Dietary isoleucine supplementation enhances growth performance, modulates the expression of genes related to amino acid transporters and protein metabolism, and gut microbiota in yellow-feathered chickens.

This study investigated the effects of dietary isoleucine (Ile) on growth performance, intestinal expression of amino acid transporters, protein metabolism-related genes and intestinal microbiota in starter phase Chinese yellow-feathered chickens. Female Xinguang yellow-feathered chickens (n = 1,080, aged 1 d) were randomly distributed to 6 treatments, each with 6 replicates of 30 birds. Chickens were fed diets with 6 levels of total Ile (6.8, 7.6, 8.4, 9.2, 10.0, and 10.8 g/kg) for 30 d. The average daily gain and feed conversion ratio were improved with dietary Ile levels (P < 0.05). Plasma uric acid content and glutamic-oxalacetic transaminase activity were linearly and quadratically decreased with increasing dietary Ile inclusion (P < 0.05). Dietary Ile level had a linear (P < 0.05) or quadratic (P < 0.05) effect on the jejunal expression of ribosomal protein S6 kinase B1 and eukaryotic translation initiation factor 4E binding protein 1. The relative expression of jejunal 20S proteasome subunit C2 and ileal muscle ring finger-containing protein 1 decreased linearly (P < 0.05) and quadratically (P < 0.05) with increasing dietary Ile levels. Dietary Ile level had a linear (P = 0.069) or quadratic (P < 0.05) effect on the gene expression of solute carrier family 15 member 1 in jejunum and solute carrier family 7 member 1 in ileum. In addition, bacterial 16S rDNA full-length sequencing showed that dietary Ile increased the cecal abundances of the Firmicutes phylum, and Blautia, Lactobacillus, and unclassified_Lachnospiraceae genera, while decreased that of Proteobacteria, Alistipes, and Shigella. Dietary Ile levels affected growth performance and modulated gut microbiota in yellow-feathered chickens. The appropriate level of dietary Ile can upregulate the expression of intestinal protein synthesis-related protein kinase genes and concomitantly inhibit the expression of proteolysis-related cathepsin genes.

Protective effects of protocatechuic acid on growth performance, intestinal barrier and antioxidant capacity in broilers challenged with lipopolysaccharide.

'Prohibition of the antibiotic uses' aggravates the problem of intestinal diseases in poultry, and nutritional regulation has become a research hotspot, such as supplementation with active ingredients derived from plants. This research was conducted to investigate the effects of protocatechuic acid (PCA) on growth, intestinal barrier, and antioxidant capacity of broilers injected with lipopolysaccharide (LPS). Four hundred and eighty 1-day-old yellow feather broilers were randomly allocated to four groups, each with six replicates of 20 broilers. The treatments were basal diet + saline injection (CON) or LPS injection (CON-LPS), and diets with 300 or 600 mg/kg PCA supplementation + LPS injection (P300, P600). Birds were injected intramuscularly on 17th and 19th day of age, then sampled on day 21. The LPS injection significantly decreased BW and average daily gain of broilers, and compared with birds in CON-LPS, PCA supplementation increased (P < 0.05) those variables; moreover, 300 mg/kg PCA also decreased the feed-to-gain ratio. No differences were observed in relative weights of immune organs (P > 0.05). LPS decreased the villus height/crypt depth ratio (V/C) in jejunum of broilers, while PCA (P300 and P600) increased (P < 0.05) the jejunal villus height and V/C compared with birds in CON-LPS. LPS challenge increased jejunal malondialdehyde (MDA) concentration and decreased total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) activities in plasma (P < 0.05); compared with birds in CON-LPS, jejunal and plasmal GSH-Px activity (P300 and P600) and jejunal T-SOD activity (P300) were decreased (P < 0.05), and hepatic MDA concentration (P600) was increased (P < 0.05). LPS significantly decreased the transcript abundances of OCLN, ZO-1, JAM2, MUC2, SOD1, CAT and GPX in jejunal mucosa of birds, and supplementation with PCA attenuated the decrease in OCLN, JAM2, and MUC2 expression compared with birds in CON-LPS; moreover, 600 mg/kg PCA offset the deduction in SOD1, CAT and GPX expression. In conclusion, dietary supplementation with PCA could improve antioxidant status and attenuate the damage in intestinal barrier and loss in growth performance of LPS-challenged broilers, and 600 mg/kg PCA showed more improved effects on antioxidant capacity.

[Analysis of influenza vaccination coverage, recommendation behaviors and related factors among health care workers in Nanshan district of Shenzhen city under the free policy between 2019 and 2020].

Objective: To investigate the current situation of influenza vaccination, vaccination willingness, recommended behavior and influencing factors of health care workers (HCWs) under the policy of free vaccination. Methods: A cross-sectional survey was conducted among 3 167 medical staff from 8 hospitals in Nanshan district of Shenzhen city based on a web-based questionnaire platform. The logistic regression was used to analyze the data. Results: The influenza vaccination rate in HCWs was 23.97%, and the recommendation rate was 25.69% from 2019 to 2020. Staff with high professional titles, high academic qualifications, and positive awareness about influenza vaccine had a higher vaccination rate. The main reasons for not recommending influenza vaccine were the fear of patients' misunderstanding of commercial benefits, fear of possible disputes caused by recommended vaccination, lack of national or institutional requirements for recommended influenza vaccine, and fear of adverse reactions of influenza vaccines. Conclusion: Under the free policy, the influenza vaccination rate and recommendation rate of HCWs in Nanshan district of Shenzhen city are relatively low. Strengthening health education on influenza and related knowledge, publicizing the policy of free influenza vaccination, providing convenient vaccination services and promoting the construction of relevant policies and regulations are the key to improve the influenza vaccination rate and recommendation rate among HCWs.

[Epidemiological characteristics of three local epidemics of COVID-19 in Guangzhou].

Objective: To understand the epidemiological characteristics of three local COVID-19 epidemics in Guangzhou and provide reference for optimizing strategies and measures of COVID-19 prevention and control. Methods: The data of local COVID-19 cases in Guangzhou reported as of June 18, 2021 were collected from National Notifiable Disease Report System of China. The software Excel 2019 and SPSS 22.0 were applied for data cleaning and statistical analysis. Results: A total of 726 COVID-19 cases were reported in the three local epidemics in Guangzhou. In the epidemic associated with the outbreak of COVID-19 in Hubei province, 366 cases were reported. Most cases were female (51.6%, 189/366), aged 18-65 years (81.4%, 298/366), jobless/unemployed (32.2%, 118/366) and retired persons (20.2%,74/366). The initial symptoms of most cases were fever (71.6%, 250/349) and cough (60.7%, 212/349). In the epidemic associated with the imported COVID-19 cases from Africa, 207 cases were reported. Most cases were aged 18-40 years (72.9%, 151/207), male (69.6%, 144/207), and engaged in commercial services (62.3%,129/207). The initial symptoms of most cases were no obvious discomfort (55.6%, 15/27) and cough (37.0%, 10/27). In the epidemic associated with Delta variant of SARS-CoV-2, 153 cases were reported, in which women accounted for 58.8% (90/153), most cases were over 41 years old (64.7%,99/153), and retired persons accounted for the highest proportion (32.0%,49/153). The initial symptoms of most cases were cough (32.9%, 48/146) and no obvious discomfort (28.1%, 41/146). The household secondary attack rates of the three local epidemics were 11.2%, 5.7% and 11.5%, respectively. The median (P25, P75) of incubation periods were 6.5 (4.0,10.8) d, 4.0 (2.5, 6.0) d and 4.0 (3.0,5.0) d. The serial intervals median (P25, P75) were 4.0 (3.0, 8.0) d, 4.0 (2.5, 6.0) d and 3.0 (2.0,5.0) d. There were significant differences in gender, age, occupation, initial symptoms, household secondary attack rate and incubation period among the three local COVID-19 epidemics (all P<0.05). In the proportion of the case finding way, passive detection in patient treatment were mainly 44.3%(162/366) in the epidemic associated with the outbreak of COVID-19 in Hubei province,but active community case screening [58.5% (121/207) and 27.5% (24/153)] and close contact management in imported case were mostly [33.3% (69/207) and 67.3% (103/153)] in the epidemic associated with the imported COVID-19 cases from Africa and with Delta variant of SARS-CoV-2, respectively. Conclusions: Due to the different sources of infection, strain types and prevention and control strategies, the epidemiological characteristics of the three local COVID-19 epidemics in Guangzhou differed in demographics, clinical symptoms, transmission routes and case finding, which suggested that it is necessary to improve the key population and common symptom monitoring in the routine prevention and control of COVID-19 to prevent the reemerge of the epidemic.

Effects and interaction of dietary calcium and non-phytate phosphorus for slow-growing yellow-feathered broilers during the starter phase.

Calcium (Ca) and non-phytate phosphorus (NPP) are fundamental minerals for bone formation and growth, and optimizing their level is required in broiler production. This experiment was conducted to investigate the effect and interaction of dietary Ca and NPP on growth performance, tibial characteristics and biochemical variables for slow-growing yellow-feathered broilers during 1-28 d (the starter phase). Seven hundred and twenty hatchling female broilers were randomly divided into nine groups, which received three levels of Ca (0.80%, 0.90%, 1.00%) each with three levels of NPP (0.40%, 0.45%, 0.50%). The results showed: (1) Dietary Ca level influenced (P < 0.05) the feed to gain ratio (F:G) and average daily feed intake (ADFI). Compared with broilers provided 1.00% Ca, ADFI of birds provided with 0.80% or 0.90% Ca and F:G of those with 0.90% Ca were decreased (P < 0.05). Dietary NPP level did not affect (P > 0.05) growth performance of broilers. (2) Dietary Ca affected (P < 0.05) tibial length. Compared with birds provided with 0.80% Ca, the length of tibia was decreased (P < 0.05) in birds received 1.00% Ca. Interactions between dietary Ca and NPP were observed (P < 0.05) on ash content, breaking strength and bone density of tibia. These three characteristics were better when birds received 0.90% Ca and 0.40% NPP or 1.00% Ca and 0.45% NPP. (3) Dietary Ca significantly affected (P < 0.05) the activity of alkaline phosphatase (ALP) in serum with decreased activity in birds fed 0.80% or 0.90% Ca. The dietary NPP influenced (P < 0.05) the contents of Ca in serum. Serum Ca was increased when birds were provided 0.40% NPP compared with other levels (P < 0.05). Again, there was interaction between Ca and NPP in diet on the contents of phosphorus (P) in serum (P < 0.05). In conclusion, interactions occurred between dietary Ca and NPP level on tibial breaking strength, density, ash content, and the content of P in the serum of young yellow-feathered broilers. Furthermore, dietary Ca affected ADFI, F:G and serum ALP activity, and dietary NPP also affected the P content in serum. Considering all indicators, 0.90% Ca and 0.40% NPP are optimal for slow-growing yellow-feathered broilers during 1-28 d of age.

Reproductive performance, metabolism and oxidative stress profile in Chinese yellow-feathered broiler breeder hens fed multiple levels of isoleucine.

1. This experiment was conducted to evaluate the effects of dietary isoleucine (Ile) on reproductive performance and certain indices of metabolism and oxidative stress in Chinese yellow-feathered broiler breeder hens.2. A total of 600, 40-week-old Chinese yellow-feathered broiler breeder hens were fed a basal diet formulated with maize, corn gluten meal and spray-dried blood cell meal containing 3.3 g/kg Ile, or supplemented to contain 4.5, 5.7, 6.9, or 8.1 g/kg Ile for five weeks. Each dietary treatment had six replicates with 20 birds per replicate. After three weeks of receiving the trial diets, 24 eggs were collected at random from each replicate to measure egg quality. Starting after four weeks of treatment, 50 settable eggs per replicate were collected for 7 d in succession for hatching. After five weeks of being fed the treatment diets, birds were slaughtered for tissue and organ collection.3. For the overall period, laying rate, egg weight, egg mass and hatchling weight linearly (P < 0.05) and quadratically (P < 0.05) increased with dietary Ile levels. Final body weight, feed intake and relative liver weight of birds fed 3.3 g/kg Ile was lower compared to birds fed the other diets (P < 0.05). There was no effect of Ile level on egg quality (P > 0.05). Hatchling weight was linearly (P < 0.05) and quadratically increased (P < 0.05) in line with dietary supplemental Ile.4. After three weeks on the trial diets, birds fed the diet containing 3.3 g/kg Ile had decreased blood TG concentrations compared to breeders fed 6.9 or 8.1 g/kg Ile (P < 0.05). Activities of CK were significantly higher in breeders fed the 3.3 g/kg Ile diet compared to all other levels of dietary Ile after five weeks of treatment. A quadratic effect (P < 0.05) was evident for glucose at 8.1 g/kg Ile level. After five weeks of treatment, plasma TG concentrations in birds fed 3.3 g/kg Ile were significantly lower than in birds fed all other levels of Ile. Glucose concentrations in breeder hens receiving the 3.3 g/kg Ile diet were lowest and the highest concentrations were in birds fed 5.7 g/kg Ile (P < 0.05). Plasma activities of LDH were highest in breeders on the 3.3 g/kg Ile diet but were only significantly different (P < 0.05) for birds fed 5.7 g/kg Ile.5. The current study indicated that Ile deficiency decreased reproductive performance and appeared to serve as a stressor. The optimal dietary Ile for Chinese yellow-feathered broiler breeder hens in the laying period was 5.79 g/kg feed (0.75 g/d).

Local crystalline order features in disordered packings of monodisperse spheres.

A new tetrahedral structure model was developed for disordered sphere packings, including not only regular tetrahedron (T), but also quartoctahedron (Q) and bcc simplex (B), the tetrahedral building blocks in fcc, hcp and bcc crystal structures, respectively. Both geometric frustrated configurations and local configurations associated with crystalline order in disordered packings can be comprehensively characterized. It is found that with increasing packing fraction, the population of T, Q, and B increases. Moreover, the crystal-type local configurations formed by face-adjacent T, Q and B increases as packing fraction increases, which is more prevalent than the geometric frustrated ones formed by face-adjacent T. In addition, as packing fraction increases, the local density of irregular simplexes is found to increase more quickly than regular ones, playing more important roles in the density increase in disordered packings. These structure features are found to be intrinsic in the jammed random sphere packings with different friction coefficients, which is independent of interparticle friction and only determined by the packing fraction. Our findings provide new understanding for the structural nature of disordered packings and the underlying structural basis of the random close packing.

Emerging salt marshes as a source of Trichoderma arenarium sp. nov. and other fungal bioeffectors for biosaline agriculture.

AIMS: Sustainable agriculture requires effective and safe biofertilizers and biofungicides with low environmental impact. Natural ecosystems that closely resemble the conditions of biosaline agriculture may present a reservoir for fungal strains that can be used as novel bioeffectors. METHODS AND RESULTS: We isolated a library of fungi from the rhizosphere of three natural halotolerant plants grown in the emerging tidal salt marshes on the south-east coast of China. DNA barcoding of 116 isolates based on the rRNA ITS1 and 2 and other markers (tef1 or rpb2) revealed 38 fungal species, including plant pathogenic (41%), saprotrophic (24%) and mycoparasitic (28%) taxa. The mycoparasitic fungi were mainly species from the hypocrealean genus Trichoderma, including at least four novel phylotypes. Two of them, representing the taxa Trichoderma arenarium sp. nov. (described here) and T. asperelloides, showed antagonistic activity against five phytopathogenic fungi, and significant growth promotion on tomato seedlings under the conditions of saline agriculture. CONCLUSIONS: Trichoderma spp. of salt marshes play the role of natural biological control in young soil ecosystems with a putatively premature microbiome. SIGNIFICANCE AND IMPACT OF THE STUDY: The saline soil microbiome is a rich source of halotolerant bioeffectors that can be used in biosaline agriculture.

Dietary L-arginine supplementation enhances growth performance, intestinal antioxidative capacity, immunity and modulates gut microbiota in yellow-feathered chickens.

This study investigated the effects of dietary Arginine (Arg) on performance, intestinal antioxidative capacity, immunity, and gut microbiota in Chinese yellow-feathered chickens. One thousand two hundred 1-day-old female Qingyuan partridge chickens were randomly assigned to 5 groups with 6 replicates of 40 birds each. Chickens were fed diets with 5 levels of total Arg (8.5, 9.7, 10.9, 12.1, and 13.3 g/kg) without antibiotics for 30 d. The ADFI, ADG, and feed conversion ratio were improved with dietary Arg levels (P < 0.05). The proportions of CD3+ and CD4+/CD8+ lymphocytes responded in a linear (P < 0.05) manner and those of CD4+ in a linear or quadratic (P < 0.05) manner as dietary Arg levels increased. Dietary Arg level had a linear (P < 0.05) or quadratic (P < 0.05) effect on the gene expression of glutathione peroxidase 1, heme oxygenase 1, nuclear factor erythroid 2-related factor 2, and the activities of glutathione peroxidase and total antioxidative capacity in the jejunum and ileum. The relative expression of IL-1ß, myeloid differentiation primary response 88, and Toll-like receptor 4 decreased linearly (P < 0.05) in the ileum with increasing dietary Arg levels; secretory IgA contents were increased. In addition, sequencing data of 16S rRNA indicated that dietary Arg increased the relative abundance of Firmicutes phylum, Romboutsia and Candidatus Arthromitus genera, while decreased that of Clostridium sensu stricto 1. A diet containing 12.1 g Arg/kg promoted growth performance, intestinal antioxidation, and innate immunity and modulated gut microbiota in yellow-feathered chickens.

Effects of dietary incorporation of linseed oil with soybean isoflavone on fatty acid profiles and lipid metabolism-related gene expression in breast muscle of chickens.

The meat quality of chicken is an important factor affecting the consumer's health. It was hypothesized that n-3 polyunsaturated fatty acid (n-3 PUFA) could be effectively deposited in chicken, by incorporating antioxidation of soybean isoflavone (SI), which led to improved quality of chicken meat for good health of human beings. Effects of partial or complete dietary substitution of lard (LA) with linseed oil (LO), with or without SI on growth performance, biochemical indicators, meat quality, fatty acid profiles, lipid-related health indicators and gene expression of breast muscle were examined in chickens. A total of 900 males were fed a corn-soybean meal diet supplemented with 4% LA, 2% LA + 2% LO and 4% LO and the latter two including 30 mg SI/kg (2% LA + 2% LO + SI and 4% LO + SI) from 29 to 66 days of age; each of the five dietary treatments included six replicates of 30 birds. Compared with the 4% LA diet, dietary 4% LO significantly increased the feed efficiency and had no negative effect on objective indices related to meat quality; LO significantly decreased plasma triglycerides and total cholesterol (TCH); abdominal fat percentage was significantly decreased in birds fed the 4% LO and 4% LO + SI diets. Chickens with LO diets resulted in higher contents of α-linolenic acid (C18:3n-3), EPA (C20:5n-3) and total n-3 PUFA, together with a lower content of palmitic acid (C16:0), lignoceric acid (C24:0), saturated fatty acids and n-6:n-3 ratio in breast muscle compared to 4% LA diet (P < 0.05); they also significantly decreased atherogenic index, thrombogenic index and increased the hypocholesterolemic to hypercholesterolemic ratio. Adding SI to the LO diets enhanced the contents of EPA and DHA (C22:6n-3), plasma total superoxide dismutase, reduced glutathione (GSH)/oxidized glutathione and muscle GSH content, while decreased plasma total triglyceride and TCH and malondialdehyde content in plasma and breast muscle compared to its absence (P < 0.05). Expression in breast muscle of fatty acid desaturase 1 (FADS1), FADS2, elongase 2 (ELOVL2) and ELOVL5 genes were significantly higher with the LO diets including SI than with the 4% LA diet. Significant interactions existed between LO level and inclusion of SI on EPA and TCH contents. These findings indicate that diet supplemented with LO combined with SI is an effective alternative when optimizing the nutritional value of chicken meat for human consumers.

Spatial distribution of perfluoroalkyl acids (PFAAs) and their precursors and conversion of precursors in seawater deeply affected by a city in China.

Conversion of perfluoroalkyl acid (PFAA) precursors in the environment has been a hotspot research in recent years. This study firstly determined the spatial distribution of PFAAs and their precursors including 8:2 fluorotelomer unsaturated acid (8:2 FTUCA), perfluorooctane sulfoneamide (FOSA), and diperfluorooctane sulfonamido ethanol-based phosphate (di-SAmPAP), then investigated the conversion of the potential precursors in the seawater and sewage treatment plants (STPs) effluents. The results indicated that the target pollutants showed a typical concentration gradient from nearshore to offshore. And the obviously increased concentration of perfluorinated carboxylic acids (△[PFCAs]) after oxidation treatment can verify the existence of PFAA precursors in the seawater and STP effluents. The concentrations of PFCAs with carbon atom numbers 4-9 (PFCAC4-C9) revealed the most increase. Moreover, the levels of △[PFCAs] and the ratios of △[PFCAs] to their concentration before oxidation (△[PFCA]/[PFCA]before oxidation) indicated obvious spatial variations in the seawater and STP effluents. The higher levels of △[PFCAC4-C12] and the lower ratios of ∑△[PFCAC4-C12]/∑[PFAA]before oxidation were observed in the STP effluents, which implied that precursors might be decomposed during the sewage treatment process. These results suggested the STP effluents might have an important effect on the PFAAs levels of seawater.

Alterations of the fatty acid composition and lipid metabolome of breast muscle in chickens exposed to dietary mixed edible oils.

The fatty acid composition of chicken's meat is largely influenced by dietary lipids, which are often used as supplements to increase dietary caloric density. The underlying key metabolites and pathways influenced by dietary oils remain poorly known in chickens. The objective of this study was to explore the underlying metabolic mechanisms of how diets supplemented with mixed or a single oil with distinct fatty acid composition influence the fatty acid profile in breast muscle of Qingyuan chickens. Birds were fed a corn-soybean meal diet supplemented with either soybean oil (control, CON) or equal amounts of mixed edible oils (MEO; soybean oil : lard : fish oil : coconut oil = 1 : 1 : 0.5 : 0.5) from 1 to 120 days of age. Growth performance and fatty acid composition of muscle lipids were analysed. LC-MS was applied to investigate the effects of CON v. MEO diets on lipid-related metabolites in the muscle of chickens at day 120. Compared with the CON diet, chickens fed the MEO diet had a lower feed conversion ratio (P < 0.05), higher proportions of lauric acid (C12:0), myristic acid (C14:0), palmitoleic acid (C16:1n-7), oleic acid (C18:1n-9), EPA (C20:5n-3) and DHA (C22:6n-3), and a lower linoleic acid (C18:2n-6) content in breast muscle (P < 0.05). Muscle metabolome profiling showed that the most differentially abundant metabolites are phospholipids, including phosphatidylcholines (PC) and phosphatidylethanolamines (PE), which enriched the glycerophospholipid metabolism (P < 0.05). These key differentially abundant metabolites - PC (14:0/20:4), PC (18:1/14:1), PC (18:0/14:1), PC (18:0/18:4), PC (20:0/18:4), PE (22:0/P-16:0), PE (24:0/20:5), PE (22:2/P-18:1), PE (24:0/18:4) - were closely associated with the contents of C12:0, C14:0, DHA and C18:2n-6 in muscle lipids (P < 0.05). The content of glutathione metabolite was higher with MEO than CON diet (P < 0.05). Based on these results, it can be concluded that the diet supplemented with MEO reduced the feed conversion ratio, enriched the content of n-3 fatty acids and modified the related metabolites (including PC, PE and glutathione) in breast muscle of chickens.

Effects of dietary lysine on productivity, reproductive performance, protein and lipid metabolism-related gene expression in laying duck breeders.

This study investigated whether dietary lysine (Lys) affects productive performance and expression of genes related to protein and lipid metabolism in laying duck breeders. Longyan duck breeders (n = 540, 19 wk of age) were randomly assigned to 6 groups with 6 replicates of 15 birds each. Breeders were fed diets with 6 total Lys levels (6.4, 7.2, 8.0, 8.8, 9.6, and 10.4 g/kg) for 26 wk duration. Egg production, egg weight, egg mass, feed conversion ratio, hatchability, hatchling weight, albumen weight, eggshell weight, yolk weight, and yolk proportion increased with dietary Lys levels (P < 0.05). Dietary Lys level had a linear (P < 0.05) and quadratic (P < 0.05) effects on maternal hepatic expression of mechanistic target of rapamycin, eukaryotic translation initiation factor 4E binding protein 1, ubiquitin conjugating enzyme E2K (UBE2K), cathepsin B (CTSB), and quadratically (P < 0.05) increased the concentrations of plasma Lys, leucine, threonine, and tryptophan in duck breeders. In contrast, maternal dietary Lys suppressed expression of proteasome 26S subunit, UBE2K, and CTSB in the liver of hatchlings. Moreover, relative expression of peroxisome proliferator-activated receptors alpha, carnitine palmitoyltransferase 1A, and very low density apolipoprotein-II increased linearly (P < 0.05) and quadratically (P < 0.05), and that of VLDL receptor (VLDLR) decreased quadratically (P < 0.05) in the liver of duck breeders with increasing dietary Lys levels; hepatic triglyceride and cholesterol contents were reduced. Maternal dietary Lys suppressed hepatic expression of VLDLR in the hatchlings. A diet containing 8.6 g Lys/kg promoted protein turnover and lipid metabolism in laying duck breeders, which positively reflected in the productivity and reproductive performance.

Sodium and chloride requirements of yellow-feathered chickens between 22 and 42 days of age.

Sodium and chloride are the key factors maintaining normal osmotic pressure (OSM) and volume of the extracellular fluid, and influencing the acid-base balance of body fluids. The experiment was conducted to investigate the effects of dietary Na+ and Cl- level on growth performance, excreta moisture, blood biochemical parameters, intestinal Na+-glucose transporter 1 (SGLT1) messenger RNA (mRNA), and Na+-H+ exchanger 2 (NHE2) mRNA, and to estimate the optimal dietary sodium and chlorine level for yellow-feathered chickens from 22 to 42days. A total of 900 22-day-old Lingnan yellow-feathered male chickens were randomly allotted to five treatments, each of which included six replicates of 30 chickens per floor pen. The basal control diet was based on corn and soybean meal (without added NaCl and NaHCO3). Treatments 2 to 5 consisted of the basal diet supplemented with equal weights of Na+ and Cl-, constituting 0.1%, 0.2%, 0.3% and 0.4% of the diets. Supplemental dietary Na+ and Cl- improved the growth performance (P<0.05). Average daily gain (ADG) showed a quadratic broken-line regression to increasing dietary Na+ and Cl- (R2=0.979, P<0.001), and reached a plateau at 0.1%. Supplemental Na+ and Cl- increased (P<0.05) serum Na+ and OSM in serum and showed a quadratic broken-line regression (R2=0.997, P=0.004) at 0.11%. However, supplemental Na+ and Cl- decreased (P<0.05) serum levels of K+, glucose (GLU) and triglyceride. Higher levels of Na+and Cl- decreased duodenal NHE2 transcripts (P<0.05), but had no effect on ileal SGLT1 transcripts. The activity of Na+ /K+-ATPase in the duodenum decreased (P<0.05) with higher levels of dietary Na+ and Cl-. In conclusion, the optimal dietary Na+ and Cl- requirements for yellow-feathered chickens in the grower phase, from 22 to 42 days of age, to optimize ADG, serum Na+, OSM, K+ and GLU were 0.10%, 0.11%, 0.11%,0.17% and 0.16%, respectively, by regression analysis.

Dietary curcumin enhances intestinal antioxidant capacity in ducklings via altering gene expression of antioxidant and key detoxification enzymes.

The study investigated the effects of dietary curcumin supplementation on tissue distribution of curcumin and its metabolites, intestinal antioxidant capacity, and expression of detoxification-related genes in ducks. A total of 720 one-day-old male Cherry Valley Pekin ducklings (initial BW 58.6 ± 0.1 g) were randomly assigned to 4 dietary groups each with 6 replicates of 30 ducks using a single factorial arrangement design. Ducks in the control group were fed a basal diet and the remainder were fed the basal diet supplemented with 200, 400, or 800 mg/kg curcumin. The experiment lasted for 21 D. Curcumin was present at 13.12 to 16.18 mg/g in the cecal digesta, 75.50 to 575.40 µg/g in jejunal mucosa, 35.10 to 73.65 µg/g in liver, and 7.02 to 7.88 µg/mL in plasma. The jejunal and hepatic contents of curcumin increased significantly (P < 0.05) in response to supplementation with 400 and 800 mg/kg of curcumin respectively, compared with 200 mg curcumin/kg group. There was a linear (P < 0.001) effect of dietary curcumin on relative abundance of SOD1, GPX1, CAT, HO-1, and Nrf2 transcripts, and a quadratic (P < 0.001) increase in the activities of GSH-Px and T-AOC in jejunal mucosa. The expression of CYP1A4, CYP2D17 increased and CYP1B1, CYP2A6 decreased linearly (P < 0.001) with dietary curcumin concentrations. In addition, dietary curcumin increased gene expression of GST, MRP6, and ABCB1 in jejunal mucosa. In conclusion, dietary supplementation with 200 to 800 mg/kg curcumin enhanced the accumulation of curcumin and its metabolites in jejunum as well as increasing the antioxidant capacity and detoxification potential, which play major roles in the protection of duck intestines against damage.

[Technical guidelines for seasonal influenza vaccination in China, 2018-2019].

Seasonal influenza vaccination is the most effective way to prevent influenza virus infection and its complications. Currently, China has licensed trivalent (IIV3) and quadrivalent inactivated influenza vaccine (IIV4), including split-virus influenza vaccine and subunit vaccine. In most parts of China, influenza vaccine is a category Ⅱ vaccine, which means influenza vaccination is voluntary, and recipients need to pay for it. To strengthen the technical guidance for prevention and control of influenza and the operational research on influenza vaccination in China, the National Immunization Advisory Committee (NIAC), Influenza Vaccine Technical Working Group (TWG), updated the 2014 technical guidelines and compiled the "Technical guidelines for seasonal influenza vaccination in China (2018-2019)" , based on most recent existing scientific evidences. The main updates include: epidemiology and disease burden of influenza, types of influenza vaccines, northern hemisphere influenza vaccination composition for the 2018-2019 season, and, IIV3 and IIV4 vaccines'major immune responses, durability of immunity, immunogenicity, vaccine efficacy, effectiveness, safety, cost-effectiveness and cost-benefit. The recommendations include: Points of Vaccination clinics (PoVs) should provide influenza vaccination to all persons aged 6 months and above who are willing to be vaccinated and do not have contraindications. No preferential recommendation is made for any influenza vaccine product for persons who can accept ≥1 licensed, recommended, and appropriate products. To decrease the risk of severe infections and complications due to influenza virus infection among high risk groups, the recommendations prioritize seasonal influenza vaccination for children aged 6-60 months, adults ≥60 years of age, persons with specific chronic diseases, healthcare workers, the family members and caregivers of infants <6 months of age, and pregnant women or women who plan to pregnant during the influenza season. Children aged 6 months to 8 years old require 2 doses of influenza vaccine administered a minimum of 4 weeks apart during their first season of vaccination for optimal protection. If they were vaccinated in previous influenza season, 1 dose is recommended. People ≥ 9 years old require 1 dose of influenza vaccine. It is recommended that people receive their influenza vaccination by the end of October. Influenza vaccination should be offered as soon as the vaccination is available. Influenza vaccination should continue to be available for those unable to be vaccinated before the end of October during the whole season. Influenza vaccine is also recommended for use in pregnant women during any trimester. These guidelines are intended for CDC members who are working on influenza control and prevention, PoVs members, healthcare workers from the departments of pediatrics, internal medicine, and infectious diseases, and members of maternity and child care institutions at all levels.

[Technical guidelines for seasonal influenza vaccination in China (2018-2019)].

Seasonal influenza vaccination is the most effective way to prevent influenza virus infection and complications from infection. Currently, China has licensed trivalent inactivated influenza vaccine (IIV3) and quadrivalent inactivated influenza vaccine (IIV4), including split-virus influenza vaccine and subunit vaccine. Except for a few major cities, influenza vaccine is a category Ⅱ vaccine, which means influenza vaccination is voluntary, and recipients must pay for it. To strengthen the technical guidance for prevention and control of influenza and operational research on influenza vaccination in China, the National Immunization Advisory Committee (NIAC) Influenza Vaccine Technical Working Group (TWG), updated the 2014 technical guidelines and compiled the "Technical guidelines for seasonal influenza vaccination in China (2018-2019)" . The main updates in this version include: epidemiology, disease burden, types of influenza vaccines, northern hemisphere influenza vaccination composition for the 2018-2019 season, IIV3 and IIV4 immune response, durability of immunity, immunogenicity, vaccine efficacy, effectiveness, safety, cost-effectiveness and cost-benefit. The influenza vaccine TWG provided the recommendations for influenza vaccination for the 2018-2019 influenza season based on existing scientific evidence. The recommendations described in this report include the following: Points of Vaccination clinics (PoVs) should provide influenza vaccination to all persons aged 6 months and above who are willing to be vaccinated and do not have contraindications. No preferential recommendation is made for one influenza vaccine product over another for persons for whom more than one licensed, recommended, and appropriate product is available. To decrease the risk of severe infections and complications due to influenza virus infection among high risk groups, the recommendations prioritize seasonal influenza vaccination for children aged 6-59 months, adults ≥60 years of age, persons with specific chronic diseases, healthcare workers, the family members and caregivers of infants <6 months of age, and pregnant women or women who plan to become pregnant during the influenza season. Children aged 6 months through 8 years require 2 doses of influenza vaccine administered a minimum of 4 weeks apart during their first season of vaccination for optimal protection. If they were vaccinated in 2017-2018 influenza season or a prior season, 1 dose is recommended. People more than 8 years old require 1 dose of influenza vaccine. It is recommended that people receive their influenza vaccination by the end of October. Influenza vaccination should be offered as soon as the vaccination is available. For the people unable to be vaccinated before the end of October, influenza vaccination will continue to be offered for the whole season. Influenza vaccine is also recommended for use in pregnant women during any trimester. These guidelines are intended for use by staff members of the Centers for Disease Control and Prevention at all levels who work on influenza control and prevention, PoVs staff members, healthcare workers from the departments of pediatrics, internal medicine, and infectious diseases, and staff members of maternity and child care institutions at all levels.

[Current situation and related policies on the implementation and promotion of influenza vaccination, in China].

Influenza can be prevented through annual appropriate vaccination against the virus concerned. In China, influenza vaccine is categorized as "Class Ⅱ" infectious diseases which the cost is paid out of the user's pockets. The annual coverage of influenza vaccination had been 2%-3%. The main reasons for the low coverage would include the following factors: lacking awareness on both the disease and vaccine, poor accessibility of vaccination service, and the cost of vaccination. To reduce the health and economic burden associated with influenza, comprehensive policies should be improved, targeting the coverage of seasonal influenza vaccination. These items would include: ① Different financing reimbursement schemes and mechanisms to improve the aspiration on vaccination and on the vaccine coverage in high-risk groups, as young children, elderly, people with underlying medical conditions; ② to ameliorate equality of vaccination services; ③ to improve knowledge of the health care workers (HCWs) and the public on influenza and related vaccines; ④ to improve clinical and preventive medical practice and vaccination among HCWs through revising clinical guidelines, pathway and consensus of experts; ⑤ to provide more convenient, accessible and normative vaccination service system; ⑥ to strengthen research and development as well as marketing on novel influenza vaccines; ⑦ to revise items regarding the contraindication for influenza vaccine on pregnancy women, stated in the Chinese Pharmacopoeia.

Effects of oxidative stress induced by high dosage of dietary iron ingested on intestinal damage and caecal microbiota in Chinese Yellow broilers.

The objective of this trial was to test the effects of oxidative stress induced by a high dosage of dietary iron on intestinal lesion and the microbiological compositions in caecum in Chinese Yellow broilers. A total of 450 1-day-old male chicks were randomly allotted into three groups. Supplemental iron (0, 700 and 1,400 mg/kg) was added to the basal diet resulting in three treatments containing 245, 908 and 1,651 mg/kg Fe (measured value) in diet respectively. Each treatment consisted of six replicate pens with 25 birds per pen. Jejunal enterocyte ultrastructure was observed by transmission electron microscopy. The results showed that a high dosage of dietary iron induced oxidative stress in broilers. Dilated endoplasmic reticulum (ER), autophagosome formation of jejunal enterocytes and decreased villi were caused by this oxidative stress. Compared to the control, concentration of the malondialdehyde (MDA) in jejunal mucosa in the 908 and 1,651 mg/kg Fe groups increased by 180% (p < .01) and 155% respectively (p < .01); activity of copper-zinc superoxide dismutase (Cu/ZnSOD) increased in jejunum (p < .01); and the concentration of plasma reduced glutathione (GSH) decreased by 34.9% (p < .01) in birds fed 1,651 mg/kg Fe. Gene expression of nuclear factor, erythroid-derived 2-like 2 (Nrf2) and zonula occludens-1 (ZO-1), in the higher dietary Fe groups was enhanced (p < .05). Species of microbial flora in caecum increased caused by oxidative stress. The PCR-DGGE (denaturing gradient gel electrophoresis) dendrograms revealed different microbiota (65% similarity coefficient) between the control and iron-supplemented groups (p < .05). These data suggest high dosage of iron supplement in feed diet can induce oxidative stress in Chinese Yellow broilers, and composition of microbiota in the caecum changed. It implied there should be no addition of excess iron when formulating diets in Chinese Yellow broilers.

Effects of dietary tryptophan levels on performance and biochemical variables of plasma and intestinal mucosa in yellow-feathered broiler breeders.

The effects of dietary tryptophan (Trp) levels on performance and biochemical variables of plasma and intestinal mucosa in broiler breeder hens were investigated in this study. A total of 780 Lingnan yellow-feathered broiler breeder hens were randomly assigned in one of five dietary treatments with six replicates per treatment (26 birds per replicate). The breeder hens were fed either the basal diet (0.11% Trp) or the basal diet supplemented to 0.15%, 0.19%, 0.23% and 0.27% Trp, from 197 to 259 days of age. Graded levels of Trp from 0.11% to 0.27% in the diet produced quadratic (p < .05) responses in laying rate, average daily egg production, and feed conversion ratio, and quadratic (p < .01) responses in total large follicle weight and average large follicle weight. An increase in fertilization rate of total eggs was observed in breeders fed 0.27% Trp, and hatchability was higher in breeders fed 0.23% and 0.27% Trp than with 0.19% Trp (p < .05). The content of uric acid N decreased with 0.15% and 0.23% dietary Trp (p < .05). The content of GSH and the GSH-to-GSSG ratio in plasma were reduced by 0.15%, 0.19% and 0.27% Trp diets (p < .05). A higher activity of GST in plasma was observed with 0.15% Trp in relation to 0.23% and 0.27% Trp (p < .05). The activity of Na+ -K+ -ATPase of plasma in birds fed 0.27% Trp was lower than in those fed 0.15% Trp and the control birds (p < .05). There were significant influences of dietary Trp levels on S6K1, B0 AT1, Nrf2, TLR4, TNF-α and IL-6 transcripts of ileal mucosa (p < .05). The optimal dietary Trp level was 0.203% or 254 mg per hen per day, for Chinese yellow-feathered broiler breeder hens aged from 197 to 259 days.