Monday, May 17, 2021

New options for improved conception when heifer calves are preferred


CONCEPTIONS  Dairy route newsletter                  Aug-Sept 2020

The industry has now had “preferred sex” semen for a decade.    At the beginning, sexed semen sold at a serious premium (four times conventional prices) and rates of conception were noticeably lower (15% less breeding heifers, 25% less if cows).  
Choice of sire was extremely limited, mostly older or lower market tier bulls.

Sexing Technologies continued to monitor results and research improvements which led to the “Sexed Ultra” straw (4 million live sperm instead of the initial 2.5-3.0 million) and the gap from conventional to sexed semen on conception rates narrowed (5% less on heifers, 15% less cows).
Cost per straw also came down, while number of bull choices went up.   ABS introduced its own sexed product as well, and has a few AI stud customers, bringing some competition.

Is there any other option?
Those using “sexed” semen still pay a 100% to 200% premium over conventional semen prices, and with the current dairy market (and deacon calf/cull cow prices) many have limited their use of sexed germ plasm.
In the meantime, an obscure product has come forth with the potential to gain on the preferred sex ratio, but which also has the ability to improve conception near the same amount that conventionally sexed semen lowers it.

This product is a combination of enzymes called “Heifer Plus” when you want to get more replacement heifers (or “Bull Plus” when you want to get more steers).   Produced by Emlabs, it is packaged in two sizes (for 1/2cc straws, or 1/4cc straws) and will last indefinitely as long as you keep it frozen until use.

The procedure will add ten minutes to the insemination time.   You thaw the vial of enzymes at the same water temp (95 F)  you thaw the straw.    You cut the straw at an angle, insert it into the vial, give a couple firm shakes (drawing semen into the enzyme vial), let it incubate for 10 minutes; then shake the fluid mix back into your straw, loads your AI gun and breed the animal.

Previous instructions suggesting 15 minutes of incubation have been CHANGED as incubating too long seemed to neutralize the “sexing” effect.    The new recommendation at 10 minutes is proving to enhance both conception and the desired sex ratio.

At a cost of $10 or less, this product is extremely competitive against buying sexed semen, and if all you get is a 5% to 10% gain in conception, you will save much more on semen expense!!

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