• 한국초지조사료학회지
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• 제42권1호
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• pp.1-9
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• 2022

본 연구는 우리나라의 남부해안지역에서 가을장마, 혹한 및 봄 가뭄과 같은 계절적 기후시나리오 간 이탈리안 라이그라스(IRG: Italian ryegrass)의 건물수량(DMY: dry matter yield)을 비교하기 위해 수행하였다. 남부해안지역의 IRG 자료(n = 203)는 1993년부터 2013년까지 농총진흥청이 제주, 남원 및 영암에서 수행한 신품종 지역적응시험 결과보고서로부터 수집되었다. 계절적 기후 시나리오를 정의하기 위해 기상청으로부터 온도, 습도, 바람 등과 같은 기상정보를 사용하였다. 정상과 이상기후 시나리오를 구분하기 위해 5% 유의수준에서 판별분석을 수행하였다. 또한 IRG 수량비교는 표본분포의 정보를 기반으로 통계적 시뮬레이션을 수행하였다. 그 결과, 남부해안지역에서 봄 가뭄에 의한 DMY 차이만 뚜렷하게 나타났다. 혹한은 정상으로부터 분명하게 구분되었지만, DMY 차이는 나타나지 않았다. 따라서 DMY 비교는 봄 가뭄에 대해서만 시뮬레이션을 수행하였다. 그 결과, 정상 및 봄 가뭄 하에서 DMY (kg/ha)은 각각 14,743.83 및 12,707.97로 봄 가뭄 발생에 의한 예상피해는 약 2,000 kg/ha로 나타났다. 또한 봄 가뭄 하에서 예측 DMY는 정상시나리오에 비해 넓고 느리게 증가하여 변동성이 큰 것을 확인하였다. 본 연구는 계절별 기후 시나리오를 고려한 통계적 시뮬레이션을 통해 봄 가뭄에 의한 IRG의 DMY 피해 및 가능성을 확인한 것에 의의가 있다.

• 한국초지조사료학회지
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• 제39권3호
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• pp.178-184
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• 2019

The objective of this study was to evaluate the dry matter yield of (DMY) of Italian ryegrass (IRG) forage crop based on two seeding date (September 25 and October 2) in 2017 and 2018, and evaluation of the potential reason of DMY reduction in IRG cultivars grown at Chuncheon, South Korea. Three cultivars of IRG including Kowinearly, Kowinmaster and Hwasan 104 were used in this experiment. The experimental field was designed as a split-split-plot arrangement. The cultivars were harvested on April 26 before the heading stage of both years. In this study, no significant effect (p>0.05) of seeding date has been found on the DMY, whereas the cultivars and year showed a significant effect on the DMY (p<0.05). Except September 25 of 2017, Hwasan 104 indicated significantly lower (p<0.05) DMY than Kowinearly and Kowinmaster in all seeding periods. Though no significant difference (p>0.05) was observed for the DMY between the two seeding dates in 2018, but the DMY was significantly lower (p<0.05) than that of 2017. Lower crude protein (CP) content of Kowinearly was observed on the seeding date of October 2 of 2017, and also in both seeding dates on 2018 (p<0.05). No significant difference (p>0.05) was observed in acid detergent fiber (ADF) between the cultivars on both seeding dates and years. Similarly, no significant difference (p>0.05) was found in neutral detergent fiber (NDF) between the cultivars in 2017. However, Kowinearly showed higher NDF content as compared to Kowinmaster and Hwasan 104 on both seeding dates and years. The seeding date has no significant difference (p>0.05). Thus, considering the extent of DMY in both years, the mean minimum temperature during winter season could be the limiting factor for the DMY of IRG cultivars. However, based on this study, the seeding dates of September 25 and October 2 have no potential effect on the DMY. Thus, on the basis of the current DMY and forge quality parameters, the cultivation Kowinmaster is recommended in Chuncheon.

• Asian-Australasian Journal of Animal Sciences
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• 제16권9호
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• pp.1239-1241
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• 2003

Korean cattle breeders have shown interest in genetic improvement of milking ability because poor milking ability and short suckling period of Korean cattle is a hindrance to growth of calves. In this study, daily milk yields by period in Korean cattle were analyzed with an animal model. The milk yields were actually measured at sequential intervals from 1 to 4 months after calving: daily milk yields from delivery to 1 month (DMY1), from 1 to 2 months (DMY2), from 2 to 3 months (DMY3), and from 3 to 4 months (DMY4). Genetic variance estimates gradually increased by the periods while environmental variance estimates gradually decreased. This resulted in a dramatic increase in the heritability by periods: 0.02 for DMY1, 0.11 for DMY2, 0.16 for DMY3, and 0.42 for DMY4. In multi-trait analyses with daily milk yield and body weight of calf, genetic correlation estimates between milk yield and body weight were quite small (-0.08 to 0.02 for birth weight and -0.10 to 0.00 for weaning weight). The trends of the heritability estimated in this study showed that the genetic effects were more influential when the milking period was longer, suggesting genetic evaluations with daily milk yield collected at a longer period.

• 한국초지조사료학회지
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• 제36권3호
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• pp.223-236
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• 2016

The objective of this study was to construct Italian ryegrass (IRG) dry matter yield (DMY) estimation models in South Korea based on climatic data by locations. Obviously, the climatic environment of Jeju Island has great differences with Korean Peninsula. Meanwhile, many data points were from Jeju Island in the prepared data set. Statistically significant differences in both DMY values and climatic variables were observed between south areas of Korean Peninsula and Jeju Island. Therefore, the estimation models were constructed separately for south areas of Korean Peninsula and Jeju Island separately. For south areas of Korean Peninsula, a data set with a sample size of 933 during 26 years was used. Four optimal climatic variables were selected through a stepwise approach of multiple regression analysis with DMY as the response variable. Subsequently, via general linear model, the final model including the selected four climatic variables and cultivated locations as dummy variables was constructed. The model could explain 37.7% of the variations in DMY of IRG in south areas of Korean Peninsula. For Jeju Island, a data set containing 130 data points during 17 years were used in the modeling construction via the stepwise approach of multiple regression analysis. The model constructed in this research could explain 51.0% of the variations in DMY of IRG. For the two models, homoscedasticity and the assumption that the mean of the residuals were equal to zero were satisfied. Meanwhile, the fitness of both models was good based on most scatters of predicted DMY values fell within the 95% confidence interval.

• Journal of Animal Science and Technology
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• 제63권4호
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• pp.799-814
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• 2021

Information is lacking about the effect of date of a fall cut of alfalfa (Medicago sativa L.) on dry matter yield (DMY), forage nutritive value, and stands persistence. The objective of this study was to determine the effect of timing of a fall cut on DMY, forage nutritive value and stand persistence of three alfalfa varieties: low-lignin Hi-Gest 360, Roundup Ready Tonica, and conventional Gunner in Northeastern Kansas in the United States. The field study was carried out by splitting plot in randomized complete block design with four replications. The harvesting data of different maturity stages were collected in each year from 2015 to 2018. Three cuts were harvested based on the stage of maturity, and the last (fourth) cut was done on September 15, September 30, October 15, and October 30 of each year. The persistence of the alfalfa stands was determined each fall after the last cut, and each spring after the first cut, by counting the number of live plants in a randomly placed quadrat in each plot. Alfalfa cut on September 15 and September 30 had a higher stand persistence compared to alfalfa cut on October 15 and October 30. The DMY of the first cut in 2016 was significantly higher in roundup ready than the low-lignin alfalfa variety. In the second cut, DMY was significantly higher in conventional alfalfa than the roundup ready. There were no significant differences in DMY between alfalfa varieties in the rest of seasonal cuttings in 2016 and 2017 and annual total yield in both years. In general, low lignin alfalfa variety had higher crude protein and relative feed value and lower acid detergent fiber and neutral detergent fiber contents than those in roundup ready and conventional alfalfa varieties. On average, nutritive value of alfalfa was generally affected by last cutting dates in 2017. Based on 3-year data the last cutting of alfalfa in the fall could be done by September 30-October 15 without harmful effect on DMY.

• 한국초지조사료학회지
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• 제42권2호
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• pp.103-107
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• 2022

This study was carried out to evaluate the seeding date and performance of early maturing rye cultivars for the Dry matter yield (DMY) and nutritive value during 2016 and 2017 in Yeongseo region of Gangwondo, South Korea. The experimental field was designed as a split-plot arrangement. The treatments were two planting dates on September 25 and October 02 as the main plots, and two cultivars of forage rye including Gogu and Koolgrazer as sub-plots. The cultivars were harvested on April 26 at the heading stage of both years. In this experiment, the sowing dates and cultivars of the forage rye did not effect on DMY. The DMY had no significant differences among the cultivars of forage rye and seeding date of both years. Similarly, no significant difference was observed in the DMY of Gogu and Koolgrazer in both seeding date and years. The CP, NDF, ADF, and RFV had no significant differences among the cultivars of forage rye and seeding date of both years. Considering the DMY and nutritive value of the current experiment, seeding of forage rye cultivars Gogu and Koolgrazer on September 25 and October 2 could be used as an recommended seeding date at northern area. In addition, based on the climate characteristics of the region, both cultivars had relatively similar forage yield and quality that makes them to be recommended for cultivation in the region. This study is meaningful in that DMY was first presented in Yeongseo region where there is no cultivation data for forage rye.

• Asian-Australasian Journal of Animal Sciences
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• 제19권9호
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• pp.1252-1256
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• 2006

This study estimated the effects of parity (1-3) and stage of lactation (early, mid and late) on daily milk yield (DMY), somatic cell score (SCS), milk urea nitrogen (MUN), blood glucose, and immunoglobulin G (IgG), their heritabilities and genetic correlations between them in Holsteins (n = 200). Means and standard deviations of DMY, SCS, MUN, blood glucose, and IgG in the experimental herd were $23.35{\pm}7.75kg$, $3.81{\pm}2.00$, $13.99{\pm}5.68mg/dl$, $44.91{\pm}13.12mg/dl$, and $30.36{\pm}6.72mg/ml$, respectively. DMY was the lowest in first parity, and in late lactation. SCS increased with parity; however, it was lowest in mid-lactation. MUN was lowest in first parity, and no difference was noted across stage of lactation. Blood glucose was similar between parities, however the highest blood glucose was observed during mid lactation. IgG level was significantly different between first and second parity; however, stage of lactation did not affect its level. Heritability of DMY was 0.16. Its genetic correlations with SCS and with blood glucose were -0.67 and 0.98, respectively. Heritability of SCS was 0.15. Genetic correlations of SCS with MUN, glucose, and IgG were -0.72, -0.59, and 0.68, respectively. Heritability of MUN was estimated to be 0.39 and had a genetic correlation of -0.35 with IgG. Heritabilities of blood glucose and IgG were 0.21 and 0.33, respectively. This study suggested that MUN, blood glucose and IgG could be considered important traits in future dairy selection programs to improve milk yield and its quality with better animal health and welfare. However, further studies are necessary involving more records to clarify the relationship between metabolic and immunological traits with DMY and its quality.

• 한국초지조사료학회지
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• 제36권3호
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• pp.205-214
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• 2016

The objective of this study was to construct a forage rye (FR) dry matter yield (DMY) estimation model based on climate data by locations in South Korea. The data set (n = 549) during 29 years were used. Six optimal climatic variables were selected through stepwise multiple regression analysis with DMY as the response variable. Subsequently, via general linear model, the final model including the six climatic variables and cultivated locations as dummy variables was constructed as follows: DMY = 104.166SGD + 1.454AAT + 147.863MTJ + 59.183PAT150 - 4.693SRF + 45.106SRD - 5230.001 + Location, where SGD was spring growing days, AAT was autumnal accumulated temperature, MTJ was mean temperature in January, PAT150 was period to accumulated temperature 150, SRF was spring rainfall, and SRD was spring rainfall days. The model constructed in this research could explain 24.4 % of the variations in DMY of FR. The homoscedasticity and the assumption that the mean of the residuals were equal to zero was satisfied. The goodness-of-fit of the model was proper based on most scatters of the predicted DMY values fell within the 95% confidence interval.

• 한국초지조사료학회지
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• 제41권1호
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• pp.47-55
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• 2021

본 연구는 기후요인과 토양요인이 알팔파 건물수량에 어느 정도 영향을 미치는지를 기여도로 평가할 목적으로, 기상변수와 토양물리성변수를 고려하여 일반선형모형으로 수량예측모델을 구축하였다. 알팔파 수량예측모델 구축과정은 알팔파, 기상 및 토양자료수집, 가공, 통계분석 및 모델구축 순이었다. 수량예측모델은 알팔파와 양적자료인 기상변수를 선택하기 위한 다중회귀분석과 질적자료인 토양물리성변수도 고려하기 위해서 일반선형모형을 사용하였다. 그 결과 DMY에 영향을 미치는 기상변수는 적산온도와 생육일수이었으며, 토양물리성변수는 점토함량이 선택되었다. DMY에 영향을 미치는 변수별 기여도는 점토함량(63%), 적산온도(21%) 및 생육일수(11%)순 이었으며 요인별 기여도는 기후요인(적산온도, 21%와 생육일수, 11%)이 32%, 토양요인(점토함량)이 63%로 나타나 토양요인이 기후요인보다 알팔파 건물수량에 더 기여하는 것으로 평가하였다. 본 연구에서 이용한 알팔파 자료는 토성, 시비수준 및 품종이 제한되어 있어 앞으로 이들 요인을 고려한 다양한 조건의 재배실험을 통하여 보다 많은 자료축적이 요구된다.

• 한국작물학회지
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• 제64권4호
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• pp.311-322
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• 2019

중부 평야지에서 사료용 벼-동계사료작물, 동계사료작물-사료용 벼 이모작 시 양질 조사료의 최대 수량성 작목 조합을 알아보기 위해 사료용 벼 최적재배 중심으로 재배하였을 때와 동계사료작물 최적 재배 중심으로 재배하였을 때로 나누어 4년 간 시험한 연구결과는 다음과 같다. 1. 사료용 벼 보통기 재배양식 중심으로 재배하였을 때 사료용 벼의 건물수량은 조생종 '조우'가 평균 15.8톤/ha로 가장 적었고 중만생종 '영우'가 21.0톤/ha로 가장 많았으나 19.2톤/ha인 '목우'와 통계적으로 차이가 없었다(p<0.01). 동계사료작물은 9월 23일 파종 시 '그린팜'(3.2톤/ha)과 '곡우'(4.5톤/ha)는 유의적으로 차이가 나지 않았고 '조성'은 12.6톤/ha로 가장 높았으며(p<0.001) 10월 11일 파종 시에는 '조성'(16.6톤/ha)>'그린팜'(10.5)>'곡우'(4.7)순으로 유의적으로 차이가 있었고(p<0.001) 10월 31일 파종한 경우 '조성'이 11.8톤/ha로 다른 두 초종보다 유의적으로 높았다(p<0.05). 호밀 '곡우'를 제외하고는 10월 11일 파종 시 건물수량이 가장 높았다. 2. 동계사료작물 최적 파종시기 중심으로 재배하였을 때 동계사료작물의 평균 건물수량은 트리티케일 '조성'이 '그린팜'(10.9톤/ha)과 '곡우'(9.6)와 비교하여 유의적으로 차이를 보이는 18.3톤/ha로 가장 높았으며 사료용 벼는 5월 10일 이앙 시 건물수량은 '목우'가 23.0톤/ha로 가장 높았으나 '영우'(21.4)와는 유의적인 차이가 없었고(p<0.05) '조우'(15.9)와는 차이가 있었다(p<0.05). 5월 25일 이앙시 '목우'가 24.2톤/ha로 가장 높았으나 '영우'(20.7)와는 차이가 없었고(p<0.05) '조우(18.6)'와 유의적인 차이를 보였다(p<0.05). 6월 11일 이앙 시 건물수량은 '영우'가 21.3톤/ha로 다른 두 품종에 비해 유의적으로 높았다(p<0.05). 3. 중부평야지에서 사료용 벼-동계사료작물 이모작 시 최대 조사료 생산 작목 조합은 사료용 벼 최적 이앙 및 수확 시기에 맞추어 동계사료작물을 연속하여 재배하였을 때는 사료용 벼 '영우'와 트리티케일 '조성' 조합으로 생산성은 33.6톤/ha이었으며 동계사료작물 최적 파종 및 수확 시기에 맞추어 연속하여 사료용 벼를 재배하였을 때는 동계사료작물인 트리티케일 '조성'과 사료용 벼 '영우' 조합으로 생산성은 39.6 (톤/ha)이었다.