Wednesday, May 8, 2024

Just pondering where we are going


Embryo transfer was first attempted surgically in the 1970s—fifty years ago, with  “super-ovulation” [hormone injections to stimulate multiple egg release] quickly developing to multiply embryo production.   Then along came ET “flushing” (non-surgical) techniques in the 1980s, harvesting embryos a week after insemination for implantation into host/incubator “recipients”, followed closely by methods for freezing embryos for later implantation.    With the advent of “Genome” testing (DNA Mapping) in 2010, demand for “In Vitro Fertilization”  [conceptions made outside the cow’s body from eggs aspirated off ovaries]  arose.    A majority of Holstein, Jersey and Brown Swiss AI sires are produced by these methods.

Genetic values: now imputed instead of evaluated

From the advent of frozen semen in the 1960s, which enabled wide-scale progeny testing, until the early 2000s (again, fifty years) the “gold standard” genetic value was the 99% Reliability progeny evaluation.   Milking daughters, production tested and type classified across a number of herds, determined AI bulls’ “genetic merit.   The analysis of pedigree—ancestral performance—was of an equal value to those seeking a more complete view of breeding potential.    Finally, the individuality or phenotype of the bull himself and his close dams and sisters added up insights for compensatory mating and potential longevity of performance.

After the advent of Genomic indexed ranking the AI industry is no longer willing to wait for the final verdict of progeny evaluation.     Less phenotypic information is provided, in fact few bulls today live to maturity for evaluation, replaced by the relentless stream of newly-hatched IVF embryos.     Increasingly, the dams of the bulls AI offers never have a calf of their own, never enter the milking string, never have to compete in the real world and be evaluated on their own production.

Is there a consequence to all this?

I cannot help but wonder if we go too far with technology?   None of us as dairies can afford to abandon natural reproduction.    Nor can we afford to turn over cow herds at a 50% culling rate demanded by the current theory of “genetic progress”.    The functioning matured cow [3rd, 4th and later lactation] still produces the most.
How much of longevity requires adherence to natural fertility as nature designs?

Comparing  costs   (utilizing all the technology available)

The sales pitch is as follows:   (1) Genomic test all heifer calves for their ranking on USDA’s “Net Merit” or Holstein USA’s “Total Performance Index” [or some hybrid that adds in patented “Wellness traits” or “Immunity Plus” or “Eco Feed”].      $50

(2) sell as deacons all heifer calves below some arbitrary level of Genomic index. 
Breed the heifers retained to gender-selected semen from the newest of Genome ranked young sires, to accelerate generations to gain genetic value faster.       $60

(3) As these heifers freshen and enter the milking herd, start culling “older” cows whose Genomic index ranking value is below the incoming heifers.    Continue to breed the new milking heifers to gender-selected semen as long as their Genomic values exceed those of the second and later cows still milking.                            $70

(4)  Breed all second and later lactation cows to “Beef” breed sires, reverse gender selected if possible, to insure mostly male deacons to be sold  (deacons that look like “beef” crosses bring premium prices at sale barns).                                         $70

Depending on your success from sexed semen and raising calves, your milking herd age is going to decrease rapidly.     You are trading a “{mature}” production herd for a “{young}” production herd.     You are raising your future herd from a “heifer” momma herd instead of a proven “cow” momma herd.                   $ 1800

Estimated added cost of buying the technology theory (per cow milked):     $ 2050

The math is simple, really.    Genomic tests are an upfront cost of collecting DNA and sending it to your lab of choice.      Using gender-selected semen generally triples semen cost over regular conventional semen and related conception rates.    While heifers conceive to sexed semen at a rate within 10% of conventional semen, cows in milk conceive at a rate 25% less than regular.  
Finally, culling cows at their peak maturity (when Zoetis’ research says cows produce 30% more than they did as heifers) rather than keeping them their full productive life costs you the value of that cow, who probably cost $1800 to raise from calf to first calving.

Why have 45% of all dairymen swallowed this theory?     Just as I used to hear “you can’t get milk out of a registration paper” I will now ask you “can you get milk out of a marginally higher index?”  (enough to cover all the added costs of trusting to acceleration theories)    

Would it not be wisest to harvest as many replacement heifers as we can from the OLDEST COMPETITIVE COWS IN THE HERD?    Cows who are proven to have adapted successfully to your environment, have the fertility to breed back and have live calves, and MILK A LOT??

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