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Simple Summary: Various kinds of yellow-feathered chickens are crossbred from Chinese local native chicken breeds and introduced broilers. The individual parts of yellow-feathered chickens are less suitable for sale after slaughtering than those of broilers, and they have mainly been sold as live whole chickens. With the establishment of cold chain logistics for chicken in China, chilled-type and processed yellow-feathered chicken products have appeared in the market. Xueshan chicken, a yellow-feathered chicken breed, which has high meat quality and good taste, is bred to meet the diversified needs of the market by Jiangsu Lihua Breeding Company. The present study used Xueshan chicken as an experimental model to determine the effect of sex on the slaughtering performance and meat quality. This study provides valuable breeding references for poultry producers by determining the basic production phenotypes of yellow-feathered chickens. The demand for high-quality chilled chicken has continued to increase in China. Chickens are sexually dimorphic, and to better understand the specific differences in chicken production based on sex, we examined how sex affects growth performance, carcass traits, and meat quality of yellow-feathered chickens. Male and female Xueshan chickens were used as the experimental model. Although males exhibited better growth performance, including body weight (BW), body slope, keel, shank length, and shank girth (p < 0.05), as well as carcass traits, such as dressed weight, leg muscle, and lean meat, females had higher carcass and breast muscle yields (p < 0.05). Males had higher follicle density and yellowness (b*) of the skin and better skin than females (p < 0.05). Among blood biochemical parameters, the serum content of corticosterone (CORT) was higher in males, while those of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), total antioxidant capacity (T-AOC), and catalase (CAT) were lower in males than in females (p < 0.05). The pH levels, shear force, and moisture content quality were better in male breast meat, while the intramuscular fat content (IMF) was lower in males than in females (p < 0.05). The redness (a*) and moisture content were higher in male leg meat, while the pH, water-loss rate (WLR), lightness (L*), and IMF were lower (p < 0.05). The muscle fiber diameter and cross-sectional area were also higher in males (p < 0.05). Consumers felt that soup of male chicken was better than female (p < 0.05), while mouthfeel and tenderness acceptance of breast meat were different between the sexes. These results indicate that female chickens can be marketed as a whole carcass, while males are more suitable for processed carcass products. This study provides significant insights into the production and processing methodologies of yellow-feathered chickens. [ABSTRACT FROM AUTHOR]

In recent years, the scale of poultry breeding in China is gradually expanding, and the demand for feed raw materials is also rising. At present, the poultry industry is facing the problem of shortage of protein feed resources, so it is urgent to find high-quality and sustainable protein feed raw materials. The edible insect black soldier fly (Hermetia illucens L., BSF) has become a potential sustainable new protein feed, which can replace traditional protein feed materials such as soybean meal and fish meal. BSF is a saprophytic insect, which mainly feeds on organic waste, and has the characteristics of rapid growth and reproduction, extensive feeding and high feed conversion rate. The larvae or pre-pupae of BSF are rich in protein, fat, minerals, and trace elements, and their content of essential amino acids is comparable to that of fish meal and soybean meal. They also contain bioactive substances such as lauric acid, antimicrobial peptides, and chitin. Based on the nutritional characteristics of BSF larvae and processed products, this paper reviewed the research progress of BSF in poultry breeding, in order to provide a reference for the wide application of BSF in poultry production. [ABSTRACT FROM AUTHOR]

The policy of "changing grain to forage" is an important means to optimize the structure of farming and breeding, a powerful measure to boost the agricultural economy, and the core of promoting high-quality development of the aquaculture industry. Based on the double difference model, panel data from eight provinces implementing the "changing grain to forage" policy was selected to explore the impact of the implementation of the "changing grain to forage" policy on the scale of livestock and poultry breeding. The research results show that the implementation of the "changing grain to forage" policy has a certain driving effect on the expansion of livestock and poultry breeding scale in China. The level of intelligent breeding and fixed asset investment has a significant promoting effect on the scale of livestock and poultry breeding. The price of calves and the intensity of disease occurrence have inhibitory effects on the scale of livestock and poultry farming. Further research has found that the implementation of the "changing grain to forage" policy can significantly promote the large-scale development of livestock and poultry in breeding farms. The level of intelligent breeding has a more significant positive effect on large-scale breeding farms. Compared to medium scale farms, the intensity of disease occurrence has a relatively small adverse impact on large-scale farms. [ABSTRACT FROM AUTHOR]

With the rapid development of intensive poultry breeding in China, the demand for poultry feed raw materials is increasing rapidly. However, the shortage of cereal feed and the persistently high price make it urgent for poultry feed production industry to explore cheaper energy alternative feed. Cassava has the characteristics of high yield, rich starch and fiber, high energy value, etc. It can replace corn or other energy feed in poultry breeding. The effective use of cassava products has been proved to reduce the feed cost of poultry production. However, the utilization of cassava is limited by many factors, such as low protein and anti-nutritional factors. Using correct processing and scientific formula, the addition level of cassava in poultry diet can be improved. In this paper, the nutritional characteristics, feed utilization, and application of cassava in poultry diet were reviewed, which provided a reference for the application of cassava in poultry diet. [ABSTRACT FROM AUTHOR]

Background: Incubation behaviour, an instinct for natural breeding in poultry, is strictly controlled by the central nervous system and multiple neuroendocrine hormones and neurotransmitters, and is closely associated with the cessation of egg laying. Therefore, it is essential for the commercial poultry industry to clarify the molecular regulation mechanism of incubation behaviour. Here, we used high-throughput sequencing technology to examine the pituitary transcriptome of Changshun green-shell laying hen, a local breed from Guizhou province, China, with strong broodiness, in two reproductive stages, including egg-laying phase (LP) and incubation phase (BP). We also analyze the differences in gene expression during the transition from egg-laying to incubation, and identify critical pathways and candidate genes involved in controlling the incubation behaviour in the pituitary. Results: In this study, we demonstrated that a total of 2089 differently expressed genes (DEGs) were identified in the pituitary, including 842 up-regulated and 1247 down-regulated genes. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that steroid biosynthesis pathway and neuroactive ligand-receptor interaction were significantly enriched based on DEGs commonly identified in pituitary. Further analysis revealed that SRC, ITGB4, ITGB3, PIK3R3 and DRD2 may play crucial roles in the regulation of incubation behaviour. Conclusions: We identified 2089 DEGs and the key signaling pathways which may be closely correlated with incubation in Changshun green-shell laying hens, and clarified the molecular regulation mechanism of incubation behaviour. Our results indicate the complexity and variety of differences in reproductive behaviour of different chicken breeds. [ABSTRACT FROM AUTHOR]

Simple Summary: Lindian chickens are a local chicken variety in northern China. To explore the growth and development characteristics of Lindian chickens, various statistical methods were used to analyze their body size and carcass traits. The results showed that multiple trait measurements of Lindian chickens rapidly increased before 10 weeks of age, while after 19 weeks of age they mainly developed reproductive organs and muscles. In addition, we also found that body size traits were closely related to carcass traits, providing a foundation for the breeding and management of Lindian chickens. As an excellent chicken breed found in a high-altitude zone of northern China, Lindian chickens are characterized by good egg and meat production, strong adaptability, cold tolerance, rough feeding resistance, excellent egg quality, and delicious meat quality. To facilitate the exploitation of the unique qualities of the Lindian chicken, the varying patterns and correlations of various body size and carcass traits of 3–22-week-old Lindian chickens were analyzed in this study. The optimal growth model of these traits was determined by growth curve fitting analysis. The results showed that most traits of Lindian chickens increased steadily with increasing age, and most of them increased rapidly before 10 weeks of age. In addition, the inflection point age of each trait was predicted to be between 4 and 10 weeks. Furthermore, this study revealed that body size traits were closely related to carcass traits in Lindian chickens. In summary, Lindian chickens are in a rapid growth stage before the age of 10 weeks, and better slaughter performance can be achieved through good feeding management during this stage. The reproductive traits and muscles are the main developmental focus after the age of 19 weeks, so it is important to adequately meet their energy requirements for subsequent good breeding performance. [ABSTRACT FROM AUTHOR]

With the intensive development of animal husbandry, the demand for feed soybean meal increases. In order to promote the development of animal husbandry and ensure the supply and quality safety of feed in China, it is necessary to reduce the proportion of soybean meal and increase the development of protein feed resources and the supply of highquality feed. Cottonseed meal has high protein content, and the vitamin content is similar to that of soybean meal. Compared with soybean meal, cottonseed meal has a wide range of sources and is more affordable. However, cottonseed meal contains gossypol, which limits its application in animal production. Therefore, the dephenolization technology of cottonseed meal, the application of cottonseed meal instead of soybean meal in animal production and matters needing attention are summarized in the paper, which provides a reference for resource utilization of cottonseed meal, reducing livestock and poultry breeding cost and improving animal product quality. [ABSTRACT FROM AUTHOR]

Poultry production in China has been experiencing a high incidence of broiler arthritis /tenosynovitis caused by avian orthoreovirus (ARV) since 2013. In the spring of 2020 severe arthritis cases from broiler flocks were identified in a large-scale commercial poultry company in Anhui Province, China. Diseased organs from dead birds were sent for diagnosis to our laboratory. ARVs, including seven broiler-isolates and two breeder-isolates, were successfully harvested and sequenced. Interestingly, the genotypes of ARVs isolated from infected chickens were inconsistent between different flocks, or even between different houses on the same flocks. Pathogenicity testing in chicks confirmed that the seven broiler-isolates were pathogenic strains, which could cause arthritis in infected chickens. Subsequently, a total of 89.66% serum samples collected from apparently healthy adult broiler flocks not vaccinated against ARV tested positive for ARV antibodies, suggesting that low and high virulence reovirus strains may be co-circulating in the farm. To this end, we collected dead embryos of unhatched chicken eggs for pathogen tracing, and the two ARV breeder-isolates isolated indicated that vertical transmission from breeders to progeny should not be underestimated for the prevalence of ARV within broiler flocks. The findings have implications for the evidenced-based formulation of prevention and control strategies. [ABSTRACT FROM AUTHOR]

Simple Summary: Most Chinese local breeds have slow growth speed and high fat deposition, while European commercial chicken strains belong to fast-growing chicken breeds with low fat deposition. In general, the word "You" in China represents excessive fat deposition, and You-chicken is considered to be a typical fatten broiler. Among more than 100 local chickens in China, Baicheng-You and Beijing-You chickens are only two kinds of You-chicken breeds. However, their special genomic characteristics have not been well studied. This study analyzed the genome changes among these chicken breeds and obtained many candidate genes related to important traits of chickens, e.g., fat deposition, immune response, and melanin production. Our data provide valuable insights for understanding the formation of germplasm characteristics of these broiler breeds, which can be used to better protect and utilize the Chinese-You chickens. As the only two You-chicken breeds in China, Baicheng-You (BCY) and Beijing-You (BJY) chickens are famous for their good meat quality. However, so far, the molecular basis of germplasm of the two You-chicken breeds is not yet clear. The genetic relationship among BCY, BJY, and European-origin broilers (BRs) was analyzed using whole genome resequencing data to contribute to this issue. A total of 18,852,372 single nucleotide polymorphisms (SNPs) were obtained in this study. After quality control, 8,207,242 SNPs were applied to subsequent analysis. The data indicated that BJY chickens possessed distant distance with BRs (genetic differentiation coefficient (FST) = 0.1681) and BCY (FST = 0.1231), respectively, while BCY and BRs had a closer relationship (FST = 0.0946). In addition, by using FST, cross-population extended haplotype homozygosity (XP-EHH), and cross-population composite likelihood ratio (XP-CLR) methods, we found 374 selected genes between BJY and BRs chickens and 279 selected genes between BCY and BJY chickens, respectively, which contained a number of important candidates or genetic variations associated with feather growth and fat deposition of BJY chickens and potential disease resistance of BCY chickens. Our study demonstrates a genome-wide view of genetic diversity and differentiation among BCY, BJY, and BRs. These results may provide useful information on a molecular basis related to the special characteristics of these broiler breeds, thus enabling us to better understand the formation mechanism of Chinese-You chickens. [ABSTRACT FROM AUTHOR]

Simple Summary: Huaixiang chicken is a famous local broiler in China. It has excellent meat quality, but its disadvantage is a low laying rate. At present, improving the laying rate of poultry via nutritional regulation has attracted the extensive attention of researchers. Canthaxanthin(CX) is a ketocarotenoid, which widely exists in marine animals, algae, and a few terrestrial plants. It has been used in poultry production. In this study, dietary CX supplementation is found to increase laying rates, promote ovulation and maintain reproductive hormone levels by increasing serum and ovarian antioxidant levels. It is suggested that CX can be used to improve the laying rate of Huaixiang broiler breeders. Canthaxanthin(CX) is a ketocarotenoid, which is widely used in poultry production as a lipophilic antioxidant. Huaixiang chickens are a local breed in China famous for their excellent meat quality; improving their laying rate via nutritional regulation has attracted extensive attention. The aim of this study was to evaluate the effects of dietary CX on the laying rate and follicular development in Huaixiang hens. A total of 180 Huaixiang hens were randomly divided into five groups with six replicates, and six chickens per replication. The control group (CON) were fed a basal diet, and the treatment group (NT) were fed a basal diet supplemented with 4, 6, 8 and 10 mg/kg CX. All chickens were 26 weeks old, living at an average environmental temperature of 25 ± 2 °C with a relative humidity of 65–75%. The results showed that supplementing the CX improved the laying rate and large white follicles (LWF) number (p < 0.05) and increased the concentration of reproductive hormones (LH, FSH, E2 and Prog) (p < 0.05), and the basal diet supplemented with 6 mg/kg CX worked best. Moreover, CX could increase the activities of antioxidant enzymes SOD and GSH-Px (p < 0.05) and reduce the content of the lipid peroxidation product MDA in Huaixiang chickens (p < 0.05); again, 6 mg/kg CX was best. In conclusion, dietary CX had positive effects on the laying rate, ovarian structure, reproductive hormone secretion, follicle development, and the antioxidant capacity of Huaixiang hens, and 6 mg/kg CX was recommended to be added to the diet of Huaixiang chickens. [ABSTRACT FROM AUTHOR]

Simple Summary: The intestinal tract is an important part of the immune system and forms a congenital barrier against food antigens and pathogenic microorganisms. In poultry, heat stress can induce intestinal mucosal injury, damage intestinal tight junctions and microvillous structures, and trigger an inflammatory response and enterogenic infection. As an essential trace element, zinc has been shown to mitigate the adverse effects of heat stress on broilers. However, how the dietary supplementation of different sources and levels of zinc can improve the heat stress capacity of Chinese landraces remains unclear. Here, we investigated the effects of different levels of zinc sulfate (ZnS) and zinc proteinate with moderate chelation strength (Zn-Prot M) on the intestinal immune function under heat stress in Xueshan chickens, which comprise an important local breed in China. Heat stress can cause intestinal inflammation, impaired barrier integrity, and decreased immunity in poultry. While zinc is known to mitigate the adverse effects of heat stress, how the dietary supplementation of different sources and levels of it can improve the heat stress capacity of Chinese landraces remains unclear. This study investigated Xueshan chickens, which are an important local breed in China. The effects of different levels of ZnS and Zn-Prot M on their intestinal immune function under heat stress were compared. We found that different levels of ZnS and Zn-Prot M could effectively reduce the secretion level of IL-6 in the serum, and 60 mg/kg was optimal. Compared with ZnS, Zn-Prot M significantly increased duodenal villus height and VH/CD ratio. ZnS and Zn-Prot M effectively increased the villus height and villus width in the jejunum and ileum at 74 and 88 days old, with the 60 and 90 mg/kg groups outperforming other groups, and Zn-Prot M was more effective than ZnS. Both ZnS and Zn-Prot M significantly down-regulated TNF-α, IL-1β, and MyD88 in 102-day-old duodenum, and IL-1β, IL-6, and NFKBIA in jejunum and ileum at 74, 88, and 102 days old, with 60 mg/kg Zn-Prot M determined as optimal. In conclusion, our study demonstrates that Zn-Prot M is superior to ZnS in improving intestinal immunity in Xueshan chickens, and 60 mg/kg is the optimal addition dose. [ABSTRACT FROM AUTHOR]

One of the most important reasons restricting the rapid development of animal husbandry in China is the shortage of protein raw materials. Urtica cannabina L. is a perennial herb rich in nutrient component and can be seen as feed to develop and utilize. The paper mainly studies the application in pigs, cattle, sheep and chicken as well as gives suggestions on the development and utilization of Urtica cannabina L., aiming to provide reference for the subsequent research and application of Urtica cannabina L. as an unconventional feed resource in livestock and poultry breeding. [ABSTRACT FROM AUTHOR]

China has a huge output of vegetables and fruits, and processed vegetable and fruit residue is rich in nutrients, rich in crude protein, crude fiber, vitamins, polyphenols, polysaccharides, flavonoids and other components, but it is not easy to preserve and has poor palatability, so it can not be directly used as animal feed. Screening of high-quality yeast and other probiotics can improve the nutritional value of vegetable and fruit residue feed and reduce feed cost, which has a positive effect on fruit and vegetable processing industry and livestock and poultry breeding industry. The paper reviewed the yeast species screening, fermentation technology and application of fermented vegetable and fruit residue in animal feed, aiming to provide reference for the research and application of fermented vegetable and fruit residue in livestock and poultry breeding. [ABSTRACT FROM AUTHOR]

As a large country of livestock and poultry breeding, China needs to timely solve the large amount of livestock and poultry manure produced every year. Composting technology, as the most widely used means of manure management, still has an influence on serious carbon and nitrogen loss, and environmental pollution. Based on the comprehensive reading of dozens of domestic and foreign literatures, this paper analyzed seven factors affecting carbon and nitrogen storage in the process of livestock manure composting, including pH value, ventilation, surface coverage, carbon nitrogen ratio, moisture, temperature, especially the types and mechanism of composting additives. It can reduce the loss of carbon and nitrogen in the composting process and environmental pollution, and improve the quality of composting through the regulation of various composting factors. [ABSTRACT FROM AUTHOR]

Reactive nitrogen (Nr) emissions aggravate air and water pollution across the world. The factors influencing Nr emissions have not been clearly uncovered, especially for regions under rapid economic growth. Here we modeled total Nr emissions in mainland China and analyzed factors driving their growth during the decade (2000–2010) of fastest socioeconomic development. Results show that total Nr emissions increased from 24.9 terrogram (Tg) to 35.2 Tg, a 41.7% increase with an average annual growth rate of 3.5%. Agricultural activities, including crop planting and livestock and poultry breeding, together took a substantial but decreasing share, from 75.2% in 2000 to 61.4% in 2010. Industrial wastewater discharge, energy use, and crop production are the three largest sources contributing to the Nr emissions growth. Factors related to scale (e.g., the amount of industrial energy use) led to a growth in Nr emissions, and factors related to efficiency (e.g., industrial energy use per unit of economic output) contributed to reduction. The decreasing effect of efficiency gains, however, was still unable to overcome the increasing effect of the activity scale. More in‐depth research studies on mitigation strategies are required, to inform the decoupling between socioeconomic development and Nr emissions. [ABSTRACT FROM AUTHOR]

The high-quality development of animal husbandry is necessary support to promote rural revitalization, and also key to building Chinese path to modernization. From perspective of connotation and era positioning, animal husbandry refers to future development of animal husbandry towards ecology, safety, and other aspects to achieve highquality and efficient development, comprehensively improve quality and quantity of social livestock and poultry product supply. Facing Chinese path to modernization, high-quality development of China's animal husbandry not only conforms to goal orientation of ecological and open cooperation in new era, but also follows Chinese law of economic and industrial layout. Therefore, it is proposed to consolidate the foundation and accelerate construction of modern livestock and poultry breeding and breeding industry. Improve security and establish an animal epidemic prevention system. Suggestions on strengthening competition and improving animal husbandry policies and measures to better play the supporting role of high-quality development of animal husbandry in process of Chinese path to modernization. [ABSTRACT FROM AUTHOR]

Simple Summary: Wenchang chickens are the only chicken breed listed in the 'animal genetic resources in China (poultry)' in Hainan Province and are famous for their excellent meat quality. Protection of this genetic resource may ensure poultry husbandry's sustainable and successful development. For more effective conservation, development, and utilization of this genetic resource, we investigated the diversity, degree of inbreeding, and runs of homozygosity (ROH) patterns for Wenchang chickens using whole-genome sequencing data. Our analysis showed that the genetic diversity of Wenchang chickens was relatively high. Selection signal analysis of Wenchang chickens based on ROH found some candidate genes that were putatively associated with meat quality traits and stress resistance traits, such as disease resistance and heat tolerance. Wenchang chickens, a native breed in the Hainan province of China, are famous for their meat quality and adaptability to tropical conditions. For effective management and conservation, in the present study, we systematically investigated the characteristics of genetic variations and runs of homozygosity (ROH) along the genome using re-sequenced whole-genome sequencing data from 235 Wenchang chickens. A total of 16,511,769 single nucleotide polymorphisms (SNPs) and 53,506 ROH segments were identified in all individuals, and the ROH of Wenchang chicken were mainly composed of short segments (0–1 megabases (Mb)). On average, 5.664% of the genome was located in ROH segments across the Wenchang chicken samples. According to several parameters, the genetic diversity of the Wenchang chicken was relatively high. The average inbreeding coefficient of Wenchang chickens based on FHOM, FGRM, and FROH was 0.060 ± 0.014, 0.561 ± 0.020, and 0.0566 ± 0.01, respectively. A total of 19 ROH islands containing 393 genes were detected on 9 different autosomes. Some of these genes were putatively associated with growth performance (AMY1a), stress resistance (THEMIS2, PIK3C2B), meat traits (MBTPS1, DLK1, and EPS8L2), and fat deposition (LANCL2, PPARγ). These findings provide a better understanding of the degree of inbreeding in Wenchang chickens and the hereditary basis of the characteristics shaped under selection. These results are valuable for the future breeding, conservation, and utilization of Wenchang and other chicken breeds. [ABSTRACT FROM AUTHOR]

The Mountainous Meihua chicken is a unique regional germplasm resource from Tongjiang County, Bazhong City, China, but its genetic structure and evolutionary relationships with other native chicken breeds in the Sichuan region remain unclear. Here, we analyzed a total of 469 sequences, including 199 Mountainous Meihua chicken sequences generated in this study, together with 30 sequences representing 13 clades and 240 sequences from seven different Sichuan local chicken breeds downloaded from NCBI. These sequences were further used to analyze genetic diversity, patterns of population differentiation, and phylogenetic relationships between groups. We show that Mountainous Meihua chicken mtDNA sequences have high haplotypic and nucleotide diversity (0.876 and 0.012, respectively) and with a T bias that is suggestive of good breeding potential. Phylogenetic analysis showed that Mountainous Meihua chickens belong to clades A, B, E, and G and have a low affinity to other chicken breeds, with a moderate degree of differentiation. A non-significant Tajima's D indicates that no demographic expansions occurred in the past. Finally, the four maternal lineages identified in Mountainous Meihua chicken showed unique genetic characteristics. [ABSTRACT FROM AUTHOR]

Rural heating is one of the main sources of carbon emissions in northern China. In this study, the“26+2”Beijing–Tianjin–Hebei air pollution transmission corridor urban agglomeration designated by the Winter Clean Heating Plan in the Northern Region (2017—2021) was used as the study area. Based on the framework of“estimating potential biomass energy-calculating alternative traditional fuel resources conversion-evaluating pollutant and carbon emission reduction effect”, the potential of biomass energy conversion and clean heating of crop straw and livestock and poultry excrement were quantitatively analyzed. Based on the panel data in 2019, the biomass energy potentials of crop straws and livestock and poultry emissions were considered. The biomass potential of these wastes indicate a reduction compared to the 6.66 million tons of standard coal or 5.5 billion m³ of natural gas, with emission reductions of approximately 0.21 million tons of pollutants (SO2, NOx) and 17.01 million tons of CO2 when fully exploited. In this study, the spatial distribution of biomass energy utilization potential of various crop straw and livestock manure in 28 prefecture-level cities (municipalities) in the study area and the effects of clean heating and emission reduction in each province were analyzed. Studies have shown that wheat and maize have the highest potential for resource utilization. The biomass energy utilization potential of the breeding industry was higher than that of planting industry, and the poultry breeding industry was the highest. The quantitative results could provide a useful reference for promoting the use of biomass energy to replace traditional fuels such as coal for clean heating in rural areas of“26 + 2”typical areas and exploring the development path from“agricultural waste”to“rural heating source”. [ABSTRACT FROM AUTHOR]

Guangdong Province is one of the largest agricultural regions in China, in addition to the robust economy. Agricultural development has been accelerated to ensure the food security in recent years. The agricultural non-point source pollution has been triggered by the large-scale investments in chemical fertilizers, pesticides, plastic mulch, and the rapid development of the livestock and poultry breeding industry. The purpose of this study is to unveil the emission quantity and sources of agricultural non-point source pollutants in Guangdong Province, elucidate the main characteristics and development trends of agricultural non-point source pollution, and thereby propose control measures targeting the primary pollutant sources. In this study, the emission coefficient was proposed to estimate the number of various pollutants that emitted by agriculture, livestock and poultry breeding, and aquaculture in Guangdong Province of China from 1991 to 2021. The data was also collected to better understand the agricultural development in the fertilization, arable land area, pig, cattle, poultry and aquaculture. The main causes were then determined for the agricultural non-point source pollution and their changing trends over time. The results show that: 1) An upward trend was found in the total discharges of chemical oxygen demand (COD), ammonia nitrogen (NH3 -N), total nitrogen (TN), and total phosphorus (TP) from the agricultural sources. The discharges of various pollutants decreased slightly since 2018, due to the reducing use of chemical fertilizer. The amount of fertilizer was applied per unit area more than twice the international average level. It is very necessary to reduce the chemical fertilizer use for the high efficiency. The discharges of COD, NH3 -N, TN, and TP from the agricultural sources increased to 1.9, 1.9, 1.7, and 2.2 times, respectively, in 2021, compared with 1991. 2) The primary contributors to the agricultural non-point source pollution were the planting, livestock and poultry breeding industries. The planting industry was contributed the most to the nitrogen discharges, accounting for 48% of NH3 -N losses, and 52% of total nitrogen losses from the agricultural sources, respectively. In addition, the water pollution that caused by the planting industry was mainly from the application of chemical fertilizers. The livestock and poultry breeding industry was the primary source of COD and TP discharge from the agricultural sources. Specifically, 90% and 51% of the total COD and TP discharges from agricultural sources were from the livestock and poultry breeding sector, respectively. The number of pollutants that discharged by the large-scale farming were accounted for more than 70% of the total pollutants discharged by the livestock and poultry breeding industry. Among different types of livestock and poultry, pigs were contributed the most to the emission of various pollutants, followed by poultry. Different pollutants that emitted by the aquaculture industry were accounted for between 10% and 16% of total emissions from agricultural sources. Aquaculture was ever increasing every year. Moreover, the effluent that produced by aquaculture (particularly mariculture) was challenging to clean up. Consequently, the number of pollutants that discharged into water from aquaculture sources will increase over time, indicating the increasing share of the total emissions from agricultural sources. Therefore, it is urgent to find the solutions for the waste disposal of large-scale pig farms. Also, the pollutant discharges from aquaculture needs to be considered. The finding can also provide a strong reference for the decision-making in the agricultural environment. [ABSTRACT FROM AUTHOR]

China has abundant edible mushroom resources, and the annual production of edible mushroom residue is huge. Edible mushroom residue has high nutritional value and is rich in active substances such as flavonoids, saponins, and sterols, which have certain medicinal value. Developing edible mushroom residue in a reasonable way as feed for livestock and poultry production can significantly improve the production performance of livestock and poultry, improve the immune and antioxidant capacity of livestock and poultry. Part of the edible mushroom residue can also promote the digestive system function of livestock and poultry, affect the structure of intestinal microbiota, improve the digestion and utilization rate of nutrients, have high application research value in animal husbandry. The article aims to analyze the nutritional value and feeding methods of edible mushroom residue, summarize its impact on the economic benefits of livestock and poultry production and breeding, providing reference for the recycling and utilization of edible mushroom residue resources, and providing new insights for solving the problem of protein feed shortage. [ABSTRACT FROM AUTHOR]

Chinese medicine is widely used in disease prevention and control, and a lot of Chinese medicine residue is produced in China every year. If these residues are not properly disposed of, they will cause damage to the environment and waste resources. The application of fermented Chinese medicine residue in the feed industry can not only alleviate the problem of feed resource shortage, but also improve the performance of livestock and poultry production. The paper reviews the fermentation process of Chinese medicine residue, the advantages of fermentation and its application in livestock and poultry production, providing reference for the resource utilization of Chinese medicine residues, reducing the cost of livestock and poultry breeding and improving the quality of livestock products. [ABSTRACT FROM AUTHOR]

The separation between planting and breeding results in an unbalanced distribution of the regional livestock and poultry manure (RLM) industry, and it has raised great concerns. A holistic analysis and problem-solving scheme using 72 townships as the research point was developed in this study. On the basis of a survey from a typical agricultural region in China, the local characteristics of manure discharge, land use, and crop cultivation were analyzed. The assessment of land carrying capacity and environmental risk assessment was conducted by simulating the nitrogen cycle. Afterwards, optimized livestock breeding strategies and inter-regional transfer and flow scheme of manure nutrients were proposed. The spatial distribution of RLM in terms of pig manure equivalent showed an imbalance of high north–south and low middle, and the nitrogen requirement of crops showed a decreasing trend from north to south. In some townships, the environmental risks were higher than level I, which indicated that pollution existed around large construction sites and water areas in the northwest. The land carrying capacity index calculated at 50% nutrient ratio displayed no overloaded risk, whereas 10–20% nutrient ratio exhibited overloaded risk. Assessments showed that the residual RLM and its nitrogen volume were 151,700 and 3574.64 tons per year, respectively. More than 80% of the study area could be used as a nitrogen nutrient sink area, and only six townships are nitrogen nutrient sources. Therefore, optimizing the allocation of manure nutrients is expected to avoid agricultural contamination from livestock manure. [ABSTRACT FROM AUTHOR]

Effective prevention and control of agricultural non-point source pollution is a major challenge faced by the Chinese local government in the context of rural revitalization, and clarifying the game relationship between stakeholders in agricultural non-point source pollution control actions will help achieve multiple co-governance better. Accordingly, this paper discusses the interactive decision-making relationships between local government and livestock and poultry breeding enterprise (LPBE) under the participation of Environmental non-government organizations (ENGOs) and public, by constructing an evolutionary game model, as well as analyzing evolutionary cooperative stability strategies and realizing the simulation of evolution processes in different scenarios by MATLAB. The results show that government subsidy has an incentive effect on LPBE to adopt the purifying strategy, yet reduces the enthusiasm of local government for supervision. Improving the participation degree and right space of ENGOs is conducive to the realization of multiple co-governance models. Furthermore, the impact of public participation on multiple co-governance of agricultural non-point source pollution is related to the local government's investigation rate and the public reporting fairness; strengthening the local government's supervision capacity and improving the public reporting fairness can achieve better collaborative governance effects. [ABSTRACT FROM AUTHOR]

Newcastle disease (ND) is one of the diseases that seriously damage the health of poultry and is widely prevalent worldwide. It is characterized by high fever, respiratory distress, dysentery, neurological disorders, and mucosal hemorrhage, seriously threatening the growth and reproduction of poultry and production of poultry meat. Newcastle disease is caused by Newcastle disease virus (NDV), which has been prevalent for nearly 100 years and can infect more than 200 species of poultry, including chickens, ducks, geese and pigeons. It has many genotypes, and the variable genotypes bring great difficulties to the prevention and control of ND. The migration of birds plays an important role in the cross-border spread of the virus, resulting in Newcastle disease outbreaks in various regions of China, bringing huge economic losses to the poultry industry and seriously restricting the healthy development of the poultry breeding industry. In view of the wide distribution of NDV and the strong host mobility, it makes an important epidemic disease threatening the poultry breeding industry. Therefore, to understand the prevalence of NDV in China, the study analyzes its molecular epidemiology and the spatial and temporal distribution of each genotype, and it is found that ND in China is mainly distributed in southern China, such as Guangxi and Guangdong, eastern China, such as Jiangsu and Anhui, and northwestern China, such as Shaanxi and Gansu. The highly pathogenic Class Ⅱ strains isolated from these regions include multiple genotypes, with genotype Ⅱ and genotype Ⅶ strains being the main prevalent strains. The collation and analysis of NDV prevalence data provide reference data for epidemic prevention control, and vaccine development. [ABSTRACT FROM AUTHOR]

Agriculture is the foundation of the national economy, and agricultural nonpoint source pollution and carbon emissions are the main environmental problems limiting the development of the agricultural economy. This study takes the Yangtze River Delta as the research object and measures agricultural carbon emissions and nonpoint source pollution in the study area from 2010 to 2020 respectively. The Tapio decoupling model is used to study types of decoupling between agricultural pollution and carbon reduction and economic growth in the Yangtze River Delta from 2010 to 2020, and the GM (1,1) model is used to predict the decoupling relationship between the agricultural environment and economic growth over the next ten years. The results show the following: (1) Agricultural COD emissions come mainly from livestock and poultry breeding, dropped from 1,130,120 tons in 2010 to 908,460 tons in 2020. Agricultural TN and TP emissions come mainly from plantations. Agricultural TN emissions dropped from 892,310 tons in 2010 to 788,020 tons in 2020. Agricultural TP emissions dropped from 149,590 tons in 2010 to130,770 tons in 2020. Agricultural carbon emissions dropped from 17,115,900 tons in 2010 to 15,786,600 tons in 2020, and come mainly from agricultural fertilizer and diesel fuel and pig breeding. (2) The decoupling effect of agricultural pollution reduction and carbon reduction in the Yangtze River Delta and economic growth has been in a long-term state, with negative decoupling occurring in a few regions, mainly in 2011, 2014 and 2020. (3) In the next ten years, except for 2021, when the coordination between agricultural pollution reduction and economic growth is poor, the two show good decoupling in the remaining years. Based on the results, this study makes recommendations on how to carry out comprehensive environmental management and promote green agricultural development. [ABSTRACT FROM AUTHOR]

Simple Summary: This is a study associated with the prevalence and persistence of ceftiofur, the third-generation cephalosporin antibiotic-resistant Escherichia coli in a chicken layer breeding farm. Notably, epidemiological studies in poultry have been primarily focused on single breeding periods and may have underestimated the maintenance of the ceftiofur-resistant Escherichia coli in different breeding periods from layer hens. Our results showed that the detection rates of the ceftiofur-resistant Escherichia coli fluctuated across different breeding periods, and the ST101 ceftiofur-resistant Escherichia coli was the most prevalent and persistent sequence type across the breeding periods. This study contextualized ceftiofur resistance in different breeding periods, monitoring which can have important implications for food animals. We determined the longitudinal persistence of ceftiofur-resistant Escherichia coli from a chicken breeding farm in China. A total of 150 samples were collected from 5 breeding periods in a flock of layer hens, and the prevalence of ceftiofur-resistant E. coli fluctuated across the 5 chicken breeding stages: eggs, 3.33%; growing period, 100%; early laying period, 36.7%; peak laying period, 66.7% and late laying period, 80%. The most prevalent ceftiofur resistance genes were blaCTX-M-55, blaCMY and blaNDM, and ST101 was the most prevalent and persistent sequence type across the breeding periods. Our results indicated that this breeder flock was heavily contaminated by ST101 ceftiofur-resistant E. coli and that its presence should be intensively monitored on chicken farms. [ABSTRACT FROM AUTHOR]

Simple Summary: Kadsura coccinea was planted in large quantities in south China in recent years, and its functions and effects need to be further studied and discovered. We had previously found that Kadsura coccinea fruit extract has anti-diarrhea effects on mice, so we want to explore its influence on broiler breeding. The result showed that added 200 mg/kg Kadsura coccinea fruit extract to basic feed can replace traditional antibiotics as a growth promoter. It can improve the growth, slaughter performance, and antioxidant and regulate intestinal microorganisms of broilers, which indicated that the Kadsura coccinea fruit extract is feasible as a feed additive. This study aimed to determine whether adding Kadsura coccinea fruit extract to the diet of broilers could replace antibiotics. For this study, 300 one-day-old AA white feathered broilers were divided into five groups (no sex separated), with six repetitions per group (n = 10), as follows: blank control group (basal feed, CK group), positive drug (basal feed + 300 mg/kg aureomycin, PD group), and Kadsura coccinea low-dose, medium-dose, and high-dose groups (basal feed + 100 mg/kg, 200 mg/kg, and 300 mg/kg of Kadsura coccinea fruit extract, LD group, MD group and HD group). The experiment period was divided into early (1–21 days) and late (22–42 days) stage. We found that supplementation with Kadsura coccinea fruit extract in the diet significantly improved the growth performance of broilers (p < 0.05), reduced the feed to meat ratio (p < 0.05), reduced the fat percentage (p < 0.05), while had no significant effect on meat quality (p > 0.05) and Kadsura coccinea fruit extract could promote the development of immune organs to different extents, enhance antioxidant capacity, the contents of SOD and GSH-Px in serum were significantly increased (p < 0.05), improve the ratio of villus height to crypt depth. Finally, Kadsura coccinea fruit extract increased the relative abundance of probiotics and beneficial bacteria (Bacteroidales, NK4A214, Subdoligranulum and Eubacterium hallii) (p < 0.05) and reduced the relative abundance of harmful bacteria (Erysipelatoclostridium) (p < 0.05) in the gut of broilers. Compared with positive drug group, most of the indexes in the medium-dose group were better or had similar effects. We believe that Kadsura coccinea fruit extract can be used as a potential natural antibiotic substitute in livestock and poultry breeding programs. [ABSTRACT FROM AUTHOR]

Salmonella enterica serovar Enteritidis (S. Enteritidis) can colonize in the intestinal tract of chickens and transmit to humans. In order to decrypt the mechanism of avian resistance to S. Enteritidis, we utilized two China local chicken breeds to generate the reciprocal crosses (the Cross and the Reverse‐cross). The two lines of hybrids were orally inoculated with S. Enteritidis at 2‐day old and sampled at 3 days post‐inoculation. Along the analysis direction of multi‐omics, differential metabolites, functional pathways and correlated microbes, we found that 12 species of microbes thrived upon S. Enteritidis challenge and probably contributed to the intestinal stability in the Cross by enhancing the production of phenylpropanoids. Our findings can help to understand the symbiotic and resistant mechanisms derived from the intestinal microbiota. [ABSTRACT FROM AUTHOR]

Antimicrobial resistance is a rapidly evolving and extremely complex issue, particularly due to the use of various types of antimicrobials within human, animal, and environmental sectors. Pleuromutilin antibiotics are used to prevent and control respiratory diseases in the rearing stage of hen chicks, but the current status of pleuromutilin resistance in the laying hen breeding process is unclear. ATP-binding cassette transporters encoded by lsa(A), lsa(E), lsa(C) , and vga(D) can be transferred by plasmids and transposons, thereby posing a potential dissemination risk. To investigate pleuromutilin resistance genes in the laying hen production chain in China, 95 samples from five environmental types were collected in four breeding stages to determine the abundances of the main resistance genes by qPCR, i.e. lsa(A), lsa(E), lsa(C) , and vga(D). The abundance (5.16 log10GC/g) and detection rate (100%) of lsa(E) was highest in all of the samples, thereby suggesting high contamination with the lsa(E) gene across the large-scale laying hen breeding environment and feces. The lsa(A) (6.02 log10GC/g) and lsa(E) (6.18 log10GC/g) genes were most abundant in flies, and the abundance of vga(D) (4.50 log10GC/g) was highest in dust (P  < .05). In addition to feces, flies and dust were important sources of contamination with pleuromutilin resistance along the laying hen production chain. In summary, we determined the abundances of four pleuromutilin resistance genes in the laying hen production chain and provided direct evidence of pleuromutilin resistance transmission and environmental contamination. In particular, the chicken breeding stage needs further attention. [ABSTRACT FROM AUTHOR]

Environmental water pollution has become one of the key factors that constrain the development of urban and rural areas in China. However, the identification of high-risk priority control regions and the development of control schemes for the total amount of water pollutants still lack systematic studies. In this study, the risk prevention potential index of residents, the government, and enterprises was incorporated to construct a comprehensive water environmental risk evaluation system based on the“pressure-state-response”and to identify the risk control levels of each control unit. On this basis, a multi-objective waste load allocation model was constructed, and a water pollutant load（NH3-N）distribution scheme was constructed in Hongya County, Sichuan Province, China. The results showed that Hongchuan Town and Yuping Town, located in the lower reaches of the Qingyi River, were high-risk control units. Hongchuan Town was significantly affected by industrial wastewater discharge, while Yuping Town was jointly affected by large-scale livestock and poultry breeding, as well as industrial wastewater discharge. According to the comprehensive optimal distribution scheme, the reduction rates of ammonia nitrogen in Hongchuan Town and Yuping Town were 19.7% and 18.9%, respectively, while the total reduction rate in Hongya County was 16.3%. This study not only achieves fair and efficient reduction of water pollutants in each control unit, but also obtains a higher regional total reduction rate, which can provide a scientific reference for regional water environment management strategy formulation. [ABSTRACT FROM AUTHOR]

Tengchong snow, which has white feathers and black meat, is one of the most important black-bone chicken breeds and a genetic treasure of black food in China. Although the black meat traits are dominant, there are some chickens with white meat traits born in the process of folk selection and breeding. The purpose of this study was to compare the differences in skeletal muscle development between Tengchong snow black meat chickens (BS) and white meat chickens (WS), as well as whether excessive melanin deposition has an effect on skeletal muscle development. The BS and WS groups were selected to determine their muscle development difference at stages of 1, 7, 14, 21, and 42 days, using histological stain methods to analyze the development and composing type of breast and leg muscle fibers, as well as the count of melanin in BS muscle fibers. Finally, we were validated key candidate genes associated with muscle development and melanin synthesis. The results showed that BS breast muscle development was inhibited at 7, 14, and 21 days, while the leg muscle was inhibited at 7, 14, 21, and 42 days, compared to WS. Melanin deposition was present in a temporal migration pattern and was greater in the leg muscles than in the breast muscles, and it focused around blood vessels, as well as the epithelium, perimysium, endomysium, and connective tissue. Additionally, melanin produced an inhibitory effect similar to MSTN during skeletal muscle fiber development, and the inhibition was strongest at the stage of melanin entry between muscle fibers, but the precise mechanisms need to be confirmed. This study revealed that melanin has an inhibitory effect on the early development of skeletal muscle, which will provide new insights into the role of melanin in the black-boned chicken and theoretical references for the future conservation and utilization of black-boned chicken. [ABSTRACT FROM AUTHOR]

China has extensive livestock and poultry industries with substantial production and use of veterinary antibacterials. The longterm and massive use of veterinary antibacterials causes environmental pollution, increases bacterial resistance, and elevates safety risks for livestock, poultry, and agricultural products, further threatening human health. In this paper, we review the use of veterinary antibacterials in livestock and poultry breeding from 2009 to 2019 in China. The characteristics of the usage of veterinary antibacterials were analyzed. The findings show that the proportion of consumption of veterinary antibacterials in veterinary chemicals was 69.6%~74.1%. The utilization of veterinary antibacterials reached a maximum in 2014, and then decreased yearly. The main types of veterinary antibacterials are tetracycline, chlortetracycline, and oxytetracycline; chlortetracycline and oxytetracycline are mainly used to promote growth. Furthermore, the analysis of the antibiotics residue in different foods showed that the detection rates of antibiotics in milk, cultured fish, and vegetables were as high as 90.9%~100%. The average residue of quinolone in cultured fish was 725.13 μg·kg-1, which exceeds the national food safety limit standard (100 μg·kg-1). Additionally, we summarize the situation of antibiotic residues in the environment and the emergence and mechanism of bacterial resistance. The effects of the massive use of antibiotics on animal and human health are discussed. Ultimately, management suggestions and strategies on the prevention of antibiotics pollution are proposed in terms of source, use, emission, and remediation to help control antibiotic pollution. [ABSTRACT FROM AUTHOR]

Simple Summary: In China, although preslaughter stunning is commonly performed in large-scale production systems, this practice is less common in smaller-scale systems. To promote the concept of animal welfare, we selected common local chicken breeds and sampled the meat and blood of chickens with and without stunning. The experimental results verified that stunning before slaughter can improve meat quality, increase flavor and reduce the stress on chickens. It is more respectful of animal welfare and provides a theoretical basis for the promotion of animal welfare concepts in China. Electrical stunning is widely utilized prior to a neck cut to induce unconsciousness in order to improve animal welfare and slaughter efficiency in the broiler production industry. However, slaughter without stunning is still very commonly used in China, in part because there is a belief that stunning reduces meat quality. The purpose of this study was to determine whether the physical (hemorrhages, pH, drip loss, and shear force) and chemical (inosinic monophosphate concentration and reducing sugar content) properties of broiler meat differed between chickens in preslaughter stunning and nonstunned slaughter groups, and whether the groups differed in their levels of cortisol as an indicator of stress. Serum cortisol levels of the nonstunned group were nearly twice as high as those in the stunned group (p < 0.05). Several meat quality indicators were better in the stunned group than in the nonstunned group. We concluded that electrical stunning prior to slaughter significantly decreases the stress caused by slaughter, resulting in both improved animal welfare and meat quality traits. [ABSTRACT FROM AUTHOR]

Tetratrichomonasgallinarum and Trichomonas gallinae can colonize the alimentary tract of domestic birds. However, little information is available on the epidemiology of the two trichomonad species in domestic free-range poultry in China. In this study, the occurrence and genetic characteristic of T. gallinarum and T. gallinae among free-range chickens, ducks, and geese in Anhui Province, China, were investigated. The 1910 fecal samples collected from 18 free-range poultry farms throughout Anhui Province were examined for the presence of T. gallinarum and T. gallinae by PCR and sequence analysis of the small subunit (SSU) rRNA gene of T. gallinarum and ITS1-5.8S-ITS2 sequence of T. gallinae. The overall occurrence of T. gallinarum in poultry was 1.2% (22/1910), with infection rates of 2.1% (17/829) in chickens, 0.2% (1/487) in ducks, and 0.7% (4/594) in geese. The constructed phylogeny tree using the concatenated ITS1-5.8S-ITS2 region and SSU rRNA indicated the T. gallinarum isolates detected in this study were closely related to previously defined genogroups A, D, and E, respectively. Nine (0.5%) fecal samples were positive for T. gallinae, with infection rates of 0.8% (7/829) in chickens, 0.4% (2/487) in ducks, and 0% (0/594) in geese. Sequence and phylogenetic analysis showed that four T. gallinae ITS1-5.8S-ITS2 sequences obtained from chicken feces and one duck fecal sample belonged to genotype ITS-OBT-Tg-1. This is the first report of the prevalence and genetic characterization of T. gallinarum and T. gallinae in free-range chickens, ducks, and geese in China. [ABSTRACT FROM AUTHOR]

Simple Summary: Wuliangshan Black-bone chickens, an indigenous chicken breed in southwestern China, have characteristics of black skin, black bones, and black meat, and are suitable for rearing at high altitudes. After six generations of selection, the bodyweights of chickens have been greatly improved: cocks and hens have reached 2.0 kg and 1.5 kg weight at 126 days of age, respectively. The breast and thigh muscles are the main meat-producing parts of chicken; assessing and documenting the morphological features of breast and thigh muscle development and meat composition in Wuliangshan Black-bone chickens is very important in terms of their genetic breeding and also consumer interest. This study was conducted to illustrate the morphological features of the breast and thigh muscles at four developmental stages (1, 42, 84, and 126 days of age) of Wuliangshan Black-bone chickens and to compare the chemical composition, fatty acid, and amino acid contents of their meat at 126 days of age (D126). In total, 80 chickens (male, n = 40 and female, n = 40) in the sixth generation from the breeding farm were used in the experiment under free-range rearing conditions. The cross-sectional areas (CSA) of muscle fibers and meat composition were compared between different sex and different muscle types. The results showed that gender did not affect the CSA of the breast muscle fibers but did affect the CSA of the thigh muscle fibers at D42, D84, and D126 (p < 0.05). Muscle types affected the CSA of muscle fibers: male chickens exhibited significantly higher values than female chickens at D42, D84, and D126 (p < 0.05). The results of moisture, crude protein, and crude fat at D126 showed that moisture contents were higher in the thigh muscles than in the breast muscles in male and female chickens (p < 0.05). Gender affected the crude protein contents and crude fat contents: the breast muscle crude protein content was significantly higher than that in the thigh muscle, both in males and females (p < 0.05), whereas the crude fat contents were significantly higher in females than in males (p < 0.05); moreover, the thigh muscle fat contents were significantly higher than those of the breast muscles both in males and females (p < 0.05). Gender and muscle types also affected the fatty acid contents: the PUFA contents of the breast and thigh muscles were significantly higher in male than in female chickens (p < 0.05). Muscle types significantly influenced the total EAA, NEAA, and flavor amino acid contents. The total EAA contents of the breast muscles were significantly higher than those of the thigh muscles in males and females (p < 0.05), whereas the total NEAA and total flavor amino acid contents of the thigh muscles were significantly higher than those of the breast muscles (p < 0.05). Our results may lead to a better understanding of the effects of gender on the breast and thigh muscle development and meat composition of Wuliangshan Black-bone chicken. [ABSTRACT FROM AUTHOR]

Altitudinal gradients create environmental variation that can strongly affect avian life history strategies. To fully understand this issue, a comparison of the demography of populations of the same species over large altitudinal differences is required. Here, we investigated the breeding ecology of two populations of Eurasian tree sparrow (Passer montanus), one in the temperate zone of central China at an altitude of 30 m and another in the alpine zone of the northeastern Tibetan plateau at an altitude of 3430 m. The breeding ecology of this species was rarely studied at such a high altitude before. Our result revealed that high-altitude tree sparrows started breeding later, had a shorter breeding period (80 versus 140 days), produced smaller broods (1.2 versus 2.5 chicks) and had significantly smaller clutches (4.0 versus 4.9 eggs) but larger eggs (4272 versus 3443 mm3) when compared with their low-altitude counterparts. Besides, tree sparrows at our high-altitude site had longer nestling periods (14.5 versus 13.4 days) than those at the low-altitude site. High-altitude tree sparrows tend to have reduced fecundity but allocate more energy into each offspring to confront the stressful conditions at high altitudes. The observed patterns are consistent with adaptive life history strategies. [ABSTRACT FROM AUTHOR]

Conservation of natural resources is a vital and challenging task. Numerous animal genetic resources have been effectively conserved worldwide. However, the effectiveness of conservation programmes and the variation information of species have rarely been evaluated. Here, we performed whole-genome and whole-genome bisulfite sequencing of 90 Chinese indigenous chickens, which belonged to the Tibetan, Wenchang and Bian chicken breeds, and have been conserved under different conservation programmes. We observed that low genetic diversity and high DNA methylation variation occurs during ex situ in vivo conservation, while higher genetic diversity and differentiation occurs during in situ conservation. Further analyses revealed that most DNA methylation signatures are unique within ex situ in vivo conservation. Moreover, a high proportion of differentially methylated regions is found in genomic selection regions, suggesting a link between the effects of genomic variation and DNA methylation. Altogether our findings provide valuable information about genetic and DNA methylation variations during different conservation programmes, and hold practical relevance for species conservation. Comparisons of genomic and methylomic changes during the conservation of indigenous chicken breeds in China provide insight into conservation programmes for these breeds and their adaptations to unique environments. [ABSTRACT FROM AUTHOR]

Marek's disease virus (MDV), an oncogenic virus belonging to the subfamily Alphaherpesvirinae, causes Marek's disease (MD). Vaccines can control MD but cannot block the viral infection; they are considered imperfect vaccines, which carry the risk of recombination. In this study, six natural recombinant MDV strains were isolated from infected chickens in commercial flocks in China. We sequenced and analysed the genetic characteristics of the isolates (HC/0803, CH/10, SY/1219, DH/1307, DH/1504 and Hrb/1504). We found that the six strains resulted from recombination between the vaccine CVI988/Rispens (CVI988) strain skeleton and the virulence strain's partial unique short region. Additionally, a pathogenicity study was performed on recombinant strains (HC/0803 and DH/1307) and reference strains (CVI988 and LHC2) to evaluate their virulence. LHC2 induced 84.6% mortality in infected chickens; however, no mortality was recorded in chickens inoculated with HC/0803, DH/1307 or CVI988. However, HC/0803 and DH/1307 induced a notable spleen enlargement, and mild thymus and bursa atrophy at 11–17 days post‐challenge (dpc). The viral genome load in the HC/0803‐ and DH/1307‐challenged chickens peaked at approximately 107 viral copies per million host cells at 17 dpc and was similar to that in LHC2‐challenged chickens, but significantly higher than that of CVI988‐challenged chickens. In summary, HC/0803 and DH/1307 displayed mild virulence with temporal damage to the immune organs of chicken and a higher reproduction capability than the vaccine strain CVI988. Our study provides direct evidence of the emergence of recombinant MDV strains between vaccine and virulence strains in nature. The emergence of natural recombinant strains suggests that live vaccines can act as genetic donors for genomic recombination, and recombination may be a safety concern when administering live vaccines. These findings demonstrate that recombination promotes genetic diversity and increases the complexity of disease diagnosis, prevention and control. [ABSTRACT FROM AUTHOR]

Background: Beijing You-chicken with a unique flavor and rich nutrition is an excellent local chicken breed in China. Clarifying the change of volatile odor during the storage of chicken is helpful to assist in judging the freshness of chicken. Methods: The total viable count (TVC), total volatile basic nitrogen (TVB-N), lightness value L* and thiobarbituric acid reactive rubstances (TBARS) of chicken breast were measured at 4C and 25C, respectively. And the electronic nose and gas chromatography mass spectrometry (GC-MS) technology were used to determine the changes of volatile compounds during storage. Result: Significant changes of the volatile compounds were observed on first day at 25C and the 8th day at 4C of storage, which agreed with the results evaluated by detection of physicochemical indicators. The results of this study could serve as a theoretical basis for future research on detecting changes in chicken freshness by using the electronic nose and GC-MS technology. [ABSTRACT FROM AUTHOR]

Simple Summary: With public concern increasing in China for animal welfare in livestock production, the welfare and economic outcomes of different farming systems for laying hens needs to be examined. Animal welfare outcomes and initiatives are linked to the economic efficiency of the farm, which for the producer may require a balance or trade-off between these issues. This study investigated animal welfare, egg production and economic parameters in cage and free-range farms in China. Our results identified potential welfare issues that can be addressed on both farm types, and potential points of income that can be improved by enhancing hen welfare. Therefore, our results offer some directions for welfare and economic improvements on cage and free-range egg farms in China. Several countries and regions have regulations in place to provide standards for the welfare of production animals, which have implications for breeding, management and trade. In the chicken egg production industry, the welfare impacts of this are not well understood. In the past decades, free-range systems were widely used for local chicken breeds in poultry industry in China, but their use has gradually declined due to the lower competitiveness compared to commercial cage systems. However, the practices of free-range systems for hens raising have gradually increased again over the past decade, as consumer individualized demand for higher food quality and animal welfare has increased. We recruited 14 free-range farms and 45 cage farms from Beijing, Shandong, Hebei, Anhui, Yunnan, Gansu and Jiangsu provinces in China, for an evaluation of hen welfare, production and economic outcomes from farm operations. This study provides data for the welfare outcomes of laying hens in China and preliminarily explored the relationship between welfare level and economic income within farming system types. The researchers visited the farms and used Welfare Quality measures to investigate the welfare, and farm self-reported profits. Nonparametric Mann–Whitney U tests were used to compare the welfare scores between cage and free-range rearing farms. Correlation and regression are used for the analysis of the animal welfare scores, economic data, and production metrics. The general income from free-range farms was linearly correlated with red mite score and stocking density (p < 0.001 and p < 0.05, respectively). The results showed less centimeters of feeder and drinker space per animal in the free-range system than in cage systems (p < 0.05 and p < 0.01, respectively). Welfare scores for both the stocking density and beak condition were significantly better in the free-range systems than the cage systems (p < 0.001), as were qualitative behavior assessment scores (p < 0.05). The total egg production and peak egg production in cage farms were much higher than in free-range farms (p < 0.001), and egg loss rate was significantly lower (p < 0.001). While the production efficiency of free-range farms was lower than that of cage farms, general income per 10,000 hens was actually higher. Our results provide some evidence that some welfare indicators and general income (per 10,000 hens) in free-range farms in China were better than those of cage farms. The results indicate that better parasite control and lower stocking densities may result in improved hen welfare on free-range farms and potentially improve profitability. The level of welfare and economic benefits of free-range farms vary widely, and there was potential room for improvement in feeding space, drinking water space and human–animal relationship. [ABSTRACT FROM AUTHOR]

Goose astroviruses (GoAstVs) are small non-enveloped viruses with a genome consisting of a single-stranded positive-sense RNA molecule. A novel GoAstV was identified in Shandong in 2016 and quickly spread to other provinces in China, causing gout in goslings, with a mortality rate of approximately 50%. GoAstV can also cause gout in chickens and ducks, indicating its ability to cross the species barrier. GoAstV has only been reported in China, where it has caused serious losses to the goose-breeding industry. However, in view of its cross-species transmission ability and pathogenicity in chickens and ducks, GoAstV should be a concern to poultry breeding globally. As an emerging virus, there are few research reports concerning GoAstV. This review summarizes the current state of knowledge about GoAstV, including the epidemiology, evolution analysis, detection methods, pathogenicity, pathogenesis, and potential for cross-species transmission. We also discuss future outlooks and provide recommendations. This review can serve as a valuable reference for further research on GoAstV. [ABSTRACT FROM AUTHOR]

The introduction of exotic breeds and the cultivation of new lines by breeding companies have posed challenges to native chickens in South China, including loss of breed characteristics, decreased genetic diversity, and declining purity. Understanding the population genetic structure and genetic diversity of native chickens in South China is crucial for further advancements in breeding efforts. In this study, we analyzed the population genetic structure and genetic diversity of 321 individuals from 10 different breeds in South China. By comparing commercial chickens with native ones, we identified selection signatures occurring between local chickens and commercial breeds. The analysis of population genetic structure revealed that the native chicken populations in South China exhibited a considerable level of genetic diversity. Moreover, the commercial lines of Xiaobai chicken and Huangma chicken displayed even higher levels of genetic diversity, which distinguished them from other native varieties at the clustering level. However, certain individuals within these commercial varieties showed a discernible genetic relationship with the native populations. Notably, both commercial varieties also retained a significant degree of genetic similarity to their respective native counterparts. In order to investigate the genomic changes occurring during the commercialization of native chickens, we employed 4 methods (Fst, ROD, XPCLR, and XPEHH) to identify potential candidate regions displaying selective signatures in Southern Chinese native chicken population. A total of 168 (identified by Fst and ROD) and 86 (identified by XPCLR and XPEHH) overlapping genes were discovered. Functional annotation analysis revealed that these genes may be associated with reproduction and growth (SAMSN1, HYLS1, ROBO3, FGF14, PRSS23), musculoskeletal development (DNER, MYBPC1, DGKB, ORC1, KLF10), disease resistance and environmental adaptability (PUS3, CRB2, CALD1, USP15, SGCD, LTBP1), as well as egg production (ADGRB3, ACSF3). Overall, native chickens in South China harbor numerous selective sweep regions compared to commercial chickens, enriching valuable genomic resources for future genetic research and breeding conservation. [ABSTRACT FROM AUTHOR]

Meat quality traits are essential for producing high-quality broilers, but the genetic improvement has been limited by the complexity of measurement methods and the numerous traits involved. To systematically understand the meat quality characteristics of different broiler breeds, this study collected data on slaughter performance, skin color, fat deposition, and meat quality traits of 434 broilers from 12 different breeds in South China. The results showed that there was no significant difference in the live weight and slaughter weight of various broiler breeds at their respective market ages. Commercial broiler breeds such as Xiaobai and Huangma chickens had higher breast muscle and leg muscle rates. The skin and abdominal fat of Huangma chickens cultivated in the consumer market in South China exhibited significantly higher levels of yellowness compared to other varieties. Concerning fat traits, we observed that Wenchang chickens exhibited a strong ability to fat deposition, while the younger breeds showed lower fat deposition. Additionally, there were significant positive correlations found among different traits, including traits related to weight, traits related to fat, and skin color of different parts. Hierarchical clustering analysis revealed that fast-growing and large broiler Xiaobai chickens formed a distinct cluster based on carcass characteristics, skin color, and meat quality traits. Principal component analysis (PCA) was used to extract multiple principal components as substitutes for complex meat quality indicators, establishing a chicken meat quality evaluation model to differentiate between different breeds of chickens. At the same time, we identified 46, 22, and 20 SNP loci and their adjacent genes that were significantly associated with muscle mass traits, fat deposition, and skin color through genome-wide association studies (GWAS). The above results are helpful for systematically understanding the differences and characteristics of meat quality traits among different breeds. [ABSTRACT FROM AUTHOR]

As a Chinese local chicken breed, Hongshan chickens have 2 kinds of tail feather phenotypes, normal and taillessness. Our previous studies showed that taillessness was a sex-linked dominant trait. Abnormal development of the tail vertebrae could be explained this phenomenon in some chicken breeds. However, the number of caudal vertebrae in rumpless Hongshan chickens was normal, so rumplessness in Hongshan chicken was not related to the development of the caudal vertebrae. Afterwards, we found that rumplessness in Hongshan was due to abnormal development of tail feather rather than abnormal development of caudal vertebrae. In order to understand the genetic foundation of the rumplessness of Hongshan chickens, we compared and reanalyzed 2 sets of data in normal and rumpless Hongshan chickens from our previous studies. By joint analysis of genome-wide selection signature analysis and genome-wide association approach, we found that 1 overlapping gene (EDIL3) and 16 peak genes (ENSGALG00000051843, ENSGALG00000053498, ENSGALG00000054800, KIF27, PTPRD, ENSGALG00000047579, ENSGALG00000041052, ARHGEF28, CAMK4, SERINC5, ENSGALG00000050776, ERCC8, MCC, ADAMTS19, ENSGALG00000053322, CHRNA8) located on the Z chromosome was associated with the rumpless trait. The results of this study furtherly revealed the molecular mechanism of the rumpless trait in Hongshan chickens, and identified the candidate genes associated with this trait. Our results will help to improve the shape of chicken tail feathers and to rise individual economic value in some specific market in China. [ABSTRACT FROM AUTHOR]

The pigeon industry is emerging after the "three birds" in the special poultry breeding. Pigeon breeding has also been well developed over more than 30 years in the animal husbandry industry in China. In this study, an improved RetinaNet model was proposed for the individual detection of caged pigeons during the breeding period. An accurate and rapid individual detection in the cage was realized to improve the breeding efficiency. The original image dataset was first collected in the Golden Green Pigeon Breeding Base in Xingning, Guangdong Province, China. The images were then enhanced by the vertically flipped, adding noise, and brightness. As such, the training and validation datasets were expanded to five times the original images. A total of 5 420 pigeon images were selected to be labeled, where 5 190 images were set as the training and validation set, and 230 as the test set. The model was improved using the RetinaNet. The Convolutional Block Attention Module (CBAM) was introduced before the classification and regression sub-networks. As such, the information of the feature map was enhanced for the better model. Two backbone networks (ResNet50 and ResNext50) were selected to compare to the Feature Pyramid Networks (FPN) with different layers on the individual detection of pigeons in the breeding period. 11 experiments were then performed on the same training, validation, and test set under the operating system of Ubuntu18.04 and graphics card: NVIDIA TITAN RTX. The commonly-used SSD and YOLOv3 in the one-stage object detection were selected to compare with the RetinaNet model framework in this case. Eight experiments were also carried out to optimize the model using the same dataset and training parameters. The results showed that the mAP of the original RetinaNet model structure was 65.44%, which was 3.21, 13.7, 4.47, 6.24, and 3.54 percentage points higher than that of SSD, YOLOv3, YOLOv4, YOLOv5s, and YOLOv5m, respectively. The overall detection effect of the original RetinaNet model was better than that of SSD and YOLOv3. Moreover, the number of FPN layers increased the detection scale, thereby effectively improving the recall of small objects. The missed detection of pigeon eggs was also reduced in the actual breeding environment using the original RetinaNet. Meanwhile, the CBAM was introduced before the classification and regression sub-network, in order to promote the detection effect on the adhesion pigeons. The improved RetinaNet model presented an average accuracy of 95.88%, 79.51%, and 67.29% on the test set of pigeons, squabs, and pigeon eggs, respectively, which were 2.16, 21.74, and 22.48 percentage points higher than the original RetinaNet model. There was also much more improvement in the average precision of adhesive squab and small pigeon eggs. Consequently, the improved model can also be expected to present the best performance. The real-time monitoring of individual changes can be achieved in the pigeon cage. The finding can provide the technical support for precision breeding, in order to timely detect and adjust the improper behavior of production management. [ABSTRACT FROM AUTHOR]

China has about 107 local chicken breeds and is considered one of the richest countries in terms of genetic resources. This diversity is a source of richness natural resources across the globe and is regarded as an excellent material for genetic improvement of breeds or breeding new breeds around the world. The present review highlights the recent evidence and studies of chicken origin and domestication in China and Southeast Asia. The evidence of molecular genetics and archeological results supported that multiple regions and event were contributed to the creation of chicken evolution from Red Jungle fowl and the findings proposed that one of events happened in domestication of chicken 8000 BP in Southeast of Asia. Several researchers confirmed that China was declared as most important of the world as a first centers for the chicken’s domestication and these chickens have remained in many archaeological sites in China. [ABSTRACT FROM AUTHOR]

[Objectives] This study was conducted to improve the production efficience of dark-shank partridge-like plumage high-qualite broilere and ensure animat welfare, ss as to meet the development needs of China's yellow-feather broiler industr.. [Methods] Sichuan Animal Sciencc Academy and Sichuan Dahen Poultry Breeding Co., Ltd., formed a joint breeding research team. The team bred Dahen 799 broilee complete set tine with locai chicken breeds as the main material and improving production efficience, stabilizing meat quality and Oavor and achieving autosexing oO chicks as the main breeding goats by modern poulte breeding technologies, after 10 yeare and 8 generations. [Resslts] The Dahen 799 broilee complete set tine was approved by Nationai Commission of Livestock and Poulte Genetic Resources in December 2020. The 66-week-olO egg production ot the breed reached 189 egg. For the commercial generation, cocks and hens showed 10-week-old weight of 2 668 and 2 269 g respectively; the feed conversion ratio was 2. 26 - 2. 35; the survivabilito was 96.7% - 97. 2%; and the average intramuscular fat contents ot cocks and hens were 1v the range of 1. 8% -2.1%, and the inosinic vid contents were 1v the range of 2.3 -3.2 mg/g. The production performancc and meat Oavos of Dahen 799 broilere were better than Dahen 699 broilee, Sichuan mountainous bone-black chickens and two othes social breeds. Compared wit Sichuan mountainous bone-black chickens, the egg production at the age of 66 weeks increased by 47 eggs; the average weight ol cocks and hens ol the commercial generation at 10 weeks increased by 45. 21%; and the autosexing rate ol chicks of te commercial generation reached 99. 3 %. [Conclusions] Dahen 799 broilee have the adrantages of good production performancc, high feed conversion ratio and excellent meat flavor and the characteristic of autosexing which othec breeds do not have, and can fuliy meet the industWal development needs of dark shanks and partridge-like plumage broilers. [ABSTRACT FROM AUTHOR]

Manure slurry is a mixture of urine, feces, flushing water, and disinfectant in the livestock and poultry breeding industry. About two billion tons of manure slurry can be produced in China every year. Among them, the composition varies greatly, due to the complex sources. There are many influencing factors on the composition of manure slurry, such as the seasons, regions, breeding scale, fecal cleaning, and manure slurry treatment. Currently, the fixed composition value cannot accurately be calculated the amount of manure slurry, when returning to the field. Therefore, it is urgent to develop an accurate, and rapid detection system suitable for the compositions in the manure slurry on site. Fortunately, Near-Infrared (NIR) spectroscopy can offer a great potential to detect manure composition at present. Nevertheless, most reports were usually focused on the near-infrared spectrometer at the large-scale laboratory level. This kind of instrument can be confined to the application of near-infrared spectroscopy analysis in fields, due to the large bulk volume, low portability, and high price. The near-infrared spectrometer can be further developed towards the miniaturization for the technical and cost feasibility during on-site detection, particularly with the development of Micro-Electromechanical Systems (MEMS) and Micro-Opto-Electro-Mechanical Systems (MOEMS) in recent years. In addition to the need for a stable and reliable hardware system, the calibration model is another important application premise of near-infrared technology. But, there is a great challenge to establish the calibration model using cloud sharing technology. It is very necessary to access the shared resources via the various data computing services anytime, anywhere, and on-demand through the Internet. In this study, a micro NIR onsite and rapid system was proposed to detect the composition of manure slurry during field return using a calibration model under cloud sharing. A complete function was also achieved for the data acquisition, upload, prediction and storage at the same time, according to the design scheme of "micro NIR sensor + calibration model cloud sharing + Android client + mobile network". The micro NIR sensor was first used to collect the spectral data of the measured sample, then to transmit the data into the Android client through the Bluetooth protocol, and finally to the cloud server through the mobile network. A calibration model was deployed in the cloud server to calculate the received spectral data. A quantitative prediction was obtained to further send back to the Android client in real time. A rapid detection was realized for the ten parameters of manure slurry compositions, such as the Total Nitrogen (TN), Total Phosphorus (TP), Total Potassium (TK), ammonium nitrogen (NH4 +-N), nitrate nitrogen (NO3 --N), amide nitrogen (CONH2-N), Available Phosphorus (AP), Available Potassium (AK), Organic Matter (OM), and pH value. The prediction relative errors of AK, TN, AP, TP, pH, NH4 +-N, and TK in the manure slurry were less than 10%, and the rest of OM, CONH2-N, and NO3 --N were between 10%-18%. Consequently, the micro NIR technology combined with the calibration model in cloud sharing can be expected to realize the onsite, rapid and accurate detection of various compositions in the manure slurry, particularly for the full sharing of the quantitative model. Moreover, the broad market prospect can be gained for the practical application, due to the portable micro NIR sensor, the simple operation of the Android client, and the lower cost of the system. There is also no need for the professional requirements of the users in the cloud sharing of the calibration model. The finding can provide data support for the high precision return of manure slurry to the field. [ABSTRACT FROM AUTHOR]

Ammonia is the only alkaline gas in the atmosphere. Reducing ammonia emissions plays an important role in controlling atmospheric pollution. Livestock and poultry breeding industry is an important source of ammonia emissions. Scientific assessment of ammonia emissions and reduction potential in different links is of great significance. In this paper, the ammonia emission factors of different livestock and poultry breeding houses in China and abroad, the main emission reduction technologies and efficiency were summarized. Combined with the number of mechanical ventilation farms and the animal population of major livestock and poultry obtained from the second national pollution source census, the ammonia emission reduction potential of exhaust air from mechanical ventilation livestock farms in China was analyzed. The results show that the reduction potential of ammonia emission from mechanically ventilated livestock houses in China is 265.6 thousand tons; pigs, laying hens and broilers were the three main sources of livestock and poultry, and their emission reduction potential were 101.8 thousand tons, 77.3 thousand tons and 67.5 thousand tons, respectively. The emission reduction potential of the three livestock and poultry types accounted for 92.8 %. Regionally, the main implementing regions are East China, South Central and North China, with ammonia emission reduction potential accounting for 35.1%, 26.9% and 14.9%, respectively. It is proposed to carry out the construction of ammonia emission reduction facilities in mechanical ventilation barn of pig, laying hens and broiler, which can provide guarantee for the national ammonia emission reduction and the improvement of atmospheric environmental quality. [ABSTRACT FROM AUTHOR]