Climatic change affects agricultural, environmental and livestock production. Forage productivity is highly dependent on the weather change. The Pyeongchang region has more difficulty in cultivation of Sorghum-Sudangrass hybrids (SSH) than other warm regions because of the cold weather. This experiment was carried out to analysis the agronomic characteristics, productivity, and nutritive value of three cultivars of Sorghum-Sudangrass hybrids in the Pyeongchang region from 2021 to 2022. Two harvests were taken in each year, and the agronomic characteristics, dry matter yield, and nutrient content of the whole SSH crops were determined. The plant height ranged between 281-291 cm and 165-172 cm in the first and second harvest, respectively. Plant height of Superdan (291±49 cm) was the highest in the first cut and Dairy mens Dream (172±30 cm) was the highest in the second cut time. Stem diameter ranged from 9.5 to 8.8 mm with Superdan having a higher level than the other two cultivars. The Dairy mens Dream variety produced significantly higher dry matter yield (15,695 kg/ha) than those of Superdan (14,584 kg/ha) and Supergreen (14,300 kg/ha) over a two-year experimental period. In terms of nutritional quality, the crude protein content, neutral detergent fiber and acid detergent fiber of SSH cultivars were analysed. There were no significant changes in the content of CP, ADF and NDF ranges among the cultivars. In addition, the Superdan cultivar had slightly higher CP content (10.17%) and was followed by Dairy mens Dream (9.84%) and Supergreen (9.54%) in the second cut time of 2-year average. Dairy mens dream had lower ADF and NDF values than other cultivars; however, no significant differences amongst cultivars in fiber content were observed. Therefore, these three cultivars displayed the potential growth characteristics, DM yield and nutritive values in Pyeongchang region. Hence, the SSH cultivars have a potential to withstand the climatic change and improve SSH productivity in the study area.

This study was conducted to determine the effect of horse manure compost application on Italian ryegrass (IRG) yield and volcanic ash soil characteristics. Because the number of horses in Korea is growing, the amount of horse manure is growing. Jeju island, where about 55 % of the horses live, is composed of volcanic ash soil. This study was conducted for about 7 months. Sowing was conducted on October 2019. Harvesting was conducted at heading stage(2020.5.). Five treatments were established based on the horse manure compost composition. These were 100 % chemical fertilizer (CF), the combination of 50 % horse manure and 50 % chemical fertilizer (combination), horse manure with 50 % nitrogen (HM 50 %), horse manure with 100 % nitrogen (HM 100 %), and horse manure with 150 % nitrogen (HM 150 %). The plant height and dry matter yield were investigated to determine the forage yield and the soil characteristics of pH, total nitrogen, available phosphate, and organic matter were analyzed. The plant heights in the CF, combination, and HM 150 % treatments were 147.8 cm, 144.3 cm, and 147.1 cm respectively (Table 2). Dry matter yield in the CF treatment was about 23,807 kg/ha, which tended to be the highest dry matter yield. HM 150 % and the combination treatment were about 18,804 and 18,455 kg/ha, respectively, which tended to be the highest dry matter yield of the treatments amended with horse manure compost. The dry matter yield of the HM 100 % and HM 50 % treatments was about 15,801 kg/ha and 14,446 kg/ha, respectively (Table 2). The pH of the surface soil tended to increase after the experiment. The soil pH of the HM 150 % treatment was significantly higher than the soil pH of the other treatments. The pH was affected by the amount of horse manure compost, with a pH of 8.1. The available phosphate in the treatments in which horse manure compost was added was higher than the available phosphate in the CF treatment. And the available phosphate in the HM 150 % treatment was significantly higher than the available phosphate in the other treatments (p < 0.05)(Table 3). These results suggest that 50 % horse manure should be applied to IRG as the basal fertilizer and the remaining 50 % should be chemical fertilizer as the top fertilizer. This can provide the proper IRG dry matter yield with less effect on volcanic ash soil.

‘Gwangyoung’, a winter forage triticale cultivar (X Triticosecale Wittmack), was developed at the Department of Rice and Winter Cereal Crop, NICS, RDA in 2018. The cultivar ‘Gwangyoung’ has leaves of wide width, medium length, and green color, and spikes of medium length and yellowish-brown color, and a large grain of yellowish-brown color. The heading date of the cultivar ‘Gwangyoung’ was April 22 which was similar to check cultivar ‘Shinyoung’. Its tolerance or resistance to cold, lodging, wet injury powdery mildew, and leaf rust were also similar to those of the check cultivar. The leaf blade ratio of ‘Gwangyoung’ (27.5%) was higher than that of ‘Shinyoung’ (21.2%). The average forage fresh and dry matter yield of cultivar ‘Gwangyoung’ at milk-ripe stages were 50.0 and 17.6 MT ha-1, respectively, which were higher than those (47.7 and 17.1 MT ha-1) of the check cultivar. The silage quality of ‘Gwangyoung’ was lower than that of the check cultivar ‘Shinyoung’ in crude protein content (5.3%) and total digestible nutrients (61.3%), while was higher than the check cultivar in neutral detergent fiber (58.2%) and acid detergent fiber (34.9%). ‘Gwangyoung’ showed the silage of 1 grade and a grain yield of 6.03 MT ha-1.

This experiment was conducted to investigate the effects of feeding TMR(Total Mixed Ration) with Sasa quelpaertensis Nakai of Jeju cross-bred horses on the body weight and blood composition. Fourteen herds of Jeju cross-bred horses older than 36 months were selected as experimental animals. The experiment was conducted by dividing the herds into seven herds for feeding TMR with 20% Sasa quelpaertensis Nakai(treatment) and another seven herds for feeding TMR without Sasa quelpaertensis Nakai(control) and water were fed ad libitum. In the 12th week, the MPV(mean platelet volume) was statistically significantly higher with Sasa TMR than with control (p<0.05). However, both MPV levels are within a normal range and there were no health problems. With regard to the levels of cholesterol, there was a statistically significant difference between the 33.8±5.9 ㎎/㎗ with individual management and 25.4±8.2 ㎎/ ㎗ with control group (p<0.05). But It are also within a normal range and there were no health problems. In conclusion, feeding TMR with 20% Sasa quelpaertensis Nakai of Jeju cross-bred horses could be utilized as a feeding method for horse.

This study was conducted to figure out the productivity of Italian ryegrass(IRG) and leaching water characteristics based on horse manure compost level in Jeju. This study was conducted for about six months. Six treatments were established : non-fertilizer(NF), chemical fertilizer 100%(CF), horse manure compost 50% and chemical fertilizer 50% combination(Combination), horse manure compost with 50% of nitrogen (50%), 100% of nitrogen(100%), 150% of nitrogen(150%). The highest amount of dry matter yield of IRG was revealed in CF(11,965± 564 kg/ha), and both 150% and Combination were second(p<0.05). Nitrate leaching tended to increase until the third analysis and then decreased. There were not significantly differences among mean nitrate concentrations. The findings of the study suggest that horse manure compost with 50% of nitrogen be applied for IRG as basal fertilization and then 50% of chemical fertilizer be applied as top fertilization.

This study was to investigate the effect of the horse grazing intensity on the vegetation of the S. quelpaertensis, and the physiological changes of the horse. This experiment was conducted at the community of the S. quelpaertensis (altitude of 550m) with the grazing intensity of 1.0AU(500kg), 1.5AU(750kg) and 2.0AU(1,000kg) at 30m × 30m for one week, and then the growth characteristics of the S. quelpaertensis, the changes of the vegetation, the damages on trees and the changes in the physiological characteristics of the horses was investigated and compared before and after the horse grazing. As the results, the 2.0AU grazing land showed that the culm number had the inverse correlation (r=-0.902, P〈0.01) to the other lands and the species diversity index of lower-level vegetation showed the correlation (r=0.773, P〈0.01) as increasing the grazing intensity.

본 시험은 사료가치가 우수하고 엔도파이트에 감염되지 않은 톨 페스큐 신품종을 개발하기 위하여 2010년부터 2017년까지 농촌진흥청 국립축산과학원 초지사료과에서 수행되었다. 톨 페스큐 신품종 ‘그린마스터4호’는 6배체 품종으로서 잎은 녹색이며, 출수기가 5월 16일경으로서 대비품종인 ‘Fawn’ 보다 5일 늦은 중생품종이고, 출수기에 초장은 74.6cm 정도이다. 지역적응시험 4개 지역평균 건물수량은 ‘그린마스터4호’가 16.2톤/ha로서 대비품종인 ‘Fawn’보다 5% 많았으며, 지역별 생산성이 4개 지역 모두에서 ‘Fawn’보다 우수하였다. ‘그린마스터4호’의 사료가치는 조단백질(CP) 함량이 15.2%, 건물소화율(IVDMD)이 70.0%, 가소화양분총량(TDN)이 63.6%, 중성세제불용섬유(NDF)가 58.7%, 산성세제불용섬유(ADF)는 32.0%로서 Fawn보다 높거나 대등하였다. ‘그린마스터4호’는 엔도파이트에 감염되지 않는 품종이면서 ‘Fawn’보다 국내 기후환경 적응성과 영속성이 우수하여 초지조성에 알맞은 품종으로서 우리나라 전국에서 재배 가능하다.

본 실험은 제주산마의 개별 사양과 군집 사양이 생산성, 생리적 특성 그리고 말고기 등심근 부위의 특성에 미치는 영향에 대하여 알아보았다. 시험축은 44개월 이상의 제주산마 16두를 공시하였으며, 처리구는 개별 사양 8두, 군집 사양 8두로 나누어 실험을 진행하였다. 농후사료는 체중의 2.5%를 1일 4회에 나누어 급여하였으며 조사료와 물은 무제한 급여하였다. 총 농후사료 섭취량은 개별 사양은 1,358.49kg 군집 사양은 1,309.34kg이었다. 농후사료 일일 평균 섭취량은 개별 사양, 군집 사양에서 각각 16.56kg, 15.96kg으로 유의적인 차이는 없었다(p>0.05). 총 증체량은 개별 사양 시 66.00kg이었고 군집 사양 시 53.37kg이었으며, 일일 증체량은 개별 사양과 군집 사양에서 각각 0.79kg 0.64kg이었다. 개별 사양이 군집 사양보다 총 증체량과 일일 증체량에서 높은 수치를 나타냈지만 유의적인 차이는 나타나지 않았다(p>0.05). 말의 생리적 이상을 확인할 수 있는 지표인 직장온도는 개별 사양이 군집 사양보다 높은 수치를 나타냈지만 처리구간 유의적인 차이도 나타나지 않았다(p>0.05). 장내 pH는 개별 사양과 군집 사양 처리구 모두에서 정상 범위보다 낮은 경향을 나타냈으며 12주차에는 군집 사양에서 개별 사양보다 유의적으로 낮은 수치를 나타냈지만(p<0.05), 산통 증상은 나타나지 않았다. 등심근 내 일반 성분에서 단백질과 조회분은 처리구별로 차이가 나타나지 않았으나(p>0.05) 지방 함량은 개별 사양에서 7.83%, 군집 사양에서 5.65%를 나타내어 개별 사양 시 등심근 내 지방 함량이 유의적으로 높게 나타났다(p<0.05). 이를 통해 개별 사양이 군집 사양보다 비육 효과가 우수함을 확인할 수 있었다. 그 외 등심근의 관능 특성과 육색 특성은 처리에 따른 차이를 보이지 않았다. 말의 개별 사양 시 산통 지표로 알려진 장내 pH 수치가 군집 사양보다 정상 수치에 가깝고 등심근 내 지방 함량도 개별 사양이 우수하게 나타나 제주산마 비육시 개별 사양 형태로 농후사료 2.5%의 급여하는 것이 제주산마의 비육 방법으로 활용될 수 있을 것으로 사료된다.

본 연구는 농후사료의 급여 횟수에 따른 제주산마의 체중변화 및 산통에 미치는 효과를 구명하기 위하여 수행되었다. 공시축으로 36개월 내외의 제주산마를 공시하였으며, 농후사료를 체중의 2.5%로 2회, 3회, 4회로 급여한 후 체중 변화 및 생리적 변화와 혈액 특성을 조사하였다. 총 증체량은 농후사료 일일 2회 급여구에서 55.80kg, 3회 급여구에서 54.40kg, 4회 급여구에서 63.00kg을 나타내 유의적인 차이는 없었다(p>0.05). 일당 증체량은 농후사료 일일 2회, 3회, 4회 급여구에서 각각 0.69kg, 0.67kg, 0.78kg을 나타내어 일일 2, 3회 급여구보다 4회 급여구에서 일일 증체량이 높은 경향을 나타냈으나 유의적인 차이는 없었다(p>0.05). 모든 처리구에서 직장온도는 정상 범위보다 높은 경향을 보였고, 분 pH는 정상 범 위보다 낮았으나 12주차에 모든 처리구에서 6.0보다 높아지는 경향을 보였다. 모든 처리구에서 높은 직장 온도와 낮은 분 pH를 보였지만 산통 증상은 나타나지 않았는데 이는 품종에 따른 차이에 의한 것으로 사료된다. 산통 지표로 알려진 피브리노겐과 질병 발생의 지표로 알려진 백혈구는 정상 범위 내에 있었고 시험 기간 동안 유의적인 차이를 나타내지 않았다(p>0.05). 결론적으로 제주산마에게 일반적인 농후사료 급여량보다 높은 양인 체중의 2.5%의 농후사료를 급여할 경우, 여러 번에 나누어 주는 것이 산통 발생 방지 및 소화에 도움이 될 것으로 가정했으나 급여 횟수에 따른 증체량, 혈액, 생리적 특성의 차이는 나타나지는 않았다. 결론적으로 제주산마에게 체중의 2.5% 농후사료를 12주간 2회, 3회, 4회 급여하는 것에 따른 생산성 및 산통 발생에 차이가 없어 노동력의 투입을 감안했을 때 2회로 나누어 주는 것이 유리할 것으로 사료된다.

This study was conducted to determine the effect of pentoxifylline levels on sperm motility, survival rate, sperm membrane integrity of frozen semen and fresh-extended equine semen in Jeju cross-bred horses. As a result of sperm characteristic comparison depending on pentoxifylline levles at 30 minutes post-thaw, the progressive motilities were 53.25±2.87 (4mM pentoxifylline) and 50.28±2.14 (8mM pentoxifylline) and significantly higher compared to the control group(40.09±5.15) and other treatment group (16mM pentoxifylline, 41.27± 2.82). The progressive fast motility were 22.44±1.62 (4mM pentoxifylline,) and 22.74±3.07 (8mM pentoxifylline) and significantly higher compared to the control group (13.47±1.48) and other treatment group (16mM pentoxifylline, 14.66±3.68) (p<0.05). As a result of sperm characteristic comparison depending on pentoxifylline levles at 30 minutes post-thaw were 68.96±1.64 (4mM pentoxifylline) and 67.90±6.72 (8mM pentoxifylline) and significantly higher compared to the control group (53.48±4.84) and other treatment group (16mM pentoxifylline, 58.14±2.65) (p<0.05). In conclusion, these results suggest that treatment groups with 4mM and 8mM pentoxifylline were higher compare to equine seperm mobility and the control group and treatment groups with more than 16mM pentoxifylline has a negative effect on sperm characteristics. After thawing, the total motility in post-thawed equine sperm has increased by 10 percent for 1 hour. these results suggest that pentoxifylline contributes to the improvement of the equine sperm motility and characteristics in post-thawed semen.

This study was conducted to evaluate the changes of pH, dry matter digestibility (DMD), NH3-N concentrate, gas production and volatile fatty acid (VFA) through in vitro fermentation by adding horse feces to various juice pomaces fermented with Bacillus, yeast and lactic acid bacteria. The pH range of fermented fluid with juice pomaces was 6.4-7.1, indicating that the digestion by microbial fermentation was normal. Juice pomaces adopted will be helpfully used to assist with digestion by microbes in intestines because approximately 109 CFU/㎖ microbes were grown after 48 hours in fermented fluid. DMD rate gradually increased from 12 hours. It was 39.19% in pomaces of apple, 38.22% in grape, 37.02% in carrot, 36.2% in citrus and 34.35% in mixture respectively after 48 hours. NH3-N concentrate was not changed significantly as it was maintained at 1.5 mg/100㎖ level in the entire treatment group from beginning of fermentation until 12 hours, but increased rapidly from 24 hours. Amount of gas produced was lowest in the mixture and increased rapidly after 12 hours. Total VFA increased from 24 hours and was highest at 48 hours. It was suggested that dry matter digestion was processed while fermented juice pomaces kept proper pH during in vitro digestion, and cellulose degrading microorganisms could act actively in the caecum and colon of horses.

In vitro fermentation was conducted to figure out alternative fiber sources for horse feed. For the development of value-added products as a horse feed resource, the pomaces from apple, carrot, grape, and citrus were fermented under solid-state conditions in the presence of 60% soybean meal with 40% of each fruit pomace at 60% of moisture content. Lactobacillus plantarum SK3873, Lactobacillus plantarum SK3893, Weissella cibaria SK3880, and Bacillus subtilis SK3889 were isolated from the fermented fruit pomace by inoculation of horse feces. For the growth of Bacillus subtilis, Saccharomyces cerevisiae, and Lactobacillus plantarum, they were inoculated in 3-step order at 0, 12, and 24 h, respectively. The fruit pomace was fermented for 48 h at 35°C. The pH of the apple, carrot, grape, citrus and all mixed pomaces decreased from 5.45~6.25 to 4.40~4.77. Microbial growth was maintained at 108~109 cfu/g. After 12 and 24 h incubation, dry matter of carrot pomace were highest at 54.84 and 56.66%, respectively (P<0.05) and that of grape pomace was lower than others during fermentation (P<0.05). Dry matter was generally reduced by about 20%. NDF decreased gradually or maintained after 24 h, indicating the fiber degradation. Ash content tended to decrease during fermentation. After 48 hours fermentation, Bacillus, yeast and Lactobacillus showed an excellent growth by using juice by-products. These results suggest that fermented juice pomace has a potential as horse feedstuff with probiotics to maintain beneficial microflora in horse gut.

This study was conducted to investigate the ovarian cycle changes of the mare according to the season. Twenty four Jeju crossbred horses(Thoroughbred x Jeju horse) raised in Subtropical Livestock Research Institute, National Institute of Animal Science, RDA were used to identify follicles and corpus luteum with ultrasonography once a week(May 2016~June 2017). Blood samples of experimental horses were collected twice a week for analysis of P4 hormone levels. The mares were considered to have resumed ovarian cyclicity on the day of ovulation if they followed by regular ovarian cycles. Only 13 cases(61.9%) of the total 21cases showed normal ovarian cycle, and 8 cases (38.1%) showed delayed ovarian cycle. Three cases(16.7%) in October, 5 cases(27.8%) in November and 5 cases(27.8%) in December(27.8%) ceased the heat and the remaining 5 cases(27.8%) showed that the estrus was maintained in winter. Horses that stopped estrus ceased the heat until March of next year, and 27.8% were continued the heat during non-breeding season. Eleven cases(61.1%) of 18 cases in April and 2 cases(11.1%) of 18 cases in May returned the estrus.

This study was conducted to analyze the effect of single nucleotide polymorphisms (SNPs) on the equine chromosomes (ECA) 3 for the body conformations of 12 month of age in Jeju crossbred (Jeju horses × Thoroughbred). A total of 199 Jeju crossbred horse samples were obtained from the National Institute of Subtropical Livestock Research Institute for this study. To correctly estimate the body conformations, we measured thirteen elements relevant to the body conformation such as body weight, wither height, body length for all the 199 horses at 12 month of age. Furthermore, all the horses were genotyped using four SNPs including the BIEC2-808466, BIEC2-808543, BIEC2-808967, BIEC2-809370, of which genomic coordinates range approximately from 105.1Mbp to 110 Mbp in the ECA3. For the phenotypic data sets, the average body weight was 193.7 ± 24.5㎏ and the height was 124.5 ± 4.0㎝. As for the genotypic data, the miner allele frequencies of the SNPs were shown to be varied from 0.01 to 0.291. Using the phenotypic and genotypic data sets, analysis of covariance was performed to find any association between those SNP genotypes and body conformations, using year of birth, month of birth, sex, and parity as the covariance components. The result showed that alternative genotypes in the BIEC2-808967 and BIEC2-809370 SNPs were significantly associated with the body length (P<0.05) and the wither height (P<0.05) respectively in the Jeju crossbred horses. Therefore, it is estimated that there are significant associations in the body conformation of 12 month of age of Jeju crossbred for those two SNPs used in this study.

Viral respiratory infections are common in horses, notably equine herpesvirus infection and equine influenza, which primarily initiate secondary bacterial respiratory infections such as strangles caused by Streptococcus equi equi. A decline in the production of stallions has been associated with these respiratory diseases leading to adverse financial implications. This study investigated the antibody responses against respiratory diseases in horses from Jeju Island a year after vaccination. A low level of equine herpesvirus type 1 (EHV-1) (11.36%) antibodies was detected from stallions, however a high level of EHV-4 (95.84%) antibodies was detected from horses without vaccination against this infection suggesting that EHV-4 is ubiquitous in this horse population. In case of equine influenza, ranch stallions showed low positive rate (12.06%) whereas stallions from Subtropical Livestock Research Institute displayed higher positive rate (81.32%). Antibody responses against equine influenza and strangles revealed positive rates of 26.32% and 55.12%, respectively. These findings may draw attention towards the importance of developing an improved disease prevention and/or immunization program that will effectively control respiratory diseases in horses.

Respiratory diseases among horses cause economic losses in foals and productivity decreases in horses being raised and in adult horses. In South Korea, fundamental studies of horses’ respiratory diseases and those related to disease occurrence are insufficient. Therefore, the aim if the current study was to use diverse hematological indicators, obtained through hematological tests and measurment of blood antibody level in horses suffering form respiratory diseases, to monitor disease occurrence and prognosis evaluation. Investigations of infection states by horses’ bacterial respiratory diseases, susceptible drugs, and resisted drugs according to pathogens showed differences between farms. Among the β-lactam-based antibiotics, cephalosporin-based antibiotics showed some efficacy against Streptococcus spp. To review age-based changes in erythrocytometer hemograms in hematological tests of riding horses, red blood cell (RBC) tended to gradually decrease with increasing age this tendency was statistically significant. In addition, leukocytometer hemograms analyzed by age showed that total white blood cell counts tended to decrease with increasing age. These results of drug susceptibility tests and hematological tests, which have not been presented thus far, will be useful as standardized data in future breeding management and disease tests of Jeju riding horses.

vThis study analyzed the coat color-related genes of MC1R, ASIP, ECA3-inversion, and STX17 of 1,462 Jeju horses administered by the Jeju Special Self-Governing Province. This was done to investigate the distributional characteristics of coat color-related genes in the Jeju horse group and the changes of its coat color-related genes by generation. The genotype frequency of the MC1R gene of E+/E+ and E+/Ee related to black coat color was 0.122 and 0.447, respectively, while Ee/Ee of the chestnut genotype was 0.429. The genotype frequency of the ASIP gene of AA/AA, AA/Aa, and Aa/Aa was 0.46, 0.448, and 0.091, respectively, where the genotype frequency of Aa/Aa turned out to be relatively low. The To/To and +/To genotype that manifests the Tobiano shape was 0.001 and 0.119, respectively, with the share of Tobiano shape around 12%. The genotype frequency of G/G and G/g of STX17 related to grey coat color was 0.002 and 0.680, respectively, with the share of grey horses among the Jeju horse group at 68.2%. As for the change of coat color genes by generation, no large changes were observed in the MC1R and ASIP genes. In ECA3-inversion, the To allele that manifests Tobiano significantly decreased following the generational change (p<0.05), while the STX17 G allele related to grey coat color significantly increased following the generational change (p<0.05). It will be necessary to examine the coat color genes when selecting breeding horses so that the diversity of coat colors among the Jeju horse group can be maintained.

Poria cocos is a well-known traditional Chinese traditional medicine (TCM) that grows around roots of pine trees in China, Korea, Japan, and North America. Poria cocos has been used in Asian countries to treat insomnia as either a single herb or part of an herbal formula. In a previous experiment, pachymic acid (PA), an active constituent of Poria cocos ethanol extract (PCE), increased pentobarbital-induced sleeping behaviors. The aim of this experiment was to evaluate whether or not PCE and PA modulate sleep architectures in rats as well as whether or not their effects are mediated through GABAA-ergic transmission. PCE and PA were orally administered to individual rats 7 days after surgical implantation of a transmitter, and sleep architectures were recorded by Telemetric Cortical encephalogram (EEG) upon oral administration of test drugs. PCE and PA increased total sleep time and non-rapid eye movement (NREM) sleep as well as reduced numbers of sleep/wake cycles recorded by EEG. Furthermore, PCE increased intracellular chloride levels, GAD65/67 protein levels, and α-, β-, and γ-subunits of GABAA receptors in primary cultured hypothalamic neuronal cells. These data suggest that PCE modulates sleep architectures via activation of GABAA-ergic systems. Further, as PA is an active component of PCE, they may have the same pharmacological effects.

A study was performed to investigate the effect of reseeding rates of Italian ryegrass (IRG)〔Lolium multiflorum L.〕on its nutritive value and productivity in native grasssland of Jeju region from Oct. 2011 to Jul. 2012. IRG was sown at reseeding rates (0 30, 40 and 50 kg/ha) in native grassland. When IRG was sown, there was no draught and lodging damage. Plant height in treatment 30 kg/ha of reseeding IRG was the tallest at all harvest stages (p<0.05). DM yield in treatment of 30 kg/ha of reseeding IRG was 12,790 kg/ha and increased 2.7 folds as compared to control. However, there was no significant difference among the treatments. The content of neutral detergent fiber (NDF) significantly decreased in treatment of reseeding, compared to control (p<0.05). In general, the content of NDF in second harvest stage was lower than that of control in first harvest stage. The content of acid detergent fiber (ADF) also showed simliar trend as content of NDF. The content of total digestible nutrients (TDN) in treatments of 30 kg/ha and 50 kg/ha of reseeding were approximately 45.2% each. The content of TDN in treatments of 30 kg/ha and 50kg/ha of reseeding increased as compared to 40 kg/ha and control of reseeding (p<0.05). Therefore, it is conclued that reseeding rate of IRG may improve the yield and nutritive values of IRG at 30 kg/ha.

Purpose – The structural changes of Korean agriculture are complex due to heterogeneous production processes and farms’ features. This study analyzed trends of dualism in Korean agriculture over the period 2000-15 based on farm-level data to clarify the specific trends of dualism in terms of farm income, farm-size, and farm operators’ age. From the results of this study, we would be able to understand the features of structural changes in Korean agriculture more profoundly. Research design, data, and methodology – We incorporated farm-level data in South Korea: Agricultural census and Farm household economy survey. As measures of inequality, we used size-weighted quantiles, and normalized Gini coefficients as well as mean and conventional quantiles. The size-weighted quantiles are more robust to changes in the number of small farms, but they are more sensitive to changes in the distribution of farm-size. Thus, they would be more useful to identify trends of dualism of Korean agriculture. Results - The results show that the farmland distribution of crop farms became more skewed and dispersed. However, the herd distribution of livestock farms became more concentrated. To be specific, their mean and 1st quantile increases more rapidly than their size-weighted 2nd quantile and size-weighted 3rd quantile. Gini coefficients of livestock farms regarding their herd distribution decreased by 0.1 on average. In the case of income distribution, the results indicate that the polarization regarding farm household/agricultural/non-agricultural income became more severe. However, we also found that the distribution of transfer income became concentrated continuously. The results imply that transfer income including subsidies would decrease farm income polarization. Lastly, during the study periods, Korean farms were aging over time, and age distribution of them more concentrated. Conclusions – The structure of Korean agriculture has been changing, even though the absolute size of it decreased over time. Land (herd) distribution became more dispersed (concentrated). Inequality regarding agricultural income became more severe, and it made farm household income more polarized even though transfer income would decrease income gaps among farms. Lastly, farms continue to age regardless of farm types and this might affect the structural changes in Korean agriculture in the future.