The mutant plumage color “extended brown (EB)” of the blue-breasted quail was genetically investigated. Mating experiments revealed that the EB plumage is controlled by an autosomal, incompletely dominant allele, for which we propose the symbol Eb. The EB plumage is characterized by dark brown color, and homozygotes for this mutation generally showed darker pigmentation than the heterozygotes. DNA sequencing and PCR-RFLP analyses of the EB mutants showed a rigid association between the EB plumage and a G-to-A nucleotide substitution at position 274 in the melanocortin 1-receptor gene (MC1R), clearly indicating that MC1R is the candidate gene for the EB plumage color in the blue-breasted quail.

The aim of this research was to investigate the deposition of carnosine in broiler muscles by feeding treatments comprising β-alanine, L-histidine, and magnesium oxide in various concentrations. The research was carried out on 120 Cobb 500 broilers divided into four groups. From weeks four to six, broilers were fed finisher mixtures as follows: P1, control group; P2, 0.5% β-alanine + 0.24% MgO; P3, 0.25% L-histidine + 0.24% MgO; and P4, 0.20% β-alanine + 0.10% L-histidine + 0.24% MgO. This paper presents the weights of broilers and their carcasses, portions of main parts of carcasses, technological quality of breast muscles, and concentrations of carnosine in breast and thigh muscles. The following traits of muscle tissue quality were measured: initial and final pH value (45 min after slaughtering pH₁, and 24 h after cooling pH₂), drip loss, color (Minolta colorimeter, expressed as CIE L*, CIE a*, and CIE b* values), meat softness, and cooking loss. Data on relative concentration of protein carbonyl (nmol/mg protein) in the muscles of breasts and thighs and levels of thiobarbituric acid-reactive substances (TBARS) in fresh and frozen breasts muscles (nmol/mg of tissue) are presented. Statistical analysis proved that feeding treatments had an effect on the live weight of broilers in the 4th, 5th, and 6th weeks of fattening (P<0.05), as well as on the carcass quality at slaughter (P<0.05; except the portion of wings), pH₁ value (P=0.035), CIE a* indicator (P=0.007), drip loss (P=0.002), and meat texture (P=0.008). Compared to the control group, synthesis and deposition of carnosine were increased in breast muscles in groups P2, P3, and P4 by 7.51%, 10.62%, and 62.93%, respectively, and in thigh muscles by 61.05%, 78.95%, and 89.52%, respectively. It was also confirmed that feeding treatments influenced the level of TBARS in frozen broiler breast muscles (P=0.014).

To determine whether buckwheat phytase can be used as an alternative phytase source, growth performance, bone quality and P retention were measured in broilers given non-phytate P-deficient diets. Non-germinated (BU) and germinated (GBU) buckwheat were used: they were ground and sieved to remove hulls before use. A total of 120 male broiler chicks (8 d of age) were divided into 8 groups (15 birds each) and given one of the following 8 diets until 42 d of age: positive control (PC) diet satisfying recommended level of all nutrients, negative control (NC) diet formulated to contain 0.16% lower non-phytate P than PC diet, and six other diets, formulated by replacing maize in NC diet with BU or GBU at 10%, 15% and 20% concentrations. Starter diets contained 23.5% crude protein (CP) and 3,200 kcal of ME/kg, and were used for 8–21 d of age. Then, grower diets with 20.5% CP and 3,250 kcal of ME/kg, and were provided for 22–42 d of age. Compared with the PC group, NC group showed impaired growth performance (BW gain, FI, and FCR), and bone quality (dry weight, breaking strength and contents of ash and P in tibia). However, in most cases, these impairments were ameliorated dose-dependently by the addition of BU and GBU in diets, and the restoration magnitude was greater in GBU than in BU treatment. Total P excretion decreased in NC group and further decreased dose-dependently with increasing levels of BU and GBU. Except for the values in PC group, total P retention increased as the total P excretion decreased. In conclusion, dietary BU and GBU restored the growth performance and bone quality impaired by the P deficiency, and improved P retention in broilers, which suggested that buckwheat, especially when germinated, can be used as an alternative phytase source in broiler diets.

Autophagy, an intracellular bulk protein degradation system in skeletal muscle, is increased under catabolic conditions resulting in muscle atrophy. This study aimed to investigate the effects of insulin, insulin-like growth factor (IGF)-I, and amino acids on autophagy (LC3-II content and expression of autophagy-related genes) in chick myotubes. Chick myotubes were incubated with insulin (1 µg/ml), IGF-I (100 ng/ml), and amino acids for 3 h. The LC3-II content, an index of autophagosome formation, and mRNA expression of LC3B and GABARAPL1 were significantly decreased by insulin. The LC3-II content, but not mRNA expression of autophagy-related genes, was also significantly decreased by IGF-I. The LC3-II content and LC3B mRNA level were also significantly decreased by amino acids. The mRNA expression of atrogin-1/MAFbx, a muscle-specific ubiquitin ligase, was also significantly decreased by insulin, IGF-I, and amino acids in chick myotubes. These results indicated that insulin, IGF-I, and amino acids regulate autophagy as well as the ubiquitin–proteasome proteolytic pathway in chick myotubes.

This study aimed to investigate the effect of replacing fat in broiler grower diet with sucrose combined with supplementation of the synthetic amino acid lysine on growth performance, gastrointestinal morphology, and blood biochemical parameters in broiler chickens. Broilers were raised for 21 days and then divided into two treatment groups (n=24 in each group). Two dietary treatments were used: corn-soy–based diet with oil (control) and corn-soy–based diet formulated with sucrose (3.30%) and lysine hydrochloride (3.36%). The experimental period was 21 days (from 21 to 42 days of age). At the end of week 6, all the birds in each treatment were slaughtered via neck slit, defeathered, and eviscerated for carcass and intestinal morphological characterization. Blood samples were collected to measure blood lipoprotein, triglyceride, and cholesterol levels. The results showed that supplementation of sucrose and lysine hydrochloride to broiler ration significantly (P<0.05) decreased feed intake by half and reduced average daily gain during the study period compared to those observed in broilers fed control diet. Further, this supplementation significantly altered gastrointestinal morphology and blood lipoprotein (HDL and LDL) and total cholesterol levels. In conclusion, corn-soy–based diet fortified with sucrose (3.30%) and lysine hydrochloride (3.36%) within current nutrient specifications has a negative effect on broiler growth performance.

The physiological functions of insulin-like growth factor-binding proteins (IGFBPs) in mammals have been evaluated in several studies. However, the physiological roles of IGFBPs in chickens have not yet been elucidated. In this study, we examined the effects of short-term (6 h) fasting and refeeding on the mRNA levels of IGFBPs in chick liver and brain. Eighteen 8-day-old chicks were weighed and allocated to three groups on the basis of body weight, and subjected to ad libitum feeding, 6 h of fasting, or 6 h of fasting followed by 6 h of refeeding. After the chicks were euthanized by decapitation, the liver and brain were excised, and the brain was dissected into six segments (telencephalon, optic lobes, cerebellum, rostral part of the brainstem, middle part of the brainstem, and caudal part of the brainstem). IGFBP mRNA levels were determined by qRT-PCR. Fasting significantly increased the mRNA levels of IGFBP-1 and -2 in the chick liver, and these changes were reversed by 6 h of refeeding. The mRNA levels of IGFBP-3 in the middle part of the brainstem and IGFBP-5 in the optic lobes were decreased by 6 h of fasting and were not reversed after 6 h of refeeding. These findings suggest that IGFBP-1 and -2 in the liver, IGFBP-3 in the middle part of the brainstem, and IGFBP-5 in the optic lobes may play physiological roles in response to short-term changes in the nutritional status of chicks.

In the present study, the effects of dietary buckwheat on phytase activity in the digesta from different parts of the digestive tract, and ileal digestibility of nutrients were determined in broilers fed with buckwheat diets. Eighty male broilers (29-d-old) were divided into four groups (20 birds each), and were fed one of the following diets until they were 36-d-old: positive control (PC) diet formulated based on the NRC recommendations, negative control (NC) diet containing 0.15% lower non-phytate phosphorus (P) than that in the PC diet, and two other diets formulated by replacing corn in NC diet with either 20% non-germinated (BU) or germinated (GBU) buckwheat. At the age of 36 d, broilers were sacrificed to collect digesta from the crop, gizzard, duodenum, jejunum, ileum, and cecum. The activity of phytase was low in the PC and NC diets, which increased in the BU diet and increased further in the GBU diet. A similar trend was observed in the crop digesta; however, the phytase activity in the crop digesta of BU and GBU diets was marginally lower when compared with that in each diet. These values decreased sharply when the digesta moved to the gizzard, and then decreased gradually. The ileal digesta exhibited significantly low activity with negligible effect of dietary treatment. The result of two-way analysis of variance with germination and digestive tract parts as main factors showed that the effect of digestive tract parts and interaction between factors was significant on the phytase activity in digesta. The dietary BU and GBU did not affect the ileal crude protein digestibility; however, it increased the ileal phytate P digestibility. These results suggest that in broilers, the crop might be the primary site of phytate degradation by buckwheat phytase, and the buckwheat might have negligible adverse effect on ileal digestibility of nutrients.

The aim of this study was to determine the changes in the expression of avian β-defensins (AvBDs) and proinflammatory cytokines and localization of AvBD2 in the intestine of broiler embryos and chicks during growth. The ileum and cecum of embryonic day 19 (ED19) and of day-old (D0) and 7-day-old (D7) chicks were collected. Gene expression levels of 10 AvBDs (AvBD1–8, 10, and 12) and proinflammatory cytokines (IL-1β, -6, and -8) were analyzed using real-time PCR, and the localization of AvBD2 was examined by immunohistochemistry. Gene expression levels of AvBD1, 2, 6, and 7 in the ileum and of AvBD1 and 4 in the cecum were higher on ED19 than on D7. The expression of AvBD10 in the ileum was higher on D0 than on ED19, whereas the expression levels of AvBD8 and 10 in the cecum were higher on D0 than on ED19, and that of AvBD10 decreased on D7. The expression levels of IL-1β, -6, and -8 in the ileum were higher on D7 than on ED19. The expression levels of IL-1β, -6, and -8 in the cecum were higher on D0 than on ED19, and that of IL-1β and -6 declined on D7. AvBD2-positive cells were localized in the lamina propria beneath epithelial cells of villi and crypts. The number of positive cells in the cecum mucosa was greater on D0 than on ED19 and D7. In conclusion, we suggest that AvBDs are expressed in the ileum and cecum of embryos and chicks at high levels before or just after hatching and decrease by D7. The expression of proinflammatory cytokines in the ileum increases with growth until D7, but is the highest in the cecum around hatching. These AvBDs and proinflammatory cytokines may play roles in host defense in the intestinal mucosa of embryos and neonatal chicks.

The aim of this study was to determine the effects of Toll-like receptor (TLR) ligands on the expression of cytokines in chicken follicular theca and to investigate whether nuclear factor-κB (NFκB) was involved in their expression. The follicular theca was collected from the largest follicle of laying hens. In experiment 1, the expression of TLRs in the theca interna and externa was confirmed using RT-PCR. The theca tissues were then incubated with or without Pam3CSK4 (TLR2 ligand), poly I:C (TLR3 ligand), LPS (TLR4 ligand), flagellin (TLR5 ligand), R837 (TLR7 ligand), and CpG-ODN (TLR21 ligand) for 3 h, after which cytokine expression (IL-1β, IL-6, TNFSF15, CXCLi2, IFN-α, and IFN-β) was analyzed by real-time PCR. In experiment 2, the theca tissues were incubated in a medium containing Pam3CSK4, poly I:C, LPS, or CpG-ODN with or without BAY 11-7085 (an inhibitor of NFκB) for 3 h. The results of experiment 1 revealed that all TLRs, namely TLR1 (type 1 and 2), TLR2 (type 1 and 2), 3–5, 7, 15, and 21, were expressed in the follicular theca, although the PCR products of TLR1 (type 2) and TLR21 were faint. Moreover, Pam3CSK4 and LPS upregulated the expression of all detected cytokines, except for IFN-α, whose expression was not upregulated by LPS. Poly I:C upregulated the expression of IL-6, CXCLi2, and IFN-β, while CpG-ODN upregulated IL-1β. Flagellin and R837 did not significantly affect cytokine expression. In experiment 2, the expression of IL-1β, IL-6, CXCLi2 and IFN-β in tissues incubated with LPS was downregulated by BAY 11-7085. These results suggest that the innate immune system, including pattern recognition by TLRs and cytokine synthesis, occur in the theca; whereas, functions for recognition of bacterial patterns is more developed than that of viral ones.

The present study investigated the effects of timing and intervals between repeated inseminations by different rooster breeds on the fathering of chicks. The semen from Barred Plymouth Rock (BP), Japanese Silkie White (JS), and White Plymouth Rock (WP) males were used. Eighteen hens (7-month-old BP) were divided into four Groups (A–D). In all groups, the hens were first inseminated with the semen from BP males at 3 pm on day 0. The hens in Group A (n=3) were inseminated with the semen from JS and WP males at 3 pm on days 5 and 10, respectively. Those in Group B (n=3) were inseminated with the semen from JS and WP males at 3 pm on days 5 and 15, respectively. The hens in Group C (n=6) were inseminated with the semen from JS and WP males at 6 am on days 5 and 10, respectively. Lastly, those in Group D (n=6) were inseminated with the semen from JS and WP males at 6 am on days 10 and 20, respectively. The chicks obtained were classified on the basis of their phenotype matching with the breeding male phenotype. The majority of chicks (82.4% to 100% in Groups A and B) were fathered by the sperm from the subsequent insemination when repeated insemination was performed in the afternoon. Moreover, the chicks produced by the most recent insemination in the groups that were subjected to morning insemination could be obtained the next day after insemination (Groups C and D). The percentage of chicks fathered by the sperm from the subsequent insemination was 95.2% to 100% when the inter-insemination interval was 10 days (Groups B and D); these percentages decreased when the duration of the interval between inseminations was decreased to 5 days in Groups A, B, and C.