Korean Ogol chicken has been registered as a natural monument in Korea and regarded as a valuable genetic resource for the world. As an initial step to investigate the genetic structures of this breed, phylogenetic analysis and calculation of genetic diversities have been performed using mitochondrial DNA (mtDNA) sequence variations. A total of 31 Korean Ogol chicken was grouped into four haplotypes and the large haplotype was represented in 12 individuals. The unrooted neighbor-joining tree indicates that the Korean Ogol chicken shared three (A to C) major chicken lineages representing the high genetic variability of this breed. These results can be used for making the breeding and conservation strategies for the Korean Ogol chicken.

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The purpose of this study was to obtain detailed quantitative information on all cell types in the testis interstitium of Korean ring-necked pheasants and to combine these data with changes in the steroidogenic function of the testis during the breeding and non-breeding seasons. For animals collected during the breeding season, their testis weights, sperm production, serum testosterone levels and leuteinizing hormone (LH)-stimulated testosterone secretion were significantly (p < 0.01) increased compared to the non-breeding season. Testes of the pheasants during the non-breeding season displayed a 98% reduction in testis volume that was associated with a decrease in the absolute volume of seminiferous tubules (98% reduction), tubular lumen (100%), interstitium (90%), blood vessels (84%), lymphatic spaces (97%), Leydig cells (79%), mesenchymal cells (51%) and myoid cells (61%) compared to the breeding season. The numbers of Leydig cells, mesenchymal cells and myoid cells per testis in the breeding season were much higher than in the non-breeding season. Although the mean volume of a Leydig cell was 74% lower in the non-breeding season, the mean volumes of myoid and mesenchymal cells remained unchanged. These results demonstrate that there are striking differences in the testicular structure of the Korean ring-necked pheasant during the breeding and non-breeding seasons. Every structural parameter of the Leydig cell was positively correlated with both testosterone serum levels and LH-stimulated testosterone secretion. The correlation of changes in hormonal status with the morphometric alterations of Leydig cells suggests that the Korean-ring necked pheasant may be used as a model to study structure-function relationships in the avian testis.

This experiment was conducted to investigate the effect of dietary supplementation of the black soldier fly (bsf) larvae on growth performance, carcass rate, and fatty acid profile of chicken meat in broiler chicks. Four hundred eighty 1-d-old broilers (Ross 308) were distributed into 3 treatments with 4 pens at 30 birds per replicate. Treatments were cornsoybean meal based broiler diet (control) and the basal diet replaced with bsf at the level of 3 and 6% respectively. Viability was not different significantly. Body weight gain was higher in control than other treatments. Feed intake was not statistically different of treatments. Feed conversion ratio was lower in control than other treatments. Relative weight of breast meat was significantly increased in all treated groups than in control. But, another relative weights of chicken meat cuts (thigh, wing, neck, back) were not significantly different among the groups. In conclusion, it could be suggested that dietary supplementation of black soldier flylarvae could beneficially improved the performanceon broiler.

ABSTRACT. Since the status of endogenous avian leucosis/sarcoma virus (ALSV) infections in Korean broiler chickens is unclear, this study examined embryonated eggs obtained from broiler farms and Korean native chicken breeds in Korea using PCR with the primer sets specific for endogenous ALSVs. The PCR assays detected the genomes of EAV, ev, ev/J and ART-CH belonging to the endogenous ALSV from all embryos tested. Phylogenetically, the Korean EAV genomes were more closely related to the prototype EAV-0 than to the other prototype, E51. The Korean ART-CH elements clustered together but were distinct from the prototype ART-CH clones, 5 and 14. Although there was comparatively little divergence in the nucleotide and amino acid sequences of the Korean ev and ev/J genomes compared with the other known ev and ev/J genomes, the Korean genomes had phylogenetically distinct branches. From these results, endogenous genomes are quite prevalent in Korean broiler chickens. In addition, the endogenous genomes circulating in Korean broiler chickens are genetically different from the other known endogenous genomes. These results are expected to provide useful information for the control and establishment of a surveillance system for endogenous ALSVs in Korea. KEY WORDS: avian leukosis/sarcoma virus, chickens, genetic divergence, prevalence.J. Vet. Med. Sci. 70(1): 17-23, 2008 Avian leukosis/sarcoma viruses (ALSVs) in chickens are classified into 6 subgroups (A, B, C, D, E and J) based on their host range, viral interference patterns with members of the same and different subgroups, and viral envelope antigens [5,9]. ALSVs can be divided into exogenous or endogenous viruses according to the way they are transmitted in nature [5]. Exogenous viruses (subgroup A, B, C, D and J) are spread as infectious virions, either vertically from hen to progeny through the egg, or horizontally from bird to bird [4]. ALSVs A, B and J are commonly encountered in the field but C and D appear to be rare [5].Endogenous viruses are integrated into the genome through the germline of normal chickens and are transmitted genetically in the Mendelian manner [6,7,14,16]. These include the endogenous viral (ev) loci and the more recently discovered moderately repetitive elements, EAV (endogenous avian virus) and ART-CH (avian retrotransposon from chicken genome), as well as the highly repetitive elements, CR1 (chicken repeat 1). The genetic sequences of the ev loci are related to the subgroup E ALSVs of which there are more than 50 different ev loci [2]. Each chicken has been reported to carry on average of approximately 5 ev loci [5]. Some of ev loci encode infectious endogenous retroviruses closely related to ALSVs, while others are defective [5]. The biological functions of the EAV, ART-CH and CR1 remain to be determined. The EAV family is restricted to all Gallus species, while the evs are specific to domestic chickens and their wild relative red jungle fowl only, and are therefore younger than EAV [2]. EAV is present at approximately 50 copies per h...