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A common failure in embryo transfer programs is the selection and preparation of recipients. I am often asked which breed should be selected for receiving embryos. To date there is no evidence that any Bos Taurus (British and European) breed is superior. However, many years ago we found Bos...

Student Quarters for Field Experiments I’ve always been interested in history so I thought it would be interesting to briefly look back at the developments in my field of bovine reproduction and as the saying goes learn from history, so our activities over the past may point out our failures...

Demonstrating the damage caused by poor transfer techniques Frequently I have heard of artificial insemination (AI) technicians claiming higher pregnancy rates when semen is placed in the uterine horns. However, a study (Can. VET. J. 1965) reported that AI technicians frequently deposited semen...

There have been many attempts to improve pregnancy rates by administering progesterone (PG) from injections to vaginal suppositories. Unfortunately, results have been well below expectations but have improved with the advent of controlled intravaginal releasing devices (CIDRs) for synchronizing...

The Achilles heel of the embryo transfer industry is the unpredictability of the final results even when optimum techniques have been utilized by experienced persons. I have often thought we should regularly obtain at least a 90% pregnancy rate when considering number one quality embryos were...

We have all experienced frozen straws containing embryos or semen exploding when exposed to the environment or water in the thermos. Unfortunately, the person thawing is accused of making a mistake, but the fault is due to the technician who froze the embryos not sealing the straw prior to...

I have often speculated after carefully transferring a #1 embryo into a recipient with a known corpus luteum (CL), on the correct date of the estrous cycle, following regular cycles, why do we not achieve pregnancy rates around 90 to 100 per cent?  As we all know that rarely occurs at least when...

Treat the IVF embryos the same as the regular  embryos,taking extra care to thaw correctly and transfer as soon as possible after thawing bacause these embryos have been damaged and they are only half the normal number of cells.  Good Luck.

The survival of frozen-thawed-transferred embryos depends on several factors, and they are based on a subjective classification of quality expressed as #1, 2 or 3 meaning excellent, good or fair quality. However, classification is not 100% reliable as the grading scores vary among practitioners...

When I was running the CSU embryo transfer laboratory our mission  was in  applying  our research results to see if they worked in  the commercial field. There are many examples where a technique works in the laboratory but does not function efficiently when applied commercially. We had over...

There was an interesting question on the effect of pH in the uterus and its effect on an embryo and subsequent pregnancy. The pH of the healthy vagina is around 4, cervical mucus 8.4, uterus 7.6 and oviductal fluid in the follicular phase 7.3 and in the luteal phase 7.5 to 7.8. There is ample...

When palpating a potential recipient I first identify a CL on an ovary,which is a solid structure with a papilla ( bump ) projecting from the surface of the ovary. Then check the body and horns of the uterus to see if the horns are of equal size with a tone which is not too firm or too soft. The...

I would make an extra effort to place frozen-thawed embryos as high as possible,because it is likely due to freezer damage their signal is not so strong. But again once you are having problems release the embryo and get out.

Steel reported that embryos graded # 1 (859) resulted in equal pregnancy rates when they were placed in either lower, middle or upper one third of the horn (73%, 73%, and 74%) respectively next to the CL on the ovary, providing the embryo was deposited past the palpable division of the horns...

We received several calls this summer regarding below average embryo collections and unsatisfactory pregnancy results in recipients. These concerns led to the creation of this month’s newsletter which addresses heat stress and its effects on bovine reproduction. Global warming is a term we are...

Yes, I would agree with you. Providing the embryo itself grades 1 or 2 a few dead extruded cells do not effect subsequent pregnancy rates. When extruded cells are present I will usually grade the embryo as a 2 as it is smaller than usual. Extruded cells do not make the embryo illegible for export.

I would only transfer a grade 4 embryo if there were extra recipients to spare. I once transferred a 3- embryo from a single embryo collection from a very famous holstein cow. it became a pregnancy,a bull calf was born and at 6 months of age it was sold for $131,000 !  There was a picture of the...

Recently a cattle owner contacted me regarding frozen embryo classification. He had some frozen embryos stored, classified as Stage 4 which are embryos developed to the compact morula stage usually observed 6 days after first observed standing heat (estrus ) . He had been informed by several...

The superovulation schedule is the same for fat cows. However there is a greater chance of failure to produce embryos as more frequently the fat cow does not ovulate and at the time of recovery you find lutein cysts instead of CLs. Yes, we have data comparing bull mating to AI and there were no...

Make sure the selected recipients are cycling regularly before synchronisation. Use proven cows as recipients.Vaccinations should be up to date. Recipients should be in good condition,that is not too fat or too thin. When they are fat lutein cysts instead of CLs are frequently present,and if...