and the correlations reached extremely significant （P<0.01） and significant （P<0.05） levels, respectively. Furthermore, the distribution rate of soil available Zn was significantly （P<0.05） correlated with the change trend of soil pH value, while the correlation between the distribution rate of available Cu and soil pH value was not significant （P>0.05）. Compared with CK, the application of cattle manure organic fertilizer increased the contents of Cu and Zn in maize plants by 45.50% to 115.38% and 44.99% to 93.29%, respectively. [Conclusion] In addition to improving the physical and chemical properties of soil, the combined application of cattle manure organic fertilizer with chemical fertilizer activated the heavy metals of Cu and Zn in the soil, enhancing the heavy metal enrichment ability of the silage maize. Therefore, when applying cattle manure organic fertilizer, the appropriate application rate should be determined strictly following the soil testing and formula fertilization to limit the contamination risk of heavy metals in the soil environment and the feeding risk of silage maize.

[Objective] This study was conducted to characterize the prevalence and the subgenotype distribution of Cryptosporidium in diarrheal lambs from a large-scale sheep farm in southern Xinjiang. [Method] A total of 60 fresh fecal samples were collected from the diarrheal lambs of four breeds less than 1 month old in a large-scale sheep farm in Xinjiang Uygur Autonomous Region, China. The species identification of Cryptosporidium oocysts was carried out by saturated sucrose flotation technique combined with microscopic examination. After the fecal genomic DNA was extracted, PCR amplifications and sequencing analyses targeting on SSU rRNA gene and gp60 gene were performed to confirm the species of Cryptosporidium and the subgenotypes of C. parvum, respectively. Furthermore, the phylogenetic tree based on the gp60 gene was constructed to reveal the molecular genetic characteristics of Cryptosporidium. [Result] Thirty-eight fecal samples were found to be positive for the presence of Cryptosporidium oocysts which were preliminarily identified as C. parvum by morphology observation. Based on the SSU rRNA gene sequence comparison, a total of 52 fecal samples were positive for C. parvum, with the infection rate of 86.67% （52/60）. Among them, 49 sequences of gp60 gene were obtained by PCR amplification, and the phylogenetic tree demonstrated that they all belonged to the subgenotype of ⅡdA19G1. [Conclusion] A high prevalence of C. parvum with the subgenotype of ⅡdA19G1 was observed in the diarrheal lambs in this farm. The results obtained in this study provides basic data for the species identification and genetic evolution analysis of Cryptosporidium in the sheep flocks in southern Xinjiang.

[Objective] The aims of the present study were to identify the bacterial pathogens causing the disease in a duck farm in Guangdong Province, to characterize the antimicrobial susceptibility and the presence of NDM resistance genes of the isolated strains, and to screen the single traditional Chinese medicine with in vitro bacteriostatic effects against the isolated strains. [Method] The clinical samples of liver and spleen from the diseased ducks were collected for bacterial isolation and cultivation. The PCR amplification, sequencing and similarity comparison of 16S rDNA gene were used to identify the species of the isolated strains. The susceptibility test of the isolated strains to 13 antibacterial agents was carried out with K-B disk diffusion method. The PCR assay was used to detect the distribution of 10 NDM resistance genes in the isolated strains. The broth double dilution method was employed to determine the minimum inhibitory concentration （MIC） of 14 single Chinese traditional medicines against the isolated strains. [Result] Two bacterial strains were obtained from the clinical samples of the diseased ducks. Through Gram staining and microscopy examination, biochemical identification, as well as 16S rDNA sequence analysis, they were identified as Proteus mirabilis （SK1 strain） and Morganella morganii （SK2 strain）, respectively. Both SK1 and SK2 strains were susceptible to neomycin, ceftazidime, cefotaxime, and cefoperazone, and resistant to doxycycline, co-trimoxazole, enrofloxacin, flufenicol, and polymyxin B. None of the 10 NDM resistance genes were detected in SK1 strain. SK2 strain carried the bla_NDM-1 gene, while the other 9 NDM resistance genes were not detected. Macleaya cordata （Willd.） R. Br. had the best bacteriostatic effect against SK1 strain, with a MIC of 3.906 mg/mL. Forsythia suspensa （Thunb）. Vahl had the best bacteriostatic effect against SK2 strain, with a MIC of 3.906 mg/mL. [Conclusion] The main pathogens causing the disease in the duck farm were Proteus mirabilis and Morganella morganii. Neomycin, cephalosporin antibiotics, as well as traditional Chinese medicine Macleaya cordata （Willd.） R. Br. and Forsythia suspensa （Thunb）. Vahl were recommended to therapy the diseased ducks.