• 한국습지학회지
• /
• 제20권3호
• /
• pp.249-255
• /
• 2018

침입외래식물인 단풍잎돼지풀(Ambrosia trifida L.)이 자생식물의 종수와 고유종인 층층둥굴레(Polygonatum stenophyllum Maxim.)의 활력도에 미치는 영향을 알아보고자 하였다. 단풍잎돼지풀의 식피율 구배에 따라서 자생식물 종수, 층층둥굴레의 사망률, 영양생장과 생식생장 등의 변화를 2015년 6월부터 2016년 10월까지 관찰하고 분석하였다. 단풍잎돼지풀의 식피율 처리는 각각 100% 제거, 40~60% 제거, 비제거구(대조구)로 하였다. 그 결과 단풍잎돼지풀의 식피율을 40% 이상 제거할 때, 출현한 식물 종수와 층층둥글레의 개체수 그리고 영양과 번식측정 항목의 활력도가 높았다. 이를 통해서 단풍잎돼지풀의 식피율을 40% 이상을 제거하는 것은 연구 지역의 식물종다양성과 준위협종인 층층둥굴레의 개체군 보전에 효과적이라고 판단된다.

• 약학회지
• /
• 제46권6호
• /
• pp.452-458
• /
• 2002

Dehydroevodiamine-HCl (DHED), which is a component separated from Evodia rutaecarpa Bentham, has novel anticholinesterase and antiamnesic activities in a scopolamine-induced amnesia model. Several studies suggest that DHED might be an effective drug for Alzheimer's disease and a vascular type of dementia. DHED was at dose levels of 0, 50, 100 and 200 mg/kg/day administered intraperitoneally to Sprague-Dawley male rats for 60 days before mating and to females from 14 days before mating to 7 days after mating. Effects of the DHED on general symptom and reproductive performance of parent animals and embryonic development were examined. In male parents, whereas no death was observed, reduction in the increase rate of body weight was found at 200 mg/kg. In female parents, both of the mating performance and the fertility of parent animals were decreased at 200 mg/kg, but not significantly. In 200 mg/kg treated group, the fetal death rate was increased but total fetuses showed no changes compared to the control group. There were no malformed F1 fetuses in all groups.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제3권1호
• /
• pp.83-88
• /
• 2001

The effect of topical application with 200,400 and 600 $\mu$g/ml 2,4-dichlorophenoxyacetic acid (2,4-D) on the fifth larval stadium of the silkworm, B. mori, was analyzed. Larvae treated during fifth larval stadium enhanced larval, cocoon and adult parameters. The larval period was significantly decreased with increase in silk gland weight at 400 and 600 $\mu$g/ml, male cocoon weight and shel1 weight in all the treated groups and filament length and weight at 200 $\mu$g/ml treated group. Length of the ovariole, eggs per ovariole and hatching percentage increased significantly in all the treated groups when compared with those of the carrier control. This suggests that the plant growth regulator 2,4-D in addition to affecting silk production also affect reproductive performance.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제19권2호
• /
• pp.215-219
• /
• 2009

The effect of mating duration and multiple use of male on fecundity and fertility was investigated in the hybrids of Silkworm, Bombyx mori L. One hour to five hours of mating duration did not affect egg laying (fecundity) significantly, while fertilization affected significantly. Below 50% fertility was noticed when mating duration was reduced to below two hours. Similarly multiple use of male caused significant reduction in fertility but not fecundity. Till fourth mating no significant reduction in fertility was observed, thereafter fertility reduced considerably.

• 한국가축번식학회지
• /
• 제11권1호
• /
• pp.22-25
• /
• 1987

This study was carried out to investigate the effects of imported pellet frozen semen on sperm motility and NAR acrosomes after thawing, and the farrowing rates, litter sizes and preweaning body weights after artificial insemination. A total of 28 sows of Landrace, Large White and Duroc were inseminated at the Chungnam Provincial Animal Breeding Station. The results obtained are summarized as follows: 1. Landrace andLarge White had higher sperm motility than Duroc by about 20% and had higher NAR acrosomes by about 10%. 2. The farrowing rates of Landrace, Large White and Duroc were 63.6, 55.6 adn 50.0%, respectively. The number of pigs born alive per litter were larger in Landrace and Large White as compared with Duroc (p<.01). 3. Duroc had the highest mean pig weight at birth, followed by Landrace and Large White (p<.01). The mean pig weights at 21 days and 56 days had no significant differences between the breeds.

• Reproductive and Developmental Biology
• /
• 제37권2호
• /
• pp.75-77
• /
• 2013

This study was conducted to investigate optimal time of artificial insemination (AI) to Hanwoo female after natural estrus. AI was occurred 12 and 24 hours after natural estrus in both heifer and multiparous recipient then pregnancy and parturition rates were estimated. Results indicated that AI performed at 24 hours after natural estrus showed significant (p<0.05) higher pregnancy rate in both heifer and multiparous recipient groups with significantly (p<0.05) higher abortion rate. However, there are no significant differences of parturition rate, twin birth and sex ratio in both heifer and multiparous recipient groups. Therefore, our results may suggest that performance of AI at 24 hours after natural estrus promise higher pregnancy rate than AI at 12 hours after natural estrus in both heifer and multiparous recipient.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제3권2호
• /
• pp.157-162
• /
• 2001

The effect of topical application with naphthoxyacetic acid on economic parameters was analyzed following treatment of fifth instar larvae. Larvae treated during the fifth instar showed significant increase in larval weight along with other enhanced larval, cocoon and adult parameters. The larval period was significantly shortened in all the treated groups with increased cocoon and shell weights in male and shell weight in female in 400 ${\mu}g$/ml treated group and filament length in all the treated groups. Fecundity increased significantly in dose dependent manner in all the treated groups, when compared to that of the carrier control group. This suggests that naphthoxyacetic acid, in addition to affecting larval growth, also affect silk production and reproductive performance.

• Toxicological Research
• /
• 제9권1호
• /
• pp.73-82
• /
• 1993

LBD-007, a newly developed recombinant human interferon alphaA, was at dose levels of 0, 3$\times$$10^6$, 6$\times$ $10^6$ and 12$\times$1$10^6$ IU/kg/day administered subcutaneously to Sprague-Dawley male rats from premating to mating period and to females from premating to early gestation period. Effects of test agent on reproductive performance of both sexes and embryonic development were examined. 1. No treatment-relared changes in food consumption, body weight and necropsy findings were observed in parent animals.

• 대한수의학회지
• /
• 제63권2호
• /
• pp.14.1-14.4
• /
• 2023

This study evaluated the effect of resynchronization programs on pregnancies in dairy cows. Of 1,342 cows confirmed not pregnant after their first artificial insemination (AI), those with a corpus luteum (CL) were resynchronized using Ovsynch or PG-GnRH-Ovsynch and those without a CL were resynchronized using GnRH-Ovsynch or modified Double-Ovsynch. There were no differences (p > 0.05) in the pregnancies per AI either between the Ovsynch (31.3%) and PG-GnRH-Ovsynch (34.0%) or between the GnRH-Ovsynch (38.7%) and modified Double-Ovsynch (39.5%). In conclusion, Ovsynch and GnRH-Ovsynch programs could be preferred to resynchronize cows with and without a CL, respectively, from the perspective of reducing costs and labor.

• Journal of Animal Science and Technology
• /
• 제65권6호
• /
• pp.1169-1179
• /
• 2023

Korean native pigs (KNPs) have been one of the traditional livestock primarily raised in rural areas of Korea for centuries. KNPs have adapted to the climate and geography of the Korean Peninsula for a long time, exhibiting excellent adaptability even in challenging environments. For these reasons, the preservation and purification of KNPs are crucial in securing unique genetic resources. Therefore, this review covers the characteristics, production status, commercial value and potential breeding directions of KNPs. Unfortunately, there is still a long way to go for the improvement of KNPs. It is crucial to acknowledge the current challenges, identify the issues, and dedicate efforts to the breed's improvement. Each section of this comprehensive review will play an important role in integrating related research and data into the overall findings. In-depth discussions on the genetic diversity, productivity, genetic conservation, ecological roles, and sustainability of KNPs will be crucial components in the future of KNP business.