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Melanocortin 1-receptor (MC1R) is one of the major genes that controls chicken plumage colour. In this study, we investigated the sequence and haplotype distribution of the MC1R gene in native Japanese chickens, along with non-Japanese chicken breeds. In total, 732 and 155 chickens from 30 Japanese and eight non-Japanese breeds respectively were used. Three synonymous and 11 non-synonymous nucleotide substitutions were detected, resulting in 15 haplotypes (H0-H14). Of these, three were newly found haplotypes (H9, H13 and H14), of which one (H9) was composed of known substitutions C69T, T212C, G274A and G636A. The second one (H13) possessed newly found non-synonymous substitution C919G, apart from the known substitutions C69T, G178A, G274A, G636A and T637C. The third one (H14) comprised a newly discovered substitution C919G in addition to the known C69T, G274A and G409A substitutions. The homozygote for this new haplotype exhibited wt like plumage despite the presence of G274A. In addition to discovering a new nucleotide substitution (C919G) and three new haplotypes, we defined the plumage colour of the bird that was homozygous for the A644C substitution (H5 haplotype) as wheaten-like for the first time; although the substitution has been already reported, its effect was not revealed. Besides detecting the new plumage colour, we also confirmed that the A427G and G274A substitutions contribute in expressing brownish and black plumage colour respectively, as reported by the previous studies. Moreover, we confirmed that the buttercup allele does not express black plumage despite possessing a G274A substitution, under the suppression effect of A644C. In contrast, the birds homozygous for the birchen allele presented solid black plumage, which was contradictory to the previous reports. In conclusion, we revealed a large diversity in the MC1R gene of native Japanese chicken breeds, along with the discovery of a new non-synonymous nucleotide substitution (C919G) and three novel haplotypes (H9, H13 and H14).

In Japan, the majority of chicken meat is obtained from fast-growing broiler chickens. Because most Japanese chicken breeds have a low meat yield and egg production, many of these breeds are endangered. Recently, the palatability of meat and eggs of native chickens has been reevaluated in the Japanese market. Jidori, which means chicken from the local, is an indigenous local chicken that is more delicious, firmer in texture, and more expensive than the broiler chickens. Most Japanese consumers recognize that the meat of Jidori chicken is richer in flavor than that of the broiler chicken. However, the reason for this rich flavor of the meat of Jidori chicken has not been elucidated. Recently, we found that arachidonic acid (AA) (C20:4n-6), a polyunsaturated fatty acid, is associated with the rich flavor of the meat and eggs of Jidori chicken. The present paper summarizes the discovery of the involvement of AA in the flavor characteristic of the meat and eggs of chicken, and also the genetic regulation of the AA content in the meat and eggs of Jidori chicken.

The aim of the present study was to evaluate the characteristic of two native Japanese chicken breeds, Uzurao (UZ) and Chabo (CB) using two types of manual restraint tests for the detection of fearfulness. Each hen was grabbed by one hand or held in an underarm with mild pressure, whereas the other hand was used to restrain the legs. Thereafter, latencies to the first struggle and frequencies of struggling were recorded. The latency in UZ was shorter than that in CB (p 0.1). These findings demonstrate that UZ birds may be confirmed to respond less fearfully in fear-eliciting situations than CB birds and further suggest that the temperamental differences may correspond to genetic characteristics of breeds. Additionally, a newly developed technique, arm restraint, is useful to detec t fearfulness in chickens, similar to hand restraint.

The objective of the present study was to evaluate the temperament of a native Japanese chicken breed (TosaJidori) using the tonic immobility test for the detection of fearfulness. Each chick (2, 5, 10 or 15-day old) was placed on its back on a table and restrained by hand. Thereafter, if the chick lay still, it was then released and observed. The number of inductions and tonic immobility duration was recorded. The duration in the male was shorter than that in the female at 2-day old, whereas higher than that in the female at 15-day old. The duration of tonic immobility was affected by age in the male (P

Recently, we reported a method for identifying the Nagoya, a Japanese chicken breed. Here we describe an improved method suitable for use in conventional laboratories. Five microsatellite markers fixed in the Nagoya breed were amplified by multiplex polymerase chain reaction (PCR). The PCR products were digested with CEL I nuclease and electrophoresed in a ready-made gel. The fragment-length polymorphisms of each marker were detected clearly in the gel, and the resultant exclusion probabilities were almost equal to that in our previous data. This method can be used in laboratories without a DNA sequencer for routinely discriminating between the Nagoya breed and other chickens.

The Nagoya breed native to Japan is popular as a dual-purpose breed for eggs and meat. The current study describes a method to discriminate between the Nagoya breed and other breeds and commercial stocks of chicken. Four strains of the Nagoya breed established at the Aichi-ken Agricultural Research Center were analyzed using 25 microsatellite markers. In these strains, 5 of the markers (ABR0015, ABR0257, ABR0417, ABR0495, and ADL0262) had a single allele. Other chicken samples (448) of various breeds and hybrids were analyzed using the same 5 markers. None of these chicken samples had the same allele combination as the Nagoya breed strains. These 5 microsatellite markers provide a practical method to accurately discriminate the Nagoya breed from other chicken breeds.

1553 Background: It is well known that estrogen contained in contraceptive pills has a relationship with the incidence of hormone-dependent cancers. Conversely, there appears to be very little discussion concerning dietary estrogen from meat in relation to cancer incidence despite the fact that beef and chicken of most daily diets comes from animals fed with estrogen supplements. Thus, we evaluated estrogen concentrations in meat. Methods: Intra-tissue concentrations of Estradiol 17 Beta (E2) and Estrone (E1) were measured in beef (produced in USA, Japan: n = 40, 40) and chicken (produced in USA, Japan, Brazil: n = 25, 25, 25) by LC-MS/MS. Fat and red meat were examined separately in each meat. As a control we also analyzed fat tissues of postmenopausal Japanese women (n = 25). Results: Estrogen levels were generally higher in fat than in red meat. Median concentrations (pg/g) in Japanese chicken fat (E2 = 21.1, E1 = 65.7) and in USA chicken fat (20.7, 54.6) were the highest, and USA beef fat (14.0, 7.7) ...

The concentrations of progesterone, testosterone and estradiol in plasma were determined in Gifujidori hens during natural autumnal moult. The moulting period lasted 16-31 days and the hens lost 22.3-67.0g of their feathers. The plasma sex steroids decreased significantly and attained the lowest levels in the middle period of moult. The mean concentrations dur-ing moult were 86±5pg/ml in progesterone, 132±12pg/ml in testosterone and 38±3pg/ml in estradiol.