본 연구는 우리나라에서 수수-수단그라스 교잡종 (sorghum bicolor L.: SSH)에 대해 극단기상과 정상기상 간 생산량을 비교할 목적으로 수행하였다. SSH 데이터 (n=1,025)는 농촌진흥청의 신품종 적응성 실험보고서(1979 ―2019)로부터 수집하였다. 기상자료는 기상청으로부터 평균기온, 최저기온, 최고기온, 최대 강수량, 누적 강수량, 최대풍속, 평균풍속 및 일조시간을 10일 기준으로 계산하 여 수집하였다. 극단기상과 정상기상 간 구별을 위해 상 자 그림을 이용하여 탐색하였다. 극단기상과 정상기상 간 생산량 차이는 5% 유의수준 하에서 t-검정 및 ANOVA를 통해 확인하였다. 그 결과, 극단기상은 극단적으로 강한 바람을 동반한 봄 가뭄, 극단적으로 높은 강우량을 기록 하는 여름장마와 가을장마가 두드러졌다. 예측 생산량 피 해(kg/ha)는 각각 1,961―6,541, 2,161―4,526 및 508― 5,582로 나타났다. 본 연구는 우리나라의 SSH에 대한 취 약성 및 피해 산정에 도움이 되는 기초자료로서 극단기상 과 정상기상 사이의 생산량 차이를 확인하는 데 의의가 있다.

The planting date of corn for silage has been delayed because of spring drought and double cropping system in Korea. This experiment was conducted to evaluate agronomic characteristics, forage production and feed value of corn at April and May in 2019. Experimental design was a split-plot with three replications. Planting dates (12 April and 10 May) were designated to the main plot, and corn hybrids (‘P0928’, ‘P1543’ and ‘P2088’) to the subplot. The silking days of the early planting date (12 April) was 79 days and that of the late planting date (10 May) was 66 days (p<0.0001), however, there were no significant differences among the corn hybrids. Ear height of the late planting date was higher than that of the early planting (p<0.05), while there were no significant differences in plant height of corn. Insect resistance at the early planting was lower than that of late planting (p<0.05), however, lodging resistance was no significant difference at planting date. The rice black streaked virus (RBSDV) infection of early planting was 3.7% and that of late planting was 0.3% (p<0.001). Dry matter (DM) contents of stover, ear and whole plant had significant difference at planting date (p<0.05). And differences in ear percentages were observed among the corn hybrids (p<0.01). And ear percentages of early maturing corn (‘P0928’) was higher than for other hybrids. Ear percentage at the early planting date was higher than that at the late planting date (p<0.01). DM and total digestible nutrients (TDN) yields had significant difference at planting date, however, there were no significant differences among the corn hybrids. DM and TDN yields at the late planting (21,678 kg/ha and 14,878 kg/ha) were higher than those of the early planting (13,732 kg/ha and 9,830 kg/ha). Crude protein content at the early planting date was higher than that of the late planting. Acid detergent fiber content of the late planting was lower than that of the early planting date (p<0.01), while there were no significant neutral detergent fiber content difference among the corn tested. Calculated net energy for lactation (NEL) and TDN at the early planting were higher than those of at the late planting (p<0.01). Results of this our study indicate that the late planting date (May) is better than early planting date (April) in forage yield and feed value of corn. Therefore, the delay of planting date by May was more suitable for use in cropping system.

본 연구는 조사료 원료인 마늘 껍질의 사료적 가치와 메탄 발생량을 조사하기 위해 in vitro 발효 실험을 수행하였다. Garlic husk를 제외하고 국내에서 널리 사용되는 4가지 조사료 원료(Oat hay, Annual ryegrass, Timothy, Tall fescue)를 실험의 처리구로 구성하였다. In vitro 48 시간 발효 후 건물 소화율, 섬유소 소화율, 암모니아태 질소, 휘발성 지방산, pH, 메탄 발생량을 평가하였다. 가스 발생량은 3, 6, 9, 12, 24, 36 및 48 시간에 각각 측정되었다. 최종 가스 발생량에서 Oat hay가 유의적으로 가장 높았다(p<0.01). Garlic husk는 처리구 중 가장 높은 메탄 발생량을 나타내었다(p<0.01). Garlic husk의 건물 소화율은 Oat hay보다 유의적으로 낮았지만 Annual ryegrass, Timothy, Tall fescue보다 높았다(p<0.01). 섬유소 소화율은 Annual ryegrass에서 가장 낮았다(p<0.01). 총 휘발성 지방산 생성량은 Oat hay에서 가장 높았고(p<0.01), Garlic husk, Timothy, Tall fescue는 유사하였다. 본 연구의 in vitro 발효 성상과 메탄 발생량을 고려할 때, Garlic husk는 국내 주요 조사료를 대체할 영양적 가치를 포함하고 있으나 메탄 저감 효과는 미미할 것으로 추정된다.

In the winter forage study, Italian ryegrass(IRG) and barley were selected. In 2018, the dry matter yield of IRG was 16,915kg per ha under the Agrivoltaic System; this was a little more than 16,750kg per ha of outdoors. On the contrary, the dry matter yield of barley was slightly less under the Agrivoltaic System than that of outdoors. In 2019, the dry matter yield under the Agrivoltaic System was 12,062kg per ha for IRG and 12,195kg per ha for the barley; this was 5.4% and 11.5% less than that of outdoors, respectively. In the summer forage study, corn and sorghum×sudangrass were selected. In 2019, the dry matter yield of corn under the Agrivoltaic System was 13,133kg per ha which was 17% less than that of outdoors. The dry matter yield of sorghum×sudangrass was 12,450kg per ha, which was 82.5% of that of outdoors. In 2020, the dry matter yield of corn under the Agrivoltaic System was 8,033kg per ha which was 7.9% less than that of outdoors. The dry matter yield of sorghum×sudangrass was 5,651kg per ha, which was 11.4% less than that of outdoors.

Cattle feeding in South Korea has been heavily dependent on domestically produced rice straw and imported grain. Around 42% of domestically produced rice straw is utilized for forage, and the remainder is recycled to restore soil fertility. Approximately 35% of round baleages were made with rice straw. However, higher quality hay is desired over rice straw. Due to increasing stockpiles of rice, there has been an economic burden on the government to store the surplus; therefore production of annual forage crops in rice fields has been further promoted in recent years. Hay import from the USA currently constitutes more than 80% of total imported hays. The main imported hays are alfalfa (Medicago sativa), timothy (Phleum pretense), and tall fescue (Festica arundinacea). The estimated forage required for cattle feeding was approximately 5.4 million MT in 2016. Domestically produced forage sates only 43% of that value, while low quality rice straw and imported hay covered the rest of demand by 33% and 20%, respectively. As utilization of domestically produced forage is more desirable for forage-based cattle production, long-term strategies have been necessary to promote domestic production of high quality baleage. One such strategy has been utilizing the fertile soil and abundance of fallow rice fields of western region of S. Korea to produce forage crops. Italian ryegrass (Lolium multiflorum) is the most successfully produced winter annual in the region and is approximately 56% of the total winter annual forage production. Forage sorghums (Sorghum bicolor), sorghum × sudangrass hybrids, and hybrid corn (Zea mays) produce a substantial amount of warm-season forage during summer. Produced forage has been largely stored through baleage due to heavy dew and frequent rains and has been evaluated according to S. Korea’s newly implemented baleage commodity evaluation system. The system weighs 50% of its total grading points on moisture content because of its importance in deliverable DM content and desirable baleage fermentation; this has proved to be an effective method. Although further improvement is required for the future of forage production in South Korea, the current government-led forage production in rice fields has been able to alleviate some of the country’s shortage for quality hay.

This study was conducted to evaluate the effects of different nitrogen levels on the yield and nutrient quality of a newly developed domestic hybrid of Teosinte, Geukdong 6〔Zea mays L. subsp. mexicana (Schrad.) H. H. Iltis〕. The field experiment was conducted in a randomized block design with three replicates and consisted of four nitrogen (N) application rates, T1 (200 kg/ha), T2 (300 kg/ha), T3 (400 kg/ha), and T4 (500 kg/ha). No differences were found in plant length, leaf length, leaf width, leaf number, dead leaves, stem hardness, tiller number, and fresh yield (p>0.05). The T3 showed significantly greater dry matter yield at harvest (heading stage) compared to the other treatments (p<0.05). The crude protein content of T4 (10.49%) was higher than those of T1 and T2 (p<0.05). However, there was no significant difference between T4 (10.49%) and T3 (9.63%). The effects on crude fat, crude ash, neutral detergent fiber (NDF), acid detergent fiber (ADF), and crude fiber were not significant (p>0.05). The sugar content was higher in the T2 treatment than the other treatments (p<0.05). For Ca, T3 showed significantly greater content (p<0.05). However, no significant effects were found in the contents of Cu, Fe, K, Mg, Mn, Mo, and Zn (p>0.05). Na content was higher in order of T2 > T4 > T3 > T1 (p<0.05). Total mineral contents were not significantly different among the treatments (p>0.05). Given these results, we recommend the amount of nitrogen fertilization necessary for “Geukdong 6” to be around 400 kg per ha (T3), when considering, high fresh yield, dry matter yield, number of leaves and content of crude protein.

‘Choyoung’, a winter forage triticale cultivar (X Triticosecale Wittmack), was developed at the Department of Rice and Winter Cereal Crop, NICS, RDA in 2015. The cultivar ‘Choyoung’ has the leaves of medium width, long length and green color and a medium grain of brown color. The heading date of the cultivar ‘Choyoung’ was April 30 which was 2 days earlier than that of check cultivar ‘Shinyoung’. Its tolerance or resistance to cold, wet injury, powdery mildew, and leaf rust was similar to those of the check cultivar. But the resistance to the lodging of cultivar ‘Choyoung’ was stronger than that of the check. The average forage fresh and dry matter yield of cultivar ‘Choyoung’ at milk-ripe stages were 40.5 and 15.7 MT ha-1, respectively, which were similar to those (40.3 and 16.1 MT ha-1) of the check cultivar. The silage quality of ‘Choyoung’ was higher than that of the check cultivar ‘Shinyoung’ in crude protein content (5.9%), while was similar to the check cultivar ‘Shinyoung’ in acid detergent fiber (33.9%), neutral detergent fiber (57.3%), and total digestible nutrients (62.2%). It showed a grain yield of 5.59 MT ha-1, which was 38% higher than that of the check cultivar ‘Shinyoung’ (4.05 MT ha-1). This cultivar is recommended for fall sowing forage crops in areas in which average daily minimum mean temperatures in January are higher than -10 ℃.

본 연구는 이탈리안 라이그라스 재배현장에서 재배환경과 재배기술의 차이에 따른 조사료 생산성의 변화 요인을 분석 하기 위하여 2016부터 2017년까지 수행되었다. 우리나라 중부 및 남부지역에서 27개 이탈리안 라이그라스 재배지의 평균 건물수량은 6,940kg/ha이였다. 이탈리안 라이그라스 재배현장의 생산성은 재배환경보다 재배기술과 높은 상관(p<0.01)이 있는 것으로 나타났다. 재배기술 중에서 파종기술 및 포장관리기술과 생산성 간에는 고도의 상관이 있었으나, 시비기술과 생산성 간에는 상관이 없었다. 이상의 결과는 이탈리안 라이그라스의 생산성 향상에는 재배환경보다 재배기술의 현장실천이 더 중요함을 제시하고 있다. 따라서 우리나라 지역별 이탈리안 라이그라스의 생산성 예측기술의 정밀도를 높이기 위해서는 그 지역의 기상 및 토양환경은 물론 재배기술의 적용을 충분히 고려하여야 할 것으로 사료된다.

This study was conducted to evaluate the forage production and feed value of Sasa borealis (S. borealis) in Jeju Island in order to improve the utilization of Sasa borealis and to help mitigate the problem of reduced plant species diversity caused by S. borealis in Hanlla Mountain. To investigate the forage production, three quadrat structures were installed in the S. borealis natural community in the middle part of Hanlla Mountain. From May to October 2017, S. borealis in quadrats was cut at a fixed time of each month, and then forage production and regenerated acidity per kg/ha were evaluated. For the evaluation of feed value, compositional analysis was performed on the monthly samples. In vitro digestion experiments were carried out using cannula mounted Hanwoo. In vitro neutral detergent fiber digestibility(IVNDFD) and in vitro acid detergent fiber digestibility(IVADFD) were measured after the experiment. Forage production of S. borealis showed relatively good regeneration ability in May and June, but the regeneration ability decreased as the cutting was repeated. In order to use S. borealis as a forage, it is considered efficient to feed black goats with good fiber decomposition or horses good palatability to S. borealis and relatively good digestibility.

Response Surface Methodology (RSM) is a widely used statistical analysis for finding an optimal point of a response variable (dependent variable) in accordance with multiple explanatory variables (independent variable). We have previously used RSM to identify optimal temperature and humidity (represented by the amount of water spray) of the fresh forage system for maximizing the growth of barley after 6 days of seeding. Consequently, RSM demonstrated that the optimal growth condition of barley was 19.70 and 1.38 l/h. However, it was not proved by empirical result, we aimed to verify the RSM result through comparative experiments. Experiments were designed four trials with different conditions. The first trial represented optimal conditions obtained from RSM, i.e., 20 and 1.4(l/h), while the rest of trials represented; 1) 20 and 1.8(l/h), 2) 18 and 1.4(l/h), and 3) 23 and 1.4(l/h). After 6 days of seeding, the average barley weight of the first trial was 11,094 g which was the highest yield compared to other trials (10,101 g, 9,757 g, and 10,233 g). This result supports that the RSM successfully predicted the optimal growth condition to be applied for the fresh forage system.

This study was designed to investigate the carryover effects of high-forage to concentrate (F: C) diet in bred heifers on feed intake, feed efficiency (FE) and milk production of primiparous lactating Holstein cows. The experiment was conducted for 589 days (d) from onset of pregnancy through to the end of first lactation. Twenty-four bred heifers (Body weight: BW= 345.8 ± 45.4 kg and 15 ± 1.2 mon of age) randomly assigned to two groups of 3 pens containing 4 heifers each and fed high forage (HF) diet with F: C ratio of 91.7: 8.3% and low forage (LF) diet with F: C ratio of 77.8: 22.2% throughout the pregnancy period. After calving, lactating cows were fed total mixed ration (TMR) based diet. No differences (p > 0.05) were observed in dry matter intake (DMI) of bred heifers and primiparous lactating cows in both HF and LF groups. The FE of mid-to-late lactation period was higher (p< 0.05) in HF than LF group. However, the HF group showed higher (p < 0.05) milk yield, 4 % fat corrected milk (FCM) and energy corrected milk (ECM) than LF group during the 305 d lactation. The LF group showed higher (p < 0.05) milk fat, crude protein (CP), milk urea nitrogen (MUN), solid not fat (SNF) and somatic cell count (SCC) than HF group. It is concluded that restriction of F: C ratio to 91.7: 8.3% to bred heifers has the potential carryover effects to maintain higher milk yield and FE with no adverse effect on feed intake and milk composition of primiparous lactating Holstein cows.

The objective of this study was to efficiently produce forage crop seed of spring oat (Avena sativa L., cultivar High Speed) in Gyeongbuk area. Forage crop oats (130 kg/ha) were sown with a randomized block design. They were sown in triplicates in 2015 and 2016 using basal fertilizer of 70 kg N, 74 kg P, and 39 kg K/ha. Agronomic traits and seed production of oats were investigated to determine the influence of seeding dates (February 28/29th, March 10th, and March 20th). Heading, flowering, and maturing dates of these oats sown on February 28/29th and March 10th were almost close to each other with 1-2 days of difference for all test plots. For oats sown on the last day (28/29) of Feb., plant heights (111.6-122.6 cm) were significantly longer than those sown in March each year. In addition, panicle number (416.7 per m2) and panicle length (17.3 cm) of oats sown on the last day of February were also significantly (p < 0.05) larger than those of oats sown in March in 2015 and 2016, respectively. Based on these results, it is recommended to sow these oats on the last day of February to have better agronomic traits in terms of plant height, stem length, panicle length, and panicle number per m2. Grain numbers (56.3 and 63.3) and kernel weights (1.72 and 2.00 g) per spike in plots of oats sown on the last day of February were also significantly (p < 0.05) larger than those of oats in other plots in 2016 and in the average of 2015~2016, respectively. The highest grain yield (6,243 kg/ha) was obtained when oats were sown on the last day of February. Feed value of harvested oats was good in terms of proximate compositions including fiber contents and TDN contents. In conclusion, sowing on the last day of February is the most effective way to increase seed production of spring oats in Gyeongbuk area of Korea.