• 한국임상수의학회지
• /
• 제40권3호
• /
• pp.238-241
• /
• 2023

This study determined the effect of ovarian status at the beginning of the modified Double-Ovsynch program on reproductive performance in dairy cows. In the study, 1,302 cows were treated with a modified Double-Ovsynch program at 56 days after calving. This program comprises administering gonadotropin-releasing hormones (GnRH), prostaglandin F_2α (PGF_2α) 10 days later, GnRH 3 days later, GnRH 7 days later, and GnRH 56 h later, followed by timed artificial insemination (TAI) 16 h later. At the beginning of the program, cows were categorized according to the size of the largest follicle and the presence of a corpus luteum (CL) in the ovaries as follows: 1) small follicle (<5 mm, SF group, n = 100), 2) medium follicle (8-20 mm, MF group, n = 538), and 3) large follicle (≥25 mm, LF group, n = 354) without a CL, or 4) the presence of a CL (CL group, n = 310). The pregnancies per AI after the first TAI were analyzed by logistic regression using the LOGISTIC procedure, and the logistic model included the fixed effects of the herd size, parity, body condition score (BCS) at the first TAI, TAI period, and ovarian status. A larger herd size, higher BCS at the first TAI, and TAI period with no heat stress increased (p < 0.05) the probability of pregnancy per AI after the first TAI. However, ovarian status at the beginning of the program did not affect (p > 0.05) the pregnancies per AI (ranges of 37.9% to 42.9%). These results show that the modified Double-Ovsynch program can be used effectively while maintaining good fertility regardless of the ovarian status in dairy herds.

• Biomolecules & Therapeutics
• /
• 제4권1호
• /
• pp.59-67
• /
• 1996

A new composite antibiotic, SM-101(sulbactam·metampicillin), was at dose levels of 0, 375, 750 and 1500 mg/kg/day administered intravenously to pregnant Sprague-Dawley rats during the organogenetic period. Two-third of dams per group were subjected to caesarean section on day 20 of pregnancy and the remaining 10 dams per group were allowed to deliver. Effects of test substance on dams, embryonal development of F1 fetuses, as well as growth, behaviour and mating performance of F1 offspring were examined. In dams, two deaths occurred at 375 and 1500 mg/kg, respectively. The decrease in the weight of adrenal glands of the 1500 mg/kg group was observed. The prolongation of pregnancy period was found at 1500 mg/kg. F1 fetuses showed no changes related to the treatment of SM-101. In F1 offspring, the increase in spleen weight was seen at all doses treated. No treatment-related abnormalities were observed in each treated group in terms of development, behaviour and reproductive performance. In F2 fetuses, no drug-induced abnormalities occurred at all doses. The results show that the no-effect dose levels (NOELS) for dams and Fl offspring are under 375 mg/kg/day and NOELs for F1/F2 fetuses are over 1500 mg/kg/day.

• 한국작물학회지
• /
• 제55권1호
• /
• pp.14-18
• /
• 2010

본 연구는 생식생장기의 고온스트레스에 의한 콩의 생육과 수량에 미치는 영향을 구명하고자 대립종인 황금콩과 소립종인 풍산나물콩을 이용하여 수행하였다. 고온처리에 따라 두 품종 모두 초장은 증가하였으나 엽면적 및 건물중은 크게 감소하였다. 고온처리에 따라 개체당 협수는 감소하지 않았으나 잎수와 100립중이 감소하여 전체 수량이 황금콩과 풍산나물콩 모두 약 45% 감소하였다. 또한 잎, 줄기, 뿌리의 질소함량에서도 고온처리에 의한 감소를 보여 주고 있다.

• 수산해양기술연구
• /
• 제55권4호
• /
• pp.349-355
• /
• 2019

Reproductive ecology of rabbit fish, Siganus fuscescens were investigated from samples collected monthly in the coastal waters off Jeju Island of Korea from February to December 2014. In male and female of S. fuscescens, the values of GSI were reached high values between July to August in which the water temperature was high, and then decreased until December. The occurrence of individuals which have mature eggs in ovary were higher from July to August. Therefore, a main spawning season was estimated from July to August, with the highest peak in July. Throughout histological observation of the ovary in the spawning period, S. fuscescens belong to an group-synchronous and has a one spawning season a year. Fecundity of ovary ranged from 380,000 to 2,600,000 during the spawning period. Size at 50% sexual maturity, determined from logistic equation, were 25.1 cm TL which is over two years.

• Animal cells and systems
• /
• 제1권1호
• /
• pp.53-61
• /
• 1997

Seasonal variation of the population structure and the reproductive pattern of the Korean striped field mouse, Apodemus agrarius, were investigated. High capture ratios in juveniles, young adult, and old adult mice were found during the period from October to November, from November to March, and from May to September, respectively, and extremely low capture ratios of old adults during the period from November to February were characteristic. It seemed that the young adults that survived during the winter might become older by summer and have been counted as the old adults. The breeding in the mice began earlier in males (from mid February or early March to late October) than in females (from mid March to late October), having a peak in August and September, and both the male and female mice weighing more than 20 g generally reached sexual maturation in general. In the breeding season, both young and old adult males had large testes with enlarged seminiferous tubules filled with numerous germ and Sertoli cells, and expanded caudal epididymides with a vast number of spermatozoa; the females had many Graafian follicles and corpora lutea in large ovaries, and developed uterine glands in the thick endometria. The lower ratios of the testis weight to the body weight in July and August in 1994 compared to 1995 seemed due to the extreme drought and considerably higher temperature in 1994, but the decrease in the ratio in mid-summer, only in the old mice, in both years might be explained partially by aging.

• Ocean and Polar Research
• /
• 제40권1호
• /
• pp.15-22
• /
• 2018

In the present study, we investigated temporal variation in the reproductive effort and biochemical contents in adult Manila clam Ruditapes philippinarum at Shi-Heung-Ri beach on the east coast of Jeju Island. Gonad-somatic index (GSI), a ratio of the egg mass to the total biomass determined using ELISA increased dramatically from late May to June (7.1% to 19.5%). In mid-July, GSI dropped to 15.1%, indicating spawning on a small scale during this period. GSI also declined dramatically from late August (15.5%) to September (4.3%), suggesting that massive spawning occurred during this period. A positive correlation was observed between clam size and potential fecundity, while potential fecundity ranged between 1.19-8.40 million eggs/clam. Total proteins and lipids in the tissue increased from late spring to mid-summer, coinciding with an increase in GSI. Protein, lipid and carbohydrate contents in the tissue were lowest in January, indicating that clams were suffering from poor nutritional circumstances, which may be associated with poor food supply from the environment. Monthly increase and/or decrease in the body weight were closely related to gonad maturation and subsequent spawning, which was also linked to temporal changes in the contents of protein, lipid and carbohydrates in the tissue.

• 수산해양기술연구
• /
• 제54권4호
• /
• pp.353-359
• /
• 2018

Basic reproductive biology of the daggertooth pike conger, Muraenesox cinereus were investigated based on the samples from August 2015 to December 2017 in Korean waters. A total of 2,328 samples was collected (1,593 females and 735 males) during the study period. The mean anal lengths (AL) were $33.5{\pm}9.2cm$ in females and $26.2{\pm}7.3cm$ in males respectively. The females were larger than males in AL (p < 0.05). Sex ratio was 2.2:1 in female to male (p < 0.05). The gonadosomatic index (GSI) varied monthly. GSI of female reached the maximum in July 2016 and June 2017 and the minimum in October 2016 and September 2017 respectively. The spawning period was from June to October. The size at sexual maturity ($L_{50}$) of females was estimated at 24.9 cm in AL (63.5 cm in TL).

• 한국가축번식학회지
• /
• 제12권2호
• /
• pp.91-96
• /
• 1988

A study was conducted to improve breeding efficiency of dairy and beef cows on Cheju Island. Milk progesterone and plasma progesterone profiles were determined by using radioimmunoassay techniques during the oestrus cycle, onset on oestrus and during the gestation period. Progesterone connections in milk were very low during the oestrus with a means value of 2.4ng/ml and 4.6ng/ml at the onset of oestrus but gradually declined at 4 to 9 hr after oestrus. In the cyclic cow, milk progesterone concentraitons in the early part of the cycle, ranged from 3 to 5ng/ml and increased from 6.0 to 11.6ng/ml on day 13 to 21 of cycle. Milk progesterone concentrations of pregnancy cows ranged from 5.0 to 40ng/ml during the gestation and grom basal line to 3.5ng/ml for nonpregnant cows. Plasma progesterone concentrations of beef during pregnancy period ranged form 3.0 to 33ng/ml and basal levels ranged from 0 to less than 2.5ng/ml for non-pregnant beef cows.

• 한국산학기술학회논문지
• /
• 제21권7호
• /
• pp.277-284
• /
• 2020

본 실험은 모돈 사료 내 Portulaca oleracea L.(POL)의 첨가가 번식성적, 혈액성상, 면역반응 및 분 중 미생물에 미치는 영향을 구명하기 위해 수행하였다. 본 실험을 위해 총 20두의 모돈(Landrace×Yorkshire; 229.2±1.15 kg)을 공시하였으며, 개시체중에 기반하여, 2처리 10반복, 반복당 1두씩 완전임의 배치하였다. 실험 처리구는 옥수수-대두박 기초사료를 대조구로 하여 기초사료 내 POL을 0.05% 첨가한 처리구가 포함되었으며, 분만 직후부터 포유기간 동안 수행하였다. 사료 내 POL을 첨가하였을 때, 모돈의 체중, 등지방두께 및 번식성적에서는 유의적인 차이가 나타나지 않았다(p>0.05). 혈액성상에서 사료 내 POL의 첨가하였을 때, 모돈의 림프구가 유의적으로 감소하는 것으로 나타났다(p<0.05). 또한, 면역반응에서 사료 내 POL을 첨가하였을 때 포유모돈의 혈 중 IL-1β의 수치는 유의적으로 감소하였으며(p<0.05), IgG는 증가하는 경향이 관찰되었다(p=0.051). 분 중 미생물에서는 POL 처리구에서 포유모돈의 coliforms이 감소하는 경향을 확인하였다(p=0.063). 본 실험의 결과들을 종합해보면, 사료 내 POL의 첨가는 번식성적에 부정적인 영향을 미치지 않으며, 모돈의 혈액성상, 면역반응 및 분 중 미생물에 긍정적인 효과를 미치는 것을 시사한다.

• 한국패류학회지
• /
• 제29권2호
• /
• pp.113-120
• /
• 2013

한국 남해안 남해 연안에서 채집한 퇴조개 (Coecella chinensis) 를 대상으로 생식주기, 생식소지수, 비만도지수 및 성비를 조직학적 분석 및 형태 계량학적 자료에 의해 조사하였다. 생식소지수 및 비만도지수의 월별 변화는 생식주기의 월별 변화와 유사한 양상을 보였다. 암컷과 수컷 퇴조개의 생식주기는 초기활성기 (4월), 후기활성기 (5월), 완숙기 (6월), 부분산란기/방정기 (6-8월), 퇴화기 (8월) 및 비활성기 (9-3월) 의 연속적인 6기 (stages) 로 구분할 수 있었다. 본 종의 산란기는 6-8월 이었으나, 주산란기는 수온이 약 $24.5^{\circ}C$인 7-8월이었다. 난경모드 조사에서, 6월에는 특히 70 ${\mu}m$ 정도의 난모세포가 다수 출현하였으나, 7-8월에는 평균 50 ${\mu}m$ 전후의 난모세포가 약 80% 정도 출현하는 대신, 60-70 ${\mu}m$ 전후의 완숙 난모세포는 감소하였다. 암 수 개체들의 성비는 1:1로 유의하게 다르지 않았으며 (${\chi}^2$=1.20, p>0.05), 자웅동체는 발견되지 않았다.