摘要：
Largemouth bass (Micropterus salmoides) is an important commercial fish species that is widely cultured throughout China. With the application of high-density culture, M. salmoides is usually infected by different pathogens in water. Particularly, co-infection with multiple pathogens was common, which has considerably outweighed the impact caused by single infections. In this research, two bacteria strains were isolated from diseased fish by incubating on brain heart infusion agar. According to the results of 16S rRNA and gyrB sequence, as well as the analysis of morphological, physiological and biochemical features, the isolated bacterial strains were finally identified as Aeromonas veronii and Nocardia seriolae, respectively. In addition, eight virulence genes related to pathogenicity including enterotoxin, lipase, elastase, quorum sensing, hemolysin and adhesion were identified in A. veronii isolate and eight virulence genes encoding mammalian cell entry family proteins, glyceraldehyde-3-phosphate dehydrogenase, mycolyltransferase, nitrate reductase subunits, and putative cytotoxin/hemolysin were detected in N. seriolae isolate. Drug sensitivity testing indicated that both A. veronii and N. seriolae isolates were susceptible to kanamycin, streptomycin, gentamycin, neomycin, doxycycline, tetracycline, ciprofloxacin and levofloxacin, and resistant to amikacin, cefpimizole, ampicillin, piperacillin, carbenicillin, oxacillin, rifampicin, trimethoprim, vancomycin, meropenem, imipenem and sulfisoxazole. Moreover, serious histopathological changes, such as typical granulomas with necrotic center, cell degeneration and necrosis, hemorrhage and inflammatory cell infiltration, were found in the naturally diseased fish. The LD(50) of A. veronii and N. seriolae isolates were 7.94×10(5)CFU/g and 3.16×10(6)CFU/g fish weight, respectively. In addition, the coinfection of A. veronii and N. seriolae induce quick and higher mortality in comparison with those challenged by single bacteria. These results revealed that both A. veronii and N. seriolae participated in the disease outbreaks of the M. salmoides, and concurrent of those two bacteria synergistically exacerbate the disease severity.
作者机构：
[张倩; 侯永清; 郭双双; 张焱焱] Hubei International Scientific and Technological Cooperation Base of Animal Nutrition and Gut Health, School of Animal Science and Nutrition Engineering, Wuhan Polytechnic University, Wuhan, 430023, China
通讯机构：
[Hou, Y.] H;Hubei International Scientific and Technological Cooperation Base of Animal Nutrition and Gut Health, China
通讯机构：
[Hongbo Chen; Liangyu Shi] H;Hubei Provincial Center of Technology Innovation for Domestic Animal Breeding, Wuhan Polytechnic University, Wuhan 430023, China<&wdkj&>Authors to whom correspondence should be addressed.<&wdkj&>Laboratory of Genetic Breeding, Reproduction and Precision Livestock Farming, School of Animal Science and Nutritional Engineering, Wuhan Polytechnic University, Wuhan 430023, China
摘要：
Simple Summary It is well known that hematologic and biochemical reference intervals (RIs) play a major role in defining the health state of an animal. China is home to over 50% of the world pig population, but the assessment of hematologic and biochemical parameters for healthy commercial pigs has not yet been well studied in China. Adopting hematologic and biochemical RIs from other regions may lead to misjudgments by clinicians or researchers. Therefore, the aim of this study was to evaluate the correlations between hematologic and biochemical parameters and to provide a basic reference for the establishment of blood RIs for commercial pigs in China. Since most hematologic and biochemical parameters were significantly different between nursery pigs and sows, we preliminarily established hematologic and biochemical RIs for nursery pigs and sows, respectively. Our results are useful for better assessing the health conditions of commercial pigs in China. Hematologic and biochemical data are useful for indicating disease diagnosis and growth performance in swine. However, the assessment of these parameters in healthy commercial pigs is rare in China. Thus, blood samples were collected from 107 nursery pigs and 87 sows and were analyzed for 25 hematologic and 14 biochemical variables. After the rejection of the outliers and the detection of the data distribution, the correlations between the blood parameters were analyzed and the hematologic/biochemical RIs were preliminarily established using the 95% percentile RI. Correlation analysis showed that albumin was the hub parameter among the blood parameters investigated, and genes overlapping with key correlated variables were discovered. Most of the hematologic and biochemical parameters were significantly different between nursery pigs and sows. The 95% RIs of white blood cells and red blood cells were 7.18-24.52 x 10(9)/L and 5.62-7.84 x 10(12)/L, respectively, for nursery pigs, but 9.34-23.84 x 10(9)/L and 4.98-8.29 x 10(12)/L for sows. The 95% RIs of total protein and albumin were 43.16-61.23 g/dL and 19.35-37.86 g/dL, respectively, for nursery pigs, but 64.96-88.68 g/dL and 31.91-43.28 g/dL for sows. In conclusion, our study highlights the variability in blood parameters between nursery pigs and sows and provides fundamental data for the health monitoring of commercial pigs in China.
作者机构：
[Cheng, Shuiyuan; Jing, Xiaoqing; Xu, Xiao; Liu, Yulan; Wei, Yu; Cong, Xin; Zhu, Huiling] Wuhan Polytech Univ, Natl R&D Ctr Se Rich Agr Prod Proc, Hubei Key Lab Anim Nutr & Feed Sci, Wuhan 430023, Peoples R China.;[Zhang, Yue; Gao, Qingyu; Cong, Xin] Enshi Se Run Mat Engn Technol Co Ltd, Enshi 445000, Peoples R China.
通讯机构：
[Xiao Xu] H;Hubei Key Laboratory of Animal Nutrition and Feed Science, National R&D Center for Se-Rich Agricultural Products Processing, Wuhan Polytechnic University, Wuhan 430023, China<&wdkj&>Author to whom correspondence should be addressed.
摘要：
Simple Summary Selenium (Se) is a crucial trace nutrient for animal maintenance and growth as well as human health. Organic Se has less poisonous and better tissue retention as well as bioavailability compared to inorganic Se. Cardamine violifolia is a newly discovered Se-enriched plant rich in MeSeCys and SeCys and has a strong antioxidant capacity. This study aimed to investigate the effects of Cardamine violifolia on plasma biochemical indices, antioxidant levels, intestinal morphology, and meat quality of broilers under acute LPS-induced oxidative stress by comparing it with inorganic Se (sodium selenite). The results showed that Cardamine violifolia alleviated tissue injury, enhanced antioxidant capacity, and improved meat quality of breast and thigh muscle after LPS stress. Cardamine violifolia is a newly discovered selenium (Se)-enriched plant rich in MeSeCys and SeCys and has a strong antioxidant capacity. This study aimed to investigate the effects of Cardamine violifolia on plasma biochemical indices, antioxidant levels, intestinal morphology, and meat quality of broilers under acute LPS-induced oxidative stress by comparing it with inorganic Se (sodaium selenite). A total of 240 one-day-old Ross 308 broilers were fed a basal diet and divided into four groups: (1) SeNa-SS, fed a diet supplied with 0.3 mg/kg Se from sodium selenite, and injected with 0.9% sterile saline, (2) SeCv-SS, fed a diet supplied with 0.3 mg/kg Se from Cardamine violifolia, and injected with 0.9% sterile saline, (3) SeNa-LPS, fed a diet supplied with 0.3 mg/kg Se from sodium selenite, and injected with 0.5 mg/kg LPS, (4) SeCv-LPS, fed a diet supplied with 0.3 mg/kg Se from Cardamine violifolia and injected with 0.5 mg/kg LPS. The experiment lasted for 42 days. Sterile saline or LPS was injected intraperitoneally two hours before slaughter, and blood and tissue samples were collected for testing. The results showed that compared with SeNa, SeCv significantly reduced the plasma levels of aspartate aminotransferase, alanine aminotransferase, and urea nitrogen after LPS challenge (p < 0.05), and increased the plasma levels of total antioxidant capacity and glutathione peroxidase, decreased malondialdehyde content in LPS-challenged broilers (p < 0.05). In addition, compared with SeNa, SeCv supplementation increased villus height and the ratio of villus height to crypt depth of jejunum and ileum after LPS challenge (p < 0.05). Additionally, SeCv could increase the redness of breast and thigh muscle, and decrease drip loss, cooking loss, and shear force (p < 0.05). In conclusion, our results indicated that supplementing with 0.3 mg/kg Se from Cardamine violifolia alleviated tissue injury after LPS challenge, increased antioxidant capacity, and improved meat quality of breast and thigh muscle after stress.
通讯机构：
[Liu Yang] C;College of Mechanical Engineering, Wuhan Polytechnic University, Wuhan 430048, China<&wdkj&>Author to whom correspondence should be addressed.
关键词：
apple;damage;finite element method;mechanical–structural properties
通讯机构：
[Li, X.] K;Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction, Ministry of Education & College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, China
通讯机构：
[Xiao Xu] H;Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan 430023, China<&wdkj&>Author to whom correspondence should be addressed.
摘要：
Simple Summary The sharp decline of laying performance and eggshell quality is a common problem in late period laying hens. Vitamin D-3 (VD3) is a necessary micronutrient which plays an important role in mineral and skeletal homeostasis. With the rapid development of genetic selection, commercial laying hens have increased requirements for performance and nutrients. The commercial supplementary dose of VD3 (62.5 mu g/kg) for late period laying hens may be not enough to satisfy the production. In addition, 25-hydroxyvitamin D-3 (25-OHD3) as an active metabolite of VD3, is a viable alternative to replace VD3. Therefore, the objective of this study was to compare the effects of different supplementary doses and sources between VD3 and 25-OHD3 on the laying performance and eggshell quality in late period laying hens. The results showed that supplementary 125 mu g/kg doses of VD3 or 25-OHD3 had better effects in late period laying hens compared with 62.5 mu g/kg doses of VD3. Additionally, there were no different effects on laying performance or eggshell quality in the hens fed dietary 125 mu g/kg doses of VD3 or 25-OHD3. The objective of this study was to compare high supplementary doses (125 mu g/kg) of vitamin D-3 (VD3) or 25-hydroxyvitamin D-3 (25-OHD3) with commercial supplementary doses (62.5 mu g/kg) of VD3 on laying performance, eggshell quality and ultrastructure, and plasma calcium levels in late period laying hens. A total of 1512 Roman Gray (60-week-old) laying hens were allotted into three treatments with 12 replicates and 42 birds in each replicate. During the 12-week trial period, the layers were fed a basal diet supplemented with different doses of VD3 or 25-OHD3 (62.5 mu g/kg VD3 in control group, CON; 125 mu g/kg VD3 in high level VD3 group, VD3; 125 mu g/kg 25-OHD3 in high level 25-OHD3 group, 25-OHD3). The results showed that high supplementary doses of VD3 or 25-OHD3 increased laying rate (p < 0.05). Moreover, the layers fed high doses of VD3 or 25-OHD3 diets had decreased unqualified egg rate and mortality (p < 0.05). High supplementary doses of VD3 or 25-OHD3 increased eggshell strength and eggshell thickness (p < 0.05). From observation in eggshell ultrastructure, high doses of VD3 or 25-OHD3 diets increased the palisade layer thickness and mammillary knob density (p < 0.05). Furthermore, high doses of VD3 or 25-OHD3 diets increased the calcium levels in plasma (p < 0.05). In summary, compared with 62.5 mu g/kg doses of VD3, supplementary 125 mu g/kg doses of VD3 or 25-OHD3 improved the laying performance, eggshell quality, and plasma calcium levels in late period laying hens. Additionally, there was an equal effect on laying performance and eggshell quality in the hens fed dietary 125 mu g/kg doses of VD3 or 25-OHD3.
通讯机构：
[Fuping Zhao; Lixian Wang] A;Authors to whom correspondence should be addressed.<&wdkj&>Key Laboratory of Animal Genetics, Breeding and Reproduction (Poultry) of Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
关键词：
genotype imputation;genome-wide association analysis;Large White pigs;total number born;number of stillborn;gestation length
摘要：
Total number born (TNB), number of stillborn (NSB), and gestation length (GL) are economically important traits in pig production, and disentangling the molecular mechanisms associated with traits can provide valuable insights into their genetic structure. Genotype imputation can be used as a practical tool to improve the marker density of single-nucleotide polymorphism (SNP) chips based on sequence data, thereby dramatically improving the power of genome-wide association studies (GWAS). In this study, we applied Beagle software to impute the 50 K chip data to the whole-genome sequencing (WGS) data with average imputation accuracy (R-2) of 0.876. The target pigs, 2655 Large White pigs introduced from Canadian and French lines, were genotyped by a GeneSeek Porcine 50K chip. The 30 Large White reference pigs were the key ancestral individuals sequenced by whole-genome resequencing. To avoid population stratification, we identified genetic variants associated with reproductive traits by performing within-population GWAS and cross-population meta-analyses with data before and after imputation. Finally, several genes were detected and regarded as potential candidate genes for each of the traits: for the TNB trait: NOTCH2, KLF3, PLXDC2, NDUFV1, TLR10, CDC14A, EPC2, ORC4, ACVR2A, and GSC; for the NSB trait: NUB1, TGFBR3, ZDHHC14, FGF14, BAIAP2L1, EVI5, TAF1B, and BCAR3; for the GL trait: PPP2R2B, AMBP, MALRD1, HOXA11, and BICC1. In conclusion, expanding the size of the reference population and finding an optimal imputation strategy to ensure that more loci are obtained for GWAS under high imputation accuracy will contribute to the identification of causal mutations in pig breeding.
