As of 2014, 89 species have been legally designated as “nationally endangered species of wild fauna and flora,” including 37 avian species in Japan. To facilitate the breeding of endangered species and the maintenance of protected habitats, a program for the rehabilitation of natural habitats and maintenance of viable populations is being established by the Ministry of the Environment and other related ministries for 49 of the species on the above list. The programs have already been established for 15 such avian species, and are currently managed by zoos or local authorities. Maintaining genetic diversity is necessary to ensure the stable procreation of endangered species. A decline in breeding potential due to inbreeding can be prevented by careful maintenance of genetic diversity. In addition to the prevention of inbreeding depression, the maintenance of genetic diversity safeguards species’ resistance to pathogens, as well as their capacity to cope with environmental change. This manuscript reports on the status of currently available genetic information for nationally endangered avian species in Japan, with a particular focus on the 15 species included in the conservation and propagation program. In the NCBI “Nucleotide” database, 315 entries were related to sequence information from the 15 endangered species. Mitochondrial DNA-related sequences constituted 238 (75.6%) of these entries. In the NCBI “Genome” database, genome sequence entries for three species were found. As is the case with mitochondrial DNA, microsatellite loci are very useful for endangered species conservation to evaluate genetic diversity. However, information about the endangered avian species’ microsatellite makers is limited. This situation could have a considerable negative impact on captive breeding projects in particular. Hence, the development of microsatellite markers for these species is a priority.
The effect of two different contamination levels of T-2 toxin (1.5 or 3.4 mg/kg feed) was investigated in a 28-days feeding trial on body weight, relative weight of liver and spleen, and some lipid peroxidation and glutathione redox parameters of 14-days old broiler chicken. The results showed that T-2 toxin decreased significantly the body weight at both contamination levels and showed a dose-dependent tendency. Relative weight of liver increased till the end of the trial, while relative weight of spleen was lower at both samplings at lower level of T-2 toxin exposure. Initial phase of lipid peroxidation (conjugated dienes and trienes) was not detected in the liver, but as product of later phase, thiobarbituric acid reactive substances increased significantly, except in the liver. Glutathione content on day 14 was higher in liver homogenate as compared to the control at the lower T-2 toxin contamination level. On day 28 it was higher in blood plasma at the higher and in liver homogenate at both levels of T-2 contamination. Glutathione peroxidase activity on day 14 was significantly higher in liver and spleen homogenates as compared to the control at the lower level of T-2 toxin contamination. On day 28, significantly higher activity was found at both T-2 toxin contamination levels in liver homogenate, and at the lower contamination level in spleen homogenate as compared to the control. The results revealed that T-2 toxin exposure initiates lipid peroxidation and activates the glutathione redox system as well, but the changes were irrespective of the dose- and partly duration of the exposure.
Brain-gut peptides play important roles in the appetite regulatory system in mammals. Glucagon-like peptide (GLP)-1, GLP-2, and oxyntomodulin (OXM) are processed from the same precursor, proglucagon, in both brain and intestines in mammals and birds. We previously showed that intracerebroventricular administration of these three peptides significantly suppressed food intake in chicks. However, peripheral roles of chicken GLP-2 have not yet been investigated, although GLP-2 plays important roles both in central and peripheral regulation of food intake in mammals. The aim of this study is to investigate whether GLP-2 functions as an anorexigenic peptide in both brain and peripheral circulation in chicks. Intracerebroventricular administration of GLP-2 significantly suppressed food intake in chicks. Twenty-four hours of fasting significantly decreased the mRNA level of proglucagon in the medulla oblongata of chicks. These results suggest that GLP-2 functions as anorexigenic peptides in the central nervous system in chicks. In addition, intravenous administration of GLP-2 significantly suppressed food intake in chicks. Lines of evidence suggest that dietary nutrients stimulate the secretion of GLP-2 from L cells in the small intestine in chickens. These findings suggest that GLP-2 functions as both central and peripheral anorexigenic signals in chicks.
Cordyceps militaris waster medium (CMWM) is a by-product of the edible portion of the fruiting body of Cordyceps fungi. This study was conducted to investigate the effects of the CMWM on the production performance, egg quality and egg yolk cholesterol of laying hens. An in vitro study showed that the reducing power of the CMWM extracts increased linearly with its concentration; at a concentration of 4.0 mg/mL, it reached a level of roughly 60% ascorbic acid at 0.5 mg/mL, while inhibition of lipid peroxidation of the CMWM extracts at 15.0 mg/mL reached nearly 50%. Sixty 22-week-old laying hens (Hendrix) were randomly allocated into 4 groups with 5 replicates, 3 birds per replicate. They were fed diets supplemented with the following levels of the CMWM: 0 (control group, corn-soybean meal), 5.0, 10.0, or 20.0 g/kg dried CMWM groups for 12 weeks, respectively. The results revealed that the 20.0 g/kg CMWM group exhibited significantly decreased feed conversion ratio (FCR) and increased egg white weight compared to the control group at 5-8 and 9-12 weeks. The supplemented CMWM groups showed significantly elevated egg mass in comparison to the control group at 5-8 and 9-12 weeks. There were no effects for egg yolk weight, egg shell weight, shell thickness and egg yolk color between the groups. Those groups which were supplemented with 10.0 and 20.0 g/kg dried CMWM showed significantly decreased egg cholesterol compared to the control group at 9-12 weeks. On the basis of these observations, we concluded that CMWM, a by-product of Cordyceps militaris, could be employed as a new feed additive that offers potential benefits for elevating egg mass and producing lower cholesterol eggs by laying hens.
The effects of supplemental protein source, and amino acid (AA) and apparent metabolizable energy (AME) densities in the diets of broilers on their growth performance and intestinal development were reported in companion studies. The effects of protein source, and AA and AME densities on the tibias of male Ross × Ross 708 broiler chicks were investigated in the current study. A completely randomized block design with a 2 × 2 × 2 factorial arrangement of treatments was applied (10 blocks, 8 treatments/block, 14 chicks/pen). Diets fed from 8 to 21 days of age (d) were formulated to contain two protein sources [high inclusion of distiller’s dried grains with solubles diet (hDDGS) or high inclusion of meat and bone meal diet (hMBM)], two AA densities (moderate or high) and two AME densities (moderate or high). Tibias from 2 chicks/pen at 21 d were sampled. Chicks fed a high AA diet exhibited longer tibias than did chicks fed a moderate AA diet. Chicks fed hDDGS diets with a high AME density exhibited larger tibia circumferences as compared to those fed hMBM diets with a high AME density. Dietary treatment did not affect tibia breaking strength, ash content, or calcium, phosphorus, potassium, zinc, manganese, and magnesium concentrations in the tibia. Because feeding chicks high AME diets increased their BW, the weights of their tibia, and tibial calcium and phosphorus weights relative to BW were decreased. In birds fed high AA diets, the feeding of hMBM diets improved tibia breaking strength relative to BW when compared to the feeding of hDDGS diets. In conclusion, either hDDGS or hMBM diets can be fed to male broilers from 8 to 21 d without affecting mineral deposition in their tibias. In addition, high AME diets may improve broiler BW without affecting tibia strength.
The present study was carried out to evaluate the effects of supplementing reduced-protein diets with L-carnitine on growth performance and occurrence of pulmonary arterial hypertension (PAH) syndrome in broiler chickens reared at high altitude. A total of 156 day-old male broilers (Ross 308) were assigned to three dietary treatments and reared up to 42 days of age. A normal-protein diet (NPD) was formulated according to the National Research Council (1994) and served as control. A reduced-protein diet (RPD) was also prepared to contain 3% less protein than that of the NPD. An additional RPD diet was prepared by supplementing L-carnitine (LC) at 100 mg/kg to the RPD. Results showed significant improvements in feed:gain and carcass yield in birds fed on RPD when supplemented with LC. The proportions of liver, heart, and abdominal fat pad relative to body weight and the right ventricular weight ratio (RV:TV) were significantly higher in birds fed on the RDP than those of the control fed the NPD. Electrocardiogram (ECG) measurements recorded from lead II supported the development of PAH in birds fed RPD as evidenced by deep S waves. Supplementing LC to the RPD significantly reduced the liver weight, abdominal fat deposition, and RV:TV, which reflected in reduced S waves. Feeding broilers with the RPD significantly reduced serum concentrations of nitric oxide (NO) and uric acid (UA). However, supplementation of the RPD with LC significantly increased the serum concentrations of NO. In conclusion, feeding reduced-protein diets to broilers reared at hypobaric hypoxia increases their susceptibility to pulmonary hypertension. Dietary LC supplementation of reduced-protein diets had beneficial effects in preventing PAH mortality mainly through enhancing blood NO concentration.
Two experiments were conducted to evaluate the effects of incubational oxygen concentration on fatty acid metabolism and heme synthesis in broiler breeder embryos. We measured the hepatic activities of δ-aminolevulinic acid dehydratase (ALAD) and 3-hydroxyacyle Co-A dehydrogenase (3-HADH) as these enzymes are the limiting steps in heme synthesis and fatty acid metabolism, respectively. We found no differences in ALAD activity between days 17 and 20 of incubation; we hypothesize that this is because heme synthesis is relatively constant at the later periods of embryonic development. 3-HADH activity was higher in chicks hatched from eggs incubated under low oxygen conditions during early incubation, while specific ALAD activity was reduced in this group as compared to controls.
The effects of fasting on expression of atrogin-1/MAFbx in various skeletal muscles of broiler chickens were investigated. Real-time PCR analyses revealed that mRNA expression of chicken atrogin-1/MAFbx was higher in the soleus, gastrocnemius, and biceps femoris than in the pectoralis superficialis under normal nutritional conditions. Compared to normal nutritional conditions, fasting (24 h) induced a 5-, 11-, 9-, and 7-fold increase in atrogin-1/MAFbx mRNA in the pectoralis superficialis, biceps femoris, gastrocnemius, and soleus muscles, respectively. These results indicate that the effects of fasting on expression of the atrogin-1/MAFbx gene vary among various skeletal muscles of broiler chickens.
Glucagon-like peptide-1 (GLP-1) is secreted by L cells in the small intestine in response to food ingestion. The influence of supplementation to diet with the amino acids, methionine (Met) and lysine (Lys), on the L cells in chicken small intestine was investigated using immunohistochemical and morphometrical techniques. Many endocrine cells showing immunoreactivity for GLP-1 antiserum were observed in the control, crude protein (CP) 0%, CP 0%＋Met and CP 0%＋Lys groups. The GLP-1-immunoreactive cells in all the groups were “open-typed” endocrine cells as viewed under light and electron microscopes. Differences in the shape and distributional pattern of GLP-1-immunoreactive cells were not observed between the control and experimental groups. Frequencies of the occurrence of GLP-1-immunoreactive cells in the CP 0%＋Met and CP 0%＋Lys groups were significantly lower than that of the CP 0% group, but significant differences were not recognized between the control group and the CP 0%＋Met and CP 0%＋Lys groups. Secretory granules in the control group were round to oval in shape. Elongated secretory granules were observed in the experimental groups, but not in the control group. Ratios of GLP-1-immunoreactive cells with elongated secretory granules in the CP 0%＋Met and CP 0%＋Lys groups were decreased compared with that in the CP 0% group. The size of round secretory granules in the control group was larger than that in all the groups. However, sizes of round secretory granules in the CP 0%＋Met and CP 0%＋Lys groups were larger than that in the CP 0% group. These morphological results indicate that amino acids may be a signal that influences on the secretion of GLP-1 in chicken small intestine.
In the present study, chicken primordial germ cells (PGCs) were transfected with GFP gene in vitro or in vivo using the piggyBac transposon vector system. PGCs cultured for 465 days were transfected in vitro, and GFP gene expression was observed in 25% of the treated PGCs after culturing for further 42 days. The cultured PGCs expressing GFP gene were transferred to recipient embryos and strong GFP gene expression was observed in the recipient gonads at day 18.5 of incubation. Circulating PGCs were transfected in vivo, and intense GFP gene expression was observed in the gonads of recipient embryos at day 18.5 of incubation. The procedure employed in the present study will contribute to successful gene transfer into chickens.
This study was carried out to investigate the presence of turkey astrovirus 2 (TAstV-2), turkey coronavirus (TCoV) and haemorrhagic enteritis virus (HEV) by molecular methods in cloacal swabs collected from both clinically healthy turkey flocks and those associated with poult enteritis mortality syndrome (PEMS) in Turkey. In the reverse transcriptase polymerase chain reaction (RT-PCR) examination of 230 cloacal swabs collected from 23 turkey flocks associated with PEMS, TAstV-2 was detected in 13.4% (31/230) of the animals and in 43.4% (10/23) of the flocks. In addition, this virus was found in two turkeys originating from one of the four clinically healthy flocks. On the other hand, neither TCoV nor HEV were detected in any of the turkey samples examined in this study. In the partial sequence analysis of four randomly selected DNA samples, 96% nucleotide identity was observed between our strains and reference Turkey astrovirus isolated from turkeys in Italy between 2000 and 2004 (sequence accession number DQ381378.1).
This study was designed to characterize the role of P22 in the intracellular survival and pro-inflammatory responses in Salmonella-infected chicken macrophage-like HD11 cells. The intracellular survival of Salmonella Typhimurium was evaluated in the presence or absence of P22 at 24 h postinfection (hpi). The production of inflammatory mediators, including nitric oxide (NO), IL-1β, IL-6, IL-8, and IL-10, was determined at 0 and 24 hpi by using ELISA kits. The survival rates of intracellular S. Typhimurium were effectively reduced to 8.1% in Salmonella-infected HD11 cells treated with P22 at 24 hpi. The secretion of NO, IL-6, IL-8, and IL-10 varied with infection period and bacteriophage treatment. The reduction of intracellular S. Typhimurium was highly correlated with the enhanced production of NO (r＝0.816, P<0.001). The results suggest that bacteriophage can be used to control the intracellular pathogens. This study would provide useful information on the bacteriophage-host interactions and open the door for designing an effective and safe bacteriophage therapeutic system.