• 한국초지조사료학회지
• /
• 제17권1호
• /
• pp.27-34
• /
• 1997

This experiment was carried out to determine growth characteristics, dry matter (DM) yield, seasonal yield distribution and nutritive value of early- and late maturity orchardgrass, 1990 to 1992. The cultivars used in this study were Potomac, Hallmark (early maturing cultivar) and Lidacta, Rancho (late maturing cultivar), and a mixture plot (Potomac 25% + Hallmark 25% + Lidacta 25% + Rancho 25%) was involved. The seeding rate was 20 kgha in all treatments. Plant height of Potomac and Hallmark was longer than that of Lidacta and Rancho. The dates of initial heading and 50% heading of early maturing cultivars (Apr. 30 and May 10) were 10 days earlier than those of late matuing cultivars. Potomac and Hallmark were upright, and Lidacta and Rancho were semi-upright type, and severe disease and weeds (30 ~ 40%) were observed at Lidacta plot. On an average of three years, the DM yields of Potomac (10,549 kglna), Hallmark (10,435 kg) and mixture (10,356 kg) were significantly (P<0.05) higher than those of Rancho (9,457 kg) and Lidacta (8,218 kg). However, seasonal yield distribution of late maturing cultivars was better than that of early maturing cultivars. The contents of crude protein, crude fat, crude fiber, nitrogen %ee extract, aude ash, neutral detergent fiber, P, K, Ca, and Mg were not significantly different between cultivars, but higher aude protein yield was found at Potomac, Hallmark and mixture plots. Based on the above results, it may be concluded that early maturing cultivars for high productivity, late maturing cultivars for seasonal yield distribution, and seeding of mixture andlor separation of early- and late maturing cultivars are recommended. Also Lidacta was a not promising cultivar due to low productivity, severe disease, and high weeds development.

• Asian-Australasian Journal of Animal Sciences
• /
• 제20권12호
• /
• pp.1858-1864
• /
• 2007

Influence of varying level of sodium bicarbonate (SB) supplementation on milk yield and its composition was examined in a randomized complete block design in early lactating Nili Ravi buffaloes during summer. Four iso-nitrogenous and iso-caloric diets were formulated. The diet 0B contained 0 while LB, MB and HB diets contained 0.50, 1.0 and 1.50% SB levels, respectively. The diets were randomly allotted to twenty buffaloes, five in each group. A linear increase in nutrient and water intake was recorded with increasing SB level. Buffaloes fed MB and HB diets showed higher nitrogen balance than those fed 0B and LB diets. A significant increase in blood pH and serum bicarbonate was noticed with increasing SB level. Urine pH increased significantly with increased SB level. A linear increase in milk yield was also noticed with increasing SB level. Milk fat% increased significantly in buffaloes fed MB and HB diets compared with those fed 0B and LB diets. Buffaloes fed HB diet had higher conception rate and less services per conception than those fed 0B diet. This study indicated that a high SB diet not only increased dry matter and water intake, milk yield, milk fat% but also increased conception rate in early lactating buffaloes during summer.

• 한국작물학회지
• /
• 제47권4호
• /
• pp.311-318
• /
• 2002

Planting date of soybeans [Glycine max (L.) Merr.] is one of production components in cultural systems. The objective of the current study was to identify the components of soybean production and cultural practices encompassing planting dates and cultivars that respond to dry matter accumulation, harvest index and yield components. Three determinate soybean cultivars were planted on May 13 (early), June 3 (mid), and June 24 (late). Planting density was 60$\times$15cm with 2 seeds (222,000 plants per ha). Soybean plants were sampled every 10 days interval from the growth stages of V5 to R8 and separated into leaves including petioles, stems, pods, and seeds. Dry matter accumulations, harvest indices, and yield components were measured. Early planting had taken 55 days from VE to R2 and late planting taken 39 days indicating reduced vegetative growth. Early planting showed higher leaf, stem, pod and seed dry weights than late planting. However, late planting appeared to be higher harvest index and harvesting rate. Vegetative mass including leaf and stem increased to a maximum around R4/R5 and total dry weight increased to a maximum around R5/R6 and then declined slightly at R8. The highest seed yield was obtained with mid planting and no difference was found between early and late plantings. Cultivar differences were found among planting dates on growth characteristics and yield components. The results of this experiment indicated that soybean yield in relation to planting dates examined was mainly associated with harvest index and harvesting rate, and planting date of cultivars would be considered soybean plants to reach the growth stage of R4/R5 after mid August for adequate seed yield.

• 한국약용작물학회지
• /
• 제24권2호
• /
• pp.110-114
• /
• 2016

Background: This study aimed to investigate the effect of harvest time on the growth, yield characteristics and loganin content in Dipsacus asperoides Wall. Methods and Results: Dipsacus asperoides seedlings were planted within a nursery environment in early May 2015 and harvested in early, middle and late October 2015, and early November 2015. Harvest time did not result significant differences in the plant height, stem diameter, branch length, leaf width and aboveground dry weight moreover, no significant differences were observed in root length, number of roots and root diameter. However, the diameter of lateral roots was greater in the harvests from the late October and period thereafter. The highest values of root dry weight and yield were recorded in early November. Specifically, the yield significantly increased from 205 kg/10 a (index: 100) in early October to 358 kg/10 a (index: 175) in early November, in terms of root part weight. Loganin contents of D. asperoides differed significantly among harvest times raging from 0.0766% in early October to 0.1704% in late November, thereby showing an increasing trend in later harvest times. Conclusions: These results suggest that the optimum harvest time for D. asperoides is early November, when the yield is the highest. Harvest time significantly affected loganin contents, which constantly increased from early October until early November.

• 한국임상수의학회지
• /
• 제33권2호
• /
• pp.93-96
• /
• 2016

This retrospective study evaluated the effect of age at first calving on the productive and reproductive performance in Holstein dairy cattle. Data were collected on 2,297 lactations from 19 dairy farms, including dates of birth, insemination, pregnancy, calving, and lactation and milk production (305-day milk yield at first lactation and lifetime milk yield). Lactation data were grouped based on age at first calving into the early (< 24 months, n = 414), moderate (24 ${\leq}$ and ${\leq}$ 28 months, n = 1,268), and late (> 28 months, n = 615) groups. The 305-day milk yield at first lactation was higher (p < 0.005) in the late group (8,461.9 kg) than in the early (8,130.8 kg) and moderate (8,261.9 kg) groups. Lifetime days in milk were shorter (p < 0.01) in the early group (1,045.7) than in the moderate (1,143.1) and late (1,110.7) groups, whereas the lifetime milk yield was higher (p < 0.05) in the moderate group (34,171.8 kg) than in the early group (31,791.6 kg). The second calving interval (days) differed (p < 0.0001) between the early (416.9), moderate (438.9), and late (455.3) groups. The culling rate at the first and second lactations tended to be higher (p = 0.08) in the early group (31.2%) than in the moderate group (26.0%), whereas it was intermediate in the late group (29.3%). In conclusion, dairy heifers aged 24-28 months at first calving showed a higher productive performance through an increased lifetime milk yield and a decreased culling rate.

• 한국초지조사료학회지
• /
• 제7권1호
• /
• pp.18-24
• /
• 1987

This experiment was carried out to investigate the effects of the final cutting time and cutting height on the winter survival, regrowth, and carbohydrate reserves in stubble, and early spring yield of orchardgrass-dominated pasture before and after the winter season. The experiment was conducted at the experimental field of the Livestock Experiment Station, in Suwon, from October 1985 to early 1986. The results obtained are summarized as follows: 1. Regrowth of plant after the final cut increased significantly (P<0.05) with plot of the early cutting time (Oct. 10) and high cutting height at the final. For winter survival, cut plant should regrow over 15cm in plant height. Therefore limit cutting time and cutting height were forced to be on Oct. 25 and at 6-9cm, respectively. 2. Total water soluble carbohydrate (TSC) content in stubble after the final cut was not significantly changed by different cutting time and cutting height. 3. The percentage of dead plant after wintering was found to be high with plot of the late cutting time and low cutting height at the final cut (P<0.05). And the correlation between the percentage of dead plant after wintering and final plant height before wintering was significantly negathe (r = -0.728**). 4. Fresh and DM yield at the early spring after wintering were increased in the plot of the early cutting time and high cutting height (P<0.05) at the final cut. And significantly positive correlation was observed between the early spring yield and final plant height before wintering (r = 0.720**).

• Asian-Australasian Journal of Animal Sciences
• /
• 제17권3호
• /
• pp.343-348
• /
• 2004

The objective of the present study was to determine the plasma level of insulin-like growth factor-I (IGF-I) in relation to mammary blood flow and milk yield including biological variables of relevance to milk synthesis in two different types of crossbred Holstein cattle at 3 different stages of lactation. Eight heifers were 87.5% HF and eight 50% HF animals were selected for the experiments. The three stages of lactation tested were: early lactation (30 days postpartum), mid-lactation (120 days postpartum) and late lactation (210 days postpartum). Animals in each group were fed a concentrate and rice straw treated with 5% urea as the source of roughage throughout the experiments. In early lactation, mammary blood flow and milk yield of 87.5% HF animals were significantly higher than those of 50% HF animals. In mid- and late lactation, both mammary blood flow and milk yield showed a proportional decrease from the early lactating period of 87.5% HF animals. The trends for persistency were observed in 50% HF animals as for udder blood flow and milk yield throughout the experimental periods. The plasma glucose level of the 50% HF animals was significantly higher than those of 87.5% HF animals in both early and mid-lactation. The concentrations of arterial plasma free fatty acids ($C_{16}\;to\;C_{18}$) were higher in 50% HF animals as compared with 87.5% HF animals in all periods of study. In early lactation, the concentration of plasma growth hormone (GH) of 87.5% HF animals was higher than those of the 50% HF animals, thereafter the mean level of plasma growth hormone declined in both mid- and late lactation. The concentration of plasma IGF-I of 50% HF animals was significantly higher than those of 87.5% HF animals in all stages of lactation. There were no differences among stages of lactation for the levels of plasma IGF-I, insulin and growth hormone in 50% HF animals. In 87.5% HF animals, the plasma levels of both IGF-I and insulin were lower in early lactating period while it showed an increase during mid- and late lactation. The present results indicated that the regulatory role for the higher mammary blood flow and milk yield during lactation in 87.5% HF are not mediated via the higher level of circulating IGF-I. Differences in mammary blood flow and milk yield between 50% HF and 87.5% HF animals are in part due to a higher concentration of circulating growth hormone. The lower level of circulating growth hormone in 50% HF animals would be regulated by higher levels of IGF-I, free fatty acid and glucose in plasma.

• Journal of Ecology and Environment
• /
• 제35권3호
• /
• pp.195-201
• /
• 2012

Seasonal variations in the profile and concentrations of essential oil in Zanthoxylum piperitum were investigated by gas chromatography-mass spectrometry. Seasonal changes in the percentages of the main constituents of the essential oil of both leaves and fruits from Z. piperitum varied. Variations in essential oil yield and the amount of monoterpenes and sesquiterpenes in leaves and fruits at different developmental stages were significant. The characteristic content of essential oil in leaves was determined mainly due to the content of monoterpenes, and that in fruits was determined largely due to the sesquiterpenes. Twenty-nine compounds in the oil from Z. piperitum leaves were detected; the major compounds were ${\beta}$-phellandrene (26.90%), citronella (15.32%), ${\beta}$-myrcene (3.24%), ${\alpha}$-pinene (2.79%), trans-caryophyllene (2.66%), and fanesyl acetate (2.30%). The highest yield of oil (43.89%) in Z. piperitum leaves was obtained in May but decreased gradually beginning in June. The yield of essential oil from Z. piperitum leaves during early periods was higher than that during later periods and usually decreased from early maturation stages to subsequent stages. However, in contrast to leaves, the oil yield in Z. piperitum fruit increased in June, and oil yield later in the season was higher than that earlier in the season. These results indicate that the essential oil produced from Z. piperitum leaves at the early developmental stages was stored in leaves, and might be transferred to fruit at the final developmental stages.

• 한국자원식물학회지
• /
• 제9권2호
• /
• pp.189-195
• /
• 1996

남부지방(南部地方)에 적합(適合)한 양파의 품종(品種)을 선발(選拔)하기 위하여 공시(供試)한 품종(品種)들에 대한 생육특성(生育特性), 구(球)의 특성(特性), 수량성등(收量性等)을 조사(調査)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. 수량성(收量性)이 높아서 선발(選拔)된 조생종(早生種) 양파는 패충조생, 극동황, 창녕청황극조생, 단오큰애기, 금정조생황이었고, 이 중(中)에서도 가장 수량성(收量性)이 높은 품종(品種)은 창녕청황극조생, 금정조생 황 이었다. 2. 조생종(早生種)의 수량성(收量性)과 가장 관계가 깊은 형질(形質)은 초장(草長), 엽초장(葉哨長), 구고(球高), 구경(球莖), 구중(球重)이었다. 3. 수량성(收量性)이 높아서 선발(選拔)된 만생종(晩生種) 양파는 창녕대고, 정풍황, 천주구형황, 천주대고, 서울대고였 고, 이 중(中에)서도 가장 수량성(收量性)이 높은 품종(品種)은 천주대고였다. 4. 만생종(晩生種)의 수량성(收量性)과 가장 관계가 깊은 형질(形質)은 초장(草長), 엽초경(葉哨莖), 구경(球莖), 구중(球重)이었다.

• 한국초지조사료학회지
• /
• 제16권4호
• /
• pp.299-306
• /
• 1996

This experiment was conducted from 1991 to 1993 at the forage experimental field, College of Agriculture and Life Sciences, SNU, Suweon to investigate the effects of previous crop residues on growth and yield of succeeding corn(2ea mays L.) and also to determine the best double cropping system necessary to maximize the total dry matter yield of winter forage crops plus corn for silage. In this experiment, treatments consisted of no crop as a control, late maturing Kodiak rye(Seca1e cereale L.), Bamapoli forage rape(Brassica napus Subsp. oleifera L.), G-sprinter oats(Avem sativa L.), Chief crimson clover(Trifolium incarnatum L.), Jackson Italian ryegrass(lo1ium rnultiJlorum L.), Vantage vetch(Vicia sativa L.) and early maturing Koolgrazer rye(Seca1e cereale L.). Corn leaf number and silking date were not significantly affected by previous crop residues, but the leaf number of corn following Italian ryegrass was reduced by 1.9 relative to no previous crop. The plant height and LA1 were significantly reduced during early development when corn followed Italian ryegrass and late maturing Kodiak rye (p<0.05). The dry matter and estimated TDN yields of corn were significantly reduced when corn followed Italian ryegrass and late maturing Kodiak rye. The yield reductions for corn following Italian ryegrass, late maturing Kodiak rye and early maturing Koolgrazer rye, relative to com when no previous crops were planted, were 34, 17 and 8%, respectively. Therefore, the reduction in corn growth and yield in this experiment could be explained by an allelopathic effect resulting from the Italian ryegrass and rye residues. The highest total dry matter yield of 30,509kg/ha was obtained from an early maturing rye-corn double cropping sequence in combination among the eight cropping systems.