• Toxicological Research
• /
• 제17권3호
• /
• pp.203-213
• /
• 2001

We investigated the toxic effects of propylthiouracil (PTU) In Sprague-Dawley (SD) rats to develop and validate an enhanced Protocol for Test Guideline 407 as OECD Project. Twenty male and female SD rats,7 weeks old, were treated with PTU in corn oil at levels of 0, 0.1, 1 and 10 mg/kg/day for 4 weeks orally. Clinical observation, body weight changes, food uptake, water consumption, urinalysis, estrus cycle and sperm analysis, serum chemist교, autopsy findings and histopathological findings were evaluated in this study. No clinical signs and mortality were observed in the study. The body weights and food uptakes in the group treated with 10 mg/kg/day were reduced from 3 weeks after the initiation of the treatment. The levels of 3,5,3'-triiodothyronine (T3) and thyroxine (T4, 3,5,3',5'-tetraiodothyrosine) were also significantly decreased in the group treated with 10 mg/kg/day. Also, the relative and absolute organ weights of thymuses were decreased. Thyroid glands of rats in the group treated with PTU 10 mg/kg/day were bigger than those of rats in the control group. In the histopathological examination, diffuse hyperplasia and hypertrophy of thyroid follicular cells were observed in all treatment groups, leading to the reduction of lumen size and papillary enfolding of lining epithelium. The degree of lesion was increased in a dose-dependent manner. The results suggested that PTU would cause toxicity in thyroid gland and decrease the levels of T3 and T4 in SD rats. However there were no effects on the other organ including testis and uterus especially in spermatogenesis and estrus cycle. On the basis of the results, enhanced protocol for Test Guideline (TG) 407 may be sensitive and reliable to detect endocrine-active substances like PTU.

• Animal Bioscience
• /
• 제34권2호
• /
• pp.198-204
• /
• 2021

Objective: The aim of this study was to ascertain the effects of adding green tea extract (GTE) to skim milk-egg yolk (SM-EY) extender on both the quality of post-thawed bull semen and the pregnancy rates of the recipient cows. Methods: Twelve ejaculates from four Simmental bulls, aged 3 to 5 years and weighing 900 to 950 kg, were diluted SM-EY extender, added with 0, 0.05, 0.1, and 0.15 mg GTE/100 mL extender and then frozen. After four weeks storage in liquid nitrogen, the sperm were thawed and evaluated for viability, motility, intact plasma membrane (IPM), and DNA fragmentation. Meanwhile, the estrus cycles of 48 recipient cows were synchronized by intramuscular administration of a single injection of 5 mg prostaglandin F2α. Estrus cows were divided into four equal groups and inseminated artificially 18 to 20 h after the onset of estrus by using semen from each extender group. Pregnancy was diagnosed by measuring serum progesterone levels at 21 days, followed by transrectal palpation 90 days after insemination. Results: The findings revealed that adding 0.1 mg of GTE/100 mL extender produced the highest percentages of sperm viability (70.67%±1.75%), motility (69.17%±1.47%), and IPM (69.23%±1.21%) and the lowest percentage of DNA fragmentation (3.00%±0.50%). The pregnancy diagnosis revealed that all cows (36/36) inseminated using frozen semen in GTE addition extender were pregnant (pregnancy rate 100%), whereas the pregnancy rate of the control group was 83.33% (10/12). Conclusion: It may be concluded that 0.1 mg GTE/100 mL extender yields the best quality of spermatozoa and that all variants doses of GTE in extender produce a higher pregnancy rate among recipient cows.

• 한국수정란이식학회지
• /
• 제23권1호
• /
• pp.51-57
• /
• 2008

The present study investigated the efficient methods to produce in vitro Hanwoo embryos, and to improve the pregnancy rate. The developmental rate, total cell number and ICM ratio of in vitro embryos were compared amongst different culture media. Comparisons were also made on the status of recipients, pregnancy rate along with day of transfer after the estrus. Development of embryos into blastocyst stage in IVMD101 supplemented with 5% fetal bovine serum (FBS) group was significantly higher (34.2%) than that of TCM-199 supplemented with 5% FBS (26.8%) and IVMD101 without FBS (25.9%) (p<0.05). The development rate to blastocyst stage was significantly faster in IVMD101(5% FBS) than that of other groups ($0.2{\sim}2.3%$) (p<0.05). The average number of inner cell mass and trophectoderm were similar among treatment groups, which were $36.0{\sim}44.7$ and $83.3{\sim}106.7$. However, total cell number in IVMD101(5% FBS and 0% FBS) was significantly higher than that of TCM199(5% FBS). There were no differences in the pregnancy rate among treatment groups (32.0%, 33.9% and 28.6%, respectively). However, the pregnancy rate of Day 6 embryos cultured in IVMD101(5% FBS) was significantly (p<0.01) higher than IVMD101 without FBS and TCM-199 + 5% FBS (38.0% vs. 17.2% and 32.4%, respectively). No significant difference was observed for the pregnancy rate between heifer and cow transferred with Day 6 embryos cultured in IVMD 101(5% FBS) (42.7% and 39.3%, respectively). However, there was a significant difference of pregnancy rate (p<0.05) in heifer between one and two embryos transferred (31.4% and 41.9%). There was no difference of pregnancy rate among transfer days after estrus between heifer and cow, but the pregnancy rate of transfer to heifer with day 6 after estrus was significantly higher (p<0.05) than that of day 7 and 8 (22.2% vs. 49.0% and 38.7% respectively). Based on the above findings, there is a possibility to produce in vitro produced embryos cultured in IVMD101(5% FBS) showed higher blastocyst rate and the increased cell number. In terms of the pregnancy rate of in vitro produced embryos, the highest pregnancy rate was observed when two embryos were cultured in IVMD101(5% FBS) and transferred.

• 한국수정란이식학회지
• /
• 제23권3호
• /
• pp.189-195
• /
• 2008

The objective of this study is to investigate the changes in concentrations of leptin and insulin in serum of Korean cattle (Hanwoo) with reproductive disorders and to examine the relationship among leptin, insulin, and body condition score (BCS). The concentration of leptin in serum of pregnant Hanwoo showed insignificant difference from that in serum of Hanwoo with reproductive disorder, such as repeat breeding, follicular cyst, corpus luteum cyst, ovarian atrophy, and feeble estrus (p>0.05). However, the concentrations of leptin and insulin in serum were changed with different BCS value. In emaciated Hanwoo (BCS $2.0\sim2.9$), they were significantly decreased compared to BCS $3.0\sim3.4$ (p<0.05). The leptin showed different genotypes with different BCS value. In BCS $2.0\sim2.9$, C/T genotype was expressed (83.3%) more than C/C (16.7%) or T/T (0%) genotype, whereas C/C genotype was expressed (62.5%) more than C/T (25.0%) or T/T (12.5%) genotype in BCS $3.5\sim4.0$. The insulin concentration in follicular fluid obtained from ovary with follicular cyst which has follicles having diameter of $25\sim40 mm$ was significantly higher (p<0.05) than those in normal follicle fluid which has follicles having diameter of $3\sim10 mm$. These results showed that concentration of leptin and insulin in serum were related to BCS value and follicular size and suggest that the changes in concentration of leptin and/or insulin in serum could be a potent biomarker for diagnosis of bovine reproductive disorder.

• 대한수의학회지
• /
• 제33권3호
• /
• pp.539-545
• /
• 1993

This study was carried out the determine the progesterone concentration for serum by enzyme-linked immunosorbent assay(ELISA) in bovine adult at estrous, pregnant, after patuation and male, female calves of 1 month old, respectively. The results obtained were summarized as follows ; 1. The assay has a sesitivity of $0.1ng/m{\ell}$. 2. Intra and inter-assay coefficient of variation were 4.5%, 6.1~9.4% when used for the determination of progesterone in samples of bovine serum. 3. The percentages of recovery for progesterone added were between 88.0 to 88.9%. 4. Progesterone concentration of adult bovine serum at estrus, pregnant and after 1 day of parturition were $0.37{\pm}0.16$, $7.1{\pm}1.0$, $0.13{\pm}0.02ng/m{\ell}$, respectively. 5. There was no differences in serum progesterone concentration of calves both male($0.16{\pm}0.03ng/m{\ell}$) and female($0.15{\pm}0.04ng/m{\ell}$) on 1 month old. From these results, progesterone determination by ELISA is very applicable to detect of early pregnancy diagnosis, factorial analysis of reproductive disorder, and also reproductive physiological functions such as veterinary therapeutic measures and monitoring of cyclicity.

• 한국수정란이식학회지
• /
• 제17권2호
• /
• pp.145-151
• /
• 2002

본 연구는 개 난자의 체외성숙율 높이기 위해 개의 발정주기가 체외성숙에 미치는영향과 체외성숙율의 효율적 향상을 위해 실험을 실시하였으며, 다음의 결과를 얻었다. 1. Anestrus, proestrus, estrus와 diestrus의 발정주기로 구분하여 MII로의 체외성숙율을 48시간과 72시간 배양후 관찰한 결과 각각 15.9%, 16.3%, 23.7%와 18.2%와 22.1%, 30.8%, 36.6%와 17.5%로 나타났다. 2. 각 발정주기별로 72시간 배양한 후의 성숙율은 estrus 및proestrus기의 난자가 anestrus 난자보다 유의 적으로 높은 값를 보였다(p＜0.05). 3. 배양시간에 따른 체외성숙율은 72시간 배양한 성숙율이 48시간 배양 후보다 높은 결과를 나타내 었다(p＜0.05).

• Asian-Australasian Journal of Animal Sciences
• /
• 제14권3호
• /
• pp.307-315
• /
• 2001

Litter size has been one of the important economic traits in porcine reproduction. The insulin-like growth factor (IGF) system has been shown to mediate actions of the steroid hormone or to synergize with other endocrine factors so that it consequently plays roles in reproductive processes, including ovulation, implantation, maintenance of pregnancy, and fetal development. However, the effect of the serum IGF system on porcine litter size has not been deeply studied. Therefore, this study was conducted to relate serum IFG-II concentration and IGF binding protein-3 (IGFBP-3) expression with porcine litter size. Moreover, the possible association of those with estrogen receptor (ER) as a candidate gene for litter size was investigated. Swine were separated into two groups showing high and low litter sizes, and sera were collected from sows in the estrous cycle to postnatal growth of their female progeny. Serum IFG-II concentration was measured by radioimmunoassay and IGFBP-3 expression was detected by Western ligand blotting. During the estrous cycle, IGFBP-3 expression in both groups decreased moderately from metestrus to estrus, but IFG-II concentration showed a reverse pattern. Also, IFG-II concentration and IGFBP-3 expression decreased gradually as pregnancy proceeded. Unlike IGFBP-3, IFG-II decreased moderately as newborn pigs grew. Significant differences in serum IFG-II amount between the two groups were detected at 60 (p<0.01), 75, 90, and 105 d (p<0.05) of pregnancy and at 60 (p<0.01), 45, and 105 d (p<0.05) of postnatal growth. Furthermore, based on ER genotypes, a high litter size group with genotypes AB and BB showed lower IFG-II concentration than a low litter size group with a genotype AA during pregnancy. Taken together, the results indicate that the serum IFG-II and IGFBP-3 are correlated with the litter size in pigs.

• Asian-Australasian Journal of Animal Sciences
• /
• 제21권10호
• /
• pp.1411-1415
• /
• 2008

The purpose of the present study was to determine the onset of breeding season, the occurrence of silent and true heats and the duration of estrus in female Markhoz goats of the Kurdistan province in Iran. Ten, 3 years-old Markhoz does with an average weight of $34.05{\pm}2.62kg$ and with one kidding record, were used. The goats were maintained in an open barn under constant nutritional levels and natural photoperiod. One aproned buck was used twice a day every 12 h to detect estrus from mid August to early January. For the determination of the onset of reproductive activity as well as occurrence of silent heat, blood samples were collected every 10 days, from the beginning of the experiment. After $2^{nd}$ standing heat, blood samples were obtained twice a week in order to assess luteal activity and the length of estrous cycles. In this study, estrous behavior was observed including sniffing, vocal exchange, following courtship, flehman, standing heat and mounting. The results of the progesterone assay indicated that in this goat silent heats occur mostly in the early breeding season. The first standing heat was observed in mid-October which was considered as the onset of the breeding season. Duration of the estrous cycle and estrus was recorded as being $20.93{\pm}1.56days$ and $38.86{\pm}15.19h$, respectively. The correlation coefficient between length of daylight and occurrence of estrus was negative (r = -0.470) but not significant (p>0.05). The data showed that there was no significant effect of body weight on estrous cycles (first, second and third) and estrous periods (first, second, third and fourth). Progesterone levels were not significantly different in the first, second and third estrous cycles at days 0, 4, 10, 12, 14 and 19. The results of progesterone assay during the estrous cycle indicate that follicular and luteal phases last 4-5 and 14-15 days, respectively and the concentration of serum progesterone in these phases was $0.88{\pm}0.08$ and $7.44{\pm}0.26ng/ml$, respectively. The study concluded that Markhoz does could be considered as a breed with a short breeding season and an optimal estrous activity in autumn.

• 한국수정란이식학회지
• /
• 제21권3호
• /
• pp.177-182
• /
• 2006

본 연구는 $MGA+PGF_{2{\alpha}}$ 투여에 의한 발정 동기화 방법이 한우의 혈청 $P_4$ 수준, 발정 발현율과 수태율에 미치는 영향을 규명하고자 수행하였다. 첫째로, 한우 미경산우에서 $MGA+PGF_{2{\alpha}}$ 투여가 혈청 $P_4$ 수준에 미치는 영향을 조사하기 위하여 한우 미경산우 10두 및 프리마틴 1두에 대하여 MGA를 1일 0.5 mg을 14일간 오전 배합 사료에 섞어 급여하였으며, 19일이 경과한 후에 $PGF_{2{\alpha}}$ 25 mg을 투여하였다. MGA feeding 후 혈청 $P_4$ 농도 수준을 분석하기 위하여 MGA 급여 기간과 급여 종료 후 발정이 관찰될 때까지는 3일 간격, $PGF_{2{\alpha}}$ 투여 시, 발정 및 인공 수정 시, 인공 수정 후 15일째 및 2개월째에 혈액을 채취하였다. 한우 미경산우의 혈청 $P_4$ 수준은 MGA급여 7일 이후부터 상승하기 시작하여 투여 9일차에는 5.4 ng/ml로써 이후 상승된 상태에서 유지되었다. $PGF_{2{\alpha}}$ 투여시점인 33일차에는 7.6 ng/ml 수준으로 피크를 나타냈고, 투여 2-3일이 경과하고 발정이 발현됨에 따라 1.4 ng/ml로 급강하하는 양상을 보였다(p<0.05). 그러나 프리마틴의 경우에는 시험 기간 동안 P4수준의 변화가 인정되지 않았다. 둘째로, 한우 미경산우 및 경산우 194두를 이용하여 상기한 $MGA+PGF_{2{\alpha}}$ 투여 방법(n=104)과 대조군으로 $PGF_{2{\alpha}}$ 투여(11일 간격 2회 투여, n=90)에 따른 발정 발현율 및 수태율을 비교하였다. 발정 발현율은 대조군인 $PGF_{2{\alpha}}$ 투여군 72.2%에 비해 $MGA+PGF_{2{\alpha}}$ 투여군에서 91.3%로써 유의적으로 높았다(p<0.05). 인공 수정 후 수태율은 $MGA+PGF_{2{\alpha}}$ 투여군이 $PGF_{2{\alpha}}$ 투여군에 비해 1회 수정 수태율(51.1 vs. 59.6%), 2회 수정 수태율(77.8 vs. 84.6%) 및 전체 수태율(88.9 vs. 94.2 %)이 유의적으로 높았다(p<0.05). 본 연구의 결과는 $MGA+PGF_{2{\alpha}}$를 이용한 발정 동기화 방법은 $PGF_{2{\alpha}}$ 투여법에 비해 높은 발정 동기화율 및 수태율을 나타냄으로서 한우의 번식 능력 향상에 적절히 활용될 수 있음을 보여준다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제16권2호
• /
• pp.176-179
• /
• 2003

Insulin-like growth factor-I (IGF-I) is a polypeptide that has the function of regulating the expression of steroid hormones through endocrine, paracrine, and autocrine actions in reproductive organs. Moreover, IGF-I is involved in ovulation, implantation, maintenance of pregnancy, and development of fetuses in animals. Therefore, this study was conducted to investigate the effects of serum IGF-I concentration on progesterone ($P_4$) concentration and pregnancy rates in Korean native cattle (Hanwoo). Blood was collected at estrus (Day 0) and Day 11. Artificial insemination was performed at Day 0. Serum IGF-I and $P_4$ concentrations were measured by radioimmunoassay (RIA). Overall, $P_4$ concentration was higher at Day 11 than Day 0, whereas the pattern of IGF-I concentration was reversed. When animals were divided into two groups depending on the pregnancy status, $P_4$ concentrations of the pregnant group was significantly higher than that of the non-pregnant group at Day 0 (p<0.05) and Day 11 (p<0.05). But, lower IGF-I concentrations were detected in the pregnant group at Day 0 (p<0.05) and Day 11 (p<0.05) compared to the non-pregnant group. In conclusion, these results indicated that serum IGF-I is inversely associated with $P_4$ concentration during early pregnancy in Hanwoo.