• The Korean Journal of Ecology
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• 제13권1호
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• pp.51-58
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• 1990

The rates of litter production and decomposition of litters from grasslands and forests in Mt. Guryong were studied. The annual litter production of Glycine soja showed the highest value 1950.88 g/$m^2$/yr in the grasslands and that in Quercus acutissima, as 2202.38 g/$m^2$/yr in the forests. The highest decay rate of the grasslands was found in G. soja as k=0.713 and that of the forests was in Salix koreensis as k=0.319. The Z values of k in the grasslands was higher than that in the forests. The shortest half-time of the litter decay in the grasslands was 0.9 years in G. soja and the longest one of the forests was S. koreensis as 2.1 years and the longest of all was Q. mongolica as 5.2 years. In the amount of total nitrogen of litters, G. soja was the highest of the grasslands and S. koreensis was the highest of the forest. The content of the total nitrogen in litters was directly propotional to the decay rates.

• The Korean Journal of Ecology
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• 제13권3호
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• pp.165-172
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• 1990

The contents of Pb and Cd in litters of Ginko biloba collected from thirty-four areas in Seoul were measured and analyzed for among relative air pollutions. S contents in litters of G. biloba were 0.88% at Hyehwadong, 0.98% at Yongsan and 0.95% at Ch angdong. Mean value were 0.65% in 0-10 km areas from Kwanghwamun, but were 0.47% in 10-15 km areas. In S contents, the correlation between 0-5 km area and 10-15 km area from Kwanghwamun was high significant, but correlation between 0-5 km area and 5-10 km area from Kwanghwamun had no significance. Pb contents were 118.95 ppm at Pildong, 112.22 ppm at Ulchiro 3-ga and 105.55 ppm at Bus terminal (Banpo). In Pb contents the correlation between 0-5 km area and 10-15 km aea from kwanghwamun was high significant, but the correlation between 0-5 km area and 5-10 km area from Kwanghwamun had no significance. In Cd contents. Cd contents were high in Youido, Shinch on, Kongdokdong, Haengdangdong, Kirum, Ch ongnyangni and Imundong.

• 아시안잔디학회지
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• 제10권2호
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• pp.167-175
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• 1996

This study was carried out to investigate the removal rate of sulphur of the litters in the Phragmites communsis, Seirpus tabernaemontani, Miscanthus sacchariflorus and Typha angustata aquatic grassland ecosystem on the lake Paldangho. The annual litter productions of sulphur were 50.91 /$m^2$, in P. communis, 180.83 g /$m^2$, in S. tabernaemontani, 25.87 g /$m^2$, in M. sacchariflorus and 151.39 g /$m^2$, in T. angustata, respectively. The removal rates r, of sulphur in the litters were 0.86 in P. communis, 0.82 in S. tabernaemontani, 0.43 in M. sacchariflorus and 0.47 in T. angustata respectively, The times required to reach 50, 95 and 99 percent of the steady state levels and turnover values of sulphur on the grass-land floor were 0.81, 3.49 and 5.82 years in the P. communis, 0.85, 3.68 and 6.13 years in the S. tabernaemontani, 1.62, 7.00 and 11.67 years in the M. sacchariflorus and 1.49, 6.44 and 10.73 years in the T. angustata, It is considered that the high removal rates of sulphur in four grasslands of aquatic ecosystem contribute to the efficient removal of sulphur, a pollutant, at the lake Paldangho. Key words: Removal rate, Accmulation, Paldaugho, Sulphur, Phragmites communis, Miscanthus saechariflorus, Seirpus tabernaemontani, Typha angastata.

• Journal of Animal Science and Technology
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• 제62권1호
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• pp.14-20
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• 2020

The goal of this study was to determine an effective interval of playing a nursing sound stimulus. One hundred forty four lactating multiparous sows (Landrace; parity range: 2 to 7) and their litters (Landrace × Yorkshire) were divided into 3 block (48 each), each of which was randomly assigned to one of the four treatment groups including control which had no call stimulus (n = 12 each). The call of nursing and suckling, plus a click sound, were used as a nursing sound stimulus that was played in the intervals of 35 min (T35), 40 min (T40) and 45 min (T45) right after the first parturition in each experimental group until the day of weaning. Nursing sound stimuli did not affect the sow feed intake and back fat thickness loss. No differences were detected among treatments in the percentages of sows returning to estrus within 5 days after weaning and sows without crushed piglets. However, the piglets' weaning weight and daily weight gain in T35 and T40 groups was greater (p < 0.01) than the controlled piglets. These results suggest that a nursing sound stimulus can improve the performance of suckling piglets, and that 35 or 40 min interval of playing a nursing sound could be the effective sound stimulus for nursing sows.

• 한국환경과학회지
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• 제32권2호
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• pp.139-143
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• 2023

The effects of essential oils on pH, pathogens, and volatile fatty acids (VFA) in two poultry litters were investigated through a lab study. Essential oil-added poultry litters were randomly divided to two groups: control (200 g poultry litter) and Treatment (50 g thymol/Briefly, 200 g broiler litter was treated with or without 50 g thymol (Control and T1, respectively; 1 groups) and 200 g duck litter was treated with or without 50 g carvacrol (Control and T2, respectively; 2 group). Adding thymol to broiler litter increased the pH, reduced pathogens, and did not affect VFA. Interestingly, adding carvacrol slightly reduced the pH of duck litter, but had no significant effect on reducing pathogens and VFA. This difference is probably because the essential oil used and the properties of the two litters are different. In addition, pH was thought to control the odor generated from the litter, but this has not been proven. Further field studies should focus on clarifying this point.

• Asian-Australasian Journal of Animal Sciences
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• 제14권11호
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• pp.1610-1615
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• 2001

Three studies were conducted to determine the effect of sex on pre- and post-weaning performance of pigs. These studies were conducted in response to observations that female pigs appear to grow faster than male pigs after weaning. In addition, female pigs have been found to grow faster than male pigs when supplied with supplemental milk before weaning. The aims of the present work were to further characterise the ontogeny of sex differences growth of nursing and growing pigs. In the first study, piglets sucking 32 sows were crossfostered to produce litters of 10 boars (n=9), 10 gilts (n=l 1) or 5 boars and 5 gilts (n=12). Liveweight of the sucking pigs was then measured weekly until weaning at 4 weeks of age. In the second study, 80 boars and 80 gilts were weaned at 26 days of age and growth performance measured until 21 days post-weaning. In the third experiment, 40 boars and 40 gilts were weaned into groups of 5 pigs at either 17 or 25 days of age and pigs were weighed until they were approximately 90 kg liveweight. All-boar litters grew more slowly than the all-gilt and mixed litters such that by 14 days of age the all-boar litters were 10% lighter than the all-gilt or mixed litters (39 vs. 43.8 kg, p=0.050). The proportional difference in litter weight appeared to be maintained at 21 days of age (53.9 vs. 59.4 kg, p=0.063) but was diminished by 28 days of age (66.5 vs. 70.8 kg, p=0.28). In the second study, gilts grew more quickly than boars over the first 7 and 21 days post-weaning and as a consequence were 10% heavier than boars at 21 days after weaning (13.7 vs 12.48 kg, p=0.001). In the third study, gilts grew more quickly than boars in the immediate 7 days post-weaning (40 vs. 5 g/day, p=0.014) whereas from 7 until 35 days post-weaning there was no significant difference in growth rate (381 vs. 360 g/day, p=0.19). Gilts also grew more quickly than boars over the 14 days after being moved into the grower (631 vs. 570 g/day, p=0.013) and finisher (749 vs. 688 g/day, p=0.038) sheds. However, these differences were not maintained over the entire period in each shed. These data support the hypotheses that gilts handle the stresses of weaning and other transitions better than boars.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1997년도 한국생물과학협회 학술발표대회
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• pp.162.1-162
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• 1997

No Abstract, See Full Text

• 수산해양기술연구
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• 제35권4호
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• pp.386-390
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• 1999

The survey of the marine litter which has sunk and accumulated on the sea-bed was conducted over a 3-years period from 1996 to 1998 in eastern part area of the Southern sea. The obtained results are as follows :There are many pots as many as to be occupies 655 of collected marine litters. The distribution of pots in area A is much more than that of pots in area B, and the near Hongdo island has the most pots compared with other areas. The density of pots is the highest when the depth is 61~70 meters.

• 아시안잔디학회지
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• 제10권2호
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• pp.151-157
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• 1996

Samples from the L, F, H and $A_1$ horizons of the Phragmites communis, Miscanthus sacchariflorus, Scirpus tabernaemontani and Typha angustata grassland were collected in Paldangho and the removal rates of ritrogen were investigated. The removal rates of nitrogen of the litters were 0.85 in P.communis, 0.56 in M sacchariflorus, 0.45 in T. angustata and 0.31 in S. tabernaemontani The time required to decay 50, 95, 99 percent of the steady state levels and turnover values of nitrogen on the grassland floor were 0.81, 3.53, 5.89 years in the P. communis, 1.23, 5.32, 8.86 years in the M sacchariflorus, 1.54, 6.68, 11.13 years in the S. tabernaemontani and 2.22, 9.63, 16.04 years in the T. angustata Key words: Removal rate, Accumulation, Paldangho, Nitrogen, Phragmites communis, Miscanthus sacchariflorus, Scirpus tabernaemontani, Typha angustata.

• 아시안잔디학회지
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• 제9권2호
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• pp.109-117
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• 1995

An investigation was performed to reveal the relation of the production and decomposition of the Zoysia japoni ica and Miscanthus sinensis litters on Mt.Kwanak. The decay constant k of litters was as follows; k of Zoysia japonica, k=0.44, k of Miscanthus sicensis, k=0.33 The time required for the decomposition of half of the accumulated organic matter of Zoysia japonice and Miscanthus sinensis was 1.6 and 2.1 years, respectively. The amount of mineral nutrients returned annually to soil is faster in the ZQvsia japonica grassland than in the Miscanthus sinensis grassland on Mt. Kwanak. Key words: Organic rnatter synthesis, Decomposition balance.