Supplementation with organic yeast-derived selenium provides immune protection against experimental necrotic enteritis in broiler chickens.

Necrotic enteritis (NE) is a potentially fatal poultry disease that causes enormous economic losses in the poultry industry worldwide. The study aimed to evaluate the effects of dietary organic yeast-derived selenium (Se) on immune protection against experimental necrotic enteritis (NE) in commercial broilers. Chickens were fed basal diets supplemented with different Se levels (0.25, 0.50, and 1.00 Se mg/kg). To induce NE, Clostridium perfringens (C. perfringens) was orally administered at 14 days of age post hatch. The results showed that birds fed 0.25 Se mg/kg exhibited significantly increased body weight gain compared with the non-supplemented/infected birds. There were no significant differences in gut lesions between the Se-supplemented groups and the non-supplemented group. The antibody levels against α-toxin and NetB toxin increased with the increase between 0.25 Se mg/kg and 0.50 Se mg/kg. In the jejunal scrapings and spleen, the Se-supplementation groups up-regulated the transcripts for pro-inflammatory cytokines IL-1ß, IL-6, IL-8, iNOS, and LITAF and avian ß-defensin 6, 8, and 13 (AvBD6, 8 and 13). In conclusion, supplementation with organic yeast-derived Se alleviates the negative consequences and provides beneficial protection against experimental NE.

Optimal planting pattern of cotton is regulated by irrigation amount under mulch drip irrigation.

Objective: It is of great importance to explore agronomic management measures for water conservation and cotton yield in arid areas. Methods: A four-year field experiment was conducted to evaluate cotton yield and soil water consumption under four row spacing configurations (high/low density with 66+10 cm wide, narrow row spacing, RS66+10H and RS66+10L; high/low density with 76 cm equal row spacing, RS76H and RS76L) and two irrigation amounts (CI:conventional drip irrigation; LI:limited drip irrigation) during the growing seasons in Shihezi, Xinjiang. Results: A quadratic relationship was observed between the maximum LAI (LAImax) and seed yield. Canopy apparent transpiration rate(CAT), daily water consumption intensity (DWCI) and crop evapotranspiration (ETC) were positively and linearly correlated with LAI. The seed yields, lint yields, and ETC under CI were 6.6-18.3%,7.1-20.8% and 22.9-32.6%higher than those observed under LI, respectively. The RS66+10H under CI had the highest seed and lint yields. RS76L had an optimum LAImax range, which ensured a higher canopy apparent photosynthesis and daily dry matter accumulation and reached the same yield level as RS66+10H; however, soil water consumption in RS76L was reduced ETC by 51-60 mm at a depth of 20-60 cm at a radius of 19-38 cm from the cotton row,and water use efficiency increased by 5.6-8.3%compared to RS66+10H under CI. Conclusion: A 5.0

Identification of elite fiber quality loci in upland cotton based on the genotyping-by-target-sequencing technology.

Genome-wide association studies (GWAS) of fiber quality traits of upland cotton were conducted to identify the single-nucleotide polymorphic (SNP) loci associated with cotton fiber quality, which lays the foundation for the mining of elite] cotton fiber gene resources and its application in molecular breeding. A total of 612 upland cotton accessions were genotyped using the ZJU Cotton Chip No. 1 40K chip array via the liquid-phase probe hybridization-based genotyping-by-target-sequencing (GBTS) technology. In the present study, five fiber quality traits, namely fiber length, fiber strength, micronaire, uniformity and elongation, showed different degrees of variation in different environments. The average coefficient of variation of fiber strength was the greatest, whereas the average coefficient of variation of uniformity was the least. Significant or extremely significant correlations existed among the five fiber quality traits, especially fiber length, strength, uniformity and elongation all being significantly negative correlated with micronaire. Population cluster analysis divided the 612 accessions into four groups: 73 assigned to group I, 226 to group II, 220 to group III and 93 to group IV. Genome-wide association studies of five fiber quality traits in five environments was performed and a total of 42 SNP loci associated with target traits was detected, distributed on 19 chromosomes, with eight loci associated with fiber length, five loci associated with fiber strength, four loci associated with micronaire, twelve loci associated with fiber uniformity and thirteen loci associated with fiber elongation. Of them, seven loci were detected in more than two environments. Nine SNP loci related to fiber length, fiber strength, uniformity and elongation were found on chromosome A07, seven loci related to fiber length, fiber strength, micronaire and elongation were detected on chromosome D01, and five loci associated with fiber length, uniformity and micronaire were detected on chromosome D11. The results from this study could provide more precise molecular markers and genetic resources for cotton breeding for better fiber quality in the future.

Variant Serotypes of Fowl Adenovirus Isolated from Commercial Poultry Between 2007 and 2017 in Some Regions of China.

The present study was performed to detect and characterize the serotypes of fowl adenovirus associated with inclusion body hepatitis (IBH) or hepatitis-hydropericardium syndrome (HHS) in commercial poultry in some regions of China between 2007 and 2017. Approximately 81 fowl adenovirus strains were isolated from liver or kidney samples from diseased poultry. A sequencing analysis of the hexon loop 1 gene revealed fowl adenovirus serotypes 8a, 8b, and 11 in samples of broilers with IBH, serotype 11 in layers with IBH, and serotype 4 in poultry with HHS. Of the fowl adenovirus serotype 4 strains, 62.07% were isolated from layers. Additionally, 74.07% of the isolated strains were fowl adenovirus serotype 11 prior to June 2014; 53.70% were serotype 4 after that time point; and strains isolated in the first half of 2017 were all serotype 8b, which was related to the widespread application of inactivated serotype 4 adenovirus vaccines. These results demonstrate that fowl adenovirus serotypes 11, 4, and 8b were the predominant serotypes in some regions of China between 2007 and June 2014, between June 2014 and 2016, and in the first half of 2017, respectively. Layers were the predominant host infected with fowl adenovirus serotype 4 and could also be infected by serotype 11.

Characterization of avian influenza H9N2 viruses isolated from ostriches (Struthio camelus).

H9N2 subtype avian influenza viruses (AIVs) have been isolated from various species of wild birds and domestic poultry in the world, and occasionally transmitted to humans. Although H9N2 AIVs are seldom isolated from ostriches, seven such strains were isolated from sick ostriches in China between 2013 and 2014. Sequence analysis showed several amino acid changes relating to viral adaptation in mammals were identified. The phylogenetic analyses indicated that these isolates were quadruple reassortant viruses, which are different from the early ostrich isolates from South Africa or Israel. Most of the ostrich virus carried a human-type receptor-binding property. The chicken experiments showed the ostrich strains displayed low pathogenicity, while they could cause mild to severe symptoms in chicken. Theses strains could efficiently transmit among chickens, and one strain showed higher transmissibility. The virus could not kill mice, and merely replicated in the lung of mice. The ostrich strains could not efficiently transmit between guinea pigs in the direct contact model. These results suggested we should pay attention to the interface between ostrich and other domestic fowl, and keep an eye on this population when monitoring of influenza virus.

Effects of dietary selenium on host response to necrotic enteritis in young broilers.

The effects of dietary supplementation of young broiler chickens with an organic selenium (Se) formulation, B-Traxim Se, on experimental necrotic enteritis (NE) were studied. Chickens treated with three Se doses (0.25, 0.50, 1.00 mg/kg) from hatch were orally challenged with Eimeria maxima at 14 days of age followed by Clostridium perfringens to induce NE. Chickens fed with 0.50 mg/kg Se showed significantly increased body weights and antibody levels against NetB, and significantly reduced gut lesions compared with non-supplemented chickens. However, there were no significant differences in Eimeria oocyst shedding between the Se-treated and non-supplemented groups. Levels of IL-1ß, IL-6, IL-8, iNOS, LITAF, TNFSF15, AvBD6, AvBD8, and AvBD13 transcripts were increased in the gut and spleen of at least one of the three Se-treated groups compared with the non-treated group. These results suggest that dietary supplementation of young broilers with Se might be beneficial to reduce the negative consequence of NE.

Immune and anti-oxidant effects of in ovo selenium proteinate on post-hatch experimental avian necrotic enteritis.

This study was conducted to investigate the effects of in ovo administration of selenium (Se) incorporated into hydrolyzed soybean protein (B-Taxim [BT]) on protection against experimental avian necrotic enteritis (NE). Broiler eggs were injected with either 100 µl of PBS alone (BT0), or 20 or 40 µg/egg of BT in PBS (BT20, BT40) at 18 days of embryogenesis. On day 14 post-hatch, the chickens were uninfected or orally infected with 1.0 × 10(4) oocysts of Eimeria maxima (E. maxima). On day 18 post-hatch, E. maxima-infected chickens were orally infected with 1.0 × 10(9) CFU of Clostridium perfringens (C. perfringens). Compared with untreated and infected BT0 controls, BT20 and/or BT40 birds showed increased body weights, decreased fecal shedding of E. maxima oocysts, lower serum α-toxin and NetB levels, increased levels of serum antibodies against C. perfringens α-toxin and NetB toxin, decreased levels of serum malondialdehyde, reduced serum catalase and superoxide dismutase catalytic activities, and increased intestinal levels of gene transcripts encoding interleukin (IL)-1ß, IL-6, IL-8, and peroxiredoxin-6, but decreased levels of transcripts for catalase and glutathione peroxidase. Interestingly, transcript levels for inducible nitric oxide synthase and paraoxonase/arylesterase 2 were decreased in the BT20 group and increased in the BT40 group, compared with BT0 controls. These results indicate that in ovo administration of broiler chickens with a Se-containing protein hydrolysate enhanced protection against experimental NE possibly by altering the expression of proinflammatory and anti-oxidant genes and their downstream pathways.

Complete Genome Sequence of an H9N2 Influenza Virus Lethal to Chickens.

An H9N2 virus lethal to chickens was isolated from an acutely ill chicken flock in 2012. Phylogenetic analyses indicated that this virus was phylogenetically related to the Y280 lineage. Sequence analysis showed 1 amino acid deletion in HA1 and 3 amino acid deletions in the NA stalk region.

Molecular and antigenic characterization of H9N2 avian influenza virus isolates from chicken flocks between 1998 and 2007 in China.

Despite extensive vaccination, H9N2 subtype influenza A viruses (IAVs) have prevailed in chicken populations in China. H9N2 IAVs have been a major cause of respiratory disease and reduced egg production, resulting in great economic losses to the Chinese poultry industry. In attempt to find reasons for lack of adequate protection by commercial vaccines, 41 H9N2 viruses isolated from chicken flocks in various regions of China through surveillance between 1998 and 2007 were systemically analyzed using molecular and serological methods in comparison to IAV Ck/Shandong/6/96 and Ck/Shanghai/F/98 that have been used in a majority of commercial vaccines for H9N2 in China since 1998. The analyses showed that the field isolates were predominantly of Beijing/94 lineage and underwent rapid genetic and antigenic changes, forming several antigenic groups. Comparisons between the field isolates and vaccine strains revealed that a majority of the field isolates examined were antigenically distinct from the vaccine strains to some extent. Therefore, the rapid antigenic evolution of H9N2 IAV and resulting antigenic difference from the earlier vaccine strains appears to be a key factor for suboptimal control of H9N2 IAV in China, emphasizing that the vaccine strain should be updated in a timely manner through surveillance and accompanying laboratory evaluation of contemporary viruses for antigenic similarity with existing vaccine strains.

Development of reverse-transcription loop-mediated isothermal amplification for the detection of infectious bursal disease virus.

To establish a reverse-transcription loop-mediated isothermal amplification (RT-LAMP) method for rapid detection of infectious bursal disease virus (IBDV), four primers specific to six regions of the VP3 gene were designed; the VP3 region was selected because it is a conserved part of the IBDV genome. After amplification in an isothermal water bath for 70 min, samples containing IBDV generated the expected ladder-like products while other viruses generated no product. The sensitivity and specificity of the RT-LAMP assay were evaluated by comparison with reverse-transcription polymerase chain reaction (RT-PCR) and virus isolation. The assay was significantly more sensitive than normal gel-based RT-PCR. Because it is specific and simple, the RT-LAMP assay can be widely applied in clinical laboratories for rapid detection of IBVD.

Protective immunity enhanced by chimeric DNA prime-protein booster strategy against Eimeria tenella challenge.

In an attempt to investigate the immune efficacy ofa DNA prime-protein booster strategy against avian coccidiosis with a chimeric construct, the Eimeria tenella antigen gene (3-1E) and chicken interferon gamma gene (ChIFN-gamma) were subcloned into the mammalian expression vector proVAX forming the plasmids proE and prol, and then linked by splicing overlap extension by polymerase chain reaction to construct the chimeric plasmid prolE; the chimeric protein (rlE) was expressed in Escherichia coli harboring the constructed plasmid pGEX/IE. Broilers were administered two intramuscular injections with the constructed DNA vaccines (50 microg); in the protein booster groups 100 microg of the rlE were given following the proIE prime. After challenge the proIE-vaccinated chickens showed the protective immunity as demonstrated by significantly reduced oocyst shedding compared with chickens immunized with proE, but the prolE vaccine did not have an additive effect of increasing antibody titer and body weight gain. The chickens in the rlE booster groups had significantly higher specific antibody responses than those immunized with prolE, and displayed further decreased oocyst shedding and increased body weight gain. Taken together, these results indicate that ChIFN-gamma exerts an adjuvant effect coexpressed with 3-1E and provide the first evidence that the DNA prime-protein booster strategy is able to augment the protective efficacy of chimeric DNA vaccine against challenge with Eimeria tenella.