[Clinical features and Y chromosome abnormalities in children with 45, X/46, XY mosaicism].

Objective: To investigate the clinical and genetic characteristics of children with 45, X/46, XY mosaicism. Methods: The retrospective study included 20 children diagnosed with 45, X/46, XY and 45, X/46, X,+mar mosaicism in the First Affiliated Hospital of Zhengzhou University from 2018 to 2022. The clinical features, gonadal pathology, treatment and follow-up were summarized. Genetic tests were performed by SRY gene test, azoospermia factor region (AZF) deletion test, copy number variation-sequencing (CNV-seq). Age at first diagnosis was compared between boys and girls using independent sample t-test. Results: The 20 patients included 3 boys and 17 girls, and the age at first diagnosis were (7.6±5.5) years, it is (2.1±1.9) years in boys, (8.7±5.4) years in girls, significantly younger for boys (t=-3.86, P=0.004). The chief complaint was external genitalia malformation for boys, and short stature (13 cases) and dysplastic external genital for girls (4 cases). Five girls presented with features of Turner syndrome. The gonadal phenotypes included mixed gonadal dysplasia (MGD, 6 cases), complete gonadal dysplasia (CGD, 10 cases), unilateral ovotestis (2 cases), possible ovaries (1 case) and undetermined gonad (1 case). One female with dysplastic genital was reassigned to male, and the gender of the remaining cases remained unchanged. Seven females were treated with recombinant human growth hormone. The height increased by (17±7) cm during the (2.9±1.2) years follow-up. No gonadal malignancy was observed. The karyotype was 45, X/46, XY in 16 cases, and 45, X/46, X,+mar in 4 cases. All of the 4 marker chromosomes were derived from Y chromosome confirmed by CNV-seq. SRY gene was detected in all 20 patients genome, and AZF deletion was found in 7 girls. Conclusions: 45, X/46, XY mosaicism presented with dysplastic external genital or female with remarkable short stature. Gonadal phenotypes included MGD, CGD and ovotestis. AZF microdeletions were found in the majority of female cases.

[miR-148b inhibits M2 polarization of LPS-stimulated macrophages by targeting DcR3].

Objective: To investigate the effect of microRNA (miR-148b) targeting decoy receptor 3 (DcR3) on macrophage polarization in sepsis. Methods: Experimental study. From December 2019 to December 2022, serum microRNA expression was detected in 3 patients with sepsis and 3 healthy controls in the clinical laboratory of Songjiang Hospital Affiliated to Shanghai Jiao Tong University School of Medicine. Phorbol 12-myristate 13-acetate (PMA) was used to induce the differentiation of human acute monocytic leukemia cells THP-1 into macrophages, and then lipopolysaccharide (LPS) was added to stimulate the establishment of a sepsis cell model, and the expression changes of miR-148b and DcR3 were detected by RT-PCR and Western blot. Overexpression of DcR3 was used to detect the expression levels of TNF-α, CD163 and IL-10 in macrophages stimulated by LPS (100 ng/ml). Overexpression of miR-148b was used to observe the changes of molecular markers of macrophage polarization. The targeting regulation effect of miR-148b on DcR3 was determined by dual-luciferase reporter assay. t test was used to analyze whether there were statistical differences among the groups. Results: The expression of miR-148b was down-regulated (P<0.05) and the expression of DcR3 was up-regulated (P<0.01) in THP-1 macrophages stimulated by LPS. Overexpression of DcR3 inhibited the expression of TNF-α (P<0.05) and promoted the expression of CD163 (P<0.01) and IL-10 (P<0.01). When miR-148b mimics was added, the opposite effect was observed. The dual-luciferase reporter assay confirmed that miR-148b targets and binds to DcR3, inhibiting its transcription and expression. The results of flow cytometry showed that DcR3 could reverse the promoting effect of miR-148b on the CD86/CD163 ratio of macrophages (P<0.05). Conclusion: miR-148b inhibits the expression of DcR3, thereby inhibiting M2 polarization in LPS-stimulated macrophage cells.

[Research progress on the relationship between COVID-19 and autoimmune diseases].

Different autoantibodies can be detected in patients with coronavirus disease 2019 (COVID-19). It is reported that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection could induce autoimmune diseases (AID), including children's multisystem inflammatory syndrome (MIS-C), Guillain Barre syndrome (GBS), Autoimmune hemolytic anemia (AIHA), immune thrombocytopenia (ITP) and thyroid autoimmune diseases. This article mainly reviews the similarities between COVID-19 and AID, the possibility of COVID-19 inducing AID, the risk of AID patients infected or vaccinated against COVID-19. The purpose is to provide strategies for the prevention, management and treatment of AID during the epidemic.

[Clinical and genetic characteristic in patients with disorders of sex development caused by Y chromosome copy number variant].

Objective: To investigate the clinical phenotype and genetic characteristics of disorders of sex development (DSD) caused by Y chromosome copy number variant (CNV). Methods: A retrospective analysis was performed on 3 patients diagnosed with DSD caused by Y chromosome CNV admitted to the First Affiliated Hospital of Zhengzhou University from January, 2018 to September, 2022. Clinical data were collected. Clinical study and genetic test were performed by karyotyping, whole exome sequencing (WES), low coverage whole genome copy number variant sequencing (CNV-seq), fluorescence in situ hybridization (FISH) and gonadal biopsy. Results: The 3 children, aged 12, 9, 9 years, the social gender were all female, presented with short stature, gonadal dysplasia and normal female external genital. No other phenotypic abnormality was found except for case 1 with scoliosis. The karyotype of all cases were identified as 46, XY. No pathogenic vraiants were found by WES. CNV-seq determined that case 1 was 47, XYY,+Y(2.12) and case 2 was 46, XY,+Y(1.6). FISH concluded that the long arm of Y chromosome was broken and recombined near Yq11.2, and then produced a pseudodicentric chromosome idic(Y). The karyotype was reinterpreted as mos 47, X, idic(Y)(q11.23)×2(10)/46, X, idic(Y)(q11.23)(50) in case 1. The karyotype was redefined as 45, XO(6)/46, X, idic(Y)(q11.22)(23)/46, X, del(Y)(q11.22)(1) in case 2. 46, XY, -Y(mos) was found by CNV-seq in case 3, and the karyotype of 45, XO/46, XY was speculated. Conclusions: The clinical manifestations of children with DSD caused by Y chromosome CNV are short stature and gonadal dysgenesis. If there is an increase of Y chromosome CNV detected by CNV-seq, FISH is recommended to classify the structural variation of Y chromosome.

[Research progress on antibody-dependent enhancement in infectious diseases].

Antibody-dependent enhancement (ADE) refers to the process in which some virus-specific antibodies (generally non-neutralizing antibodies) bind to the virus and bind to some cells expressing FcR on the surface through their Fc segment, thereby mediating the endocytosis and replication of the virus and enhancing the infection of the virus. This review summarized experience of ADE in respiratory syncytial virus, dengue virus, influenza virus infection and explored the possible mechanism of COVID-19 high incidence and severity of the disease, which implied challenges in the process of vaccine development and provided some insights for COVID-19 pathogenesis.

Effects of full-fat rice bran inclusion in diets on growth performance and meat quality of Sichuan goose.

This trial was conducted to study the effect of full-fat rice bran inclusion in diets on growth performance, carcass and meat quality and fatty acid composition in Sichuan goose. A total of 204 Sichuan white male geese (28-d-old, 984 ± 15 g) were used in the 42-d assay. Full-fat rice bran inclusion in diets was 0%, 6%, 12% and 18%, respectively. On d 70, two geese from each pen were randomly selected and killed for measuring the carcass and meat quality and the meat fatty acid composition. The results showed that full-fat rice bran inclusion had no effect on average daily gain during 28-56 d, but rice bran inclusion at 18% increased average daily gain during 57-70 d. In addition, the full-fat rice bran supplementation decreased the subcutaneous fat yield, and the inclusion of full-fat rice bran in amounts of 12% and 18% decreased the half-eviscerated carcass yield, eviscerated carcass yield and crude fat content in goose meat. Moreover, full-fat rice bran supplementation had no effect on the content of total saturated fatty acid (SFA), but decreased the content of total monounsaturated fatty acid (MUFA). The inclusion of full-fat rice bran in amounts of 12-18% increased the content of total polyunsaturated fatty acid (PUFA) and total n-6 in goose meat and in the amount of 18% increased n-3 fatty acids content in goose meat. The results indicated that the rice bran inclusion had a positive effect in geese by stimulating growth performance and improving meat quality and fatty acid composition of goose meat.

Technical note: Isolation and characterization of porcine mammary epithelial cells.

Within the mammary gland, functional synthesis of milk is performed by its epithelial (alveolar) cells. The availability of a stable mammary epithelial cell line is essential for biochemical studies to elucidate cellular and molecular mechanisms responsible for nutritional regulation of lactation. Therefore, porcine mammary epithelial cells (PMEC) were isolated from mammary glands of a 9-mo-old nonpregnant and nonlactating gilt and cultured to establish a nonimmortalized cell line. These cells were characterized by expression of cytokeratin-18 (an intermediate filament specific for epithelial cells), ß-casein (a specific marker for mammary epithelial cells), and α-lactalbumin. In culture, the PMEC doubled in number every 24 h and maintained a cobblestone morphology, typical for cultured epithelial cells, for at least 15 passages. Addition of 0.2 to 2 µg/mL prolactin to culture medium for 3 d induced the production of ß-casein and α-lactalbumin by PMEC in a dose-dependent manner. Thus, we have successfully developed a useful PMEC line for future studies of cellular and molecular regulation of milk synthesis by mammary epithelial cells of the sow.

Effect of low dosage of chito-oligosaccharide supplementation on intestinal morphology, immune response, antioxidant capacity, and barrier function in weaned piglets.

This study was conducted to determine the effect of dietary supplementation of a low dose of chito-oligosaccharide (COS) on intestinal morphology, immune response, antioxidant capacity, and barrier function in weaned piglets. A total of 120 weaned pigs (21 d of age; 7.86 ± 0.22 kg average BW) were randomly assigned (6 pens/diet; 10 pigs/pen) to 2 dietary treatments consisting of a basal diet (negative control) or the basal diet supplemented with COS (30 mg/kg) for a 14-d period. Six randomly selected piglets from each treatment were killed for blood and tissue sampling. No significant differences were observed in ADG, ADFI, and G:F between treatment and the control group. Piglets fed the COS-supplemented diet had greater ( < 0.05) stomach pH than those fed the control diet on d 14 postweaning. Dietary supplementation with COS reduced villus height ( < 0.05) and villus height:crypt depth ( < 0.05) in the ileum. Dietary COS supplementation tended to reduce villus height in the duodenum ( = 0.065) and jejunum ( = 0.058). There was no effect on crypt depth in the intestinal segments of treatment group. Piglets fed the COS-supplemented diet increased ( < 0.05) the number of intraepithelial lymphocytes in duodenum or jejunum and goblet cells of ileum. However, COS decreased ( < 0.05) the number of intraepithelial lymphocytes in ileum of weaned piglets. The concentrations of IL-10 (duodenum, jejunum, and ileum) and secretory immunoglobulin (SIgA; duodenum and ileum) were higher in piglets fed the COS-supplemented diet compared with control ( < 0.05). Dietary COS supplementation reduced ( < 0.05) the concentration of total antioxidant capacity and superoxide dismutase of the jejunum or ileum. The mRNA expression of occludin in the ileum and ZO-1 in jejunum and ileum had a significant change in piglets fed the COS-supplemented diet compared with the control group ( < 0.05). In conclusion, these results indicated that dietary COS supplementation at 30 mg/kg had no effects on promoting growth performance and tended to reduce villus height in the duodenum or jejunum of weaned piglets. The results further showed that supplemental COS at this level may cause an immune and oxidative stress response in small intestine and have compromised the intestinal barrier integrity in weaned piglets. The research will provide guidance on the low dosage of COS supplementation on weaning pigs.

Metabolic profiles in the response to supplementation with composite antimicrobial peptides in piglets challenged with deoxynivalenol.

Deoxynivalenol (DON) causes various toxic effects in human and animals. However, our previous studies have shown that composite antimicrobial peptides (CAP) can have a protective effect in piglets challenged with DON. This study was conducted to evaluate the effect of the CAP GLAM 180# on the metabolism of piglets challenged with DON using a nuclear magnetic resonance (NMR)-based metabolomics approach. A total of 28 individually housed piglets (Duroc × Landrace × Large Yorkshire) weaned at 28 d of age were randomly assigned into 4 treatment groups (7 pigs/treatment) based on a 2 × 2 factorial arrangement that were fed, respectively, a basal diet (NC), basal diet + 0.4% CAP (basal + CAP), basal diet + 4 mg/kg DON (basal + DON), and basal diet + 4 mg/kg DON + 0.4% CAP (DON + CAP). A 7-d adaptation period was followed by 30 d of treatment. Blood samples were then collected for metabolite analysis by proton NMR (H-NMR) spectroscopy and liquid chromatography tandem mass spectrometry (LC-MS/MS). The combined results of H-NMR spectroscopy and LC-MS/MS showed that DON increased ( < 0.05) the serum concentrations of low-density lipoprotein, glycoprotein, urea, trimethylamine-N-oxide (TMAO), and lactate as well as those of almost all essential AA and some nonessential AA but decreased the concentrations of high-density lipoprotein (HDL), unsaturated lipids, citrate, choline, and fumarate compared with those in NC treatment ( < 0.05). There was a significant interaction effect ( < 0.05) of supplementation with DON and CAP on some metabolites showed that the serum concentrations of HDL, unsaturated lipids, Pro, citrate, and fumarate were greater ( < 0.05) whereas those of glycoprotein, urea, TMAO, Gly, and lactate were lower in the DON + CAP treatment compared with those in the basal + DON treatment ( < 0.05). These findings indicated that DON causes disturbances in AA, lipid, and energy metabolism and that CAP could partially attenuate the above metabolic disturbances induced by DON.

Technical note: Isolation and characterization of ovine brown adipocyte precursor cells.

Brown adipose tissue (BAT) plays a critical role in regulating body temperature in newborn lambs. Availability of a stable BAT cell line would be invaluable for biochemical studies to elucidate cellular and molecular mechanisms responsible for nutritional regulation of fetal BAT growth and development. Ovine brown adipocyte precursor cells (BAPC) were isolated from fetal lambs at d 90 of gestation and cultured to establish a stable cell line. These cells were characterized by adipogenic differentiation and expression of a hallmark gene, (). The BAPC doubled every 24 h. After a 9-d induction with a serum-free Dulbecco's modified Eagle Ham/F12 medium, BAPC differentiated into brown adipocytes with large lipid droplets. The differentiation medium induced expression of mRNA and protein in BAPC. Furthermore, after BAPC were passaged 30 times, they maintained similar cell morphology, the potential for adipogenic differentiation, and the ability to express . Taken together, we have established a stable ovine BAPC cell line for studying nutritional regulation of BAT growth and development in the fetus.

The effects of enzyme supplementation on performance and digestive parameters of broilers fed corn-soybean diets.

The study was performed to evaluate the effects of enzyme supplementation on performance and digestive parameters of broilers fed corn-soybean diets from 1 to 21 d of age. A total of 480 one-day-old Cobb broilers were allocated to 1 of 4 treatments, with 6 replicate pens per treatment and 20 birds per pen. The experiment consisted of a 2 × 2 factorial arrangement of treatments with 2 dietary ME levels (high ME, energy 1, 12.13 MJ/kg or low ME, energy 2, 11.92 MJ/kg) and 2 levels of supplemental enzyme (including xylanase, 1,800 IU/g, ß-glucanase, 500 IU/g, and α-amylase, 800 U/g; 0 or 0.1% of diet). Enzyme supplementation had no effect on average daily weight gain, feed intake, and feed:gain. However, enzyme supplementation decreased the relative weight of the pancreas (d 7 and 21) in broilers fed the high ME diet. Low dietary ME level increased pancreatic lipase (d 7, P = 0.015), trypsin (d 14, P = 0.01; d 21, P = 0.014), amylase (d 21, P = 0.027), and pepsin (d 7, P = 0.001; d 21, P = 0.042) activity, but reduced pancreatic lipase (d 14, P = 0.03; d 21, P = 0.004) and amylase (d 14, P = 0.027) activity. Enzyme supplementation resulted in an increase in pancreatic amylase (d 7, P = 0.023), trypsin (d 7, P = 0.02; d 21, P = 0.004), lipase (d 21, P = 0.001), pepsin (d 7, P = 0.001; d 14, P = 0.004; d 21, P = 0.001), and maltase (d 14, P = 0.011, in ileum) activity. Moreover, broilers fed low dietary ME and enzyme supplementation diets had an increase in pancreatic lipase (d 21, P = 0.001) and pepsin (d 7, P = 0.001) activity. Low ME diets reduced jejunum villus height and jejunum and ileum crypt depth (d 7, 21). However, enzyme supplementation, especially enzyme supplementation in low ME diets, increased jejunum and ileum villus height and villus surface area. This suggested enzyme supplemented with low ME diet might be more effective to improve the activity of digestive enzymes and the absorptive capacity of the small intestine.

Effects of Enzyme Complex Supplementation to a Paddy-based Diet on Performance and Nutrient Digestibility of Meat-type Ducks.

Paddy rice is rarely used as a feed because of its high fiber content. In this study, two experiments were conducted to study the effects of supplementing an enzyme complex consisting of xylanase, beta-glucanase and cellulase, to paddy-based diets on the performance and nutrient digestibility in meat-type ducks. In the both experiments, meat-type ducks (Cherry Valley) were randomly assigned to four treatments. Treatment 1 was a basal diet of corn-soybean; treatment 2 was a basal diet of corn-paddy-soybean; treatment 3, had enzyme complex added to the corn-paddy-soybean basal diet at levels of 0.5 g/kg diet; and treatment 4, had enzyme complex added to the corn-paddy-soybean diet at levels of 1.0 g/kg diet. The results showed that the enzyme complex increased the ADG, and decreased the ADFI and F/G significantly (p<0.05) in the ducks, and the ADFI for the ducks fed the corn-paddy-soybean diet showed no difference compared to the ducks fed corn-soybean diets at all stages of the experiment (p<0.05). When corn was partially replaced by paddy, the digestibility of CP and NDF was decreased and increased, respectively (p<0.05), and the level of enzyme complex had a significant effect on both CP and NDF digestibility (p<0.05). As for the AME, addition of enzyme complex increased it significantly (p<0.05), but both diet types and levels of enzyme complex had no effect (p>0.05). The outcome of this research indicates that the application of enzyme complex made up of xylanase, beta-glucanase, and cellulase, in the corn-paddy-soybean diet, can improve performance and nutrition digestibility in meat-type ducks.

Effect of L-arginine on intestinal mucosal immune barrier function in weaned pigs after Escherichia coli LPS challenge.

The effects of l-arginine (Arg) supplementation on intestinal mucosal immune barrier function in weaned pigs after Escherichia coli LPS challenge were evaluated. Twenty-four weaned pigs were allotted to four treatments including: (i) non-challenged control; (ii) LPS-challenged control; (iii) LPS + 0.5% Arg; and (iv) LPS + 1.0% Arg. On d 16, pigs in the LPS, LPS + 0.5% Arg and LPS + 1.0% Arg groups were challenged by injection with 100 µg/kg of body mass LPS, whereas the control group were given sterile saline. At 48 h post-challenge, all pigs were sacrificed for evaluation of small intestinal morphology and mucosal immune barrier function. In the jejunum and ileum, LPS caused villous atrophy and intestinal morphology disruption, whereas 0.5% or 1.0% Arg supplementation mitigated villus atrophy and intestinal morphology impairment caused by LPS challenge. Arg (0.5%) supplementation increased the numbers of IgA-secreting cells, CD8(+) and CD4(+) T cells in the ileum (P < 0.05). Arg supplementation prevented the elevation of mast cell numbers induced by LPS challenge (P < 0.05). Dietary supplementation of Arg caused a decreased lymphocyte apoptosis of Peyer's patches in pigs challenged by LPS (P < 0.05). These results indicated that Arg supplementation protects and enhances intestinal mucosal immune barrier function and maintains intestinal integrity in weaned pigs after E. coli LPS challenge.

Isolation and characterization of tetranucleotide repeat polymorphic microsatellite loci in Larus saundersi (Aves, Laridae).

Nine polymorphic microsatellite loci were isolated, using tetranucleotide repeat oligonucleotide probes from an enriched DNA library of the globally "vulnerable" Saunders's gull (Larus saundersi), collected from the Yancheng coastal wetland, one of the three remaining breeding sites in China. Six breast muscle tissues and 16 blood samples from 22 gulls and eight eggshell membrane tissues were collected for this analysis. The number of alleles per locus ranged from 4 to 15, with a mean of 8.9. The observed and expected heterozygosities ranged from 0.58 to 0.89 and 0.58 to 0.9, with means of 0.77 and 0.81, respectively. No significant linkage disequilibrium and no divergence from Hardy-Weinberg equilibrium were detected among these loci. Based on Micro-Checker tests, no null alleles are present at any of the loci. The microsatellite loci described here will be valuable for exploring population genetic structure and for other relevant genetic studies of Saunders's gull.

Effect of three mycotoxin adsorbents on growth performance, nutrient retention and meat quality in broilers fed on mould-contaminated feed.

1. A study was conducted to investigate the effects of an esterified glucomannan (EGM), a hydrated sodium calcium aluminosilicate (HSCAS) and a compound mycotoxin adsorbent (CMA) on performance, nutrient retention and meat quality in broilers fed on mould-contaminated feed. Mould-contaminated diets were prepared by replacing half of the non-contaminated maize in the basal diets with mould-contaminated maize, which contained 450·6 µg/kg of aflatoxin B1, 68·4 µg/kg of ochratoxin A and 320·5 µg/kg of T-2 toxin. 2. The mould-contaminated diet significantly decreased body weight gain (BWG) between 10 and 21 d, feed intake (FI) between 35 and 42 d, the apparent retention of crude lipid and phosphorus, and the lightness (L*) value of breast and thigh muscle. It also significantly increased the redness (a*) and yellowness (b*) value in breast muscle and the b* value in thigh muscle. 3. The addition of 0·2% HSCAS significantly increased FI between 35 and 42 d and the apparent retention of phosphorus. Supplementation with 0·1% CMA in the contaminated diet significantly improved BWG from 10 to 21 d, and increased FI from 35 to 42 d and from 10 to 42 d. CMA also significantly increased the apparent retention of crude lipid, crude protein, ash and phosphorus. All three mycotoxin-adsorbent treatments significantly improved the L* values of breast and thigh muscle when compared with the mould-contaminated group. Supplementation with 0·1% CMA in the contaminated diet significantly decreased b* value and improved tenderness in thigh muscle. 0·05% EGM significantly decreased b* value of thigh muscle compared to mould-contaminated group. 4. The results indicated that mycotoxins in contaminated feed retard growth, nutrient retention and meat quality, whereas the addition of 0·05% EGM, 0·2% HSCAS or 0·1% CMA prevents the adverse effects of mycotoxins to varying extents, with 0·1% CMA being the most effective adsorbent treatment.

Dietary protein, energy and arginine affect LAT1 expression in forebrain white matter differently.

L-type amino acid transporter-1 (LAT1) transports large, branched-chain, aromatic and neutral amino acids. About 64 Duroc × Landrace × Yorkshire pigs were used to study the effects of dietary crude protein (CP), energy and arginine on LAT1 expression in forebrain. The results showed that LAT1 expression in forebrain was sensitive to different levels of CP, energy and arginine. On the basis of Western blot analysis, a lower level of LAT1 presented in the brain tissues of pigs fed the low dietary CP diet (P < 0.05), a higher level were found in pigs fed the higher CP diet, with moderate to intense staining seen in pigs fed the diet plus 1% arginine. In contrast, pigs fed the control-energy diet had weak LAT1 expression, and those fed the diet supplemented with 1% arginine showed lowest LAT1 expression (P < 0.05). These results showed that LAT1 was highly expressed in the forebrain, and expression of LAT1 was affected by dietary protein, energy and arginine differently.

Dietary L-arginine supplementation alleviates immunosuppression induced by cyclophosphamide in weaned pigs.

A study was conducted to investigate the effects of L-arginine (Arg) on performance and immune function in cyclophosphamide (CY) immunosuppressed weaned pigs. The weaned pigs were allotted randomly into one of three treatments, including: (1) non-challenged control; (2) CY-challenged group; and (3) CY + 0.5% Arg. On days 14 and 21 of the trial, pigs were injected with CY or sterile saline. Blood samples were obtained on days 21 and 28 of the trial for further analysis. On day 28, delayed-type hypersensitivity reaction was evaluated. Arg alleviated the decrease of average daily gain (P < 0.05) induced by CY challenge from days 21 to 28. Arg mitigated the CY-induced decrease of total white blood cell numbers (P < 0.05) on day 28 and improved the lymphocyte percentage on day 21 (P < 0.05). Arg increased the delayed-type hypersensitivity reaction (P < 0.05), and attenuated the decrease of bovine serum albumin antibody level caused by CY treatment (P < 0.05) on day 28. In addition, Arg elevated the levels of serum interleukin-2 and interferon-gamma (P < 0.05) on day 28, and mitigated the decrease of serum interferon-gamma level on day 21 (P < 0.05). These results indicate that Arg supplementation has beneficial effects in attenuating the immunosuppressive effects of CY challenge, therefore improving growth performance of young pigs.

Impact of feeding 2-hydroxy-4-(methylthio)butanoic acid and DL-methionine supplemented maize-soybean-rapeseed meal diets on growth performance and carcase quality of broilers.

1. This experiment was conducted to compare the effectiveness of DL-2-hydroxy-4-(methylthio)butanoic acid (HMTBA) and DL-methionine (DLM) on growth performance and carcase quality of broilers in a 2 x 3 x 2 factorial experimental design including two methionine (Met) sources, three equimolar levels of Met supplementation and two sexes. 2. No difference was observed between the two Met sources in growth performance and muscle deposition from 10 to 49 d. With increasing Met levels, average daily gain was increased in the starter, grower and overall phases, average daily feed intake was increased in the starter phase, and feed:gain ratio was decreased in the grower and overall phases. Met supplementation increased breast muscle content and decreased abdominal fat content. Broilers given HMTBA had breast and thigh muscle coloration that was characterised as superior to those fed DLM. 3. These results indicated that Met supplementation improved growth performance and carcase quality irrespective of the Met sources. Compared to DLM, HMTBA has the same molar bioefficacy for improving the growth performance and carcase quality; however, HMTBA-fed birds had superior meat colour to DLM-fed birds.

Seroprevalance and identification of influenza A virus infection from migratory wild waterfowl in China (2004-2005).

Outbreaks of a highly pathogenic avian influenza (H5N1) were reported in birds in more than eight Asian countries. We sought to identify the origin of this infection, and herein report the results of serological and virological monitoring of migrant wild waterfowl in mainland China. From a total of 493 serum samples, collected from 15 migratory wild waterfowl species for 9 months (from June 2004 to May 2005) in mainland China, we detected only low-level antibodies against influenza subtypes H2, H9 and H10 in the relict gull, little egret, black-crowned night heron, bar-tailed godwit, whimbrel and the common greenshank. No virus was identified from the 1052 cloacal and oropharyngeal swabs except dead bar-headed geese. These data show that the influenza type A virus subtypes H2-H13 did not circulate at detectable levels within the sampled population.