Recent content by ETschool

With rising costs and decreasing value of cows it is more than time to tighten the belt. There is significant expense and time in preparing recipients to receive an embryo. They may have been purchased for this purpose, shipped home, vaccinated, wormed, estrous synchronized, observed for...

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...

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...

I am not aware of data referring to differences in heifer and cow embryo placements,however it could be true as the heifer uterus is much smaller so the embryo trophoblast cells excreting interferon ( which stops the production of prostaglandin ) has a relatively larger field of response...

Upper refers to closest to the ovary end.

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...

As I reported in the newsletter grading is unfortunately subjective, one technician will grade an embryo a 2, while another will grade the same embryo a 1. Also there are differences in the pregnancy rates of # 1 embryos from two different donors,that is why I impress on my students keep...