IMPORTANCE OF PLACEMENT OF EMBRYOS IN THE UTERINE HORN

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.

However,  there were significant differences in pregnancy rates for embryos graded 2 or 3 when they were placed in different parts of the horn. As expected when the embryo was delivered in the upper one third of the horn a pregnancy rate of 66% ( 209 embryos ) was achieved, but for # 2 embryos 59% (151 embryos ) pregnancy rate when  placed in the middle one third of the horn and  only 49% (41 embryos ) when placed in the lower one third of the horn.

Embryos graded #3 continued this trend. Placed in the upper one third of the horn 41% pregnancy rate was achieved (91 embryos ), in the middle one third of the horn 35% pregnancy rate (55 embryos) and embryos delivered to the lower one third of the horn only 26% became pregnancies (23).

These results are subjective of course relying on the grading skills of the technician and the quality of the transfers. In other words some technicians will be more skillful than others but these excellent records point out obvious differences which many of us suspected.

So the take home message is careful, accurate palpation taking particular note of the tone of the uterus, and depositing the embryo in as little time as possible, high in the horn without damaging the cells of the uterine wall and causing hemorrhage in as little time as possible.

Dr. Peter Elsden
http://www.ETschool.com

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Does it make a difference with thawed grade 1&2 embryos vs fresh 1&2 embryos

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.

What exactly am I feeling for to determine if a cow is a good recipe or not?

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 tone is a very important point to check because if it is too hard or too soft, it indicates there is a problem such as an infection. In the case of an early pregnancy one horn will be larger. Older cows with a  large uterus extending into the abdominal cavity usually make poor recipients.