Poultry
farmers know this—“no eggs, no income”.
Swine producers know this as well—“no sows nursing piglets, no pork
chops to sell”. Sheep flocks are
pushed to lamb twice in fifteen months.
Beef cow-calf operators know this very painfully at today’s calf
values—“no calf, no income”. Why when
it comes to Dairy, has the production industry been so casual about
reproduction?
Remember when Monsanto was promoting the eighteen
month calving interval, and some of the rBST users were bragging up 1000-day
lactations (cows who only calved once in their life)?
Today’s replacement heifer shortage (in spite of widespread use of “gender
selected” semen) and the record-setting
prices that are now double what springing heifers brought as recently as
three years ago, brings me to review all
the high technology adaptive concepts that have been promoted to trusting
dairymen, in the constant chase for “more milk”.
It really all began with the development of Predicted
Transmitting Ability, the ranking of sires primarily on first-lactation
milk volume. Heifers who “peaked” the
highest gave their sires the magic +1000 PD Milk rating, even if it took
them 500 days to calve back—only the first 305 days’ milk multiplied by “ME”
(Mature Equivalent) factors counted “genetically”. In each generation bred this way, average
conception rates fell, average calving intervals fell, percentage of stillborn
calves increased, and incidence of post-calving metabolic disease rose. The Genetics industry blamed your
bad luck on nutritionists and veterinarians, instead of taking
responsibility for the accumulating inbreeding effects from “single trait”
genetic selection they promote.
Breeders who continued to base their breeding programs on
strong maternal lines with strong natural fertility and competitive longevity
could not compete with a genetic ranking system that was biased in favor of
sire stacks of +1000 PD Milk bulls. Today, under Genomic theories, cow values
cannot produce enough “data” to alter the sire-centric pedigree-bound
calculations.
How do we
reclaim profitable levels
of fertility in
our dairy herds?
The industry error is to act as if “selection” and “mating”
are one and the same. Cull rates,
and 75 years of herd observations in the
“aAa” breeding guide, prove these two functions different. By ignoring this, basing all selection on
intragenerational sire comparison, the half of your herd genetic profile
descended from your cow lines is
being mismanaged. Your best cows are
not being given the chance to produce the best possible offspring. Your worst cow is treated as if she will
breed exactly the same as your best cows.
New cull cows are being reproduced.
Milk yield is half sire genetics, half cow physical
capability and “aAa” focuses on
the physique.
