The characterization of optimal selenized garlic polysaccharides and its immune and antioxidant activity in chickens.

The purpose of this study was to optimize modification conditions of selenized garlic polysaccharides (sGPS) and investigate its structural characterization, immune and antioxidant activities. Herein, selenized garlic polysaccharides (sGPS) were prepared using by HNO3-Na2SeO3 selenylation method. And then modification conditions of sGPS were optimized through L9 (34) orthogonal test. The structural characterization of sGPS were identified by the Fourier-transform infrared (FT-IR), Solid-State nuclear magnetic resonance (NMR) spectra, X-ray diffraction (XRD) and thermogravimetric (TGA). The morphology of sGPS was detected using scanning electron microscope (SEM) and transmission electron microscope (TEM). In vivo investigation showed that sGPS significantly improved serum hemagglutination-inhibition (HI) antibody titers against Newcastle disease virus, enhanced secretory IgA (sIgA), IFN-γ, IL-2 secretion in jejunum and trachea irrigation compared with vaccine immunized control group. Furthermore, it showed that sGPS had some effects on the antioxidant activities in livers of chickens. In conclusion, the optimal modification conditions of sGPS were as follows: reaction temperature was 70 °C, the dosage of Na2SeO3 was 400 mg and reaction time was 6 h. The selenylation modification of garlic polysaccharides (GPS) could improve its immune and antioxidant activity in chickens.

Characterization of immunological properties of chicken chemokine CC motif ligand 5 using new monoclonal antibodies.

CCL5 (formerly RANTES) belongs to the CC (or ß) chemokine family and is associated with a plethora of inflammatory disorders and pathologic states. CCL5 is mainly produced and secreted by T cells, macrophages, epithelial cells, and fibroblasts and acts as a chemoattractant to recruit effector cells to the inflammation sites. Chicken CCL5 (chCCL5) protein is closely related to avian CCL5 orthologs but distinct from mammalian orthologs, and its modulatory roles in the immune response are largely unknown. The present work was undertaken to characterize the immunological properties of chCCL5 using the new sets of anti-chCCL5 mouse monoclonal antibodies (mAbs). Eight different mAbs (6E11, 6H1, 8H11, 11G1, 11G11, 12H1, 13D1, and 13G3) were characterized for their specificity and binding ability toward chCCL5. Two (13G3 and 6E11) of them were selected to detect native chCCL5 in chCCL5-specific antigen-capture ELISA. Using 13G3 and 6E11 as capture and detection antibodies, respectively, the ELISA system detected serum chCCL5 secretions in Clostridium perfringens- and Eimeria-infected chickens. The intracellular expressions of chCCL5 in primary cells or cell lines derived from chickens were validated in immunocytochemistry and flow cytometry assays using both 13G3 and 6E11 mAbs. Furthermore, 6E11, but not 13G3, neutralized chCCL5-induced chemotaxis in vitro using chicken PBMCs. These molecular characteristics of chCCL5 demonstrate the potential application of anti-chCCL5 mAbs and CCL5-specific antigen-capture detection ELISA for detecting native chCCL5 in biological samples. The availability of these new immunological tools will be valuable for fundamental and applied studies in avian species.

Supplemental 25-hydroxycholecalciferol Alleviates Inflammation and Cardiac Fibrosis in Hens.

Broiler breeder hens with efficient feed conversion rate under restricted feed intake (R-hens) or allowed unlimited access to feed (Ad-hens) progressed with cardiac functional failure and suffered early sudden death. A supplement of 69 µg 25-hydroxycholecalciferol (25-OH-D3)/kg feed improved heart health and rescued livability in both R- and Ad-hens throughout laying stage (26-60 wks). Improvements occurred through cardiac hypertrophic remodeling, reduced arrhythmias, and pathological cues. Here, we further demonstrated consistently decreased circulating and cardiac IL-6 and IL-1ß levels in conjunction with reduced cardiac chemoattraction and leukocyte infiltration by 25-OH-D3 in Ad-hens and in R-hens at later time points (35 and 47 wks) (p < 0.05). Supplemental 25-OH-D3 also ameliorated cardiac fibrosis, endoplasmic reticulum (ER) stress, and autophagy, mostly in Ad-hens, as both collagen content and expression of COL3A1, as well as CCAAT box binding enhancer homologous protein (CHOP) and activating transcription factor 6 (ATF6), were consistently decreased, and suppression of microtubule-associated protein 1 light Chain 3 beta (LC3B) and Sequestosome 1 (SQSTM1) was rescued at 35 and 47 wks (p < 0.05). Vitamin D receptor-NF-κB signaling was shown to mediate these beneficial effects. The present results demonstrate that ER stress and autophagic processes along the sequence from inflammation to fibrotic changes contribute to pathological cardiac remodeling and functional compromise by Ad-feed intake. 25-OH-D3 is an effective anti-inflammatory and anti-fibrotic supplement to ameliorate cardiac pathogenesis in broiler breeder hens.

Immune responses upon experimental Erysipelothrix rhusiopathiae infection of naïve and vaccinated chickens.

Erysipelas, a disease caused by Erysipelothrix rhusiopathiae (ER), is an increasing problem in laying hens housed in cage-free systems. This study aimed to monitor immune responses during ER infection of naïve chickens and chickens vaccinated intra muscularly with a commercial inactivated ER vaccine. Chickens were infected intra muscularly with ER at 30 days of age and blood leukocyte counts, serum levels of mannose binding lectin (MBL) and ER-specific IgY were monitored until the experiment was terminated at day 15 after infection. ER was detected in blood from more chickens and at higher bacterial counts in the naïve group (day 1: 1 of 7 chickens; day 3: 6 of 6 chickens) than in the vaccinated group (day 1: 0 of 7 chickens; day 3: 1 of 6 chickens). During the acute phase of infection transient increases in circulating heterophil numbers and serum MBL levels were detected in all ER infected chickens but these responses were prolonged in chickens from the naïve group compared to vaccinated chickens. Before infection IgY titers to ER in vaccinated chickens did not differ significantly from those of naïve chickens but vaccinated chickens showed significantly increased IgY titers to ER earlier after infection compared to chickens in the naïve group. In conclusion, the ER infection elicited prompt acute innate responses in all chickens. Vaccinated chickens did not have high IgY titers to ER prior to infection but did however show lower levels of bacteraemia and their acute immune responses were of shorter duration.

Egg-laying and brooding stage-specific hormonal response and transcriptional regulation in pituitary of Muscovy duck (Cairina moschata).

Broodiness is an interesting topic in reproductive biology for its reduced egg production. The strong brooding trait of Muscovy duck has become a major factor restricting the development of its industry. Broody phenotype and environmental factors influencing broodiness in poultry have been extensively studied, but the molecular regulation mechanism of broodiness remains unclear. In this research, the Muscovy duck reproductive endocrine hormones and pituitary transcriptome profiles during egg-laying phases (LP) and brooding phases (BP) were studied. During BP (n = 19), prolactin (PRL) levels was higher, while progesterone (P4) and estradiol (E2) were lower as compared to ducks during their LP (n = 20) (P < 0.01). We then examined the pituitary transcriptome of Muscovy duck at the 2 reproductive stages. A total of 398 differentially expressed genes included 20 transcription factors were identified (fold change ≥ 1.5, P < 0.01). There were 109 upregulated and 289 downregulated genes at brooding phases (n = 6) compared with egg-laying phases (n = 6). Real-time quantitative PCR analysis was carried out to verify the transcriptome results. The present study suggested that neuroactive ligand-receptor interaction pathway, calcium signaling pathway, and response to steroid hormones biological process are critical for controlling broodiness in the ducks. Further analysis revealed that SHH, PTGS2, RLN3, and transcription factor AP-1 may act as central signal modulators of hormonal and behavioral regulation mechanism associated with broodiness.

A Tissue Comparison of DNA Methylation of the Glucocorticoid Receptor Gene (Nr3c1) in European Starlings.

Negative feedback of the vertebrate stress response via the hypothalamic-pituitary-adrenal (HPA) axis is regulated by glucocorticoid receptors in the brain. Epigenetic modification of the glucocorticoid receptor gene (Nr3c1), including DNA methylation of the promoter region, can influence expression of these receptors, impacting behavior, physiology, and fitness. However, we still know little about the long-term effects of these modifications on fitness. To better understand these fitness effects, we must first develop a non-lethal method to assess DNA methylation in the brain that allows for multiple measurements throughout an organism's lifetime. In this study, we aimed to determine if blood is a viable biomarker for Nr3c1 DNA methylation in two brain regions (hippocampus and hypothalamus) in adult European starlings (Sturnus vulgaris). We found that DNA methylation of CpG sites in the complete Nr3c1 putative promoter varied among tissue types and was lowest in blood. Although we identified a similar cluster of correlated Nr3c1 putative promoter CpG sites within each tissue, this cluster did not show any correlation in DNA methylation among tissues. Additional studies should consider the role of the developmental environment in producing epigenetic modifications in different tissues.

Genome-wide association studies reveal genetic loci associated with plasma cholinesterase activity in ducks.

Plasma cholinesterase (PCHE) activity is an important auxiliary test in human clinical medicine. It can distinguish liver diseases from non-liver diseases and help detect organophosphorus poisoning. Animal experiments have confirmed that PCHE activity is associated with obesity and hypertension and changes with physiological changes in an animal's body. The objective of this study was to locate the genetic loci responsible for PCHE activity variation in ducks. PCHE activity of Pekin duck × mallard F2 ducks at 3 and 8 weeks of age were analyzed, and genome-wide association studies were conducted. A region of about 1.5 Mb (21.8-23.3 Mb) on duck chromosome 9 was found to be associated with PCHE activity at both 3 and 8 weeks of age. The top SNP, g.22643979C>T in the butyrylcholinesterase (BCHE) gene, was most highly associated with PCHE activity at 3 weeks (-logP = 21.45) and 8 weeks (-logP = 27.60) of age. For the top SNP, the strong associations of CC and CT genotypes with low PCHE activity and the TT genotype with high PCHE activity indicates the dominant inheritance of low PCHE activity. Problems with block inheritance or linkage exist in this region. This study supports that BCHE is a functional gene for determining PCHE levels in ducks and that the genetic variations around this gene can cause phenotypic variations of PCHE activity.

Light-dark rhythms during incubation of broiler chicken embryos and their effects on embryonic and post hatch leg bone development.

There are indications that lighting schedules applied during incubation can affect leg health at hatching and during rearing. The current experiment studied effects of lighting schedule: continuous light (24L), 12 hours of light, followed by 12 hours of darkness (12L:12D), or continuous darkness (24D) throughout incubation of broiler chicken eggs on the development and strength of leg bones, and the role of selected hormones in bone development. In the tibiatarsus and femur, growth and ossification during incubation and size and microstructure at day (D)0, D21, and D35 post hatching were measured. Plasma melatonin, growth hormone, and IGF-I were determined perinatally. Incidence of tibial dyschondroplasia, a leg pathology resulting from poor ossification at the bone's epiphyseal plates, was determined at slaughter on D35. 24L resulted in lower embryonic ossification at embryonic day (E)13 and E14, and lower femur length, and lower tibiatarsus weight, length, cortical area, second moment of area around the minor axis, and mean cortical thickness at hatching on D0 compared to 12L:12D especially. Results were long term, with lower femur weight and tibiatarsus length, cortical and medullary area of the tibiatarsus, and second moment of area around the minor axis, and a higher incidence of tibial dyschondroplasia for 24L. Growth hormone at D0 was higher for 24D than for 12L:12D, with 24L intermediate, but plasma melatonin and IGF-I did not differ between treatments, and the role of plasma melatonin, IGF-I, and growth hormone in this process was therefore not clear. To conclude, in the current experiment, 24L during incubation of chicken eggs had a detrimental effect on embryonic leg bone development and later life leg bone strength compared to 24D and 12L:12D, while the light-dark rhythm of 12L:12D may have a stimulating effect on leg health.

Dynamics of serum phosphorus, calcium, and hormones during egg laying cycle in Hy-Line Brown laying hens.

Understanding serum dynamic patterns of P, Ca, and P-Ca metabolism related hormones would help us in developing feeding strategies that can be used to reduce dietary inorganic P input and decrease P excretion in laying hens. In the current study, Hy-Line Brown laying hens (35-wk-old, n = 15) were fed with a corn-soybean meal-based commercial laying hen diet containing 0.24% non-phytate P, 3.59% Ca, 2,040 IU/kg vitamin D3, 2,500 FTU/kg phytase, 2,636 kcal/kg ME, and 15.9% crude protein. Blood samples from each laying hen were collected immediately after the first oviposition; 3, 6, 9, 12, 15, 18, and 21 h after the first oviposition; and immediately after the second oviposition. As a result, after the first oviposition, serum P and Ca levels of the laying hens were gradually increased, peaked in 6 h, and then gradually decreased all the way down until the second oviposition. Similarly, serum fibroblast growth factor 23 (FGF-23) level was gradually increased after the first oviposition, but peaked in 9 h, and then gradually decreased all the way down until the second oviposition. Serum 1,25-dihydroxy-cholecalciferol [1,25(OD)2D3] level was linearly and quadratically decreased during the egg laying cycle we observed. The serum levels of parathyroid hormone, calcitonin, and alkaline phosphatase were erratically fluctuated during the egg laying cycle in patterns that are very different from that of serum P, Ca, FGF-23, and 1,25(OD)2D3. In conclusion, the result that serum FGF-23 peaked after serum P indicates that the dynamics in serum FGF-23 levels might be driven by serum P levels during the egg laying cycle.

Quantitative proteomics using tandem mass tags in relation to the acute phase protein response in chicken challenged with Escherichia coli lipopolysaccharide endotoxin.

The inflammatory response in chickens (Gallus Gallus domesticus) is an integral part of the bird's response to infection. Detailing proteomic changes occurring during infection would be beneficial to the poultry industry, offering opportunities for comparative pathophysiological analysis. The objective of this study was to quantify the changes in the plasma proteome in chickens challenged with lipopolysaccharide (LPS), a bacterial endotoxin known to stimulate the host innate immune system. Plasma from chicken (N = 6) challenged with Escherichia coli (LPS) (2 mg/kg body weight) was collected pre (0 h) and at 12, 24, 48, and 72 h post-injection along with plasma from a control group (N = 6) challenged with sterile saline. Samples were analysed by a quantitative Tandem Mass Tags approach using a Q-Exactive-Plus mass-spectrometer. Identification and relative quantification were performed using Proteome Discoverer, and data were analysed using R. Gene Ontology terms were analysed by Cytoscape based on the Gallus gallus database. Finally, 87 significantly regulated proteins were found, including serum-amyloid-A, ovotransferrin and alpha-1-acid-glycoprotein, showing a significant effect of time post-injection in the LPS-treated group. Different pathways related with protein activation cascade and heterotopic cell-cell adhesion were affected by LPS-challenge. LPS-challenged chickens demonstrate significant changes to the plasma proteome with both increases and decreases of individual proteins within 12 h of challenge. SIGNIFICANCE: The injection of chicken with bacterial lipopolysaccharide followed by sequential plasma and clinical analysis of the bird, is a long established and a widely used model for inflammation and infection studies. This study, utilising and combining proteomic and immunoassay analysis with bioinformatic analysis, revealed that several biological pathways are modulated during this early period of inflammation. In addition, proteins with biomarker potential were identified and successfully validated. This experimental model also demonstrated potential for pathophysiological mechanism investigation and as an inflammatory model for biomedical research. There is, despite plasma being an easily accessible biological matrix which is representative of the health status of the bird, scarce data on the chicken plasma proteome. This research makes a positive contribution to the current field, generating significant data for continuing comparative analysis.

Selection for growth rate and body size have altered the expression profiles of somatotropic axis genes in chickens.

The growth hormone / insulin-like growth factor-1 (GH/IGF-1) pathway of the somatotropic axis is the major controller for growth rate and body size in vertebrates, but the effect of selection on the expression of GH/IGF-1 somatotropic axis genes and their association with body size and growth performance in farm animals is not fully understood. We analyzed a time series of expression profiles of GH/IGF-1 somatotropic axis genes in two chicken breeds, the Daweishan mini chickens and Wuding chickens, and the commercial Avian broilers hybrid exhibiting markedly different body sizes and growth rates. We found that growth rate and feed conversion efficiency in Daweishan mini chickens were significantly lower than those in Wuding chickens and Avian broilers. The Wuding and Daweishan mini chickens showed higher levels of plasma GH, pituitary GH mRNA but lower levels of hepatic growth hormone receptor (GHR) mRNA than in Avian broilers. Daweishan mini chickens showed significantly lower levels of plasma IGF-1, thigh muscle and hepatic IGF-1 mRNA than did Avian broilers and Wuding chickens. These results suggest that the GH part of the somatotropic axis is the main regulator of growth rate, while IGF-1 may regulate both growth rate and body weight. Selection for growth performance and body size have altered the expression profiles of somatotropic axis genes in a breed-, age-, and tissue-specific manner, and manner, and alteration of regulatory mechanisms of these genes might play an important role in the developmental characteristics of chickens.

Comparative Effect of Dietary Soybean Oil, Fish Oil, and Coconut Oil on Performance, Egg Quality and Some Blood Parameters in Laying Hens.

Two hundred and sixteen 28-wk-old Hy-line laying hens were randomly distributed to three dietary treatments and fed 1of 3 diets containing 8% soybean oil, fish oil, or coconut oil from 28 to 47 wk of age to investigate comparative effect of dietary soybean oil, fish oil, and coconut oil on the performance, egg quality and blood malondialdehyde (MDA), aspartate transaminase (AST) and uric acid (UA). Hens fed fish oil showed poor performance compared with soybean oil or coconut oil, and especially egg weight throughout the trial was significantly and consistently decreased (P < 0.05) due to dietary fish oil. Unexpectedly, shell reflectivity throughout the majority of the trial was consistently and significantly higher (P < 0.05) when hens fed fish oil than that when fed soybean oil or coconut oil. Dietary treatments affected (P < 0.05) shell shape at 4 of 8 time points tested. Average shell shape in fish oil treatment was higher (P < 0.05) than that of coconut oil group. Albumen height, Haugh unit and yolk color were influenced by dietary treatments only at 1 or 2 time points. However, average albumen height and Haugh unit in fish oil treatment were higher (P < 0.05) than that of soybean oil or coconut oil treatments and average yolk color in coconut oil treatment was higher (P < 0.05) than that of soybean oil group. Serum MDA, AST and UA concentrations were increased (P < 0.05) by fish oil during the majority of the first 2 mo of the trial. These data suggested that the inclusion of fish oil into feed may reduce the performance of laying hens, especially the egg weight, decrease the intensity of egg brown color and increase blood MDA, AST and UA levels compared with soybean oil or coconut oil. As a result, hens fed fish oil may lay smaller, longer and lighter-brown eggs whereas those fed coconut oil produce blunter and darker-brown eggs relative to soybean oil.

Rapid growth rate results in remarkably hardened breast in broilers during the middle stage of rearing: A biochemical and histopathological study.

The high incidence of meat of impaired quality poses a serious problem in the poultry industry. In recent years, the incidence of the pectoralis major muscle that appeared pale colored, remarkably hardened, and exudative, called "wooden breast" or "woody breast" has increased in slaughter houses. In the present study, 19-day-old Ross 308 broiler chickens affected (n = 10) and unaffected (n = 10) with remarkably hardened breast were selected from a commercial broiler farm, and reared to 55 days of age under a controlled environment. Among the affected birds, 5 of 10 birds appeared exhausted with markedly suppressed weight gain and 4 of 10 birds died during the rearing period. In contrast, all unaffected birds survived and most gained weight. Four of 10 unaffected birds lost the ability of back-to-back wing contact by the late stage of rearing. The biochemical analysis of blood plasma samples of 20-day-old birds revealed that creatine kinase and L-aspartate aminotransferase values in most affected birds were higher than those in unaffected birds; however, these values in unaffected birds increased rapidly with lost wing contactability and increasing age. Postmortem examinations revealed that the mean diameter of myofibers in affected birds was smaller than that in unaffected birds. Moreover, symptoms of degenerative and regenerative muscles were observed in most birds in both groups. Among them, a decrease in, or defect of, the characteristic polygonal shape of myofibers was the most common change within the pectoralis major muscles in both groups. The present study demonstrated that broilers affected with remarkably hardened breast during the middle stage of rearing would have suppressed physical status and weight gain, or would die. It was suggested that rapid growth in broilers might be a cause of remarkably hardened breast.

Simultaneous detection of chicken cytokines in plasma samples using the Bio-Plex assay.

A chicken multiplex cytokine assay (Bio-Plex) to detect four different cytokines (IL-2, IL-12, IL-10, and interferon gamma) simultaneously in plasma samples was designed. Most standard curves range between 1 to 5 pg/mL and 5,000 pg/mL, except for IFNγ with the range of 50 to 25,000 pg/mL. Such a chicken multiplex assay proved to be fast and reliable, and comparable in sensitivity, accuracy, and reproducibility to conventional enzyme-linked immunosorbent assays. Comparison of the multiplex assay with the ELISA technique using the same clones of detection and capture antibodies resulted in correlation coefficients for all cytokines ranging from 0.95 to 0.99. Lower limit of detection and limit of quantification values were obtained for all tested cytokines by the Bio-Plex assay compared with ELISA. To reduce the risk of cross-reaction with other proteins, the Bio-Plex system was used, combining the principle of sandwich immunoassay with the Luminex bead-based technology. The cytokine standard recoveries for each cytokine varied between 86 and 118% in dynamic concentration ranges. A chicken multiplex cytokine assay (Bio-Plex) provided a more complete picture of differences between the Th1/Th2 cytokine profiles of the immunized via a new system of antigen delivery into chicken antigen-presenting cells and control groups. This multiplexed fluorescent-bead-based detection assay can be used as a quantitative or comparative tool for the study of the chicken ex vivo cellular immune response.

Growth Performance, Mineral Digestibility, and Blood Characteristics of Ostriches Receiving Drinking Water Supplemented with Varying Levels of Chelated Trace Mineral Complex.

The effects of water supplementation of chelated trace minerals (CTM, which is named Bonzaplex designed with chelate compounds technology) on growth performance, apparent total tract digestibility (ATTD) of minerals, and some blood metabolites, TM, and antioxidant enzyme values in African ostriches were investigated from 8 to 12 months of age. A total of 20 8-month-old ostriches (five birds in five replicate pens) was randomly allocated into one of the following four treatments: (1) control (basal diet + tap water), (2) low CTM (basal diet +100 mg/bird/day CTM powder in tap water), (3) medium CTM (basal diet +1 g/bird/day CTM powder in tap water), and (4) high CTM (basal diet +2 g/bird/day CTM powder in tap water). Compared with control, medium CTM improved (P < 0.05) daily weight gain and ATTD of phosphorous, zinc, and copper in 12-month-old ostriches. Furthermore, the feed conversion ratio was lower, and ATTD of magnesium was higher in the medium- and high-CTM groups than that in the control group (P < 0.05). At the end of the trial, ostriches receiving high-CTM treatment exhibited the lower (P < 0.05) serum triglyceride and very low-density lipoprotein cholesterol concentrations and higher copper levels compared to those of the control treatment. Supplementation of higher amounts of CTM (medium and high CTM) also increased the activity of serum superoxide dismutase (P < 0.05). No differences were detected for other blood parameters including glucose, total protein, albumin, cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, iron, magnesium, and glutathione peroxidase values. In conclusion, supplementation of CTM at the level of 1 g/bird/day to the drinking water can be recommended for improving growth performance, mineral absorption, and antioxidant status of ostriches fed diets containing the recommended levels of inorganic TM.

Performance and serum biochemical profile of Japanese quail supplemented with silymarin and contaminated with aflatoxin B1.

The aim of this study was to evaluate the hepatoprotective effect of silymarin in diets contaminated or not with aflatoxin B1 (AFB1) on the productive performance and serum biochemical profile of Japanese quail (Coturnix coturnix japonica) in the laying phase. A total of 240 12-week-old Japanese quail was used in a completely randomized design in a 3 × 2 factorial scheme (additives x contaminated or not with AFB1 - 1,500 µg/kg), totaling 6 treatments and 5 replicates of 8 birds each. The additives used were silymarin (500 g/ton), adsorbent (1 kg/ton), and a control diet (without additive). Of the total aflatoxin content, 84.64% was AFB1; 4.28% was AFB2; 11.07% was AFG1; and AFG2 was not detected. The data were submitted to ANOVA, and means were compared by Tukey's test. There was no interaction (P > 0.05) between the additive and AFB1 on performance parameters. However, the inclusion of AF in diets reduced (P < 0.05) egg weight and feed intake, impairing feed conversion compared to the unchallenged groups. There was an increase (P < 0.05) in blood concentrations of aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT), and creatine kinase (CK) in birds challenged with AFB1, regardless of the additive used, characterizing a possible alteration in hepatic metabolism. Serum total protein and globulin levels were reduced (P < 0.05) in birds challenged with toxins. The consumption of diets contaminated with 1,500 µg AFB1/kg altered hepatic function in quail, impairing productive performance and egg weight. The concentrations of silymarin and adsorbent evaluated in this study were not able to mitigate the negative effect of toxins on the metabolism and performance of laying quail.

A study on the sternum growth and mineralization kinetic of meat duck from 35 to 63 days of age.

The sternum as an important part of the skeleton and not only provides a crucial attachment site for the pectoral muscles and protects internal organs such as the heart and lungs for meat duck, but may also be considered as the primary ventilator in the avian respiratory system. Therefore, this study focuses on the sternum growth and mineralization kinetics of ducks from 35 d to 63 d of age. A total of 72 one-d-old males and 72 females were chosen and fed with the same diet until the age of 9 weeks. The sternum and serum were harvested at 35 d, 42 d, 49 d, 56d, and 63 d of feeding. Results showed that the sternum width rapidly grew from 35 d to 42 d and the value changed little after 42 d, while the keel length and the sternum depth did not significantly change until 49 d age. The sternum defatted weight and density increased assumed to "S" with ducks' age and their plateau in the 56 d. The sternum ash content, calcium (Ca), and phosphate (P) levels increased with duck age, then all three reached a plateau in 49 days. Similarly, serum alkaline phosphatase (ALP) activity was higher in the ducks at both 35 and 42 days, followed by 49 days, and the value was lowered to a minimum on both days 56 and 63. Conversely, serum tartrate resistant acid phosphatase (TRAP) activity substantially increased until 49 days irrespective of duck gender. Results indicate that the dimensions of the sternum were already at the maximum in 49-day-old ducks and the sternum of the ducks rapidly mineralized from 42 d to 49 d of age and achieved a plateau phase after 49-days resulting from the high activity of ALP at the sternum early mineralization.

Variations in native protein glycation and plasma antioxidants in several birds of prey.

Birds are an anomaly among vertebrates as they are remarkably long-lived despite having naturally high blood glucose and metabolic rates. For mammals, hyperglycemia leads to oxidative stress and protein glycation. In contrast, many studies have shown that domestic and wild birds are relatively resistant to these glucose-mediated pathologies. Surprisingly very little research has examined protein glycation in birds of prey, which by nature consume a diet high in protein and fat that promotes gluconeogenesis. The purpose of this study was to evaluate protein glycation and antioxidant concentrations in serum samples from several birds of prey (bald eagle (BAEA), red-tailed hawk (RTHA), barred owl (BAOW), great horned owl (GHOW)) as protein glycation can accelerate oxidative stress and vice versa. Serum glucose was measured using a commercially available assay, native albumin glycation was measured by mass spectrometry and various antioxidants (uric acid, vitamin E, retinol and several carotenoids) were measured by high performance liquid chromatography. Although glucose concentrations were not significantly different between species (p=0.340), albumin glycation was significantly higher (p=0.004) in BAEA (23.67±1.90%) and BAOW (24.28±1.43%) compared to RTHA (14.31±0.63%). Of the antioxidants examined, lutein was significantly higher in BAOW (p=0.008). BAEA had the highest beta-cryptoxanthin and beta-carotene concentrations (p<0.005). The high concentrations of antioxidants in these birds of prey relative to other birds likely helps protect from complications that may otherwise arise from having high glucose and protein glycation.

Environmental conditions can modulate the links among oxidative stress, age, and longevity.

Understanding the links between environmental conditions and longevity remains a major focus in biological research. We examined within-individual changes between early- and mid-adulthood in the circulating levels of four oxidative stress markers linked to ageing, using zebra finches (Taeniopygia guttata): a DNA damage product (8-hydroxy-2'-deoxyguanosine; 8-OHdG), protein carbonyls (PC), non-enzymatic antioxidant capacity (OXY), and superoxide dismutase activity (SOD). We further examined whether such within-individual changes differed among birds living under control (ad lib food) or more challenging environmental conditions (unpredictable food availability), having previously found that the latter increased corticosterone levels when food was absent but improved survival over a three year period. Our key findings were: (i) 8-OHdG and PC increased with age in both environments, with a higher increase in 8-OHdG in the challenging environment; (ii) SOD increased with age in the controls but not in the challenged birds, while the opposite was true for OXY; (iii) control birds with high levels of 8-OHdG died at a younger age, but this was not the case in challenged birds. Our data clearly show that while exposure to the potentially damaging effects of oxidative stress increases with age, environmental conditions can modulate the pace of this age-related change.

Effect of dietary supplementation of organic or inorganic zinc on carbonic anhydrase activity in eggshell formation and quality of aged laying hens.

This study evaluated the effects of different dietary levels and sources of zinc (Zn) on performance and carbonic anhydrase (CA) activity in eggshell formation and quality in aged laying hens. A total of 504 Hy-line Grey layers aged 59 wk were fed a basal diet (Zn, 28.4 mg/kg) for 4 wks, then randomly allocated to 7 groups that were fed a basal diet or a basal diet supplemented with inorganic (ZnSO4·H2O) or organic (amino acid metals, 9.58%) Zn at 35, 70, or 140 mg Zn per kg of feed for 6 weeks. Each group had 6 replicates of 12 hens. Results showed that egg weight decreased linearly with the supplemental level of organic Zn (P < 0.05). Dietary Zn supplementation had linear and quadratic effects on the CA activity in plasma (P < 0.05), and it was higher in the organic Zn-added groups at wks 2 and 4 (P < 0.05). Dietary Zn supplementation had a quadratic effect on the CA activity in the eggshell gland (P < 0.05). Shell thickness was greater in the organic Zn-added groups (P < 0.05), and its relationship with the supplemental level of Zn showed linearly and quadratically, increasing with the organic Zn and with the inorganic Zn at wk 4, while linearly increasing with the inorganic Zn at wk 6 (P < 0.05). At wk 4, the supplemental level of inorganic Zn had a linear effect on shell weight, and linear and quadratic effects on shell index and ratio (P < 0.05), while shell weight, the index, and ratio increased linearly and quadratically with the organic Zn level in the diet (P < 0.05), with more obvious effects in the organic Zn-added groups (P < 0.05). Overall, dietary Zn supplementation, up to 140 mg/kg feed, could increase eggshell thickness by enhancing CA activity in the plasma and eggshell gland of aged layers; thicker eggshells were found in the organic Zn-added groups, but the breaking strength did not increase despite the eggshell thickness increasing.