Some productive and reproductive performance, eggshell quality, serum metabolites and immune responses due to L-threonine supplementation in Japanese quail breeders' diet.

A dose-response experiment was conducted to evaluate the effects of graded levels of dietary digestible threonine (dThr) during the first laying cycle on productive and reproductive performance, egg quality and immune responses of Japanese quail breeders (Coturnix coturnix japonica). Also, dThr requirements were determined based on nutrient dose-response data. A total of 450 (360 females and 90 males) 11-week-old breeders were allocated to five increment (+0.03%) levels of dThr (0.49%, 0.52%, 0.55%, 0.58%, 0.61% and 0.64%) with five replicates per treatment and 15 (12 females and three males) birds each. The experiment lasted for 12 weeks. In response to increasing dietary dThr levels, egg production, egg mass, feed efficiency, egg specific gravity, eggshell relative weight, eggshell thickness, egg fertility (EF) and immune response against sheep red blood cell (SRBC) inoculation were improved with quadratic trends and egg hatchability as set eggs was improved with linear trends. Japanese quail breeders fed a diet with 0.58% dThr concentration (threonine/lysine ratio of 59%) showed the productive performance traits, EF, eggshell quality and immune response against SRBC inoculation in the highest values. However, feed intake, egg weight, egg albumen and yolk relative weight, egg shape index, haugh unit and egg composition were not affected by increasing dietary dThr level. Based on the broken-line regression model, the dThr requirements to optimize productive performance, eggshell quality, EF and immune response against SRBC inoculation were estimated at 159-188, 169-183, 175 and 178 mg/bird per day, respectively. It is concluded, in the Japanese quail breeders during the first laying phase a daily dThr intake of 188 mg/bird, dietary dThr concentration at 0.58% (threonine/lysine ratio of 59%) is adequate for optimized productive and reproductive performance, eggshell quality and immune responses. The estimated requirements depend on what production parameter is taken into considered for optimization.

Polystyrene microplastics disrupted physical barriers, microbiota composition and immune responses in the cecum of developmental Japanese quails.

Microplastics, a new type of emerging pollutant, is ubiquitous in terrestrial and water environments. Microplastics have become a growing concern due to their impacts on the environment, animal, and human health. Birds also suffer from microplastics contamination. In this study, we examined the toxic effects of polystyrene microplastics (PS-MPs) exposure on physical barrier, microbial community, and immune function in the cecum of a model bird species-Japanese quail (Coturnix japonica). The one-week-old birds were fed on environmentally relevant concentrations of 20 µg/kg, 400 µg/kg, and 8 mg/kg PS-MPs in the diet for 5 weeks. The results showed that microplastics could cause microstructural damages characterized by lamina propria damage and epithelial cell vacuolation and ultrastructural injuries including microvilli breakage and disarrangement as well as mitochondrial vacuolation in the cecum of quails. In particular, blurry tight junctions, wider desmosomes spacing, and gene expression alteration indicated cecal tight junction malfunction. Moreover, mucous layer breakdown and mucin decrease indicated that chemical barrier was disturbed by PS-MPs. PS-MPs also changed cecal microbial diversity. In addition, structural deformation of cecal tonsils and increasing proinflammatory cytokines suggested cecal immune disorder and inflammation responses by PS-MPs exposure. Our results suggested that microplastics negatively affected digestive system and might pose great health risks to terrestrial birds.

The influences of Tylosine and licorice dietary supplementation in terms of the productive performance, serum parameters, egg yolk lipid profile, antioxidant and immunity status of laying Japanese quail under heat stress condition.

By reducing feed consumption, animals suffering from heat stress prefer to reduce their heat output. Heat exposure has also contributed to major adverse effects on the productive and reproductive performance of quails. Therefore, this research was intended to estimate the preventive function of licorice as a safe feed additive against the negative effects caused by heat stress conditions on laying quail productivity. A total number of 180 Japanese quail birds (120 females and 60 males), nine-weeks old were divided into five groups. Each group contained 36 birds in four replicates (nine birds) with completely randomized design. The dietary treatments were a basal diet without supplementation as control (T1), basal diet + 100 mg Tylosine kg-1 diet (T2), (T3), (T4) and (T5) fed basal diet + 250, 500 and 1000 mg licorice kg-1 diet, in respect. The results indicated that dietary supplementation with different feed additives had no significant effects on egg-laying rate, egg number, average egg weight, egg mass and feed conversion ratio compared with control. Also, different treatments showed no significant variations on serum IgG, total protein, globulin, albumin, creatinine, ALT and TAC and caused significant (P ≤ 0.05) improvement in IgM, AST, ALP, uric acid and MDA concentrations as compared to the control. Results indicated that total serum lipids, triglycerides, total cholesterol and LDL concentrations were significantly decreased due to different feed additives. However, HDL concentrations and HDL/LDL ratios were markedly increased by the other treatments than the control group. In addition, yolk total lipids were significantly (P ≤ 0.001) decreased with increasing licorice root powder's dietary levels compared with the control group. Also, a significant (P ≤ 0.01) reduction in egg yolk cholesterol level was observed in the group fed with 500 mg licorice compared to other treatments. In conclusion, fortified laying quail diets with licorice powder could be a useful strategy to alleviate adverse effects induced by heat stress as alternative to antibiotics on laying Japanese quail.

Growth performance, hemato-biochemical indices, thyroid activity, antioxidant status, and immune response of growing Japanese quail fed diet with full-fat canola seeds.

Dietary supplementation of full-fat canola seeds (FFCS) can be part of the global solution to the problem of incessant raise in feed cost. Genetic improvement via plant breeding constantly introduces varieties of canola with higher content of unsaturated fatty acids and lower content of anti-nutritional factors. This experiment was conducted to evaluate the dietary inclusion effect of new mutant of FFCS on growth performance, carcass traits, blood metabolites, thyroid activity, antioxidant status, and immune response of growing Japanese quails. A total of 640 21-day-old quails were used in a completely randomize design with and equally allotted to four experimental groups and eight replicates each. The experimental groups fed diets supplemented with 0, 50, 100, and 150 g FFCS/kg diet from 21 to 49 days of age. All experimental diets were isocaloric and isonitrogenous. The inclusion level of FFCS did not affect body weight and body weight gain at all studied periods, while feed intake was reduced and feed conversion ratio was enhanced linearly under all experimental periods except the duration from 28 to 35 days of age. All carcass traits were not statistically affected with graded levels of FFCS. Hemoglobin, leucocytes, mean corpuscular hemoglobin (MCH), and MCH concentration values were linearly increased. Serum protein fractions, liver enzymes activities, renal function biomarkers, and triiodothyronine concentration were not affected. However, serum lipid profile was significantly altered, where high-density lipoprotein was linearly increased while triglycerides and low-density lipoprotein (LDL) were linearly (and quadratically for LDL) decreased. Antioxidant and immune statuses were improved; significant increment in glutathione and glutathione peroxidase values and antibody titer against Newcastle disease virus were elevated in groups treated with 10% and 15% FFCS. In conclusion, studied levels of FFCS, however, were not able to promote the growth rate of growing Japanese quails; they were more effective in boosting their antioxidant status and humoral immune response.

Chronic lead exposure induces histopathological damage, microbiota dysbiosis and immune disorder in the cecum of female Japanese quails (Coturnix japonica).

Lead (Pb) is one of the most hazardous metals to human and wildlife and it also has multiple negative impacts on birds. However, its influences on bird gut morphology and intestinal microbiota were still unclear. We used female Japanese quails (Coturnix japonica) to examine the effects of chronic lead exposure (0, 50 ppm and 1000 ppm) on cecal histology, microbial communities and immune function. The results showed 50 ppm lead exposure caused subtle damages of cecum cell structure. However, 1000 ppm lead exposure caused severe cecum histopathological changes characterized by mucosa abscission, Lieberkühn glands destruction and lymphocyte proliferation. Moreover, both lead concentrations induced ultrastructural damages featured by nucleus pyknosis, mitochondrial vacuolation and microvilli contraction. Meanwhile, microbial community structure, species diversity, taxonomic compositions and taxa abundance in the cecum were affected by lead exposure. Furthermore, the mRNA relative expression of immunity-related genes such as interleukin 2 (IL-2) and gamma interferon (IFN-γ) was significantly downregulated while that of interleukin 6 (IL-6), tumor necrosis factor α (TNF-α) and natural killer kappa B (NF-κB) was significantly upregulated in the cecum of 50 and 1000 ppm lead exposure groups. We concluded that lead exposure may cause gut health impairment of female Japanese quails by inducing cecal histopathological changes, microbiota dysbiosis and cecal immune disorder.

Development and reactivity of the immune system of Japanese quail lines divergently selected for the shape of the growth curve.

1. Selection strategies for broilers must balance rapid growth with the welfare and health of animals, strategies must deal with the trade-off with other vital functions.2. Divergent selection of Japanese quail for high (HG) and low (LG) relative body weight gain between 11 and 28 days of age has been conducted to accelerate linear phase growth without influencing the final adult body weight. Higher body growth rate is often connected with a weakened immune system. Therefore, the present study explored the immunological characterisation of quail from HG and LG lines, which differ substantially in their growth rate.3. The trial evaluated the maternal investment to immunologically active substances, cell-mediated immunity stimulated by phytohaemagglutinin (PHA) injection and the acute phase of the immune response to lipopolysaccharide (LPS) administration in three different phases of early postnatal growth.4. Except for higher lysozyme activity in the LG group when compared to the HG line, the maternal investment did not differ between the two lines. Plasma antibody concentrations responded quickly to any change in growth rate in both lines. Overall, it seems that initial rapid growth of the LG line had long-lasting effects on immune responsiveness, even after the growth rate of the HG line escalated during the linear phase of growth.5. The study indicated that changes in the growth rate caused by the selection for growth in meat-type Japanese quail can influence the acute phase of the immune response and development of the immune system.

Impact of temperature-humidity index on egg-laying characteristics and related stress and immunity parameters of Japanese quails.

The aim of this study was to investigate the effect of temperature-humidity index (THI) level on productive parameters, welfare, and immunity in Japanese quails. One hundred and eighty (180) birds of Japanese quail, 14 weeks old, were used. Birds were divided randomly into three equal groups, control (at low THI, less than 70), H1 (at moderate THI, 70-75), and H2 (at high THI, 76-80). Birds in the control group had higher body weight (281.2 g, p = 0.001), egg mass (745 g, p = 0.001), fertility (85.4 %, p = 0.039), hatchability (80.4 %, p = 0.001), and immune response titer to Newcastle disease virus (p = 0.031), compared with H2 group. Furthermore, the thermoneutral group had higher internal egg quality score [albumen height (5.14 mm, p = 0.001), yolk height (10.88 mm, p = 0.015), yolk index (42.32 %, p = 0.039), and Haugh unit (92.67, p = 0.001)]. Nevertheless, there were no significant differences in fertility percentage, immune response, and corticosterone concentration between control and H1 group. Birds in the H2 group had the lowest total leucocytic count and lymphocyte percentage (p = 0.001 and 0.020, respectively) but the highest H/L ratio (0.83, p = 0.001). Corticosterone concentration was lower in control and H1 groups (5.49 and 6.41 ng/mL, respectively, p = 0.024) than that in H2 group. Japanese quail exposed to heat stress revealed drop in production and immunological parameters, as well as a detrimental effects on welfare. Thus, practical approaches might be used to reduce the detrimental effects of greater THI level.

Effects of medium-chain fatty acids on performance, carcass characteristics, blood biochemical parameters and immune response in Japanese quail.

This study had the aim of evaluating the effects of medium-chain fatty acids (MCFA) on performance, carcass characteristics, some blood parameters and antibody titre against sheep red blood cells (SRBC) in quail. A total of 240 quail chicks were allotted to 4 treatments consisting of respectively 0, 1, 2 and 4 g/kg dietary MCFA. There were no significant differences in body weight, feed intake and feed conversion ratio among treatments at different stages of the experiment. MCFAs had no significant effect on breast, thigh, liver, spleen and bursa of Fabricius weight ratios. However, the relative weight of abdominal fat significantly decreased in quail receiving 0.2 and 0.4 MCFA as compared to other treatments. Concentrations of low-density lipoprotein-cholesterol (LDL), triglycerides and total cholesterol were decreased and high-density lipoprotein (HDL)-cholesterol was increased in quail chicks receiving MCFA compared with control quail chicks. The concentrations of SRBC antibody were not statistically different among treatments. It is concluded that MCFA significantly decreased LDL, triglycerides, cholesterol and abdominal fat and increased HDL in quail chicks.

Impact of cage stocking density on egg laying characteristics and related stress and immunity parameters of Japanese quails in subtropics.

The aim of this study was to investigate the effects of different cage stocking densities on egg production parameters, as well as related stress and immunity indices in Japanese quails under subtropical Egyptian conditions. Two hundred and sixteen birds of Japanese quail at 14th week of age were used in this experiment. The birds were divided randomly into three groups: 60, 72 and 84. Each group subdivided into 4 replicates, where the cages' floor spaces were 200 (S1 ), 167 (S2 ) and 143 (S3 ) cm(2) /bird, respectively. Birds housed at 200 cm(2) /bird (S1 ) had superior fertility (fertility % (p = 0.013) and hatchability % (p = 0.041)), egg production (egg weight (p = 0.034) and egg mass (p = 0.001)) and immunity parameters (higher geometric mean of antibody titres against Newcastle disease virus, p = 0.024). Furthermore, they had higher internal egg quality score: albumen height (p = 0.003), yolk height (p = 0.023), yolk index (p = 0.006) and Haugh unit (p = 0.035). Birds housed at 143 cm(2) /bird (S3 ) had the lowest total leucocytic count and lymphocyte % (p = 0.022), but the highest H/L ratio (p = 0.001). Corticosterone concentration was lower in S1 group (p = 0.031) than that in groups housed at higher densities. Japanese quail housed at high densities revealed drop in fertility, hatchability, production and immunity parameters, indicating a detrimental effects on both welfare and economic income.

Effect of active immunization with OPN5 on follicular development and egg production in quail under different photoperiods.

OPN5 is one of the main deep brain photoreceptors (DBPs), converting photoperiodic information into neuroendocrine signals to regulate reproduction in birds. This study investigated the mechanism of OPN5-mediated photoperiodic regulation of reproduction by active immunization against OPN5. 96 female quail were divided into OPN5-immunized and control group under the same photoperiod: 16 L:8 D (d 1 to d 35), 8 L:16 D (d 36 to d 70) and 12 L:12 D (d 71 to d 126). OPN5-immunized group was conducted with OPN5 protein vaccination and control group was given a blank vaccine. Samples were collected on d 1, d 30, d 60, and d 126. Results showed switching photoperiod to 8 L:16 D decreased the laying rate, GSI%, numbers of YFs and WFs, serum levels of PRL, P4 and E2, and pituitary PRL and TSHß protein expressions in both groups (P < 0.05). Whereas the OPN5-immunized group exhibited higher laying rates than the control group (P < 0.05). The control group showed reduced GnRHR and TSHß gene expressions in the pituitary and increased GnIH and DIO3 transcript and/or protein abundance in the hypothalamus. (P < 0.05). The OPN5-immunized group had lower DIO3 expression at both mRNA and protein levels. (P < 0.05). Switching photoperiod from 8 L:16 D to 12 L:12 D increased the laying rates, GSI%, numbers of YFs and WFs, serum levels of PRL, and PRL protein expression in both groups (P < 0.05), and the responses were more pronounced in OPN5-immunized group (P < 0.05). In contrast to the control group, quail with OPN5-immunization had higher OPN5 and DIO2 transcript and/or protein levels but lower DIO3 expressions in the hypothalamus along the transition photoperiods (P < 0.05). The results revealed that OPN5 responds to photoperiod transition, and its activation mediates related signaling to up-regulate TSH-DIO2/DIO3 pathway and VIP-PRL secretion to prime quail reproductive functions.

Dietary supplementation with Dunaliella salina microalga promotes quail growth by altering lipid profile and immunity.

The goals of the current research are to ascertain the impacts of Dunaliella salina (DS) on quail growth, carcass criteria, liver and kidney functions, lipid profile, and immune response. Two hundred and forty 7-day-old quail chicks were divided equally into 4 separate groups with 6 replicates with 10 birds each. The groups were as follows: 1) control diet (the basal feed without DS), 2) control diet enriched with 0.25 g DS/kg, 3) control diet enriched with 0.50 g DS/kg, and 4) control diet enriched with 1.00 g DS/kg. Results elucidated that the birds which consumed 0.5 and 1 g DS/kg diet performed better than other birds in terms of live body weight (LBW), body weight gain (BWG), and feed conversion ratio (FCR). There were no significant changes in feed intake (FI) and carcass characteristics due to different dietary DS levels. Compared to the control group, DS-treated groups had better lipid profile (low total cholesterol and LDL values and high HDL values) and immune response (complement 3 values). The quails consumed feeds with different levels of DS had greater (P < 0.038) C3 compared to control. Adding 0.5 and 1 g DS/kg lowered blood concentrations of triglycerides and total protein (TP) values. The high level of DS (1 g/kg) had higher albumin values and lower AST values than other groups (P < 0.05). The creatinine values were at the lowest levels in the group consumed 0.50 g DS/kg feed. No changes (P > 0.05) were demonstrated among experimental groups in the ALT, urea, and lysozyme values. In conclusion, adding D. salina to growing quail diets enhanced growth, immune system, blood lipid profile, and kidney and liver function.

Exploring the effects of varying levels of selenium-chitosan on production performance, egg quality, and immune health in laying japanese quail.

The purpose of this research was to see how different levels of Se-chitosan, a novel organic source of Se, affected the production performance, egg quality, egg Se concentration, microbial population, immunological response, antioxidant status, and yolk fatty acid profile of laying Japanese quail. This experiment used a totally randomized design, with 5 treatments, 6 repeats, and 10 birds in each repetition. The dietary treatment groups were as follows: no Se supplementation (control group), 0.2 mg/kg Na-selenite supplementation, and 0.2, 0.4, and 0.6 mg/kg Se-chitosan supplementation. The feed conversion ratio (FCR) improved linearly in quails fed different levels of Se-chitosan compared to the control group (P < 0.05). Furthermore, Se-chitosan at concentrations of 0.2 and 0.4 mg/kg demonstrated both linear and quadratic increases in albumen height, Haugh unit, and yolk color in fresh eggs compared to the control group. Additionally, Se-chitosan contributed to enhanced shell thickness and strength, along with an increased Se concentration in the yolk. Se-chitosan supplementation at different levels linearly and quadratically reduced coliforms (COL) while increasing lactic acid bacteria (LAB)/coliform ratios (P < 0.05). Se-chitosan supplementation linearly and quadratically increased the total antibody response to sheep red blood cells (SRBC) and IgG titers (P < 0.05). It also linearly decreased the level of malondialdehyde in fresh and stored egg yolks and increased the activity of antioxidant enzymes catalase and glutathione peroxidase linearly, and superoxide dismutase (SOD) both linearly and quadratically in quail blood serum (P < 0.05). Additionally, supplementation of Se-chitosan at levels of 0.2 and 0.6 mg/kg linearly decreased the ∑ n-6 PUFA/∑ n-3 PUFA ratio in the yolk compared to the control group (P < 0.05). It can be concluded that incorporating Se-chitosan as a novel organic source of Se in the diet of laying quails can enhance production performance, egg quality, egg Se concentration, yolk lipid oxidation, microbial population, immune response, antioxidant enzyme activity, and yolk fatty acid profile.

Live performance, nutrient digestibility, immune response and fecal microbial load modulation in Japanese quails fed a Bacillus-based probiotic alone or combination with xylanase.

Animal industry seeks cost-effective solutions to enhance performance and health of domestic animals. This study investigated the effects of supplementing Bacillus spp. probiotics and xylanase on 2000 one-day-old Japanese quails, randomly assigned to four treatment groups (10 replicates). The control group received no supplementation, while the others were supplemented with a Bacillus-based probiotic at 7.5 × 107 cfu/kg of feed, xylanase enzyme (2,000 U/kg) alone or in combination. Quails receiving both probiotic and enzyme exhibited significantly (p < 0.01) higher weekly and overall weight gain, and lower feed conversion ratios compared to the control group. Dressing percentage was higher (p < 0.01), and mortality lower in birds supplemented with a combination of enzyme and probiotic. Antibody titres against infectious bronchitis and infectious bursal disease were significantly (p < 0.01) higher in quails receiving combined probiotic and enzyme supplementation, while titres against Newcastle disease virus were higher (p < 0.01) in groups supplemented with probiotic and enzyme individually or in combination. Additionally, digestibility was significantly (p < 0.01) higher in groups receiving combined enzyme and probiotic supplementation, with higher apparent metabolizable energy compared to the control. The populations of beneficial Lactobacillus increased, while harmful E. coli and Salmonella decreased significantly in quails supplemented with both probiotic and enzyme. In conclusion, supplementing xylanase enzyme and probiotic together in Japanese quails positively influenced growth, nutrient digestibility, immune response, and cecal microbiota.

Effects of dietary digestible lysine levels in breeding Japanese quails on productive and reproductive performance, egg quality, blood metabolites and immune responses.

BACKGROUND: The vegetable-based diet alone does not provide the lysine (Lys) needed to maximize poultry productive performance. OBJECTIVES: This experiment aimed to evaluate the effects of dietary digestible Lys (dLys) level on productive and reproductive performance, egg quality, blood metabolites and immune responses in breeding Japanese quails (Coturnix japonica). METHODS: The experiment was conducted in a completely randomized design with 6 treatments, 5 replicates and 15 (12 females and 3 meals) 10-week-old breeding Japanese quails each. A basal diet was formulated to meet nutritional requirements of breeding quails except dLys. The basal diet was supplemented with graded (+0.82 g/kg) levels of l-Lys-HCl, corresponding to dietary dLys levels of 0.690%, 0.755%, 0.820%, 0.885%, 0.950% and 1.015%. The experiment lasted for 12 weeks, which was divided into 3-4-week periods. RESULTS: Significant differences were observed for egg production (EP), egg mass (EM) and feed efficiency (FE) in response to increasing dietary dLys concentration with quadratic trends. The highest traits were observed in the birds fed with a diet containing 0.885% dLys. However, feed intake, egg quality, reproductive performance, blood metabolites and immune responses against sheep red blood cell inoculation were not significantly affected by increasing dietary dLys concentrations. The dLys requirements during 11-14, 15-18, 19-22 and 11-22 (overall) weeks of age for optimal EP, EM and FE, based on the quadratic broken-line regression analysis, were estimated 272, 265, 250 and 266; 293, 285, 264 and 279; and 303, 294, 281 and 293 mg/bird/day, respectively. CONCLUSIONS: The dLys requirements vary depending on the EP phase and the trait being optimized. The estimated dLys requirement for FE was higher than those for EP and EM. During the peak stage of the first laying cycle, the dietary dLys level of 0.932% and a daily intake of 303 mg dLys/bird are sufficient for optimal performance.

Protection of Chinese painted quails (Coturnix chinensis) against a highly pathogenic H5N1 avian influenza virus strain after vaccination.

Chinese painted quails immunized with a single dose (6 µg HA) of inactivated H5N1 (clade 1) influenza vaccine NIBRG-14 and challenged with 100 LD50 of the heterologous A/Swan/Nagybaracska/01/06(H5N1) (clade 2.2) strain were protected, whereas unvaccinated quails died after challenge. No viral antigens or RNA were detected in cloacal swabs from immunized animals. Sera obtained post-immunization gave low titres in serological assays against the vaccine and the challenge viruses. Our results demonstrate the protective efficacy of the NIBRG-14 strain against the challenge virus and the usefulness of these small birds in protection studies of influenza vaccines.

Growth and innate immunity are not limited by selection for high egg testosterone content in Japanese quail.

The effects of maternal androgens on fitness-related traits of offspring are generally assumed to be epigenetic adaptations to the environment that may be encountered by the next generation. Possible constraints of high yolk androgen transfer are still not understood, although a suppressed immune response in offspring is frequently considered. The aim of our study was to examine the innate immune defence in high (HET) and low egg testosterone (LET) lines of Japanese quail, which differ in the hormonal milieu of their eggs, thus providing a good physiological model for the study of androgen-mediated maternal effects. Acute phase response was induced by a lipopolysaccharide injection in 12-day-old quail and plasma corticosterone and the heterophil:lymphocyte ratio were measured at 1 and 3 h post-treatment. Basal levels of non-specific antibodies (IgY) were determined in the circulation. We found that HET quail were heavier than LET quail from the second week of age, indicating enhanced post-hatching growth. At 1 h post-lipopolysaccharide challenge, plasma corticosterone concentrations increased in the HET but not in the LET line. The heterophil:lymphocyte ratio rose in both lines at 3 h post-immune challenge, with a more pronounced response in HET quail. Moreover, HET chicks displayed higher IgY levels than LET chicks, suggesting either enhanced passive immunoprotection or stimulated endogenous antibody production. In conclusion, our data demonstrate that the genetic selection for high egg testosterone content positively influences growth and, simultaneously, does not limit the acute phase response in young quail.

Relative sensitivities of Japanese quail to foreign red blood cell challenges for immunotoxicity testing.

Given evidence that the immune system is sensitive to environmental contaminants, evaluating immunocompetence in toxicology studies is increasingly important. By incorporating a test of humoral response into controlled reproductive and developmental studies, more comprehensive results can be gathered to assess the potential for disease. The foreign red blood cells (RBC) challenge is a minimally invasive method for evaluating humoral responses to a foreign antigen. Typically, antibody response is assessed following injections of sheep erythrocytes; however, Japanese quail (Coturnix japonica) are only minimally sensitive to sheep RBC. In the present study, adult Japanese quail were treated with 5% solutions of RBC from goose, goat, cow, donkey, or pig in primary and secondary challenges. After each treatment, plasma samples were taken and antibody responses were measured for total immunoglobulins (Ig), IgG, and IgM. Overall, goose RBC generated the poorest responses in both primary and secondary challenges, while the strongest antibody responses were to pig and donkey RBC. Therefore, pig RBC appear to be a superior antigen for testing humoral response in Japanese quail.

Effect of feed contamination with aflatoxin B1 and administration of exogenous corticosterone on Japanese quail biochemical and immunological parameters.

Stress is the loss of homeostasis by external forces or stressors. Manipulation, transport, contamination, and other procedures involved in production could be considered stressors. Contamination is a problem commonly faced by producers in the poultry industry. Aflatoxicosis is one of the most common infections resulting from feed contaminated with Aspergillus flavus and Aspergillus parasiticus. This study evaluated the potential effects of the combined administration of aflatoxin B(1) (AFB(1)) and corticosterone on biochemical (concentration of globulins, proteins, and albumin) and immunological (inflammatory response and heterophil:lymphocyte ratio) parameters of Japanese quail. Potential sex effects on those parameters were also considered. The provision of corticosterone in drinking water is a method used for mimicking the effects of chronic stress in avian species. At 35 d of age, 24 mixed-sex groups of 4 animals (2 males and 2 females) were housed in cages and assigned to 1 of 4 treatments: plain drinking water and laying diet, corticosterone administration in drinking water, feed contamination with AFB(1) (100 µg/kg of feed), or corticosterone plus AFB(1) administration. There were 6 cages per treatment. No significant effect of sex in any of the parameters analyzed was detected. Hypoproteinemia, hypoalbuminemia, and hypoglobulinemia were observed in animals treated with corticosterone or contaminated feed. These responses were exacerbated when the factors were combined. The immunodepressive effect of corticosterone administration was confirmed, and a higher effect was noticed when combined with the aflatoxin contamination. Aflatoxin contamination affected birds' physiology similar to a chronic stressor stimulation because it elevates the heterophil:lymphocyte ratio. This study suggests that the effects of the AFB(1) contamination are further increased when overlapped with a chronic stressful stimulation and emphasizes the importance of controlling potential stressor combinations during animal rearing to preserve not only the animal's health status but also their welfare.

Lead induced thymic immunosuppression in Japanese quail (Coturnix japonica) via oxidative stress-based T cell receptor pathway signaling inhibition.

The human-induced lead (Pb) contamination brings about serious environmental issues around the world and it also poses severe risks to wildlife including birds. Avian thymus is one of primary lymphoid organs and it plays an important role in regulating T cell-based cellular immunity. Therefore, in this study, we tried to examine toxic effects and potential molecular mechanism of Pb on avian thymus using a biological model species-Japanese quail (Coturnix japonica). One-week-old Japanese quails were exposed to 0, 50, 500 and 1000 ppm Pb concentrations in drinking water for three weeks when thymus reached developmental climax. The results showed body weight, thymus weight and thymic size were reduced significantly by Pb exposure. Meanwhile, histopathological changes including vacuolation, cortex atrophy and nuclear debris were detected in thymic cells of Pb exposure. In addition, ultrastructural alterations such as mitochondrial damage, chromatin condensation, and nuclear destruction were found in the thymus of Pb treatments. The increase of reactive oxygen species (ROS) and Malondialdehyde (MDA) as well as the inhibition of antioxidant system indicated that Pb exposure caused oxidative damages in the thymus. Pb exposure also increased thymic cell apoptosis. Moreover, RNA-Seq analysis revealed that thymic functional pathways were disrupted by Pb exposure. Especially, Pb exposure disturbed T cell differentiation and led to T helper type 1 (Th1) /T helper type 2 (Th2) imbalance by interfering with T cell receptor signaling and cytokine signaling. This study implied that Pb caused thymic immunosuppression through causing morphological deformation, structural destruction, oxidation and molecular signaling disruption.