Synthetic oligodeoxynucleotides (ODN) containing CpG motifs activate innate and adaptive immune responses in numerous vertebrate species. The protective effects of CpG ODN against viral, bacterial and protozoal pathogens have been well documented in various mouse models of disease. CpG ODN are also being evaluated in humans as an immunotherapeutic agent against infectious diseases, cancer, allergy and as a vaccine adjuvant. In species of veterinary importance where the immune activity of CpG ODN has been investigated, CpG ODN has shown the greatest potential in chickens, as indicated by its protective effects against experimental bacterial infections. Surprisingly, chicken do not appear to express Toll-like receptor 9 (TLR9), the receptor that is involved in CpG-mediated immune activation in humans and many animal species. We will review progress on CpG research with particular emphasis on avian species.

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Many seasonal breeding animals can estimate the day length (photoperiod) and prepare for breeding in the optimal season. The Japanese quail (Coturnix japonica) is an excellent model for studying photoperiodism because of its rapid and dramatic response to the photoperiod. Recent molecular analysis using the quail has revealed that local thyroid hormone activation by thyroid hormone deiodinases (DIO2 and DIO3) in the mediobasal hypothalamus (MBH) plays a critical role in the regulation of seasonal reproduction in birds. However, the molecular dynamics of gene expression that regulates photoperiodic thyroid hormone activation in the MBH during the photoinduction process remains unclear. The chicken genome project has enabled the analysis of the conservation of the genetic interaction networks for studying photoperiodism. This review focuses on genome-wide transcriptional studies of avian photoperiodism.

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Adipose differentiation-related protein (ADFP) plays an important role in regulating lipid storage and affecting body fat distribution. The objective of the current research was to identify the polymorphisms in chicken ADFP gene and their associations with carcass traits. We screened all coding sequence and part of introns (totally 2155bp) of the ADFP gene by using single strand conformation polymorphism method in individuals from Sanhuang chicken, Mountainous Black-bone chicken and a commercial crossbred chicken (totally 427 birds). Three novel single-nucleotide polymorphisms were found in intron 4 (SNP1), intron 5 (SNP2) and exon 8 (SNP3), respectively. The association analyses showed that genotypes of SNP1 were significantly associated with abdominal fat weight and percentage of abdominal fat (P<0.05), genotypes of SNP2 were significantly associated with breast muscle weight and percentage of abdominal fat (P<0.05), and the main haplotype/haplotypes combination (their frequencies were higher than 5%) were marginally significantly associated with breast muscle weight, abdominal fat weight, and percentage of abdominal fat (0.05<P<0.1). Haplotype H2 (A-C-A) was an advantageous haplotype for breast muscle weight and H5 (T-C-G) was an advantageous haplotype for weight and percentage of abdominal fat. Conversely, H3H3 (A-T-G/A-T-G) was a disadvantage haplotype combination for accumulation of abdominal fat. These results suggested that polymorphisms of ADFP gene were associated with carcass traits, especially with fatness traits. ADFP is a potential major gene or in close linkage disequilibrium with the QTL affecting fatness traits in chickens.

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The WW domain containing E3 ubiquitin protein ligase 1 (WWP1) is classified into one of ubiquitin ligases which play an important role in ubiquitin-proteasome pathway. Previously, we identified the WWP1 gene as a candidate gene of chicken muscular dystrophy by linkage analysis and sequence comparison. However, the mechanism causing pathological changes and underlaying gene function remains elucidated. In the present study, we analyzed the WWP1 gene expression in various muscles and tissues of normal chickens, and compared with those from muscular dystrophic chickens. Two mRNA isoforms were detected in all tissues examined and revealed almost equal expression level. The WWP1 expression of dystrophic chickens was decreased in almost all skeletal muscles including unaffected muscles. These data indicate that there might not be a causal relationship between the alteration of WWP1 expression level and the severity of muscular dystrophy.

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The effect of feeding of different levels of thyme (Thymus valgaris L) on performance, blood constituents, gastrointestinal tract and carcass characteristics was studied in broiler chickens. An experiment of five dietary treatment groups with different levels of thyme was conducted in broiler chickens from 1 to 42 days of age. Dietary thyme significantly increased body weight and body weight gain, and improved feed conversion ratio. The serum levels of glucose, total protein, and globulin were significantly increased by the addition of thyme. The serum levels of triglyceride and cholesterol were significantly decreased. The lengths of gastrointestinal tract segments were decreased by feeding 1.0%, 1.5% and 2.0% thyme. The same levels of thyme improved dressing and breast percentage of female broilers, and 1.5% and 2.0% thyme feedings improved significantly the leg and wing percentage. Same trends were observed in male broilers. These findings suggest that thyme can be used as a natural growth promoter in broiler rations particularly at 1.5% and 2.0% level.

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This experiment was performed to determine the effects of dietary ascorbic acid (ASA) supplementation on blood components, leukocyte and tonic immobility of male turkeys under summer conditions. A total of 120 one-day-old male turkeys were fed with three different diets. The experimental diets were: control without ASA (ASA-0), 150mg of ASA/kg (ASA-150) and 300mg of ASA/kg (ASA-300) of diet. The turkeys received the experimental diets for 18 weeks. Diets in mash form and water were provided ad libitum. In the ASA-150 and ASA-300 groups, the eosinophile and basophile ratios were higher than those of the ASA-0 group at 12 weeks of age (P<0.05 and P<0.001), but lymphocyte (L), heterophil (H), monocyte, H: L ratio and tonic immobility were not influenced by the ASA levels (P>0.05). Both dietary ASA levels caused a quadratic decrease in serum cholesterol, low density lipoprotein (LDL) and glutamic-oxaloacetic transaminase (SGOT) (P<0.05), whereas dietary ASA caused a liner increase in serum iron concentration of turkeys (P<0.05). Serum glucose, triglyceride, high density lipoprotein (HDL), total protein, albumin, globulin, lactate dehydrogenase (LDH), glutamic-pyruvate transaminase (SGPT), urea, uric acid and alpha amylase were not affected by the addition of ASA to the diets (P>0.05). As a conclusion, blood haematological profile, serum biochemical components and tonic immobility of turkeys were not significantly affected by dietary ASA levels at chronic high summer temperatures in general, and, therefore, there is no need for ASA supplementation in turkeys' diets under summer temperatures that do not exceed 31.7°C.

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To investigate the effects of dietary mulberry leaves on egg yolk color and egg quality, a total of 192 laying hen CP Brown were randomly allotted into 4 groups with 4 replicate of 12 chickens per replicates. Each replicate was furthermore divided into 4 large cages (40×40×36cm) with 3 birds. Dried mulberry leaves were supplemented to a basal diet (17.50 CP, 2750kcal/kg ME) at 0 (control), 1, 2 and 3% for 45 days. Compared to control, any adverse effects were not observed in feed intake, body weight gain, egg production rate, egg weight, yolk weight, albumin weight, shell thickness and Haugh unit in dietary mulberry leaves groups. However, pigmentation score of yolk color measured using Roche yolk color fan was higher in all treatment groups (10.73 to Effects of Dietary Mulberry Leaves (Morus alba L.) on Egg Yolk Color10.86) than in the control (10.34) (P<0.05), and the 2% dietary mulberry leaves group showed the highest value. These results suggest that the mulberry leaves can improve the pigmentation of egg yolk, and that the mulberry leaves also can become the egg color source until 3% supplementation.

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Experiments were conducted to investigate the effect of the Bacillus subtilis var. natto fermented soybean (FS) on growth performance, microbial activity in the caeca and cytokine gene expression in spleen of domestic meat type chickens. Chicks were fed commercial diets supplemented with 0 (control), 1 or 2% FS for 80 days from 0 to 80 days of age, and a fourth group of chicks were fed control diet from 0 to 27 days of age, and then fed a 2% FS diet from 28 to 80 days of age. Supplementation with FS did not decrease feed intake compared to chicks fed the control diet, and there were no significant differences in body weight gain and feed efficiency due to dietary treatment. FS supplementation had no effect on carcass weight, breast and thigh meat composition, or abdominal fat deposition. There were no significant differences in pH, NH₃-N concentration, or number of microorganisms in the cecum content in each group; however, total acetic acid concentration increased (P<0.05) in chicks fed the 2% FS supplemented diet from 0 to 80 days of age. Supplementation with FS did not affect IFN-γ, IL-4 and IL-13 gene expression in spleens.
It can be concluded from this study that supplementing FS to meat type chicken diets has no deleterious effect on the growth performance, and has beneficial effects on intestinal microbial activity, as observed by increases in VFA concentration.

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In previous studies, two types of offspring were generated from germline chimera between NH-413 strain (donor) and White Leghorn L-M strain (recipient). Phenotype and symptom of type-I offspring were quite similar to that of the NH-413 strain. In the other offspring of type-II, feather color showed mixture of white and brown and the symptom was not dominantly indicated.
In the present studies, sexually matured males and females of the type-I were mated each other. Form these mating, chickens manifesting completely same phenotype to that of the donor NH-413 strain; brown feather color and symptoms of muscular dystrophy, were regenerated. Therefore, complete regeneration of the muscular dystrophy chickens could be achieved by mating males and female offspring derived from the germline chimeras. Fertility, hatchability and survival rate of these regenerated offspring were significantly improved as compared to that of the original NH-413 strain.
The established strategies should be one of the useful systems to regenerate chickens with muscular dystrophy.

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The current study aimed to determine the optimal time of busulfan (1,4-butanediol dimethanesulfonate) administration for the preparation of suitable recipient embryos to generate germline chimeras in chickens. We compared two different administration times, with regards to the degree of endogenous primordial germ cell (PGC) depletion and donor PGC incorporation in recipient embryos. A dose of 75μg busulfan in 50μL sustained-release emulsion was injected into the yolk of chicken embryos incubated for 0h or 24h. Both busulfan treatments resulted in significant reduction in the number of PGCs compared with that of controls (P<0.01). The number of PGCs in the blood at stage 14 was significantly lower after busulfan treatment at 0h of incubation than after treatment at 24h of incubation (P<0.01). No significant difference was observed in the numbers of PGCs in the gonads at stage 29 between the two treatment groups. The number of donor PGCs after busulfan treatment at 0h was significantly higher than that after treatment at 24h and in controls (P<0.01). The ratios of donor to recipient PGCs in the gonads of both busulfan treated groups were higher than in controls (P<0.01). In conclusion, injecting busulfan sustained-release emulsion into the yolk of recipient embryos at 0h of incubation was a suitable method of preparing them for the generation of germline chimeras.

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The generation of germline chimeras by the transfer of primordial germ cells (PGCs) requires incorporation of the PGCs of the donor into the gonadal tissue of the recipient embryo. We investigated the utility of soft x-irradiation with application of a lead (12×3×0.25mm, ∼0.1g) shield to the embryo proper for the production of chicken-quail germline chimeras. Chicken embryos shielded during irradiation for 120 s (∼7.2Gy) at stages 13 to 17 showed a hatchability of 35% (106/301), whereas the hatchability of unshielded embryos was 26% (27/105). The relative population of gonadal PGCs at stage 30 for embryos irradiated at stage 13 with or without shielding was 13 and 5%, respectively, of the value for nonirradiated controls. Chicken embryos irradiated at stages 13 or 14 with or without shielding and transfused with quail embryonic blood containing PGCs each exhibited ∼130 relative population of donor PGCs in the left gonad at stage 30. Xenotransplanted hatchlings exhibited donor-derived PGCs as detected by Southern hybridization and PCR. Exposure of chicken embryos to ∼7.2Gy of x-radiation at stage 13 with the application of a lead shield to the embryo proper is thus a feasible approach to depletion of endogenous germ cells and the production of chicken-quail germline chimeras.

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The aim of the present study was to determine if some naturally-occurring substitutions of amino acid residues of insulin could act differentially within the central nervous system (CNS) of neonatal chicks to control ingestive behavior. Intracerebroventricular (ICV) administration of chicken insulin (20ng) inhibited food intake in ad libitum chicks over the 120-min experiment period. A lower dose (2ng) also shows a suppressive effect at 60min post-injection, but not at 30 and 120min. Similar to chicken insulin, a higher dose of porcine insulin (20ng) significantly inhibited food intake at 60 and 120min post-injection, but a significant difference is not detected at 30min post-injection. Treatment with human and bovine insulin had no effect in this study. Finally, we compared the effect of ICV injection of chicken and porcine insulin on food consumption in starved chicks. The results of the present study indicate that chicken insulin has a higher potent ability to depress feeding behavior in the CNS compared with porcine, human, and bovine insulin. Therefore, it seems that the ranking in order of potency of the insulins on the anorexic effect in neonatal chicks is chicken insulin>porcine insulin>human insulin>bovine insulin. It is suggested that the 8^th-10^th amino acids of the A-chain and/or the C-terminal amino acid of the B-chain in insulin have an important role in bioactivity in the CNS with special reference to feeding behavior.

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A variety of fruits have traditionally been used in Asian cultures to enhance resistance to diseases and treat cancers. However, limited information exists on the underlying mechanisms responsible for these effects. The present investigation was conducted to examine the ability of three Korean indigenous fruits (persimmon, raspberry and tomato) to stimulate lymphocyte proliferation and macrophage nitric oxide production as parameters of innate immunity, and to inhibit tumor cell growth. In vitro co-culture of chicken spleen lymphocytes with methanol extracts of persimmon (Diospyros kaki) or tomato (Lycopersicon esculentum) induced greater cell proliferation compared with cells treated with the vehicle control. Stimulation of chicken macrophages with extracts of persimmon or raspberry (Rubus crataegifolius), but not tomato, stimulated robust nitric oxide production to levels similar to that produced by interferon-γ. All fruit extracts uniformly inhibited the growth chicken tumor cells in vitro. These results provide a rational basis for future studies investigating the effects of medicinal fruits on innate immunity and carcinogenesis in humans and animals.

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This study was conducted to evaluate the effects of dietary safflower leaf on protective immunity against coccidiosis, the most economically important parasitic disease of poultry. White Leghorn chickens were fed a standard diet with or without safflower leaf and were either uninfected or orally infected with 5,000 sporulated oocysts of Eimeria acervulina. Protective immunity was assessed by body weight gain, fecal oocyst shedding, splenic lymphocytes proliferation, T lymphocyte subpopulations, and proinflammatory cytokine gene expression. We observed that the effect of safflower on experimental coccidiosis was dependant on the dose of the supplement used. A 0.1% (wt/wt) safflower-supplemented diet increased body weight gains of coccidia-infected chickens to a level identical to that of uninfected controls, and significantly reduced fecal oocyst shedding compared with animals that were given a non-supplemented standard diet. Furthermore, increased splenic lymphocyte proliferation as well as greater percentages of CD4⁺ T cells and decreased CD8⁺ cells were observed in animals fed a 0.1% safflower-supplemented diet. Finally, IFN-γ, IL-8, IL-15 and IL-17 transcripts in the 0.1% safflower-supplemented group were higher than the non-supplemented controls. These results indicate that safflower leaf when given as a dietary supplement possesses immune-enhancing properties that augment protective immunity against experimental coccidiosis.

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The present experiment was designed to study progressive changes in the physiological responses of broiler chickens (Gallus gallus) exposed to different durations of acute heat stress. Male broiler chickens (n=8) at 16 days of age, were exposed to acute heat stress of 34°C for 6, 12 or 18h while control chickens were kept at 25°C. Exposure to different durations of heat stress resulted in significant decreases in the levels of blood HCO₃^- and pCO₂, while pH and pO₂ were not changed. Hemoglobin, hematocrit and Na⁺ values were reduced after 6h while no such change was observed after 12 or 18h of heat stress. In contrast, K⁺ levels were lowered by 6 or 12h of heat stress and no differences in blood calcium levels were observed between the control and heat-stressed groups. In conclusion, there is evidence that exposure of broiler chickens to different durations of acute heat stress resulted in distinct time-dependent physiological responses. Data set from this experimental model could provide an overview of physiological state in the typical acute heat-stressed birds.

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