• Journal of Ecology and Environment
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• v.45 no.4
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• pp.228-236
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• 2021

Background: A review of the literature was carried out to study dust and sandstorm (DSS) in terms of its ecosystem processes and relationship to other dryland disasters in Northeast Asia. Drylands are ecosystems that include grasslands, semi-deserts, and deserts, and these types of ecosystems are vulnerable due to their low primary productivity that depends on a small amount of precipitation. Results: Drought, dust, desertification, and winter livestock disasters (called dzud) are unique natural disasters that affect the region. These disasters are related in that they share major causes, such as dryness and low vegetation cover that combine with other conditions, wind, cold waves, livestock, and land-surface energy, to dramatically impact the ecosystem. Conclusions: The literature review in this study illustrates the macroscopic context of the spatial and temporal patterns of DSS according to geography, climate, and vegetation growth in the drylands of Northeast Asia. The effects of ocean climates and human activities were discussed to infer a possible teleconnection effect of DSS and its relations to desertification and dzud.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.1
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• pp.35-40
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• 2021

This study was conducted to evaluate the forage productivity and feed value of Sasa borealis (S. borealis) using growing black goats(S. borealis) in order to improve the utilization of S. borealis and to help mitigate the problem of reduced plant species diversity caused by S. borealis in Hanlla Mountain. One control and three treatments were made by the level of addition of S. borealis silage to the TMR feed. T1(10%), T2(20%), and T3(30%) treatments showed more daily weight gains than control group. Feed conversion ratio of T2 is 4.4g, which is significantly lower than control(P<0.05). The nitrogen retention in the control, which had relatively high dry matter intake, was 12.5g, which was significantly higher than that of T3. Sasa. borealis silage is considered to be able to use as a forage source for black goats, and if it is fed in an appropriate amount, it is considered that it will help improve livestock productivity, such as weight gain and feed conversion ratio.

• Journal of The Korean Society of Grassland and Forage Science
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• v.43 no.4
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• pp.240-247
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• 2023

This experiment investigated the effects of feed additives of Sasa quelpaertensis Nakai (SQN) extract on Landrace pigs on economic traits such as the quality, physiological characteristics, and productivity. Sixteen pigs with an average age of 154 days were selected as experimental subjects. The experiment was conducted by dividing the group into eight pigs for the supplementation group, feeding with SQN extract, and another eight for the control group feeding without SQN extract. Water was fed ad libitum. On the 30th day, there was no significant difference between meat quality and productivity. However, the glucose and thyroxine were statistically lower with the supplementation group than with the control group (p<0.05). Also, the levels of creatinine difference between 1.18 ± 0.12 mg/㎗ with the supplementation group and 0.70 ± 0.06 mg/㎗ with the control group (p<0.05). However, all serum biochemistry values were within a normal range, with no health problems. The present study will help solve the problem of reducing the diversity of plant species in Halla Mountain by increasing the availability of the SQN as a pig feed additive.

• Journal of The Korean Society of Grassland and Forage Science
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• v.16 no.3
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• pp.183-189
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• 1996

The productivity and utilization of four different grasdlegume pastures for grazing management were examined. The pasture mixtures used in this study were orchardgrass + ladino clover (Tl), orchardgrass + alfalfa (T2), perennial ryegrass + alfalfa (T3), and orchardgrass (T4, without legumes) respectively. The pastures were mtationally grazed 7 times with growing cow which had an initial weight of ca 243kg. The gmwth of pasture plants, dry matter (DM) yield, DM distribution, daily DM production, and pasture utilization were investigated at the NLRI, in Suwon, from April to October in 1991 and 1992. The average plant height at each grazing was 32-33m. The average DM content was 17.8%, wil the lowest in TI (16.4%) and highest in T3 and T4 (18.4%). The annual DM production were 9,609 kg (T3), 9,420 kg (Tl), 9,402 kg (T2), and 9,194 kgha (T4) in that order, but no significant differences were found in forage yield between treatments. Most of forage DM was produced in spring season, particularly in May. The daily DM production was highest in May (81.9kg), and lowest in August (33.0kg/ha). The average efficiency of pasture utilization was about 79%, with the lowest in TI (77%), and highest level of utilization was observed in T4 (82%). In this experiment, production and utilization of each pastures were observed similarly. However, the forage nutritive value, botanical composition, and animal performance as affected by different pasture mixtures for suitable grazing management are needed to ascertain.

• Journal of The Korean Society of Grassland and Forage Science
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• v.16 no.1
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• pp.53-60
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• 1996

A field experiment was carried out to determine the effects of grazing stage and intensity on the forage production and nutritive value in orchardgrass dominant pasture, 1989 and 1990. The grazing stages were 20- 25m, 30-35cm and 40-45cm of plant height, and high and medium grazing intensity were set by the number of growing cows (initial body weight: 230-250kg), which was adJusted according to the pasture production. The high level of grazing intensity was 150% of medium intensity. Annual grazing frequency was 10 times in 20-25cm. 8 times in 30-35cm. and 6 times in 40-45cm of plant height. Dry matter(DM) yield was increased with increasing of plant height at grazing : 7,090kg in 20-25cm 7,882kg in 30-35n and 8,260 kgha in 40-45cm of height. Higher DM was observed at medium grazing intensity. In spring, daily DM production was more vigorous than those in summer and autumn season. Cmde protein (CP), digestible DM, and DM intake were decreased with increasing of plant height at grazing. CP content was 25.8% in 20-25cm 22.4% in 30-35m and 19.2% in 40-45cm, while the contents of neutral detergent fiber and acid detergent fiber were increased with higher plant height. Relative feed value was 11 1.2 in 20-25cm, 104.4 in 30-35n and 99.6 in 40-45cm. Also nutritive value of pre-grazing pasture plants was remarkably higher than that of post-grazing, and not significant differences of nutritive value were found between grazing intensity. From the above mults, it may be concluded that optimum plant height for grazing was 20-25cm and 30- 35cm in pasture mixtures dominated by orchardgms, and medium grazing intensity was very desirable for pasture productivity.

• Journal of The Korean Society of Grassland and Forage Science
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• v.10 no.2
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• pp.89-95
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• 1990

This experiment was carried out to determine the effects of nitrogen(N) fertilizer levels (0, 120, 240 and 360kg $ha^{-1}Y^{-1}$ Y-') on seasonal grass growth, dry matter (DM) yield and botanical composition in pasture under shade condition. Investigation date was on 7 , 14, 21, 28 and 35 days after harvesting in spring (May), summer (July) and autumn (Sept.), 1988, respectively. Shade degree was controlled artificially ca. 45-50%, and each annual level of N was distributed 5 times equally. Grass growth and DM productivity were most vigorous in spring. Higher DM yield was produced with N 240 kg spring, and Nl2Okg in summer and autumn. Higher significant relationships, in spring, were found between grass height and DM, and N level and DM yield. However, low relationships were observed between those in summer and autumn. In botanical composition, grass coverage was decreased in summer and autumn, and bareland was increased, especially in higher N plots. Based on the results, it is suggested that 200kg $ha^{-1}$ of N in this experiment is more effective for forage production and pasture persistence. Also a littie more amount of N (50-70kg $time^{-1}$) in spring, and low level of N (20-30kg $time^{-1}$) in summer and autumn may be desirable.

• Animal Bioscience
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• v.36 no.2
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• pp.322-332
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• 2023

Objective: We determined the impact of maintaining pasture-based dairy cows and calves together over 100 days on cow milk production, cow and calf behavior, and calf liveweight and carcass quality. Methods: Six Holstein-Friesian cows and their male calves were monitored for 106±8.6 days. Cows were temporarily separated twice a day for milking with calves remaining in the paddock. Cow and calf behaviors were recorded via scan sampling at 6 different timepoints, for the first 7 days and twice a week thereafter. Calves were weighed weekly and immediately processed for meat quality and rumen development analysis at 106±8.6 days. Daily cow milk yields were collected from enrollment until 109±8.6 days (3 days post-weaning). Results: The average daily gain of calves was 1.4±0.73 kg/d, with an average carcass dressing percentage of 59%. Calves had the greatest frequency of observed close proximity to cow and suckling in the first two weeks and decreased with experiment duration. During separation for milking, cow vocalizations and attempts to return to their calf decreased over time. Reticulorumen weight was on target for calf age, but as a proportion of total stomach weight was lower than industry averages of calves the same age due to the larger abomasum. Cows produced an average of 12±7.6 kg of milk yield per day over the 3-days before the calves were weaned and increased to mean of 31±8.3 kg/d the 3 days after weaning, indicating a consumption of close to 20 kg per calf per day. Conclusion: The impact of a pasture-based cow-calf rearing system on cow and calf behavior and the potential for high levels of calf liveweight gain when provided ad-libitum milk and feed were determined. Further research is required to determine the practicality of replicating such systems with large herds and impact on reared calves post-weaning.

• Journal of Animal Science and Technology
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• v.47 no.6
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• pp.919-924
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• 2005

This study was carried out to estimate the effects of parity, milking time, milking interval and days in milk(DIM) on variation in milk yield between consecutive milkings(am to pm to am), morning and evening milk yield and its components, somatic cell counts(SCS), milking duration, milk flow rate and peak milk flow in Holstein dairy cattle. Records from one hundred and twenty two heads of Holstein cattle at National Livestock Research Institute, Korea were used for this study from July 1 to August 8, 2005. The experimental herd had average 1.6$\pm$0.9 parities, 199.8$\pm$109.1 DIM and 12.26$\pm$4.06kg milk yields at each milking. Milking yield, percent milk fat and SNF, milking duration and average milk flow were significantly varied by parity, milking time and DIM. Percent milk protein and lactose were varied by parity and DIM, however SCS and average milk flow were affected by parity and milking time. Milking interval significantly affected the consecutive, morning and evening milk yield and average milk flow. However, MUN was not affected by parity, milking time, DIM and milking interval. Milk yield was decreased with increasing parity. Milk yield in the morning was higher than that of in the evening. Milk yield between consecutive milking was not affected by parity, however, affected by milking time. Percent milk Fat, SNF and SCS were higher at in evening milk than those of in morning milk. Milk protein, lactose, SNF, SCS, milking duration and peak milk flow rate were influenced by parity. This study suggested that milk yield variation between consecutive milking, milking flow rate, and milking duration could be important traits for enhancing Holstein cattle productivity however, and more study is needed to estimate genetic parameters for such traits.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.3
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• pp.168-175
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• 2021

The optimal determination of seeding rate is critical to minimizing uncertainties about the large variations observed in forage quality and productivity when alfalfa is cultivated under different geographical areas and growing conditions. The objective of this investigation was to provide information about the proper seeding rate according to harvest timing for alfalfa cultivation in the Northern regions of Korea. Alfalfa was sown in September 2018 at a seeding rate of 20, 30 or 40 kg/ha and harvested four times in 2019: May 3, July 2, September 11, and October 13. Regardless of seeding rate, alfalfa plant height was longest at the third harvest (113 cm) and the shortest in the last annual harvest (43.8 cm). However, seeding rate had no effect on alfalfa plant height at any harvest. Forage relative feed value was increased in the first cutting but decreased in the third cuttings as seeding rate increased. However, seeding rate had slight effect on alfalfa forage quality components at the second and fourth cuttings. Total annual DM and crude protein production (in 4 harvests) was greater at higher seeding rates. Plots seeded at a rate of 40 kg/ha produced on average 1,257 and 2,620 kg/ha more forage (DM basis) than those seeded at a rate of 30 or 20 kg/ha, respectively. Forage DM production at the first, second, third, and fourth harvests accounted for 36.1, 24.0, 27.1, and 12.8 % of total annual DM production, respectively. Overall, small differences were seen when alfalfa seeding rate was different but maximum forage DM production (in four harvests) was detected when seeding rate was 40 kg/ha. These data could be useful to the alfalfa growers by allowing them to make more accurate trade-offs between seed price and the expected magnitude of forage yield gains in order to select the best seeding rate.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.4
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• pp.333-338
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• 1999

The experiment was carried out to find the effects of the application method of dairy liquid manure on productivity of silage corn(P3352) and sorghum $\times$ sudangrass hybrid(P988) and physical and chemical properties of soil during 2 years at Suwon. Crude protein content of T1(Chemical fertilizer) was highest by 6.5%, 8.9% in both forage, respectively, but total digestible nutrient(TDN) percent of T3(dairy liquid manure, basal + chemical fertilizer, topdressing) was highest by 73.8%, 59.0% in both forage, respectively. In TND yield, it was little different between T1(9.5 MT/ha) and others(8.4~9.3 MT/ha) at silage corn, but T4(chemical fertilizer at basal + dairy liquid manure at topdressing) was highest as 13.3 MT/ha at sorghum $\times$ sudangrass hybrid(p<0.05). pH of the soil after experiment was lower than that of the soil before experiment in the both forages, but soil organic matter was high at after trial than before trial. Available phosphorous and exchangeable cation were not shown the regular trend in this experiment. Based on the results of this experiment, it was not shown among different application method for silage corn (P3352), but application of chemical fertilizer at basal and liquid manure at topdressing was good for sorghum $\times$ sudangrass hybrid(P988).