Identification and characterization of chicken circovirus from commercial broiler chickens in China

Diverse Small Circular DNA Viruses Identified in an American Wigeon Fecal Sample

American wigeons (Mareca americana) are waterfowls that are widely distributed throughout North America. Research of viruses associated with American wigeons has been limited to orthomyxoviruses, coronaviruses, and circoviruses. To address this poor knowledge of viruses associated with American wigeons, we undertook a pilot study to identify small circular DNA viruses in a fecal sample collected in January 2021 in the city of Tempe, Arizona (USA). We identified 64 diverse circular DNA viral genomes using a viral metagenomic workflow biased towards circular DNA viruses. Of these, 45 belong to the phylum Cressdnaviricota based on their replication-associated protein sequence, with 3 from the Genomoviridae family and the remaining 42 which currently cannot be assigned to any established virus group. It is most likely that these 45 viruses infect various organisms that are associated with their diet or environment. The remaining 19 virus genomes are part of the Microviridae family and likely associated with the gut enterobacteria of American wigeons.

Molecular characteristics of novel chaphamaparvovirus identified in chickens

Chicken chaphamaparvovirus (CkChpV) is a novel parvovirus species that belongs to the Chaphamaparvovirus genus and is frequently detected in different vertebrates exhibiting diarrhea symptoms. In this study, screening tests were performed on samples from 478 chickens, including 357 with diarrhea and 121 healthy, collected from 25 farms in China to investigate CkChpV infection in China. CkChpV, avian nephritis virus, rotavirus, chicken parvovirus, Newcastle disease virus, infectious bronchitis virus, chicken proventricular necrosis virus, and chicken circovirus were all detected in the samples at a positivity rate of 32%, 9%, 6%, 2%, 2%, 1%, 0%, and 0%, respectively. Statistical analyses suggested a correlation between the infection by the virus and diarrhea (P < 0.05). The genome of 9 strains from the CkChpV-positive samples, whose length was 4,432 nucleotides, have been completely sequenced. The strains shared 97.2 to 98.7% genomic similarity, 98.1 to 99.1%, and 98.2 to 99.2% amino acid similarity, respectively, for NS1 and VP1 compared with CkChpV strain RS/BR/15/2S in GenBank. The genetic relationship between these strains and CkChpV was established through phylogenetic analysis. These findings indicated the infection existence of CkChpV in China, which enriches our understanding of the diversity of the chaphamaparvoviruses and its host spectrum.

Long read sequencing revealed proventricular virome of broiler chicken with transmission viral proventriculitis

Background

Transmissible viral proventriculitis (TVP) causes significant economic loss to the poultry industry. However, the exact causative agents are obscure. Here we examine the virome of proventriculus from specified pathogen free (SPF) chickens that reproduced by infection of proventricular homogenate from broiler chicken with TVP using long read sequencing of the Pacific Biosciences RSII platform. The normal SPF chickens were used as control.

Results

Our investigation reveals a virome of proventriculitis, including three Gyrovirus genera of the Aneloviridae: Gyrovirus homsa1 (GyH1) (also known as Gyrovirus 3, GyV3) (n = 2662), chicken anemia virus (CAV) (n = 482) and Gyrovirus galga1 (GyG1) (also known as avian Gyrovirus 2, AGV2) (n = 11); a plethora of novel CRESS viral genomes (n = 26) and a novel genomovirus. The 27 novel viruses were divided into three clusters. Phylogenetic analysis showed that the GyH1 strain was more closely related to the strains from chicken (MG366592) than mammalian (human and cat), the GyG1 strain was closely related to the strains from cat in China (MK089245) and from chicken in Brazil (HM590588), and the CAV strain was more closely related to the strains from Germany (AJ297684) and United Kingdom (U66304) than that previously found in China.

Conclusion

In this study, we revealed that Gyrovirus virome showed high abundance in chickens with TVP, suggesting their potential role in TVP, especially GyH1. This study is expected to contribute to the knowledge of the etiology of TVP.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03339-9.

Herbal Plants Application in Organic Poultry Nutrition and Production

Background:

Medicinal plants and natural feed additives are the most important alternatives in animal production, especially broiler production, due to the ban on the use of certain antibiotics, their cost-effectiveness and harmful residual effects.

Objective:

In this mini-review article, some important medicinal herbs and plants with positive effects on organic broiler production have been highlighted.

Methods:

A literature search was conducted in Science Direct, Google, Google Scholar, Springer, Medline and PubMed.

Results:

Medicinal plants such as ginger, ginkgo, thyme, ponderosa pine, soybean, forsythia, peppermint, Chinese star anise, astragalus, mistletoe, schisandra, cumin, capsicum, garlic, hooker chives, artichoke, Borreria latifolia, zataria, pomegranate, turmeric, lingzhi, Lippia javanica, neem, oriental chaff flower, mulberry leaf, goji berry, Aloe vera, pumpkin, grape, common nettle, marigold, coriandrum, Citrus sinensis, Alisma canaliculatum, Persian hogweed, Eucommiaulmoides, bamboo leaf extract, rosemary, Morina citrifolia, chestnut, green tea, wild mint, clove, sumac, satureja, ashwagandha, Lonicera japonica, Acacia, liquorice, Artemisia annua, milk thistle, cinnamon, black cumin and etc. have positive effects on organic broiler production.

Conclusion:

Herbal medicines lead to increased body weight due to a higher feed intake and a higher feed conversion ratio, and improve antioxidant activity of broiler chickens based on their phenolic compound contents. The combination of medicinal herbal additives also has a positive impact on broiler production. In organic broiler production with the usage of herbal plants, reducing hormones, growth promoters and antibiotics should be organized as well as considering appropriate organic feed management and higher production.

Active Yeast but Not Henhouse Environment Affects Dropping Moisture Levels in Egg-Laying Hens

Simple Summary

The high dropping moisture content of chicken feces can impose a serious burden on poultry production costs and the environment. In the first part of this study, we investigated the correlations among chicken dropping moisture content, environmental factors, and production performance. In the second part, we explored whether the addition of three types of additives added individually could reduce the dropping moisture content. The results showed that the dropping moisture level was not associated with production performance or any environmental factors at different locations at the same henhouse height. The probiotic additive (active yeast) significantly reduced the dropping moisture rate. These findings can improve strategies for dealing with high dropping moisture levels and contribute to the enhancement of chicken production.

Abstract

Dropping moisture (DM) refers to the water content in feces. High DM negatively affects poultry production, environment, production costs, and animal health. Heredity, nutrition, environment, and disease may affect DM level. DM has medium inheritability and is related to cage height in henhouses. We examined the relationship among DM level, production performance, and environmental factors at different locations at the same henhouse height and effects of three types of additives. We measured the correlation between environmental factors including temperature, humidity, CO₂ concentration, absolute pressure, and DM levels and laying performance of 934 Rhode Island Red hens. DM level was not significantly associated with environmental factors or production performance. We divided 64 persistently high DM hens into control and treatment groups supplied with different additives (probiotics, anisodamine, and antibiotics). DM levels, laying performance, egg quality, and serum biochemical indices were determined. Compared with the control and antibiotics, probiotics significantly reduced DM levels and eggshell strength while improving yolk color but did not significantly affect production performance. The additives reduced the b value of eggshell color; compared with probiotics, anisodamine decreased serum globulin levels. Exogenous active yeast supplementation can significantly reduce DM levels.

Novel Cyclovirus Identified in Broiler Chickens With Transmissible Viral Proventriculitis in China

In October 2018, an outbreak of transmissible viral proventriculitis (TVP) occurred in 30-day-old commercial broiler chickens on a farm in Weifang, China. TVP, an infectious viral disease characterized by runting and stunting, is associated with many viruses, and has a significant economic impact on the global poultry industry. TVP is diagnosed according to clinical symptoms, gross and histological lesions, and negative PCR results for pathogenic bacteria, avian leukosis virus subgroup J, Marek's disease virus, reticuloendotheliosis virus, infectious bursa disease virus, avian reovirus, chicken anemia virus, infectious bronchitis virus, chicken proventricular necrosis virus, gyrovirus 3 and chicken circovirus. To further detect the possible causative pathogens of TVP, we used PacBio third-generation sequencing to examine proventricular samples. A dominant abundance of the novel cyclovirus (CyCV), chCyCV-SDAU-1, was identified in broilers with TVP. The complete chCyCV-SDAU-1 genome was verified via inverse PCR, was 1936 bp long, and consisted of Rep, Cp, and two intergenic regions. Phylogenetic tree analysis showed that chCyCV-SDAU-1 formed an independent branch with other cycloviruses. The homology of chCyCV-SDAU-1 with 20 others known cycloviruses was < 40%. Retrospective investigation showed that the CyCV infection rate in the broilers with TVP was 80% (16/20), while no CyCV was found in healthy chickens. In conclusion, a novel CyCV was identified in chickens with TVP, though its role in this disease is unclear.