This study was designed to screen out the key genes related to intramuscular fat deposition through detecting the fat contents in longissimus dorsi muscle (LDM) and psoas major muscle (PMM), and explore the differentially expressed genes between the two types of muscle of Qianbei black pigs using high-throughput sequencing technology. Five 12-month-old healthy Qianbei black pigs were slaughtered, and LDM and PMM were collected. Some of them were used to detect total fat content, and the rest were used for total RNA extraction, library constructing and sequencing. The annotation genes were obtained by comparing the obtained unigenes with RefSeq database of pig. The differentially expressed mRNAs were analyzed by DESeq2 1.26.0 software, and moreover gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis of differentially expressed mRNAs were analyzed by GOseq 1.15.5 software and KOBAS 3.0 software. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to verify the candidate genes related to fat deposition. The results showed that the fat content in the PMM was significantly higher than that in the LDM (P＜0.01). A total of 162 differentially expressed genes were obtained by high-throughput sequencing, of which 66 were up-regulated and 96 were down-regulated. Six differentially expressed genes associated with fat deposition were screened out by GO, KEGG analysis combined with the function searching. qRT-PCR results showed that the expression of LPL, PPARA, COX2, PRKAG2 and SCD existed in significant differences between LDM and PMM. The above results lay a foundation for exploring the molecular mechanism of intramuscular fat deposition in Qianbei black pigs, and further provide an experimental basis for the protection, development and utilization of Qianbei black pigs.

Haemonchosis is caused by Haemonchus contortus parasitic in the ruminant abomasum. In order to study the function of zinc metalloproteinase NAS-31 gene (Hc-nas-31) in the free-living period (especially L3) of this kind of worm, real-time quantitative polymerase chain reaction (qRT-PCR) was conducted to detect the transcription level of the target gene in different developmental stages of H. contortus. Rapid amplification of cDNA ends (RACE), genome walking and fusion PCR methods were used to amplify Hc-nas-31 gene and the gene structure was analyzed after that. Then, prokaryotic expression plasmid was constructed and transformed into BL21 to express the recombinant protein. A New Zealand white rabbit was immunized with the purified recombinant Hc-NAS-31 (rHc-NAS-31) to prepare polyclonal antibodies, which were used to analyze the expression pattern of Hc-NAS-31 in H. contortus by indirect immunofluorescence assay. The results showed that Hc-nas-31 was transcribed in all stages of the worms, while the transcription level of L3 was the highest. Polyclonal antibody was made successfully and its specific binding with Hc-NAS-31 natural protein was confirmed by Western blotting. Indirect immunofluorescence analysis showed that Hc-NAS-31 protein was mainly expressed in the epithelial syncytia of L3, while in adults, it was distributed in the intestines, gonads, muscle tissues and early eggs. In summary, we confirmed the expression pattern of NAS-31 in H. contortus. This experiment lays the foundation for further research on the biological functions of Hc-nas-31.

The study focuses on the effects of fermented feed with tea residue, soybean meal and bran as substrates on growth performance, nutrient metabolic rates and serum indexes of broiler chickens. Using single factor test design, 240 one-day-of-age Ross 308 broiler chickens with similar body mass and good health were randomly divided into five groups [control group T_l, fed the basic diet; experimental group T₂, fed the basic diet＋methylene salicylic acid bacitracin (40 mg/kg); experimental groups T₃, T₄, T₅, fed the fermented feed to replace 2%, 4% and 6% soybean meal in the basic diet, respectively] with six replicates per treatment and eight chickens per replicate. The test period was 42 d. The results showed that: 1) Compared with the control group T_l, the average daily gain from 1 to 21 days of age, 21 day-of-age and 42 day-of-age body masses of broiler chickens in the T₄ group significantly increased (P＜0.05), and the feed-to-gain ratio was significantly reduced from 1 to 21 days of age (P＜0.05). 2) The apparent metabolic rates of crude protein of broiler chickens in T₄ and T₅ groups were significantly higher than those in T₁ and T₂ groups (P＜0.05). 3) Compared with the control group T_l, the serum albumin levels of the T₂ and T₅ groups significantly increased (P＜0.05), and the serum antioxidant indexes (total superoxide dismutase, catalase activities, and malondialdehyde content) of the T₅ group were significantly different (P＜0.05). In summary, the addition of fermented feed with tea residue, soybean meal and bran as substrates in the diets can improve broiler chickens’ growth performance, slaughter performance, apparent metabolic rates of crude protein and serum index levels, reflecting growth-promoting effects similar to antibiotics.

In order to explore the regulation of nucleobindin-2 (NUCB2)/Nesfatin-1 in the growth and development of Chinese sucker (Myxocyprinus asiaticu), the full-length cDNA sequence of NUCB2 was cloned by rapid amplification of cDNA ends (RACE) technology, and the expression and distribution of Nesfatin-1 in the diencephalon and hepatopancreas were observed by quantitative real-time polymerase chain reaction (qPCR) and immunofluorescence technique, respectively. The results showed that the full-length cDNA of NUCB2 was 2 090 bp, including a 99 bp 5′ untranslated region (UTR), a 1 449 bp open reading frame (ORF) and a 542 bp 3′ untranslated region. The NUCB2 gene encoded 482 amino acids, consisted of a signal peptide region of 23 amino acids and a NUCB2 peptide region of 459 amino acids. Two propeptide cleavage sites were in NUCB2 peptide region, lysine (Lys) 106-arginine (Arg) 107 and Lys179-Arg180, then three functional peptides of Nesfatin-1, Nesfatin-2, and Nesfatin-3 were divided according to the two cleavage sites. Phylogenetic tree analysis showed that the sequence of M30, the domain region of Nesfatin-1, was highly conserved in fish. In the same age, the expression level of Nesfatin-1 mRNA in the hepatopancreas was highly significantly higher than that in the diencephalon (P＜0.01); however, in the same tissue, such as diencephalon and hepatopancreas, no significant differences were found between three and six-year-old M. asiaticus (P＞0.05). The strong positive immunofluorescence signal was detected in the pancreatic cells instead of hepatocytes in the hepatopancreas. In the diencephalon, positive immunofluorescence signals were only detected in the lateral tuberal nucleus, anterior periventricular nucleus and preoptic nucleus magnocelluar part. In conclusion, the expression of Nesfatin-1 in the diencephalon is significantly lower than that in the hepatopancreas during two typical growth stages of Chinese sucker, indicating that the central and peripheral regulation of Nesfatin-1 on the growth and development of Chinese sucker has obvious difference.

To investigate the antimicrobial resistance of bacteria from animals in Jinhua City and Taizhou City of Zhejiang Province in May of 2020, a total of 284 anal swab samples were randomly collected from seven livestock and poultry farms in the two cities, respectively. Escherichia coli and Enterococcus were isolated by selective culture media and were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The minimal inhibitory concentration (MIC) was determined by broth microdilution method. The results showed that the antimicrobial resistance rate of E. coli to tetracycline was the highest (87.5%), followed by sulfamethoxazole (81.2%), while the antimicrobial resistance rate to colistin was the lowest (0%) in Jinhua City. In addition, the antimicrobial resistance rate of E. coli to sulfamethoxazole was the highest (97.1%), and the resistance rates to meropenem and colistin were both 0% in Taizhou City. The antimicrobial resistance rate of Enterococcus to sulfamethoxazole was 100% in both cities, followed by tamoxifen (98.6%). No amoxicillin/clavulanate and vancomycin resistant Enterococcus was found in the two cities. In terms of the overall antimicrobial resistance rate, MIC distribution and antimicrobial resistance pattern, the level of antimicrobial resistance in Taizhou was higher than that in Jinhua. In conclusion, through monitoring and comparing the level of antimicrobial resistance in livestock and poultry breeding in two cities, it is found that the levels of antimicrobial resistance of E. coli and Enterococcus from animals are high and different. Therefore, continuous surveillance of antimicrobial resistance dynamics is essential through veterinary antibiotics reduction initiatives by agricultural authorities.

The adaptive immune system can protect the body from various pathogens by producing a variety of antibodies. The antibody repertoire is so vast that the traditional low-throughput sequencing method cannot completely sequence it. In this study, the library of porcine B cell receptor (BCR) heavy chain was amplified from porcine peripheral blood mononuclear cell (PBMC) by multiplex polymerase chain reaction (PCR). The characteristics of porcine antibody repertoire were analyzed by next-generation sequencing. The results showed that several IGHV, IGHD and IGHJ genes were preferentially used by three-week-old piglets under normal conditions, and IGHV1-4 and IGHV1S2 were the two most frequently used variable (V) genes. The total frequencies of the use of eight IGHV genes accounted for more than 80%. In addition, the length of heavy chain complementarity determining region 3 (HCDR3) was a normal distribution with the average length of 15.8 amino acids. This study successfully constructs a high-throughput sequencing method suitable for porcine antibody repertoire, which provides an effective approach for further understanding the specific composition of it in physiological and pathological states.

A headspace-gas chromatograph (HS-GC) (external standard method) was established for the determination of the volatile fatty acid (VFA) contents in rumen fluid of ruminants. Under the optimized headspace sampling conditions (balance temperature at 85 ℃ and equilibrium time of 30 min), the method was verified and used to detect the VFA. The coefficient of determination of regression equation for each compound was not less than 0.999 7. The limit of detection (LOD) was 0.036-0.329 mmol/L. The recovery rates of three different concentrations of standards were 93.540%-108.130%. The detection results showed that the relative standard deviations (RSDs) of VFA in all samples were less than 2.3%, and the method was stable within three days. The developed method is simple, which has accurate quantity and good repeatability, and suitable for the quantitative analysis of VFA in rumen fluid of ruminants.

Guinea pig is a laboratory animal model to study the illness and stimulation of infection. The previous studies showed that the sensitivity of Zmu-1∶DHP outbred guinea pig to foot-and-mouth disease virus was 100%, which was significantly different from DHP (parental strain). This study took three strains of guinea pigs (Zmu-1∶DHP outbred line, Zmu-2∶DHP outbred line and DHP strain) as the experimental groups. The RNA extracted from spleen of different strains of guinea pigs was transcribed into cDNA and amplified by polymerase chain reaction. The amplified products were sequenced by high-throughput sequencing to analyze the structure, haplotype and polymorphism of MHC classⅠgene in guinea pigs, so as to detect whether there were differences in the expression of MHC classⅠgene among different strains. The results showed that eight MHC classⅠsequences in guinea pig were found and some of these haplotypes had 23 amino acids deletion in exon 3. There were significant differences in the frequencies of haplotype expression reads among some strains (P＜0.05), which suggested that the difference of MHCclassⅠhaplotype expression might be related to the difference of immune ability among different strains. The research provides a theoretical basis for the application of guinea pig strains in disease model and vaccine development.

In order to compare the morphological differences of otoliths among different Harpodon nehereus populations, five measurement indexes of sagittal otoliths including distance from geometric center to rostrum (A₁), distance from geometric center to veutro (A₂), distance from geometric center to dorsal (A₃), distance from geometric center to excisural notch (A₄) and distance from geometric center to excisural minor notch (A₅) were examined by paired t-test. The results showed that the P values were greater than 0.05, indicating no significant differences between left and right otoliths. The cumulative contribution rates of the first principal component (PC1) in seven measurement indexes, including A₁-A₅, major axis length (L) and minor axis length (H), and the ellipticity (X₁) and radial ratio (X₂) were 93.114% and 99.950%, respectively. The results of one-way analysis of variance showed that the ellipticity could be used as the main feature to distinguish Zhoushan population from the others. The hierarchical clustering tree demonstrated that the specimens from the southern East China Sea and the South China Sea first gathered together into one branch, and then followed by Sanmen and Zhoushan populations. Haikou population was located at the outermost of the clustering tree and separated apart from other populations. The average discriminant accuracy rate was 80.63%, of which Zhoushan population was the highest (89.29%), while Ningde population was the lowest (71.43%). The above results suggest that the multivariate statistical analysis of morphological characteristics of otolith could be used as the basis for population identification of H. nehereus.

In order to understand the annual epidemic situation of Chinese sacbrood disease and European foulbrood disease pathogens [Chinese sacbrood virus (CSBV) and Melissococcus pluton, respectively] in Chinese honeybee (Apis cerana cerana) of Chun’an County of Zhejiang Province, the workers in Chinese honeybee colonies were collected from five breeding sites in Chun’an County from January to December in 2019, and the dynamic changes of the two main disease pathogens in the Chinese honeybee colonies were monitored by polymerase chain reaction (PCR). The results showed that the colony infection rate of CSBV was the highest in March of spring (84%), and it decreased to the lowest in July of summer, then increased from autumn to winter. The infection rate of M. pluton increased from spring to summer, and then increased from autumn to the highest level of 72% in late autumn (October) and early winter (November), and decreased slightly in winter. Furthermore, there was co-infection phenomenon of these two disease pathogens in honeybee colonies in the whole year. The results of real-time quantitative PCR showed that the viral load of CSBV in colonies with M. pluton in autumn was significantly higher than that in the colonies with a single infected CSBV (P＜0.05). In conclusion, the annual epidemic dynamics of two main disease pathogens of Chinese honeybee is clarified in Chun’an County of Zhejiang Province, which can provide theoretical guidances for the prevention and control of Chinese honeybee diseases in this region.

This study aimed to establish the optimal preparation method of outer membrane vesicles (OMVs) from rabbit Bordetella bronchiseptica (Bb). The FX-1 strain of rabbit Bb was used as the research object. Centrifugal ultrafiltration and ultrasonication were compared, and followed by the optimization of the preparation technics, such as culture time, antibiotic addition and filtering method. The physical and chemical properties of OMVs were examined with transmission electron microscope (TEM), scanning electron microscope (SEM) and nanoparticle tracking analysis (NTA), etc. The protein compositions were analysed with Bradford protein quantification, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The results showed that centrifugal ultrafiltration was a better preparation method of OMVs, and the optimum culture time, cefalexin concentration and filtering method were 18 h, 64 μg/mL and filtration though 0.45 μm membrane once, respectively. The OMVs showed a spherical shape with the diameter of 127.83 nm±0.68 nm, containing a range of proteins associated with virulence and infection mechanisms. This preparation technique could significantly promote the production of OMVs, which making industrial production possible. Furthermore, analysis of the protein composition lays a foundation for novel subunit vaccine research and development.

This study was designed to evaluate the effects of bioactive selenium on performance, egg quality and selenium content in the egg yolk of laying hens. The healthy Roman grey laying hens with similar body mass and laying rate were selected as the testing objects. All hens were fed with corn-soybean meal-based diets for 7 d and then assigned to corn-soybean meal-based diets containing 0 (as the control group), 0.6%, 0.8%, and 1.0% bioactive selenium for 35 d, respectively. The results showed that: 1) When compared with the control group, there were no significant differences in production performance as dietary bioactive selenium contents increasing from 0.6% to 1.0% (P＞0.05). 2) When compared with the control group, no remarkable differences in eggshell thickness, eggshell strength, egg yolk mass and Haugh unit were observed among all the bioactive selenium-added groups (P＞0.05). In general, the thick albumen height increased in the 0.6% to 1.0% bioactive selenium groups on 7 and 21 d. Meanwhile, a significant increase of yolk percentage in bioactive selenium groups was observed relative to the control group on 28 d (P＜0.05). 3) The selenium content in the egg yolk increased linearly with the increase of dietary bioactive selenium contents (P＜0.05). In conclusion, dietary bioactive selenium has no significant effect on laying hen’s performance, but to some extent, it can improve the laying rate, egg quality and increase the selenium content in yolk.

The trend of genetic diversity of Zhejiang Royal Jelly bee (Pinghu) among 2012, 2015 and 2019 years was analyzed using five microsatellite loci and two mitochondrial DNA sequences, which could provide scientific basis for the resource conservation of Zhejiang Royal Jelly bee. The results based on microsatellite loci showed that the mean observed allele number (N_a) and mean effective allele number (N_e) were 10.6 and 3.859 1, respectively; and the mean observed heterozygosity (H_o) and mean effective heterozygosity(H_e) were 0.567 4 and 0.685 8, respectively; the mean polymorphism information content(PIC)was 0.653 1 in the overall Zhejiang Royal Jelly bee (Pinghu) population. The results indicated high genetic diversity in Zhejiang Royal Jelly bee (Pinghu). There were no significant differences in all genetic diversity indicators among 2012, 2015 and 2019 years, indicating that the genetic diversity of Zhejiang Royal Jelly bee (Pinghu) was stable. The results based on mitochondrial DNA showed that the main haplotype was more and more prevalent in Zhejiang Royal Jelly bee (Pinghu). In view of the fact that the population number of Zhejiang Royal Jelly bee (Pinghu) may decrease substantially in the future, it is suggested to strengthen the protection of Zhejiang Royal Jelly bee (Pinghu) and the monitoring of the resources in order to take necessary protective measures.

In order to investigate the adaptability of Alosa sapidissima to high temperature stress, they were placed under three water temperature gradients (24 ℃, 28 ℃, 30 ℃) for 96 h, and the changes of antioxidant enzyme as well as non-specific immune enzyme activities in their liver and serum were studied at different time (0, 3, 6, 12, 24, 48, 96 h) under different water temperatures. The results showed that in the liver, the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) in the 28 ℃ and 30 ℃ groups increased over time, and the malondialdehyde (MDA) content increased and then decreased with time, while there were no significant changes in the 24 ℃ group; the activities of SOD and CAT at 48 and 96 h were significantly higher than those in the 24 ℃ group (P＜0.05), and the GSH-Px activity and MDA content in the 30 ℃ group at 96 h were significantly higher than those in the other two groups (P＜0.05). In the serum, SOD activity and MDA content in the 30 ℃ group showed changes that increased first, then decreased, and then increased with time. The SOD activity and MDA content in the 30 ℃ group at 96 h were significantly higher than those in the 24 ℃ and 28 ℃ groups (P＜0.05). The 24 ℃ and 28 ℃ groups remained basically stable. The CAT and GSH-Px activities in the 28 ℃ group at 48 h showed an increasing trend with time, and were significantly greater than the other two groups (P＜0.05), while the CAT and GSH-Px activities in the 30 ℃ group showed a decreasing trend with time, and at 24-96 h, it was significantly smaller than the other two groups (P＜0.05), and the 24 ℃ group remained basically stable. Under the high temperature stress, the alkaline phosphatase (AKP) and acid phosphatase (ACP) activities of liver in the 28 ℃ and 30 ℃ groups decreased with time (P＜0.05), while it was basically remained stable in the 24 ℃ group; the AKP and ACP activities at 48 and 96 h were significantly smaller than those in the 24 ℃ group (P＜0.05). The activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the 30 ℃ group increased with time, and the AST activity at 96 h and the ALT activity at 48 h were significantly higher than those in the 24 ℃ group (P＜0.05); the AST activity in the 28 ℃ group increased with time, and was significantly higher at 96 h than that in the 24 ℃ group (P＜0.05), while the ALT activity increased first and then decreased with time. The above results show that high temperature stress has a significant impact on the antioxidant and non-specific immune enzyme activities of A. sapidissima, causing certain damage to its liver. Therefore, in the process of practical production and industrial aquaculture, it is necessary to avoid high temperature stress response from A. sapidissima, and recommend that the breeding temperature is controlled below 28 ℃.

This study focuses on the effects of tea polyphenols (TPPs) on anti-inflammation and promoting wound healing in vivo and its mechanisms. ICR mice were selected as animal materials to make the wound. The wounded mice were treated with 0.3%, 0.5%, 0.8% and 1.0% TPPs, respectively. The treatment with artificial cell healing membrane was used as the positive control, and the blank control was set up. The effects of different concentrations of TPPs on the immune system and granulation tissue of wounded mice were measured after 9 d. The results showed that 0.5% TPPs could accelerate the wounded mice healing and the healing speed of this treatment was faster than the positive control. Meanwhile, 0.3% and 0.5% TPPs treatment groups could reduce the concentrations of tumor necrosis factor-α (TNF-α)and interleukin-2 (IL-2) in the late stage of wound healing to prevent excessive inflammatory reaction. Superoxide dismutase (SOD) activity in wound tissues was decreased significantly by the TPPs treatment as compared with the blank control group, which showed that TPPs may help to eliminate excessive free radicals in wound, and then to prevent its damage to the body. Hematoxylin-eosin (HE) staining sections of granulation tissue at the wound showed that TPPs treatment could promote the formation of capillaries in the wound. The function of TPPs in promoting wound healing was related to its concentration. At lower concentrations (below 0.5%), with the increase of concentration of TPPs, the ability of promoting wound healing increased; at higher concentrations (above 0.8%), TPPs showed the physiological characteristics of inhibiting wound healing. To some extent, the experimental results elucidate the partial mechanisms of promoting wound healing and anti-inflammation by TPPs and find that the suitable concentration range of TPPs for promoting wound healing is 0.3%-0.8%.

A study on florfenicol (FF) and florfenicol amine (FFA) residue depletion raws was conducted in eggs. After the chickens were administered successively florfenicol (FF) powder of 15 mg/kg (prevention group) and 30 mg/kg (treatment group) of body mass in the form of premix for 5 d, the eggs of each group were collected at administration period and 1, 2, 3, 5, 7, 10, 12, 15, 18 d at withdrawal period. Then FF and FFA residues of egg, egg yolk and egg white were detected using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The results showed that the limits of detection (LOD) of FF and FFA in egg, egg yolk and egg white were 2 μg/kg, and the limits of quantitation (LOQ) were 5 μg/kg. The average recoveries were in the range of 78.9%-105.0% when the egg samples were added with FF in the range of 1.0-5.0 μg/kg, and the intraday precision and the interday precision was 2.22%-4.22% and 4.22%-6.54%, respectively. The peak values of FF residues (520.70, 797.12 μg/kg) of egg white in prevention group and treatment group, respectively, were higher than those of egg yolk (285.96, 442.40 μg/kg), while the peak values of FFA residue (218.40, 646.14 μg/kg) of egg yolk in prevention group and treatment group, respectively, were higher than those of egg white (87.36, 36.89 μg/kg). The elimination rates of FF and FFA in egg white were faster than those in egg yolk. FF and FFA residues and their total residues were positively correlated with the dosage. FF and FFA mainly existed in the egg yolk, and FF mainly existed in the egg white. The FF residual time of egg yolk in different dosage groups was 18 d.

In order to investigate the expression profile of β-defensin genes in the blood of Chinese alligator and the effect of stocking density on them, reverse transcription quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression levels of β-defensin genes in blood samples from 41 seven-year-old Chinese alligators and study the defensin gene expression level differences between sexes and populations with different stocking densities. The results showed that only the AsBD5 and AsBD8 genes expressed in the blood of Chinese alligator, and there was a significantly positive correlation between their expression levels. There was no significant sex-biased difference of the defensin gene expression levels. However, their expression levels were significantly different between the two populations with different stocking densities. The defensin gene expression levels were significantly higher in the Chinese alligator population with higher stocking density, which indicating that the stocking density has some effect on the immune status of the captive Chinese alligator.

To understand the prevalence of porcine Pasteurella multocida in Tibet, a total of 60 samples (lungs, n=30; tonsil, n=30) were sterilely collected from the diseased and dead Tibetan swine in Tibet to analyze the capsular serotypes and virulence gene distribution of the porcine P. multocida. The results showed that one D-type porcine bacillus strain was obtained from the lung tissue, and the positive rate was 3.33% (1/30). However, there were not bacillus isolates from the tonsil. Moreover, the isolated strain carried 16 virulence genes and was closely related with P. multocida isolated from the poultry in Iran (GenBank No. AY225343). In addition, the strain was resistant to tetracycline, doxycycline, ampicillin and amoxicillin, but was sensitive to kanamycin, streptomycin, neomycin, spectinomycin, ciprofloxacin, norfloxacin and enrofloxacin. In conclusion, a capsular serotype D porcine P. multocida is isolated from the Tibetan swine, which provides references for the etiology and epidemiology investigation of porcine P. multocida in Tibet.

In order to optimize prawn breeding mode, growth of white shrimp (Litopenaeus vannamei), phytoplankton species and environmental variation in six greenhouse ponds located in Zhoushan City of Zhejiang Province were monitored at the interval of 15 d between August 16 and October 30, 2017. The results showed that the body length (L/cm) and body mass (m/g) of the white shrimp increased with the breeding time (t/d), and the regression equations were described as L=0.744 9×t^{0.594 6} and m=0.004 2×t^{1.823 7}, respectively. During the investigation period, water temperature and pH in the ponds decreased with the prolongation of time. The reactive phosphate (\mathrm{P}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{3}－}-P) and total phosphorus (TP) contents in the ponds significantly increased after the 15th day of stocking the shrimp seed. The total ammonia nitrogen (TAN), total nitrogen (TN) contents and five-day biochemical oxygen demand (BOD₅) value significantly increased, while the total alkalinity (TA) significantly decreased, after the 30th day of stocking the shrimp seed. The chemical oxygen demand (COD_Mn) value significantly increased, while the dissolved oxygen (DO) value declined, after the 45th day of stocking the shrimp seed. The species of Chlorophyta, Cyanophyta, Bacillariophyta and Euglenophytadominated in the ponds. Chlorophyll a (Chl a) content increased from the 0th to the 30th day after stocking the shrimp seed and then gradually declined. Growth rate in body length or body mass of the shrimp positively correlated to nitrite nitrogen (\mathrm{N}{\mathrm{O}}_{\mathrm{2}}^{－}-N), nitrate nitrogen (\mathrm{N}{\mathrm{O}}_{\mathrm{3}}^{－}-N), TN, \mathrm{P}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{3}－}-P, TP, Chl a contents, and COD_Mn, BOD₅ values, but negatively correlated to water temperature, DO value, pH and TA. These results suggest that water temperature, DO, pH and TA might be the environmental factors regulating growth of the white shrimp reared in the greenhouse ponds. Abnormally high water temperature in summer might limit growth of the white shrimp, and maintaining pH constant should be an important aspect in water quality management.

Fifty sows with similar body mass, parity and due dates were selected and randomly divided into five groups with five replicates per group and two sows per replicate. The sows in the control group were fed on a basal diet, and those in the experimental groups were fed on the basal diet supplemented with 50, 100, 150 and 200 mg/kg Callicarpa kwangtungensis Chun. extract, respectively, from the 30th day of gestation to the 25th day of lactation in order to investigate the effects of C. kwangtungensis extract on reproductive performance, immune function, antioxidant capacity and intestinal flora of sows. The results showed as follows: 1) Compared with the control group, dietary 50 and 100 mg/kg C. kwangtungensis extract significantly increased the birth body mass, and dietary 100 and 150 mg/kg C. kwangtungensis extract significantly increased the birth litter body mass, and dietary 150 mg/kg C. kwangtungensis extract significantly increased the weaning body mass and weaning litter body mass of piglets (P＜0.05); 2) C. kwangtungensis extract could improve serum superoxide dismutase (SOD) activity and decrease malondialdehyde (MDA) content of sows at mid-gestation, farrowing and weaning stages with different degrees; 3) C. kwangtungensis extract could reduce the levels of serum inflammatory cytokine including interleukin-1β (IL-1β), interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α) of sows at mid-gestation, farrowing and weaning stages with different degrees; 4) C. kwangtungensis extract could significantly increase the beneficial bacterial amounts of Bifidobacterium and Lactobacillus in the sows, and dietary 100 mg/kg and above C. kwangtungensis extract significantly reduced the amount of intestinal Escherichia coli and Clostridium perfringens (P＜0.05); 5）by establishing quadratic regression curves, the optimal addition range of C. kwangtungensis extract in the sows was 121-165 mg/kg. In conclusion, the recommended optimal addition range of C. kwangtungensis extract in the sows is 121-165 mg/kg to improve reproductive performance and serum antioxidant level, alleviate postpartum inflammatory reaction, and optimize intestinal flora structure.

Taking Mytilus coruscus as the research object and using hexavalent chromium [Cr(Ⅵ)] standard substance as the poisoning reagent, the content of chromium (Cr) in M. coruscus with the same speciation was compared, and the speciation of Cr at different time nodes was monitored, and the transformation of Cr(Ⅵ) in M. coruscus was discussed. The results showed that the trivalent chromium [Cr(Ⅲ)] and organic Cr were confirmed as the two main states of Cr in M. coruscus by using Cr(Ⅵ) standard substance as the poisoning reagent, with percentages of 21.0%-29.9% for Cr(Ⅲ), and 70.1%-79.0% for organic Cr. Cr(Ⅵ) could not be stable in M. coruscus. In the exposure experiment,accumulation of Cr(Ⅵ) in M.coruscus in vivo was converted into Cr(Ⅲ) and organic Cr, resulting in the contents of total Cr, Cr(Ⅲ) and organic Cr increased significantly. With the increase of Cr content in M. coruscus, the conversion rate of total Cr, Cr(Ⅲ) and organic Cr decreased gradually, as well as the content growth rate. When the enrichment tended to equilibrium, the Cr content increased nearly stagnation, and the conversion rates of total Cr, Cr(Ⅲ) and organic Cr decreased significantly, and the proportion of organic Cr to Cr(Ⅲ) continued to increase.

Single nucleotide polymorphism (SNP) of DQA2 gene in yak was analyzed via genomic DNA pooled amplification and directly sequencing, and further the influence of SNP sites on the secondary structures of mRNA and protein of DQA2 gene were predicted and analyzed by bioinformatic software. The results showed that the polymorphism of DQA2 gene in yak was high, and 14 SNP sites were detected. Only one SNP site was located on the intron 1, while 13 SNP sites were located on exon regions. Nine SNP sites were missense mutations, which resulted in changes in corresponding amino acids. The results of secondary structure prediction showed that eight SNP sites increased the stability of secondary structure of mRNA, and four SNP sites reduced the stability of secondary structure of mRNA. The SNP sites of missense mutation changed the secondary structure of DQA2 protein in yak. The proportion of random coil was the highest, followed by extended strand, and β-turn was the lowest among components of protein secondary structure before and after mutation. The results can provide basic data for further research on yak major histocompatibility complex (MHC) gene and theoretical basis for screening the molecular markers of yak disease resistance.

The present study was conducted to investigate the effect of mastitic milk-derived exosomes on the viability and innate immune function of bovine mammary epithelial cells (MECs), with the aim to understand the role of exosomes in the pathogenesis of mastitis. Primary MECs were stimulated with heat-killed mastitis causing bacteria (Escherichia coli) for 24 h and subjected to RNA-sequencing and gene ontology (GO) functional classification analysis. It was found that 21 differential expression genes between pathogen-stimulated cells and normal cells were enriched in the cellular component “extracellular vesicular exosome” (GO: 0070062), suggesting that infection may alter the physiological function of exosomes derived from host cells. Based on this finding, MECs were stimulated with the exosomes derived from normal milk (N-exo) and mastitic milk (M-exo), respectively, for 24 h. The cells cultured in the exosome-depleted medium were served as the controls. The cell viability was determined by methyl-thiazol-diphenyltetrazolium (MTT) assay, and the expression of pro-inflammatory cytokines interleukin-8 (IL-8), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in the MECs was measured by quantitative real-time PCR (qPCR). The results showed that the exosomes derived from normal milk (N-exo) had no effect on the MEC viability, and those isolated from mastitic milk (M-exo) led to a significant reduction in the cell viability. The exosomes derived from both sources had no effect on the expression of IL-8 and TNF-α. However, the normal milk-derived exosomes significantly induced the expression of IL-1β; in contrast, the exosomes derived from mastitic milk failed to stimulate IL-1β expression. The above results suggest that the exosomes present in milk in the process of udder infection might reduce MEC viability and mediate the formation of a microenvironment favoring the immune escape of pathogens. Thus, it is very likely that exosomes contribute to the pathogenesis of mastitis by helping spread the infection in udder.

Eighty 200-day-old Shaoxing ducks were randomly divided into two groups, including the ground group (control group) and the caged stress group (treatment group). Then the tissue damage degree of the duodenum and antioxidant indicators were determinated, and the relative expression levels of endoplasmic reticulum stress gene, inflammation-related gene and apoptotic gene mRNA were detected by real-time fluorescence polymerase chain reaction (RT-PCR) at 1, 2, 4, 7 and 10 d after cage rearing, which providing theoretical basis for the large-scale breeding of laying ducks and the scientific prevention for caged stress disease. The results showed that: 1) With the increase of caged stress time, the damage degree of the duodenum in the treatment group gradually increased, mainly manifested by inflammatory cell infiltration and intestinal gland epithelial cell shedding. 2) During the progress of caged stress, the duodenal malondialdehyde (MDA) content, total antioxidant capacity (T-AOC), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), activities in the treatment group showed fluctuating changes, while the catalase (CAT) activity increased significantly at the 7th day after cage rearing (P＜0.05). 3) RT-PCR results showed that compared with the control group, the endoplasmic reticulum stress-related genes glucose regulated protein 78 (GRP78)and CCAAT/enhancer-binding protein-homologous protein (CHOP) mRNA expression levels showed fluctuating changes, and increased significantly in the Shaoxing ducks at the 2nd and 10th day after cage rearing (P＜0.05). In addition, the expression level of apoptosis-related gene Bcl-2 associated X protein (Bax) mRNA increased significantly at the 7th and 10th day after cage rearing (P＜0.05), while the expression of cysteinecontaining aspartate-specific proteases-3 (Caspase3) mRNA expression level was not significantly different from the control group (P＞0.05). At the same time, the cyclooxygenase-2 (COX-2) mRNA expression level was significantly up-regulated and increased significantly at the 10th day after cage rearing (P＜0.05), while the expression level of inducible nitric oxide (iNOS) showed a trend of decreasing first and then increasing. The above results indicate that the stress of caged rearing causes different degrees of tissue damage on Shaoxing duck duodenum, which enhances the body’s antioxidant capacity. At the same time, the up-regulation of endoplasmic reticulum stress intensity eventually leads to apoptosis and inflammation.

In order to understand the effects of different culture patterns on the nutritional components of fish body, young fish Alosa sapidissima cultured in outdoor and shaded ponds were analyzed by biochemical analysis method, and the nutritive quality was analyzed and compared. The results showed that the body water content of shaded pond group (69.22%) was significantly lower than that of the outdoor pond group (70.68%) (P＜0.05), while the body crude fat content of shaded pond group (10.79%) was significantly higher than that of the outdoor pond group (7.48%) (P＜0.05). No significant differences in the contents of crude protein and ash in body were found between the two groups (P＞0.05). A total of 18 kinds of amino acids were found, and there were no significant differences in the contents of 11 kinds of amino acids (threonine, glycine, valine, methionine, tyrosine, phenylalanine, histidine, arginine, proline, tryptophane, cystine) between the two groups (P＞0.05), while in other seven kinds of amino acids (aspartate, serine, glutamic acid, alanine, isoleucine, leucine, lysine), the contents of outdoor pond group were significantly higher than those in shaded pond group (P＜0.05). The percentage contents of total amino acid (TAA), non-essential amino acid (NEAA) and delicious amino acid (DAA) in dry body of outdoor pond group were significantly higher than those of shaded pond group (P＜0.05), while there were no significant differences in the percentage contents of essential amino acid (EAA) and half-essential amino acid (HEAA) in dry body between the two groups (P＞0.05). There were no significant differences in the ratios of EAA/TAA, EAA/NEAA and DAA/TAA, and the body essential amino acid indexes (EAAI) of shaded pond group and outdoor pond group were 76.49 and 76.46, respectively. The total content of saturated fatty acid (SFA) of outdoor pond group (35.91%) was significantly higher than that of shaded pond group (27.70%) (P＜0.05), while the total content of poly-unsaturated fatty acid (PUFA) of outdoor pond group (13.66%) was significantly lower than that of shaded pond group (21.35%) (P＜0.05). There were no significant differences in the total contents of mono-unsaturated fatty acid (MUFA) and eicosapentaenoic acid+docosahexaenoic acid (EPA+DHA) between the two groups. The results indicated that the body protein quality of young fish A. sapidissima cultured in the outdoor pond was slightly better than that of young fish cultured in the shaded pond, but the body fatty acid quality of young fish A. sapidissima cultured in the shaded pond was much better. So, we suggest the composition of fatty acids in formulated feed should be optimized to increase the content of PUFA, especially the content of EPA and DHA.

This study mainly compared the virulence genes and drug resistance characteristics of Escherichia coli in laying ducks under the two different breeding modes: net bed with pool and net bed dry-system. Six farms including three net beds with pool and three net bed dry-systems were selected in Wenzhou, Zhejiang Province, and ten laying ducks were collected from each farm. The cotton swabs were used to collect microorganisms in the rectum forthe isolation of E. coli. The VITEK 2 COMPACT analysis system was used to identify the isolates and analyze the drug resistance profile. The virulence genes, drug-resistant genes and class Ⅰ integron genes were amplified by polymerase chain reaction. The results showed that the isolation rate of E. coli in laying ducks was 100%. The detection rates of virulence genes eae, ipa H, invE, aggR and pic of E. coli in the net bed dry-system were higher than those in the net bed with pool. For the drug-resistant phenotype, the proportion of strains with ≥3 resistance in E. coli in the net bed dry-system was 23.33%, while the proportion of strains with ≥3 in the net bed with pool was 10.00%. Similarly, the detection rates of the drug-resistant genes and the class Ⅰ integron genes in the net bed dry-system were also higher than those in the net bed with pool. Four of the 10 strains of class Ⅰ integron-positive E. coli carried the gene cassette insert, one of which derived from the E. coli class Ⅰ integron gene cassette of laying duck in the net bed with pool was dfrA12-aadA2, and the other three strains derived from the E. coli class Ⅰ integron gene cassette of laying duck in the net bed dry-system were dfrA1-aadA1. The above results indicate that the virulence gene carrying rate and drug resistance of E. coli in the intestinal tract of laying duck in the net bed dry-system are higher than those in the net bed with pool. It is suggested tha the changes of breeding mode may have some effect on the drug resistance characteristics of bacteria in waterfowls.

This study aimed to investigate the selection potential for early body mass in a layer resource population, and to compare three inference methods based on their efficiency and accuracy, including restricted maximum likelihood method (REML), Markov chain Monte Carlo method (MCMC), and integrated nested Laplace approximations (INLA). The genetic parameters were estimated by animal models. The layers were collected from a resource population, which were set up by Dongxiang blue-shelled layers crossbred with White Leghorn layers. The total amount of layers, made up of three generations, were 5 405. The phenotypic variance was dissected with the REML and Bayesian approaches. The results showed: 1) The heritability on body mass of the five-week-old layers ranged from 0.49 to 0.59, depending on the estimation method. 2) The MCMC method seemed a slow and low accuracy for genetic evaluation. 3) The use of INLA method could calculate the standard error for variance components, without approximations or use of normality assumptions. 4) Due to the advantage of computation time and accuracy, REML remained the best practical choice for the genetic evaluation in the poultry production. Considering the abundance of genetic potential in the resource population of five-week-old layer, it is better to select on early body mass with animal model.

In order to study the effects of the major royal jelly proteins (MRJPs) on the endocrine endocrinology in female mice during the perimenopausal period, an experiment was conducted for the natural aging female ICR mice with the age of 11-13 months. Fifty female mice were randomly divided into five equal groups, including low, middle and high dose groups of MRJPs (administrated with 125, 250, 500 mg/kg MRJPs, respectively), positive control group (administrated with 125 mg/kg casein) and old model group (administrated with physiological saline). Meanwhile, ten female mice with the age of five months were set as the young control group (administrated with physiological saline). Intragastric administrations were conducted for seven weeks once daily continuously. The indexes of uterus and ovary were calculated, and serum levels of estradiol (E₂), progesterone (P), follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were detected by radioimmunoassay. The real-time polymerase chain reaction was used to detect the expressions of estrogen receptor α (ERα), estrogen receptor β (ERβ) and progesterone receptor (PR). The histomorphological observation of the uterus and ovary was also carried out under an optical microscope. The results showed that MRJPs supplement in the medium and high dosages could increase the uterus index and ovary index. Serum levels of E₂ and P were significantly elevated in the MRJPs groups, while the levels of FSH and LH were decreased as compared with the old model group. The expressions of ovarian ERα, ERβ and PR were up-regulated significantly in the MRJPs groups. Follicular development was also improved. In conclusion, the above results suggest that MRJPs possess the protective activity in reproduction of mice during the perimenopausal period. It provides scientific evidences of royal jelly and MRJPs in prevention and improvement of perimenopause syndrome.

To investigate the effects of spermine on goose immune organ indexes and expression levels of genes related to immune factors, the Sichuan adult white geese (female) were intragastrically administered with 5 and 10 mg spermine per kilogram body mass, and then the indexes of liver, thymus, spleen and bursa of Fabricius were measured. In addition, the expression levels of TNF-α, IL-1β, IL-6 and IFN-γ genes and polyamine contents in the liver, thymus, spleen and bursa of Fabricius were determined. The control group was intragastrically administered with physiological saline. The results showed that the liver index in the geese treated with 10 mg/kg spermine was significantly lower than the control group (P＜0.05). The expression levels of TNF-α, IL-1β, IL-6 and IFN-γ genes in the thymus and bursa of Fabricius of geese treated with 5 mg/kg spermine were significantly lower than the control group (P＜0.05), respectively. The expression levels of TNF-α and IFN-γ in the bursa of Fabricius and IFN-γ in the liver of geese treated with 10 mg/kg spermine were significantly lower than the control group (P＜0.05), respectively. The expression level of IFN-γ was significantly decreased in the spleen by the treatments of spermine compared with the control group (P＜0.05). The contents of spermine in the liver of geese treated with spermine were significantly greater than the control group (P＜0.05). In summary, these results suggest that spermine regulates the immunologic function of geese by mediating the expression levels of genes related to immune factors with the tissue-specific and dose-dependent manner.

In order to research deeply the transcription and splicing situations of chicken G-protein alpha subunit gene (GNAS), we used 5′ and 3′ rapid-amplification cDNA end (RACE) technology to clone and sequence the chicken GNAS gene, and used quantitative polymerase chain reaction (PCR) to detect the expression level of GNAS spliceosome in seven tissues of chicken， such as skin, pectoral muscle, heart, brain, liver, lung, and abdominal fat. The results showed that the chicken GNAS gene had two transcriptional spliceosomes of 1 554 bp and 1 796 bp, respectively. Both of spliceosomes included 12 exons, and only the length and position of their first exon were different, and the second to twelfth exons were the same. Clone 1 (1 554 bp) coded 417 amino acids, while clone 2 (1 796 bp) coded 379 amino acids. Protein alignment in the NCBI database showed that the similarity between the 379 amino acid sequence of the clone 2 and Gαs subunits of the known human and mouse GNAS genes was 93%. The 417 amino acid sequence of the clone 1 was more similar with the XLαs subunit, and their similarity was 87%. The gene expression detection showed that these two transcriptional spliceosomes had different degrees of expression in the seven tissues: the highest expression in the brain (P＜0.01), next in the skin (P＜0.01 or P＜0.05), and the lower expressions in the lung, pectoral muscle, heart and abdominal fat.