Helicoverpa armigera is a serious polyphagous pest inflicting losses to various kinds of food crops. Among dis-infestation methods, methyl bromide (MeBr) has been widely used in quarantine treatments. However, after regulation as ozone depleting substance, MeBr is restricted in use. Phytosanitary irradiation has been suggested as an useful alternative to MeBr. In this study, H. armigera adults were irradiated with 400 Gy which was decided as a critical dose to the adults by the preliminary experiments. The irradiated females and males were mated reciprocally with fresh ones. Some of the both sexes were subjected to comet assay to determine the degree of DNA damage by gamma ray irradiation. There was no significant difference in fecundity among mates. However the irradiation significantly affected hatchability of F1 eggs. No F1 eggs hatched in the mate of treated female (TF) x treated male (TM). Hatchability of F1 eggs from TF x UM (untreated male) and UF x TM mates were 0.3% and 1.1%, respectively. A few larvae from UF x TM mate developed up to adults. Comet assay indicated that gamma-ray irradiation is efficient in damaging male's DNA than female's which may be the cause of dramatic decrease in F1 hatchability.

genetic selection has resulted in modern dairy cow with very high milk yields but reduced fertility, due mainly to an increase in reproductive disorders. The study was conducted to estimate the proportion of reproductive disorders among dairy cattle. The factors analyzed were; milk yield, cow parity, periparturient disorders, and reproductive status. The result of this study showed the incidence of reproductive disorders in high yielding dairy cows was prevalent. Repeat breeding was the major postpartum reproductive problem comprising (42.3%) of the samples. Higher reproductive disorders were also associated with lower parity. These disorders subsequently reduced reproductive performance by prolonged intervals from calving to first artificial insemination and from calving to pregnancy. Abnormalities in the reproductive system such as repeat breeder, silent heat, anestrous and ovarian cysts, as well as lower fertility have been recorded during the summer months (June to August). In conclusion, the study revealed that incidence of repeat breeder is mostly prevalent in dairy cows. Moreover, the incidence of reproductive disorders was higher in summer season and hence appropriate preventive and or therapeutic measures as per the type of abnormalities need to be undertaken.

본 연구는 흑염소 사양체계 확립에 대한 기초자료를 얻고자 방목과 사사형태의 사육이 흑염소의 번식능력과 자축의 발육성적에 미치는 영향을 조사하였다. 공시축은 흑염소 36두를 방목구와 사사구로 나누어 처리구당 18두씩 공시하여 2011년 4월부터 11월까지 8개월간 수행하였다. 단태의 비율은 방목구가 31.5%, 사사구가 37.0%로 통계적인 차이는 나타나지 않았다. 산자수는 방목구와 사사구가 각각 1.76과 1.69두로 사육형태에 따른 차이가 나타나지 않았으며, 이유 시의 두수는 방목구가 사사구 보다 높은 경향으로 나타났다(p=0.11). 사육형태에 따른 생시체중은 방목구가 2.3 kg, 사사구가 2.29 kg 로 나타나 차이가 나타나지 않았으나, 생후 90일 령 이유 시 방목구가 9.97 kg 로 사사구의 9.45 kg 보다 높은 경향으로 나타났으며(p=0.09), 포유기간 일당증체량에서도 방목구가 사사구 보다 높은 경향으로 나타났다(p=0.13). 이상의 결과를 종합해 보면, 흑염소를 방목과 사사형태로 사육하였을 때, 분만형태, 산자수 및 생시체중에는 차이가 없었으나, 이유두수 및 자축의 일당증체량에서는 방목사육 형태가 우수한 경향으로 나타나, 방목이 흑염소의 생리적 욕구를 충족시켜 건강한 흑염소 생산에 기여 할 것으로 판단된다.

본 연구는 흑염소 사양체계 확립에 대한 기초자료를 얻 고자 방목과 사사형태의 사육이 흑염소의 번식능력과 자축 의 발육성적에 미치는 영향을 조사하였다. 공시축은 흑염 소 36두를 방목구와 사사구로 나누어 처리구당 18두씩 공 시하여 2011년 4월부터 11월까지 8개월간 수행하였다. 단 태의 비율은 방목구가 31.5%, 사사구가 37.0%로 통계적인 차이는 나타나지 않았다. 산자수는 방목구와 사사구가 각 각 1.76과 1.69두로 사육형태에 따른 차이가 나타나지 않았 으며, 이유 시의 두수는 방목구가 사사구 보다 높은 경향 으로 나타났다(p=0.11). 사육형태에 따른 생시체중은 방목 구가 2.3 kg, 사사구가 2.29 kg 로 나타나 차이가 나타나지 않았으나, 생후 90일 령 이유 시 방목구가 9.97 kg 로 사사 구의 9.45 kg 보다 높은 경향으로 나타났으며(p=0.09), 포 유기간 일당증체량에서도 방목구가 사사구 보다 높은 경향 으로 나타났다(p=0.13). 이상의 결과를 종합해 보면, 흑염 소를 방목과 사사형태로 사육하였을 때, 분만형태, 산자수 및 생시체중에는 차이가 없었으나, 이유두수 및 자축의 일 당증체량에서는 방목사육 형태가 우수한 경향으로 나타나, 방목이 흑염소의 생리적 욕구를 충족시켜 건강한 흑염소 생산에 기여 할 것으로 판단된다.

This study was carried out to investigate the reproductive and growing performances in sow farms located in Chungnam. Data collected from a total of 15 sow farms divided into 3 farm groups for 1 year were analyzed. The results obtained were as follows; The average of sow at small and large farms were 114.25 and 487.88 heads, respectively. And then, the difference among 3 groups in sow farm was not found significantly in farrowing rate. The significant difference among 3 farm groups was significantly found(p<0.05) in total litter size. The litter size born alive at sucking in small sow farm and middle farms were 9.93, and 10.48 pigs. The difference between small and large farms in number of pigs at weaning were significantly shown 8.89, and 9.35 pigs(p<0.05), respectively. The difference among 3 sow farms for ages at weaning showed significantly (p<0.05). The cycles of farrowing rate per year in small, large and middle farms were 2.17, 2.23 and 2.32, respectively. The significant difference among 3 sow groups was found in farrowing rate(p<0.05). The growing rate up to weaning for middle farms was significantly the higher level(94.70%) than that for other farms(p<0.05). The differences among 3 farm groups for marketing weight were not significantly shown.

본 연구에서는 지구온난화 조건에서 한국의 주요 작물인 백태와 서목태의 식물계절, 잎 수, 원줄기의 마디 수, 가지 수, 식물개체당 총 종자 수와 총 꼬투리 수, 식물개체당 총 종자 무게, 꼬투리당 종자 수 그리고 종자 하나의 무게에 대한 반응을 알아보았다. 이를 위해 CO2농도가 일반 대기조건과 같은 대조구와, CO2농도와 온도를 상승시킨 처리구에서 두 종의 콩을 생육시켜 관찰하였다. CO2농도는 540 ppm으로, 온도는 처리구가 대조구보다 2.2℃ 상승하도록 설계하였다. 그 결과 백태의 최초 개엽시기, 서목태의 최초 개화시기와 열매성숙시기는 대조구보다 처리구에서 늦어졌다. 백태와 서목태의 잎, 가지 그리고 원줄기의 마디의 수는 대조구와 처리구간에 차이가 없었으나 서목태의 가지 수는 처리구에서 6월에만 적었다. 백태의 종자 하나당 무게와 꼬투리당 종자 수는 대조구와 처리구 간 차이가 없었으나, 식물개체당 총 꼬투리 수와 식물개체당 총 종자 수는 대조구보다 처리구에서 적었다. 그러나 식물개체당 총 종자무게는 대조구와 처리구 간에 차이가 없었다. 서목태의 종자 하나당 무게와 꼬투리당 종자 수는 대조구와 처리구 간 차이가 없었으나, 식물개체당 총 꼬투리 수는 대조구보다 처리구에서 적었다. 또, 식물개체당 총 종자 수는 대조구와 처리구간 차이가 없었으나, 식물개체당 총 종자 무게는 대조구보다 처리구에서 더 가벼웠다. 이상으로 볼 때, 지구온난화로 백태는 종자 수가 감소하고 서목태는 최초 개엽, 개화, 성숙시기, 그리고 가지 형성시기가 늦어지며, 그 결과 꼬투리 수와 종자 무게가 감소되어 생산량이 줄어들 것이다. 이러한 개체군의 생장을 연구하는 것은 지구온난화에 대한 육상식물의 생태적 반응 연구에 중요한 자료로 활용될 것이다.

Presently, the first pregnancy age of dairy heifers attended National Dairy Herd Improvement Program (NDHI) in Korea has increased, and more research have been requested to evaluate the possibility of decreasing the first pregnancy age of dairy heifers. Accordingly, this study was investigated the effects of the month of age at the first service and pregnancy on the reproductive efficiency of Holstein heifers. For these, the reproductive performance of heifers was analyzed by evaluating the effects of first insemination service at 12-14 months of age (12 month old), 15-16 months of age (15 month old), 17-19 months of age (17 month old), and > 20 months of age (20 month old) in Holstein heifers. The service numbers per conception in the first insemination months were 1.85±1.22, 1.59±0.77, 1.58±0.72, and 1.76±0.97 times at 12, 15, 17 and 20 months of age, respectively. The conception rates in the first service were 51.2, 57.8, 54.8, and 52.9% at 12, 15, 17 and 20 months of age, respectively. The conception ages were 453.2±78.9, 512.1±75.9, 590.1±98.0, and 713.0±74.5 days in the heifers serviced firstly at 12, 15, 17 and 20 months of age, respectively. There was significantly difference in the conception age among groups (p<0.05). The cumulative conception rates in the heifers serviced firstly at 12, 15, 17 and 20 months of age were 51.21, 57.8, 54.8 and 53.0% by the first service, 29.8, 30.1, 32.3, 23.5% by the second service, and 19.0, 12.1, 12.9 and 23.5% by the third service, respectively. The service numbers per conception in the first pregnancy months were 1.31, 1.55, 2.0, 2.05 times at 12, 15, 17 and 20 months of the first service age, respectively. The service numbers per conception in the 12 and 15 months of age were significantly lower than those in the 17 and 20 months of age (p<0.05). The rates of repeat-breeder were 6.0, 11.3, 22.0, and 41.0% in the heifers serviced firstly at 12, 15, 17 and 20 months of age, respectively. These results demonstrate that first pregnancy of Holstein heifers should be conducted at 15 months of age, because the age at first pregnancy in heifers can be substantially influenced through implementation of reproductive management and performance.

The objective of this study was to determine the effects of E. coli on boar sperm quality and reproductive performance in sows after artificial insemination. Three different levels of E. coli were artificially inoculated to semen with following concentrations; Control, 500, 5,000 and 50,000 colony forming unit (cfu)/ml. Semen samples were preserved at 17℃ for 5 days. Sperm motility was significantly decreased (p<0.05) on day 3 in the group inoculated with 5,000cfu/ml compared to control groups. In all treatment groups, sperm motility was gradually decreased as storage time increased, but the decline pattern was more drastic in the groups inoculated with 5,000 and 50,000 cfu/ml groups from day 3 (p<0.05) compared to control group. After 3 day of storage at 17℃, sperm viability in sample inoculated with the highest concentration (50,000 cfu/ml) of bacteria was less (p<0.05) than that of control group. The pH of semen sample pH was maintained 7.2～7.5 in all groups during the experimental period. No differences (p>0.05) were found for both storage time and bacterial concentration. The pregnancy rate and live born piglets tend to decrease by increasing the concentration of E. coli in semen. In particular, the rate of pregnancy was lower in the group inoculated with 50,000 cfu/ml (58.3%) compare to the other groups (81.8, 75.0, 76.5%). These results suggest that the contamination of E. coli in boar semen negatively affects fertilizing ability of boar sperm and the reproductive performance obtained from sows after artificial insemination.

본 연구는 지구온난화와 광, 토양수분 및 영양소가 종지 나물의 생육과 생식기관에 어떤 영향을 미치는 지 알아보기 위해 지구 온난화 조건 하에서 생육시킨 후, 그 결과를 비교 하였다. 대조구는 대기 중 CO2 농도를 그대로 반영하였으 며 지구온난화처리구는 대조구보다 CO2 농도와 온도를 더 높게 상승시켰다. 그리고 대조구와 지구온난화 처리구 내에 서 각각 토양수분(100, 90, 70, 50, 30%), 토양유기물(20, 15, 10, 5, 0%) 그리고 광(100, 70, 30%)구배를 처리하여 잎 수와 꽃 수의 변화를 알아보았다. 그 결과 대조구에서 종지나물의 잎은 수분100%에서 가장 많았다. 유기물과 광 조건에서는 각각 10%와 70%에서 초기에 가장 많았으나 시간이 지날수록 영향을 받지 않았다. 꽃은 광70%에서 가 장 많이 피었으며 수분과 유기물의 영향은 받지 않았다. 지 구온난화처리구에서 잎은 수분50%와 70%, 광 70%에서 가 장 많았으며, 유기물의 영향은 받지 않았다. 꽃 수는 광, 수분, 유기물의 영향을 받지 않았다. 이를 종합해 보면 현재 대기의 CO2 농도 하에서 종지나물은 토양 내 수분이 충분 히 있는 지역에서 생육이 잘 되고, 빛이 강한 곳 보다는 약간 그늘진 곳에서 번식이 잘 이루어지는 것으로 판단된 다. 또한 지구온난화가 더 심화되면, 토양 내 수분함량이 현재보다 적은 지역과 약간 그늘진 곳에서 생육이 잘 되었 지만, 번식은 모든 환경에서 현재보다 잘 이루어지지 않을 것으로 판단된다.

It is imperative to know the reproductive parameters of the existing swine breed for profitable farming in Bangladesh. This study was designed to determine the reproductive parameters of sows at hilly areas. A total of 245 pigs with 47 breedable sows were included. The data on age at puberty, oestrous cycle length, oestrus duration, gestation length, interval between furrowing and onset of oestrus, first service pregnancy rate, service per pregnancy and number of piglets born per sow in local and cross bred sows were determined. The present study revealed that age at puberty of local and cross breed sows was 232.5±8.4, 221.3±6.9 days, respectively. Oestrous duration was 41.1±3.1 hours. The interval between furrowing and onset of oestrus was shorter in cross bred sows. There was no variation in values of oestrus cycle length and gestation length. The first service pregnancy rate was higher in both the local and cross bred sow. Number of piglets per sow per farrowing was 6.1±2.2 and 60.9% local sows gave birth of 3 to 5 piglets per farrowing whereas 75.0% cross bred sows gave birth of 6 to 9 piglets. These results suggest that reproductive parameters of local sow need to be improved for better production, and cross bred sows should be reared for obtaining expected productivity.

Oral exposure of humans by excess amounts of arsenic may cause disturbances of the reproductive system. In the present study, such exposure was modelled in rats, with the support of sperm principal parameters and histopa-thological observations. Male Sprague–Dawley rats were randomly divided into three groups where the group I was served as a normal control, group II was received sodium meta-arsenite as arsenic (10 mg/kg b.w/day) and a combi-nation of sodium meta- arsenite and sodium selenite (3 mg/kg b.w/day) in group III. After 6 weeks, there was no significant change in testis weight and in total motility of all the three experimental groups, whereas, rapid moving spermatozoa, moderately moving spermatozoa and slow moving spermatozoa were significantly decreased in arsenic treated rats as compared to control rats. The other sperm principal parameters like progressiveness, average path velocity, straightness linear velocity (VSL), curvilinear velocity (VCL), straightness, linearity sperm head elongation ratio, area, linearity amplitude of lateral head department (ALH) and beat cross frequency (BCF) were found to be reduced in arsenic intoxicated rats. These results are not correlated with the histological studies. On oral admini-stration of selenium ameliorated the adverse effects of arsenic as compared to arsenic alone treated rats. Our findings clearly demonstrate that administration of selenium could prevent some of the deleterious effects of arsenic in the testis.

The reproductive disorders are the major causes of reproductive infertility in cows that affect the total annual calf crop, resulting in great economic loss in Bangladesh. The aim of the study was to find out the reproductive disorders (RD) in dairy cows that markedly influences the reproductive performances in aspect of Bangladesh. A total number of 1658 dairy cows were selected according to their body condition score (BCS) in different farms at the southern part of Bangladesh during the period of 2011 to 2012. The preliminary data (basic information) were collected directly from the dairy farmer’s record books and asking questions according to a prescribed questionnaires as well as the diagnosis of RD was presumptively confirmed on the basis of history, clinical signs and examination of animals by ultrasonography and others necessary tools. There are thirteen major reproductive disorders were identified. Overall prevalence of reproductive disorders at that area were 23%, among of these anoestrus 5.1%, repeat breeder 3.7%, metritis 4.4%, poor heat detection 1.6%, ovarian cyst 0.36%, retain placenta 4.6%, dystocia 0.97% and pyometra 0.24%. It is indicated that anoestrus and retention of placenta after calving was most hazardous cause of infertility whereas the metritis and repeat breeder were the second line of consequence. RD had shown significantly higher incidence in low BCS (≤2) than that of fair (2.5) and very good (≥3∼3.5). In conclusion, the highest RD especially anoestrus and retention of placenta is very alarming for reproductive loss which might be needed further research to identify the specific cause of these disorders for establishment a profitable dairying and dairy population.

Plasminogen activators (PAs) are serine proteases that convert plasminogen to plasmin. Two type of PAs are urokinase-type PA (uPA) and tissue-type PA (tPA). Plasminogen is present in most extracellular fluids. PAs play in various reproductive processes including implantation, ovulation and fertilization. In the spermatozoa, PAs and PAIs play a role in sperm motility and fertilization. PAs in the sertoli cell are stimulated spermatozoa maturation and sperm activation through the phospholipase A2. The oocyte maturation is the process for fertilization and implantation. PAs in cumulus-oocyte complexes (COCs) are related to oocyte maturation by protein kinase A and C. In the ovulatory process, PAs activity are changed and it are related to reducing the tensile strength of ovarian follicle wall. The uterine environment is important for reproduction and the uterus undergo tissue remodeling. In the uterus and oviduct of mammals, expression and activity of PAs are changed during estrous cycle. Thus, expression and activity of PAs are concerned to many reproductive functions. Therefore, PAs seem to important factor of regulator in reproductive events.

Beta-catenin (CTNNB1, catenin (cadherin-associated protein), beta 1) is involved in various biological processes, including embryogenesis, tumorigenesis, angiogenesis and progression of metastasis. CTNNB1, as a multifunctional and oncogenic protein, has important roles in adhesion between Sertoli cells through an N-cadherin-dependent manner and in various cancer types through its over-activation. In addition, CTNNB1 can interact with estrogen/estrogen receptor alpha complex, which regulates the transcription of WNT (wingless-type MMTV integration site family)/CT-NNB1 target genes. Recently, we investigated the functional roles and expression pattern of CTNNB1 during the morphological changes of embryonic gonads of chickens and the estrogen-dependent regulation of CTNNB1 in oviduct development and potential functions as a biomarker of CTNNB1 in human epithelial ovarian cancer using the chicken as a biological research model. Therefore, in this review, we provide a new insight of potential role of CTNNB1 in the development of the female reproductive tract during early embryogenesis and ovarian carcinogenesis of laying hen models.

The study was set for one year to measure the effects of concentrate supplementation on reproductive performances and semen quality in indigenous rams. The study was conducted at the Department of Surgery and Obstetrics, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh, Bangladesh during the period from May 2011 to April 2012. Forteen ram lambs (4∼5 months) were randomly divided into two equal groups (n=7); supplemented vs control. The animals of control group were maintained on natural grazing. Along with natural grazing the supplemented group was on supplemented feeding. The concentrate supplementation (Wheat bran, Crushed maize, Soy bean meal, Fish meal, DCP powder, Vitamin mineral premix, Salt) was provided @ 300 g/head /day to the supplemented group. Body weight, scrotal circumference, BCS and libido index were measured weekly. Age, body weight and scrotal circumference at puberty were recorded. Semen was collected once in a weak using artificial vagina and chilled at 5℃ for 48h for evaluation. Concentrate supplementation did not influence (p>0.05) body condition score, age, weight, scrotal circumference at puberty and libido index. Final body weight (kg), growth rate (g/d), scrotal circumference (cm) and scrotal growth rate (mm/15d) were significantly (p<0.05) higher in supplemented group of rams compared to control. Volume, concentration, motility and membrane potentiality of spermatozoa were varied significantly (p<0.05) in supplemented and control groups. However, density, mass motility, viability and sperm with normal acrosome, midpiece and tail were not differed insignificantly (p>0.05) in different observation times. It was concluded that concentrate supplementation with free grazing improved weight and scrotal circumference gain and semen production with increased quality in indigenous ram.

This study was conducted among 120 different breed cows at selected areas of Sirajgonj district from March to July 2010 to compare the reproductive performance of crossbred and Desi cows at farmer’s level. The results showed that the average daily milk yield of Desi, Shahiwal × Desi, Friesian × Desi and Jersey × Desi cows was 2.3 ± 0.2, 4.9 ± 0.9, 6.0 ± 1.0 and 5.7 ± 0.9 liters, respectively. The milk yield of crossbred cows (5.5 ± 0.6 liters/day) was significantly (p<0.01) higher than Desi cows (2.3 ± 0.2 liters/day). The average age at puberty of Shahiwal × Desi, Friesian × Desi and Jersey × Desi was significantly (p<0.01) lower than that of Desi breed. The crossbred cows had significantly (p<0.01) lower pubertal age (20.4 ± 1.2) than Desi (25.9 ± 1.1). The age at first calving in Desi cows was significantly (p<0.01) higher (37.6 ± 1.1 months) than crossbred cows (31.2 ± 1.3 months). The average gestation length of Desi, Shahiwal × Desi, Friesian × Desi and Jersey × Desi was 289.9 ± 1.4, 285.0 ± 0.0, 285.0 ± 4.2 and 282.1 ± 2.4 days, respectively. It is suggested that the overall reproductive performance of Friesian × Desi, Jersey × Desi and Shahiwal × Desi cows were better than that of Desi cow.

We analyzed the fatty acid and dimethyl acetal (DMA) compositions of phospholipid (PL) classes [phosphatidylcholine (PC) and phosphatidylethanolamine (PE)] obtained from the reproductive organs of male (testis, vas deferens, seminal vesicle and spermatophoric sac) and female (ovary, oviduct, oviducal gland and nidamental gland) common squid. The PL contents in the male and female reproductive organs were 0.45-1.94 and 1.25-5.88 g/100 g tissues, respectively. The prominent PL classes in the male and female reproductive organs were PC (39.1-54.5% and 59.8-77.0%, respectively) and PE (30.6-40.6% and 18.7-31.8%, respectively). The prominent fatty acids of PC and PE in the reproductive organs were docosahexaenoic acid (DHA, 22:6n-3), 16:0, eicosapentaenoic acid (EPA, 20:5n-3), 20:1n-9, 18:0 and/or 20:4n-6. The percentage of DHA was higher in PC of male and female reproductive organs, while that of EPA was higher in the PE of both reproductive organs. The PE of male and female reproductive organs contained 18:0, 16:0, 16:1 and 20:0 DMAs, which derived from plasmalogen, especially 18:0 DMA was the richest (5.26% of total fatty acids and DMA) in the PE of the testis in all the organs tested. Consequently, these results suggest that the reproductive organs of male and female of the squid could be used as good sources for PC, PE, n-3 PUFA and plasmalogen.

Pig producers have been shown keen interest of the number of spermatozoa in a semen dose since pig artificial insemination introduce. However, determining the minimal number of spermatozoa need per AI without detrimental effect on overall reproductive performances is not an easy question to answer. To increase the efficiency of semen utilization in pig AI, optimum number of spermatozoa per dose needed to determine. The objective of this study was to determine the reproductive performance and factors that affect on-farm application of low-dose semen insemination in sows. Data were collected from Darby Genetics AI studs from 4th of June to 7th of July, 2012 (n=401). The numbers of parturition were 84, 234 and 83 in sows inseminated with doses of 1.5×109, 2.0×109 and 2.5×109 spermatozoa in 100ml extender, respectively. There were no significant differences on reproductive performances such as gestation pe-riod, total born, total born alive, stillbirth and mummy in sows inseminated with different semen doses. The average number of born alive was 10.5, 11.0 and 10.4 from sows inseminated with 1.5×109, 2.0×109 and 2.5×109 sperms, re- spectively. Also, number of spermatozoa per dose did not affect litter size (p>0.10). There were no significant differ-ences of maternal genetic line difference on gestation period, total number born, number born alive, born dead and mummy. The estimated correlation coefficients of the different semen doses with total number born, number born alive, born dead and mummy were r=—0.00, —0.01, 0.02 and 0.02, respectively. Taken together, the result of this study suggested that when semen was appropriately inseminated after induced ovulation, insemination with low-dose (1.5∼2.0×109) semen dose not adversely affect sow’s fertility.

Many countries have implemented genetic evaluation for fertility traits in recent years. In particular, reproductive trait is a complex trait and need to require a system-level approach for identifying candidate genes related to the trait. To find the candidate gene associated with reproductive trait, we applied a weighted gene co-expression network ana-lysis from expression value of bovine genes. We identified three co-expressed modules associated with reproductive trait from bovine microarray data. Hub genes (ZP4, FHL2 and EGR4) were determined in each module; they were topologically centered with statistically significant value in the gene co-expression network. We were able to find the highly co-expressed gene pairs with a correlation coefficient. Finally, the crucial functions of co-expressed modules were reported from functional enrichment analysis. We suggest that the network-based approach in livestock may an important method for analyzing the complex effects of candidate genes associated with economic traits like repro-duction.

The objective of this study was to analyze the reproductive ability by strains and age in weeks of Korean native chicken and to compare the egg weight by body weight of Korean native chicken cock. Six strains (L=black, W=white, O=Ogol chicken, G=gray, R=red, and Y=brown) of Korea native chicken were used in this study. The fertility of strains W and Y were 89.6% and 86.3% respectively, and significantly higher than the other strains (p<0.05). Strains R and W showed high hatchability (90.7%, 89.6%, respectively) and strains L and O showed low rate (78.9%, 87.3%, respectively). There was no significant difference by weeks in each strain. The fertility was the highest at 28 weeks of age and the hatchability showed the highest value at 26 weeks of age. Egg weights of strains L and R were significantly high (p<0.05) but strains W and G were significantly low (p<0.05). Egg weight was higher in 1.65 ㎏ of Korea native chicken cock than in 2.00 ㎏ of Korea native chicken cock. These results suggest that the using average weight (1.65 ㎏) of Korea native chicken cocks could have an advantage for the feed cost savings and productivity improvement.