Showing papers in "Theriogenology in 1999"

TL;DR: Under defined culture conditions, addition of citrate and myo-inositol improved blastocyst development to rates comparable to those obtained with serum, BSA or co-culture and that the quality of blastocysts was not affected by the absence of serum or BSA.

TL;DR: Although overall synchronization rate with Ovsynch was above 85%, there were clear differences in response according to day of protocol initiation, with cows in which Ov synch was initiated at midcycle having smaller ovulatory follicles and greater pregnancy rates.

TL;DR: The cardiopulmonary abnormalities observed in the calves and fetuses occurred in utero in conjunction with placental abnormalities, and it is likely that the cloning technique and/or in vitro embryo culture conditions contributed to these abnormalities, although the mechanism remains to be determined.

TL;DR: In this article, a MoFlo flow cytometer/cell sorter was used to test the DNA-binding dye Hoechst 33342 on fresh sperm collected from 22 bulls of unknown fertility of various beef and dairy breeds.

TL;DR: Development of the these technological improvements in the Beltsville Sexing Technology that has brought sexed sperm to a new level of application are described.

TL;DR: It has yet to be determined whether seminal plasma would have similar effects on flow cytometrically sorted spermatozoa of other species, and what its effects might be on the in vivo fertility of flow sorted boar.

TL;DR: A better comprehension of the relationships between oocyte quality and follicular characteristics after superovulation can be gained using in vitro techniques, which will subsequently be used for the optimization of embryo production needed for the genetic improvement of livestock and the development of new biotechnologies.

TL;DR: Fertilizing capacity of flow-sorted sperm is quite acceptable as predicted by simple laboratory assays, and sexed bovine sperm for commercial AI may be available within 2 years.

TL;DR: The presence of dogs, the presence of poultry, and the feeding of moldy maize-silage during summer are considered to have potential biological relevance and suggest a possible role of these species in the transmission of N. caninum.

TL;DR: The results supported the hypotheses that deviation occurs rapidly (within 8 h), that elevated systemic LH concentrations are present during deviation, and that deviation is not preceded by an increase in systemic estradiol.

TL;DR: The objective of this article is to review the role of uterine defense mechanisms in natural resistance to chronic or persistent endometritis and the exact role of seminal components in breeding-induced inflammation needs further investigation.

TL;DR: Sperm motility is a useful indicator of sperm fertilization capacity in vivo and it is critical that the number of spermatozoa used during insemination is sufficiently low to detect differences in sperm fertilizing efficiency.

TL;DR: IVF also has proven useful as a bioassay for improving sperm-sorting procedures such as determining potential detrimental effects of laser power, and it is likely that use of IVF in cattle breeding programs will increase considerably when sexed, frozen sperm become commercially available.

TL;DR: It is concluded that milk production is the primary factor affecting the incidence of double ovulation in lactating dairy cows and may explain the effect of parity on twinning rate.

TL;DR: Reconstructed embryos obtained by nuclear transfer of muscle cell-derived cell lines can develop to the blastocyst stage, and some are sufficiently competent to develop to term, and the finding that special culture protocols for somatic cells prior to nuclear transfer were not necessary is indicated.

TL;DR: The HOS test is a simple and accessible method which could be used as a complement to routine equine semen analysis and has the added advantages of being less susceptible to the immediate effects of cold shock and of evaluating individual spermatozoa rather than the population as a whole, as does progressive motility.

TL;DR: FSH treatment of bovine oocyte donors aspirated once a week enabled a similar number of transferable embryos to be produced per donor week as aspiration twice a week without FSH treatment.

TL;DR: The results indicate that a close temporal coupling between a change in FSH concentrations and the follicular response could establish the deviation mechanism in < 8 h or before the second largest follicle reaches a similar critical diameter.

TL;DR: Use of sexed semen would make terminal crossbreeding systems more efficient and sustainable in beef cattle, and more could be devoted to producing highly efficient, terminal crossbred sons.

TL;DR: In vivo pluripotency of the cells was demonstrated by birth of a chimeric piglet, documented by pigmentation and DNA markers, and the ability to direct the development of nuclear-transfer embryos to the blastocyst stage was demonstrated.

TL;DR: Improvements over the last several years are the ability to store embryos at 5 degrees C and thus ship them to a centralized station for transfer into recipient mares, and collection of equine oocytes by transvaginal, ultrasound-guided puncture and the transfer of these oocytes into recipients is now being used to produce pregnancies from donors that had previously been unable to provide embryos.

TL;DR: It is inferred that O2-.

TL;DR: The present study confirms that the largest follicle of Wave 1 is dominant in the ewe and that subluteal progesterone concentrations can prolong its lifespan and extend this dominance.

TL;DR: It is concluded that IVM is a major factor limiting in the in vitro production of viable embryos, although factors such as the lack of normal preovulatory development of IVM oocytes contributed to the observed differences.

TL;DR: Ovarian changes determined by daily transrectal ultrasonic scanning, and its correlation with serum progesterone (P4) and estradiol (E2) concentrations were studied in seven cyclic Saanen goats, suggesting that the presence of follicular dominance and the production of E2 are different among waves.

TL;DR: Transfer of embryos collected from nonheat-stressed superovulated donors significantly increased conception rates in heat stressed dairy cattle, however, transfer of IVF-derived embryos had no advantage over AI.

TL;DR: This study is the largest that has been carried out on frozen-thawed dog semen AI and shows that using a good method for cryopreservation, together with nonsurgical intrauterine AI employing the Norwegian catheter, can yield whelping rates and litter sizes similar to those reported from well-controlled natural matings.

TL;DR: The Beltsville Sperm Sexing Technology, which is based on the sorting of X- and Y-bearing sperm through the process of flow-cytometric sperm sorting, is well suited for validation in the laboratory by "sort reanalysis" of the sperm X-and-Y-bearing fractions for DNA content.

TL;DR: It is concluded that male Creole goats in Northern Mexico, fed constantly throughout the year, exhibit seasonality in their reproductive activity.

TL;DR: The findings indicated the possible broader application for OPS, as they demonstrated that the physical advantages of rapid cooling and warming may be accompanied by different chemical composition (holding media, cryoprotective additives) according to the requirements of the biological structure.