• Journal of Practical Agriculture & Fisheries Research
• /
• v.8 no.1
• /
• pp.43-51
• /
• 2006

An experiment was conducted to examine how the response of dairy cows to a change from twice to thrice-daily milking is affected by deficiencies in the dietary supplies of three amino acids, His, Met and Lys. The amino acid deficiencies were obtained by feeding the cows a diet of grass silage and a cereal-based supplement containing feather meal as the sole protein supplement. Taken overall, the results show that when cows were given the feather meal diet, even though dietary ME was in considerable excess, a deficiency of specific amino acids prevented any increase in milk yield in response to increasing the frequency of milking from twice to thrice daily. The results of half-udder milking showed that when cows consumed the diet deficient in amino acids, milking one half of the gland more frequently reduced the secretion of protein and lactose by the control gland. Neither MBF nor the ratio of 3-MH/creatinine in urine was affected by thrice-daily milking. The present results go a stage further in showing that, against a background of insufficient dietary amino acids, the stimulus of thrice-daily milking is not sufficient to induce a measurable change in the partition of amino acid use between body and udder.

• Korean Journal of Environmental Biology
• /
• v.32 no.1
• /
• pp.68-74
• /
• 2014

Scientific study has investigated the body condition differences by habitat characteristics in larvae Korea salamander (Hynobius leechii) from March to April in 2012. To examine the sensitivity of external environment (predation risk), we divided two groups according to habitat characteristic; 1) Permanent pond and 2) Temporary pond. Howere, each larva was measured by head width at the level of the eye (HWE), largest head width (LHW) and snout-vent length, and we calculated the ratio of the head size by dividing HWE/LHW. As a result, larvae were larger in permanent pond group, had a faster growth rate than in temporary pond group. When exposed to the predator, larvae in permanent pond were smaller HWE/LHW than larvae in permanent pond. Therefore, these results indicate larvae in temporary pond more sensitive to the external environment.

• Korean Journal of Environment and Ecology
• /
• v.26 no.3
• /
• pp.342-347
• /
• 2012

This study was conducted to demonstrate the relationship between experience of cannibalism and difference of phenotype in the Korean salamander Hynobius leechii from March to April 2011. We examined whether the different polyphenism of larval salamander is induced as a result of indirect cannibalism in early life cycle. We divided into two groups(one group continuously exposed to the indirect cannibalism and the other group never exposed to the cannibalism). We measured the head width at the level of eyes(HWE), the largest head width(LHW) and snout-vent length(SVL) of the each larva then calculated the ratio of the head size by dividing HWE by LHW. We found that exposure of indirect cannibalism in early life cycle cause the different polyphenism. Our result means the larval salamander responded to the chemical cue from conspecific.

• Korean Journal of Environment and Ecology
• /
• v.25 no.5
• /
• pp.666-672
• /
• 2011

This study examined the different growth rate of larval salamander Hynobius leechii by the predation risk. We collected salamander's eggs from Mountain Inwang. Eggs were treated by two different conditions: (1) cue - which had a predation risk three times a day; (2) no cue - which had no predation risk. Predation risk was conducted by using chemical cue from Chinese minnows. The chemical cue treatment started from the next day after the collection and ended one week after the hatching. Between the first week and the second week after the hatching we fed salamander larvae with tubifex ad. libitium. After the treatment phase, we measured snout - vent length of the each larva on the first week and the second week after the hatching. The results showed that there was a significant difference in the growth rate by the predation risk. From these results we found that predation risk can cause the different growth rate to the larval salamander and these changes could be affect their mortality.

• Journal of Aquaculture
• /
• v.5 no.1
• /
• pp.69-79
• /
• 1992

The muscle extracts of the ascidian, Halocynthia roretzi cultured for two and three years old on the southern coast near Chungmu and the eastern coast near Pohang of Korea, were analyzed for extractive nitrogen (EN), free amino acids (FAA), combined amino acids (CAA), nucleotides and related compounds (NRC), quaternary ammonium bases and guanidino compounds using specimens collected in February 1989 and in April 1989, and compared for those contents with each other. As for the amount of EN, no remarkable difference was found between two- and three-year-old samples collected at St. 1 in the spring and winter seasons, while at St. 2 in the spring season the two-year-old sample was distinctly lower than the three-year-old one. Taurine, proline, glutamic acid, glycine and alanine were the major FAA in every sample. The amount of taurine, the most prominent FAA, was higher in three-year-old sample than in two-year-old one regardless of sampling station and season. Most of the other major FAA showed a similar tendency to EN at both sampling stations in both seasons. Adenosine 5'-triphosphate (ATP), adenosine 5'-diphosphate (ADP), adenosine 5'-monophosphate (AMP), inosine 5'-monophosphate (IMP), inosine (Ino) and hypoxanthine (Hyp) were detected in all the samples and ATP, ADP and AMP were the major ingredients. The amounts of total NRC were in parallel with those of EN and total FAA. As for the contents of betaines, two- and three-year-old samples collected in the winter season exhibited a great discrepancy each other, the former being clearly lower than the latter, but no remarkable difference was observed between two samples of two groups in the spring season. In proximate composition of the muscles, the two-year-old sample was considerably higher in moisture content and lower in protein and glycogen contents than the three-year-old one at St. 2 in the spring season. The large discrepancies observed between two- and three-year-old samples from St. 2 seems to be attributable to the difference in size of samples rather than to the difference in age.

• Animal Systematics, Evolution and Diversity
• /
• v.2 no.2
• /
• pp.79-87
• /
• 1986

한국산 산호충류의 계통분류학적 연구의 일환으로 1970년부터 1985년까지 한국 황해 연안에있는 군락지와 흑산도에서 채집된 실꽃말미잘( Cerianthus filiformis)을 동정한 결과 한국미기록종으로 밝혀졌다. 1985년 4월에 채집된 개체는 몸속에 플라눌라 유생을 지니고 있었으며, 이들은 다양한 자포를 약간 갖고 있었고, 몸밖으로 나온 플라눌라 유생에서는 보다 분화된 자포를 갖고 있었다. 특히 성체에서는 체벽에 있는 자포 중 ptychocyst가 처고형성에 지주 역할을 함을 볼 수 있었다.

• Korean Journal of Environment and Ecology
• /
• v.24 no.6
• /
• pp.744-750
• /
• 2010

This study examined the different polyphenism of larval salamander Hynobius ieechii according to two habitats, pond and stream. We collected salamander's eggs from three regions including Mountain Inwang, Surak and Gwangju. Eggs were treated by four different conditions according to predation level and habitat: high risk - which had a predation risk three times a day; low risk - which had no predation risk, pond and stream habitat. Predation risk was conducted by using chemical cue from Chinese minnows. The chemical cue treatment started from the day of collection and ended one week after the hatching. After the treatment phase, we measured the head width at the level of the eyes(HWE) and the largest head width(LHW) and snout-vent length of the each larva. We calculated the ratio of the head size by dividing HWE by LHW and made a comparison with each of the average ratio of head size according to the predation risk. The results showed that there was a significant difference in the ratio of the head size and snout-vent length according to the predation risk and habitat. From these results we found that predation risk and habitat condition can cause the different polyphenism to the larval salamander and these morphological changes could be affect their mortality.

• 월간낙농육우
• /
• v.23 no.3 s.251
• /
• pp.180-183
• /
• 2003

전화기 사양관리시 전환기를 일컫는 기간은 여러 연구자들에 따라 약간의 기간적 차이가 있지만 여기서는 건유기간 $60\~70$일 중 건유후기(분만 전 3주)와 분만 및 분만직후 기간(분만 후 3주간)을 포함한다. 전화기 사양관리는 다음 산차의 유생산에 중요한 요인으로 작용할 뿐만 아니라 젖소의 건강과 번식성적 개선 측면에서도 중요한 요인으로 작용한다.

• Feed Journal
• /
• v.2 no.6
• /
• pp.92-95
• /
• 2004

푸르른 실록의 5월이 지나 6월에 접어들면 우리나라의 경우 더위의 시작과 장마가 찾아오는 시기로 접어든다. 덥고 습윤한 환경은 우리 인간 뿐만 아니라 가축에게도 스트레스를 주고 생산성 저하를 유발시키고 경제적인 손실을 준다. 특히 착유우에 있어 덥고 다습한 환경은 체유지와 유생산을 위한 영양소의 섭취를 저해시키는 요인으로 작용하고 있다. (중략)

• The Korean Journal of Zoology
• /
• v.36 no.1
• /
• pp.84-96
• /
• 1993

한국산 도롱뇽(Hynobius leechii) 유생의 다리 발생 과정을 관찰하고 잠재적 돌연변이 유발물질인 제-methyl-N'-nitro-N-nitrosoguanidine(MNNG)과 잠재적 기형 유발물질인 retinol palmitate가 다리 발생에 미치는 영향을 알아보았다. 정상적인 개체에서 됫다리의 발생 단계는 외부와 내부의 형태적 특징을 기준으로 하여 7단계로 나누어 볼 수 있었으며 전연골세포의 밀집에 따른 골격형성은 다리 발생아의 근위부에서 시작하여 원위부로 진행됨을 확인할 수 있었다. 도롱뇽 유생을 MNNG(10 rpm)나 retinol palmitate(37.5 lpm)로 처리한 경우, 공통적으로 다리 원위부의 골격 형성이 억제되었으며, 특히 이러한 골격 형성 억제 현상은 처리시기가 이를수록 보다 심하게 나타났다. 이러한 결과는 발생을 저해하는 물질에 대한 미분화 상태의 세포들의 반응성이 발생과정 중 특정 단계에 국한됨을 시사하는 것으로 해석된다.