Appropriate timing of various seasonal processes is crucial to the survival and reproductive success of animals inhabiting temperate regions. When seasonally breeding animals are subjected to annual changes in daylength, dramatic changes in neuroendocrine-gonadal activity ensue. However, the molecular mechanism of photoperiodic (or seasonal) time measurement (PTM) is not well understood for any organism living. Japanese quail is an excellent model for studying PTM because of the rapid and dramatic response to photoperiod. Here I describe recent progress in understanding the molecular mechanism of PTM in Japanese quail.

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Guineafowl has been classified into the order Galliformes. However, little genetic information was available to establish the phylogenetic position of the Guineafowl. In the present study we subjected the mitochondrial DNA (mtDNA) of Numida mereagris, a representative member of Guineafowl, to complete sequencing. It was revealed that the mtDNA is a circular DNA of 16,726bp with a genomic structure the same as that of Gallus gallus var. domesticus and Coturnix japonica mtDNAs, though it is 62bp smaller than G. g. domesticus mtDNA and 29bp larger than C. japonica mtDNA. Similarities of the 13 genes and two ribosomal RNAs except D-loop and transfer RNAs between N. meleagris and G. g. domesticus and between N. meleagris and C. japonica ranged from 77.0% to 88.8% and from 76.2% to 88.4%, respectively. As the sequences of NADH dehydrogenase subunit 2 and cytochrome b genes have been reported for nine species (Bambusicola thoracis, Coturnix chinensis, C. japonica, G. g. domesticus, Gallus varius, Pavo cristatus, Perdix perdix, Phasianus colchicus, Tympanchus phasianellus) in the order Galliformes, the concatenated nucleotide sequences and amino-acid sequences of these two genes were subjected to phylogenetic analysis of N. meleagris against these nine species with Ayathya americana (Anseriformes) as an outgroup using a maximum likelihood (ML) method. The ML analyses of the first/second bases of codons, the third base of codons, and the amino-acid sequence consistently demonstrated that N. meleagris did not form clades with other species in the order but stayed in a remote position in the tree.

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To examine the appearance of ingested nonylphenol in the blood, liver and egg yolk of maternal Japanese quail (Coturnix japonica), 1 or 2mg of nonlyphenol in corn oil was orally administred once a day for 3 or 5 days. The droppings and eggs were collected during the 4th and/or 6th day of each experimental regime, then blood and liver were obtained by cervication at the end of that day. The HPLC-ECD method was used to determine the concentration of nonylphenol in each sample. Nonylphenol appeared in the blood, liver, egg yolk and droppings on the 4th and 6th day. In each case, its appearance significantly correlated with the dosage (p<0.01). The correlations in the blood, liver and egg yolk were similar, and no difference was observed between the 3-day and 5-day regime except for droppings. The results indicate that orally administered nonylphenol is absorbed in the alimentary canal, circulated in the blood, and accumulated in the egg yolk in Japanese quail.

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Shochu distillery by-product (SDBP) is usually dried before using as an ingredient of formula feed. But drying is costly and causes destruction of the nutrients. In the present study, a new technique for drying SDBP by the fermentation using Aspergillus Awamori was established. In a ventilated container with blender, 6ton of wheat bran, 70ton of SDBP and 4.9ton of used oil were successively mixed and fermented by Aspergillus Awamori (6kg) for 70 days at 40°C. At the end of the fermentation, a sample was taken to measure the nutrient contents and activities of enzymes. Crude protein content of the fermented product (30.1%) was almost twice that of wheat bran (17.7%). Fiber content of the fermented product (10.2%) was reduced to the half compared with SDBP (22.4%). Totally 65,958kg of water was evaporated during the fermentation which represents 99% of the total original moisture. Interestingly, 88% of the lipids and 58% of the fiber were consumed by the fermentation. More interestingly, crude protein loss was the lowest (25%) among all the nutrients. The cost of drying SDBP is much lower than that of the usual drying method using heat. It is also noteworthy that the fermentation product contains high activities of carbohydrases and protease which may help digestion in animals. In conclusion, the present fermentation method is an excellent low cost technique to dry SDBP and provide a high protein source of feed.

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Salmonellosis caused by Salmonella enteritidis (S. enteritidis) is a worldwide problem in recent years affecting the poultry production as well as public health. The ovarian immunity may play significant role in preventing such contamination because transmission of the bacteria in the ovary has been suggested as one of the routes of contamination of eggs. The aim of this study was to determine whether the expression of major histocompatibility complex class II (MHC-II) mRNA changes in response to S. enteritidis invasion of cultured ovarian tissues of laying hens. Ovarian stroma and the theca layer of small white follicles (SWF), the largest and third largest follicles (F1 and F3) were incubated with PBS (control), 1×10³ S. enteritidis (SE-low group) or 1×10⁶ S. enteritidis (SE-high group) for 0h, 2h and 4h in vitro. The expressions of MHC-II mRNA in these tissues were determined by reverse transcription-polymerase chain reaction (RT-PCR). MHC-II mRNA of a product size of 210bp was observed in ovarian stroma and follicular tissues. The expression of MHC-II mRNA was significantly increased following 4h of incubation with S. enteritidis in both SE-low and -high groups but not by 2h of incubation. Significant differences were not observed in the mRNA expression between SE-low and -high groups within the corresponding time regime. The expression of MHC-II mRNA was not significantly different among the SWF, F3 and F1 follicles incubated for same period and received similar doses of S. enteritidis bacteria. These results indicate that MHC-II mRNAs were expressed in the ovarian tissues and their expressions were increased in response to S. enteritidis invasion in these tissues and hen ovary is an inductive sites for immunoresponse against the invading S. enteritidis bacteria.

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The extracellular matrix surrounding the oocyte before ovulation is called perivitelline membrane (PL) in avian species. We previously reported that one of its components, ZPC, is produced in the ovarian granulosa cells by the stimulation of follicle-stimulating hormone and testosterone. Another component, ZP1, is synthesized in the liver, and might be transported to surface of the oocyte in the follicles. These glycoproteins are assembled to form a three-dimensional network of coarse fiber between the granulosa cells and the oocyte. In order to address the mode of PL formation, we investigated the progressive changes in contents of ZP1 and ZPC in PL during the follicular development in quail ovary. Western blot analysis using specific antisera indicated that ZP1 band was first appeared as 97kDa in molecular mass when the granulosa layer was isolated from the fourth largest follicle, and the intensity of the band was dramatically increased after the follicle matured to the third largest one. On the other hand, immunoreactive ZPC appeared as early as in the granulosa layer obtained from the small yellow follicles (SYF), and the intensity of the immunoreactive band increased progressively during follicular development. The immunohistochemical analysis indicated that the immunoreactive ZP1 and ZPC were not detected on the sections of follicular wall of the very small stroma-embedded white follicles. The immunoreactive ZPC was detected in the PL of SYF sections, whereas no detectable ZP1 was seen in the SYF sections. These results demonstrated that the accumulation of ZP1 was not synchronized to that of ZPC in the PL during follicular development. Alternatively, the accumulation of ZPC in the PL was preceded to that of ZP1 during follicular development in quail ovary.

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Some kinds of saponins are considered to depress body weight gain in chicks by reducing feed intake. Although the mechanism by which saponins exert such effects is unclear, tea saponin (TS) is known to delay the crop emptying. The purpose of the present experiment was to compare effects of TS, Quillaja saponin (QS) and Yucca saponin (YS) on growth rate and crop emptying using force-fed chicks. Chicks fed ad libitum a diet containing 0.5% TS, 0.5% QS or 2% YS depressed body weight gain and feed intake in a 7-d experiment. These adverse effects were alleviated by the concomitant addition of cholesterol. The growth retardation did not occur when feed intake of the diet containing 0.5% QS or 2% YS for 10d was equalized to that of the basal diet by force-feeding. On the other hand, it was difficult to continue the force-feeding of the diet containing 1% TS more than 3d because of the severe crop distention due to the ingesta. YS at the 2% in the diet also delayed the crop emptying, extent of which was milder than 1% TS. The concomitant addition of cholesterol alleviated the delayed crop emptying due to TS or YS. Force-feeding the diet containing 1% QS had little effect on the crop emptying, although the adverse effect of QS on feed intake was similar to that of TS or greater than that of YS. On the other hand, half of chicks force-fed the diet containing 1% QS died within 24-36h after feeding. These results indicate that the decreased feed intake plays an important role in the growth retardation due to saponins, and they also suggest that the delayed crop emptying is associated with the decrease in feed intake due to some saponins but not to all saponins.

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In order to examine the effects of the calcium regulating hormones on the differentiation of hen medullary bone osteoclasts, isolated medullary bone marrow cells were cultured for 8 days in media including parathyroid hormone (PTH), 1,25-dihydroxyvitamin D₃ [1,25(OH)₂D₃] or 17β-estradiol (E₂), respectively.
After 8 days of culture, tartrate-resistant acid phosphatase (TRAP) activity, a marker for osteoclasts, was enzymehistochemically detected on the cultured marrow cells and these cells were also stained with Mayer’s hematoxylin. Thereafter, TRAP-positive multinuclear cells were counted as osteoclast-like cells, and the effects of the calcium regulating hormones on the osteoclast differentiation from medullary bone marrow cells were indicated as the percentage (%) of the controls when vehicle was added in place of the hormones. As a result, treatment with PTH or 1,25(OH)₂D₃ significantly stimulated the differentiation of osteoclast-like cells, up to 218.3% or 159.2%, respectively. On the other hand, E2 treatment resulted in a moderate, but not significant, suppression of differentiation (85.8% of controls).
These results indicate that PTH and 1,25(OH)₂D₃ stimulate medullary bone osteoclast differentiation, but E2 is likely inhibitory.

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The goal of this study was to localize the T cell subsets and B cells in the testis and epididymis of roosters. Frozen sections of testis and epididymis were immunostained for CD4, CD8 and Bu1, which are the specific surface antigens of helper/inducer T cells, cytotoxic/suppressor T cells and B cells, respectively. Both CD4+ and CD8+ T cells were located in the interstitial tissues of testis. In the epididymis many CD4+ and CD8+ T cells were localized in the subepithelial layer (subepithelial stroma and fibromuscular layer) of efferent ductules and epididymal duct. Both T cell subsets were also distributed in the epididymal interstitial tissues. Some CD4+ and CD8+ T cells were localized in the lumen of efferent ductules and epididymal duct. No significant difference was observed in the frequencies between CD4+ and CD8+ T cells in each tissue. The Bu1+ B cells were observed in the testicular and epididymal interstitial tissues at a low frequency. These results suggest that in the testis and epididymis immunodefense system to pathogens are formed primarily by T cells. Cell-mediated immunoresponse to sperm may occur in the ductules of the epididymis, whereas induction of auto-antibodies to sperm may be prevented because of a low population of B cells and possibly by the regulation of CD8+ T cells.

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Shiitake mushroom stalk meal (SMM), which remains after the fruiting body is separated from the whole mushroom, had high moisture content (90%), and took four days to sun-dry or two days to dry in an electrical oven at 65°C. The chemical composition of the dry matter (DM) component was 15.11% crude protein (CP), 0.87% ether extract (EE), 27.87% crude fiber (CF), 49.18% nitrogen free extract (NFE),0.47% calcium (Ca) and 0.35% phosphorus (P). The CP, EE and P content in SMM were 66, 40 and 67% in the whole mushroom, respectively. The present findings that the SMM does not always fall far below rice bran in chemical composition suggest that the SMM has a possibility to be utilized as an alternative poultry feed.
True digestibility (TD) and metabolizable energy (ME) of SMM were determined using six Rhode Island Red cocks (one year old, 3.0kg) and six broiler cockerels (nine weeks old, 2.3kg). The digestibility of SMM in both chicken strains was almost the same, and averages were 34.19%DM, 26.9% CP, 72.33% EE, 45.66% CF and 56.05% NFE. True ME and apparent ME values of SMM were 1.58 and 1.20kcal/g air dry (or 1.71 and 1.30kcal/g DM) in Rhode Island Red cocks, and 1.50 and 1.17kcal/g air dry (or 1.62 and 1.27kcal/g DM) in broiler cockerels, respectively. The present results that the digestibility and the ME showed similar values in both chicken strains demonstrate that the values of digestibility and ME in new feed source estimated from layer chicken strain could also be applied to the broiler diets.

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