• 한국동물생명공학회지
• /
• 제34권2호
• /
• pp.106-110
• /
• 2019

Sexed sperm can contribute to increase the profitability of the cow industry through the production of offspring of the craved sex, such as males for meat or females for dairy production. Therefore, the utilization of sexed sperms plays a very important role in the production of offspring of superior cattle. In this study, we examined the pregnancy rates and calves sexing proportion of male and female calves produced using AI, both performed using sexed and conventional sperm. In the result, the conception rates after ET were 73.3% (33/45) sexed semen and 52% (55/104) conventional semen. Thus, the sex ratio for sexed-semen inseminations was 70% (21/30) females for singleton births within a 272 to 292 day gestation interval. The sex ratio for conventional semen was 61% (34/56) females for births. As a result, it is suggested that the use of sex classification sperm will play a very important role in the offspring production of Korean bovine.

• 한국수정란이식학회지
• /
• 제29권3호
• /
• pp.283-287
• /
• 2014

Sexed semen is commonly used for the production of calves of the desired gender. Gender selection is important in animal production industries. For example, female cattle are required for the dairy industry while males are preferred in the beef cattle industry. The present study was to assess the in vivo embryo production efficiency using the semen separated according to sex during superovulation in Hanwoo. Seventy Hanwoo donor cows were flushed on day 7 of estrus cycle with same FSH and artificial insemination by the same technicians. Embryos were recovered on 7 days after the third insemination by flushing the uterus with embryo collection medium. KPN semen straws used artificial insemination contained 20 million sperm (total number 60 million per donor). Sex-sorted semen straws contained 4 million sperm (total number 12 million per donor). The results obtained were as follows: No differences were observed in the efficiency of superovulation rates on KPN semen 87%, and sexed semen 100%, respectively. The mean numbers of total embryos are each $12.58{\pm}8.31$ and $13.25{\pm}7.86$. The mean numbers of transferable embryos, sexed semen were significantly lower than KPN semen ($3.75{\pm}1.98$ vs. $8.23{\pm}6.07$, P<0.05). The rates of unfertilized embryos from superovulation using sexed semen were significantly higher than KPN semen (50% vs. 15%, P<0.05). The rate of degenerated 2-cell embryos from sexed and KPN semen was 60.87% and 11.11%, respectively (p<0.05). In conclusion, these results indicate that superovulation using sexed semen was useful, but efficient embryo production was important to reducing the damage caused by the Flowcytometer-based sperm sorting procedure.

• Asian-Australasian Journal of Animal Sciences
• /
• 제31권9호
• /
• pp.1387-1392
• /
• 2018

Objective: In a nucleus breeding scheme, the sire of dam's pathway plays an important role in producing genetic improvement. Selection proportion is the key parameter for predicting selection intensity, through truncating the normal distribution. Semen sexing using flow cytometry reduces the number of vials of sperm that can be obtained from a proved bull. In addition, a lower fertility of this kind of sperm is expected because of the lower sperm dosage in sex sorted semen. Both of these factors could affect the selection proportion in the sire of dam's pathway ($p_{SD}$). Methods: In the current study, through a deterministic simulation, effect of utilizing sex sorted semen on selection ($p_{SD}$) was investigated in three different strategies including 1: continuous use of sex sorted semen in heifers (CS), 2: the use of sex sorted semen for the first two (S2) and 3: the first (S1) inseminations followed by conventional semen. Results: Results indicated that the use of sex sorted semen has a negative impact on the sire of dams (SD) pathway due to increase in selection proportion. Consequently selection intensity was decreased by 10.24 to 20.57, 6.38 to 8.87 and 3.76 to 6.25 percent in the CS, S2, and S1 strategies, respectively. Conclusion: Considering the low effect of sexed semen on genetic improvement in dam pathways, it is necessary to consider the joint effect of using sex sorted semen on the sire and dams pathway to estimate about the real effect of sexed semen on genetic improvement in a nucleus breeding scheme.

• 한국동물번식학회:학술대회논문집
• /
• 한국동물번식학회 2001년도 발생공학 국제심포지움 및 학술대회 발표자료집
• /
• pp.6-10
• /
• 2001

No. Sperm can be sexed with 90% accuracy by flow cytometry/cell sorting. No. The current speed of sexing is about 5,000 live sperm of each sex per second, remarkably fast considering that each sperm is individually sexed. No. Although fast, sperm sexing is not fast enough to use standard numbers of sperm per AI dose. No. With well managed heifers, pregnancy rates with low doses of sexed, frozen sperm are 70-80% of those with unsexed sperm with normal sperm numbers. Pregnancy rates are lower in lactating dairy cows. No. Calves from sexed sperm appear to be normal. No. Sexed, frozen semen from a few bulls currently is available commercially in the United Kingdom, and likely will be available in several other countries in 2002, probably at a premium of US ＄30-50 per straw. (omitted)

• Animal Bioscience
• /
• 제34권12호
• /
• pp.1879-1885
• /
• 2021

Objective: Owing to the lack of a breeding index for efficient and quick fertility evaluations of Holstein bulls when using traditional or genome-wide detection methods, this study aimed to determine whether in vitro fertilization (IVF) could be used as an indicator of conception rate of artificial insemination (AI). Methods: Conventional and sexed frozen semen from nine bulls were used for IVF and AI. Results: The IVF and AI conception rates of each bull were confirmed to be positively correlated between the conventional frozen and sexed frozen semen. The correlation coefficient R values of nine bulls between IVF and AI methods were 0.73 and 0.97 for the conventional frozen and sexed frozen semen, respectively. The average conception rate of three bulls undergoing AI was 69.5% and 64.2%, 61.8% and 58.8%, and 48.2% and 46.2% in first-, second-, and third-born cows when conventional frozen and sexed frozen semen were used, respectively, which showed a positive correlation with the fertilization rate in the same parity. We propose an evaluation standard to assess the fertilization ability of bulls based on their IVF test results, which is categorized into three grades: grade one, normal fertility bull with an AI conception rate of 40%±5% and IVF rate of 45% to 60%; grade two, higher fertility bull with an AI conception rate of 50%±5% and IVF rate of 61% to 80%; and grade three, highest fertility bull with an AI conception rate of 60%±5% and IVF rate of >80%. Conclusion: These findings reveal that IVF results can be used as a breeding index for bulls to evaluate their AI conception ability, which may shorten the time required to select bulls for breeding.

• 한국수정란이식학회지
• /
• 제30권1호
• /
• pp.45-50
• /
• 2015

본 연구는 백한우 개체 1두에서 성판별된 정자를 제조하고 원하는 성을 가진 후대를 생산하고자 인공수정을 실시하였다. 채정이 가능한 백한우 종모우 1두를 선발하고, 정자 성 분리 전용 유세포 분리기인 MoFlo XDP기기로 성분리 동결정액을 생산하였다. 성분리 X 정자의 농도에 따른 임신율과 출산율을 비교하기 위하여 대조군으로서 KPN 768정액을 이용하였으며 그 총 정자수는 $20{\times}10^6$로 추정되었다. 실험군으로서 성 판별된 백한우 X 정자를 이용하였으며, 정자수 $2{\times}10^6/straw$와 $4{\times}10^6/straw$를 처녀우 한우에 2회 인공수정하였다. 백한우의 정액 기형도는 $24.9{\pm}7.31%$로 관찰되었으며, 중편부 반전 정자기형이 약간 높은 정자로 검사되었다(11.7%). 성판별된 백한우 X-정자수가 $2{\times}10^6/straw$와 $4{\times}10^6/straw$를 인공 수정할 때 실험군에서 임신율의 차이는 없었으며, 보증씨수소 정자를 이용한 대조군의 경우, 임신율이 유의적으로 높게 나타났다(p<0.05). 대조군 KPN 768와 실험군 $2{\times}10^6/straw$ 정자와 $4{\times}10^6/straw$ 정자 처리군에서 임신율은 각각 85.0%, 26.3% 및 50 %로 관찰되었다. 산자 생산율은 각각 80.0%, 15.8% 및 21.4% 로 관찰되었고, 암컷 출현율은 각각 43.8%, 100% 및 100%로 조사되었다. 이러한 결과는 백한우 성 판별된 정자로 원하는 성을 가진 후대 생산이 가능함을 보여주고 있으며, 성 판별된 정자를 활용하여 원하는 성을 가진 백한우 후대를 생산하는데 최적화된 정자수의 대한 기본 자료를 제공할 수 있을 것으로 기대된다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제27권10호
• /
• pp.1411-1416
• /
• 2014

Gender selection is important in livestock industries; for example, female calves are required in the dairy industry. Sex-sorted semen is commonly used for the production of calves of the desired gender. However, assessment of the sex ratio of the sorted semen is tedious and expensive. In this study, a rapid, cost effective and reliable method for determining the sex ratio was developed using a multiplex real-time polymerase chain reaction (PCR) assay. In this assay, the X and Y chromosome-specific markers, i.e., bovine proteolipid protein (PLP) gene and sex-determining region Y (SRY) were simultaneously quantified in a single tube. The multiplex real-time PCR assay was shown to have high amplification efficiencies (97% to 99%) comparable to the separated-tube simplex real-time PCR assay. The results obtained from both assays were not significantly different (p>0.05). The multiplex assay was validated using reference DNA of known X ratio (10%, 50%, and 90%) as templates. The measured %X in semen samples were the same within 95% confidence intervals as the expected values, i.e., >90% in X-sorted semen, <10% in Y-sorted semen and close to 50% in the unsorted semen. The multiplex real-time PCR assay as shown in this study can thus be used to assess purity of sex-sorted semen.

• Asian-Australasian Journal of Animal Sciences
• /
• 제28권3호
• /
• pp.451-455
• /
• 2015

The buffalo is an important livestock resource in several countries of South Asia and the Mediterranean regions. However, reproductive efficiency is compromised due to known problems of biological and management origins, such as lack of animal selection and poor nutrition. Under optimal conditions puberty is attained at 15 to 18 months in river buffalo, 21 to 24 months in swamp buffalo and is influenced by genotype, nutrition, management and climate. However, under field conditions these values deteriorate up to a significant extant. To improve reproductive efficiency, several protocols of oestrus and ovulation synchronization have been adopted from their use in commercial cattle production. These protocols yield encouraging pregnancy rates of (30% to 50%), which are comparable to those achieved in buffaloes bred at natural oestrus. The use of sexed semen in buffalo heifers also showed promising pregnancy rates (50%) when compared with conventional non-sexed semen. Assisted reproductive technologies have been transferred and adapted to buffalo but the efficiency of these technologies are low. However, these latest technologies offer the opportunity to accelerate the genetic gain in the buffalo industry after improving the technology and reducing its cost. Most buffaloes are kept under the small holder farming system in developing countries. Hence, future research should focus on simple, adoptable and impact-oriented approaches which identify the factors determining low fertility and oestrus behaviour in this species. Furthermore, role of kisspeptin needs to be explored in buffalo.

• Reproductive and Developmental Biology
• /
• 제36권1호
• /
• pp.1-6
• /
• 2012

This study evaluated a sexed sperm ability to produce embryos by flow cytometer. Hanwoo bulls sperm were separated to X and Y sperm via Hoechst 33342 stained with near UV laser or performed the pre-sorted without near UV laser beam in flow cytometry. Pre-sorted sperm had significantly higher viability ($84{\pm}1.15%$, $p$<0.05) compared to other sorted groups in frozen-thawed semen. For fresh semen, pre-sorted sperm had the higher viability ($79{\pm}3%$, $p$<0.05) than those of the X and Y sperm ($44.7{\pm}1.67$ and $41.7{\pm}1.2%$) separated by differences of DNA content. On the other hand, pre-sorted and X sperm sorted according to differences in DNA content had significantly higher viabilities ($24.3{\pm}1.2$ and $25.7{\pm}0.9%$, $p$<0.05) compared to that of the sorted Y sperm ($13.7{\pm}1.2%$) in the hypoosmotic swelling test. The proportion acrosome reaction in the sorted X sperm was higher ($55.0{\pm}1.7$ and $45.0{\pm}1.5%$) than those of the sorted Y-sperm ($32.3{\pm}0.9%$, $p$<0.05). However, the sperm morphologies of the sorted groups were not significantly differences. In conclusion, the sex-sorting procedure by flow cytometry affected some characteristics of Hanwoo sperm. Further study is needed to determine the optimal procedures to enhance male and female embryos and sorting accuracy.

• 한국수정란이식학회지
• /
• 제26권3호
• /
• pp.181-186
• /
• 2011

Spermatozoa sorted by flow cytometry have been successfully used to produce offspring in domestic animals and are commercially available for cattle. Also sheath fluid is the important environment for viability of sex-sorted sperm in flow cytometry. The aim of this study was to investigate whether or not HEPES (N-2-hydroxyethylpiperazine-N'-2-Ethanesulfonic acid) has any effect on the viability in sex-sorted Hanwoo (Korean native cattle) sperm. In this study, the semen was collected from Hanwoo of Hoengseong Livestock Cooperation by artificial vagina method then pooled and subjected to cryopreservation in straws. Sperm were cultured for 0, 30, 60 and 120 min with 0, 2.5, 5, 7.5 and 10 mM of HEPES added to the sheath fluid and incubated at 4, 20 and 38$^{\circ}C$, respectively. For the cytometric analysis the frozen-thawed semen was extended with 5 mM HEPES extender to final concentration ($2{\times}10^7$ spermatozoa) at 4, 20 and 37$^{\circ}C$. Sperm viability was assessed with SYBR-14 and propidium iodide (PI) staining. This study shows that the viability of sperm was decreased with prolongation of incubation time in all of test. But the viability of sperm which were treated with 38$^{\circ}C$ was gently decreased than that of treated with other temperature. The viability of the control was sharply decreased (p<0.05) than all of the HEPES treatment group at 60 to 120 min in 38$^{\circ}C$. X-sexed sperm was more sensitive than Y-sexed sperm to temperature during f10w cytometry (p<0.05). In conclusion, the results of this study suggest that the sheath fluid with 5 mM HEPES has effect on maintenance of viability after sperm sexing at 37$^{\circ}C$ in Hanwoo.