Saturday, May 30, 2015

Heritage Breeds, or Russian Roulette with Genetics

We have heard about conserving our genetic diversity in the wild, trying to undo the threatened extinction of thousands of species.  The same concept applies equally well to farms, livestock, and loss of heritage breeds, chickens included.

In Canada, only 7 people have self-identified as committed to sustaining 1 or more heritage breeds for fowl or poultry.

The Livestock Conservancy has created a map of their registry.  There are just 10 in Canada for all breeds of animal.  Some are with horses, pigs, sheep, goats, turkey, ducks, and chickens.

Of course, these are a few small farms with very limited resources (ie. knowledge, money, and hours in the day).  There are thousands of breeds in each of these species, far more than what a few individuals can focus on and sustain.

While there are similar individuals around the world, I suggest and fear that that dedicated effort will not be sufficient to stop or slow the commercialization of a few hybrids that are most profitable, and the extinction of all the rest.

Starting with the Chicken of Tomorrow contest in the late 1940's, we have accelerated the pace of chicken hybridization.  Before that, there was a huge amount of diversity in the genetic pool.  Commercialization has led to monopolization of the genetic stock.  Make a small tweak to any bread, and you now "own" that genetic material.

David Bollier blogged:
"This trend got its start in 1980 when the U.S. Supreme Court first allowed the patenting of lifeforms in the Chakrabarty case, which allowed the patenting of microorganisms.  That in turn opened the floodgates to the patenting of genes, plants, bioengineered crops, and much else.  Harvard University famously owns the patent of a specially bred mouse for cancer experiments, the “onco-mouse.”  There is much to be said for the fruits of biotech research, but there is also much to be lamented and condemned as far as the needless privatization of knowledge and stifling of competition and innovation."
In Dec. 2002, Canada's Supreme Court ruled against the patenting of higher life forms. The test case was Harvard University’s 17-year quest for ownership of its genetically engineered "oncomouse".  Biotech plants, microorganisms, and seeds can be patented, but not higher life forms like mice or people.

How does this apply to chickens?  A 2008 study estimated that commercial broiler chickens are already missing about 50% of the genetic diversity contained in all historic breeds of chicken.  It is estimated that 90% of the improvement in chicken productivity came from selective breeding efforts (eg. kg of chicken meat per kg of feed consumed, or kg of chicken meat per week of growth, etc.).  The proprietary commercial breeds of today have rapid growth and extra meat (especially breast meat), but this has also included infertility, obesity, cardiovasular disease, lameness, ascites (abdominal fluid retention), sedentary lifestyles preferences, skeletal abnormalities, male-female aggression, irregular ovulation, .  Pushing genetic selection far past the optimum so as to maximize Big Ag profits, we have many drawbacks.

Disappearance of the heritage breeds, either now or in the near future, means that those genetics of maximum profit becomes a 1-way street, with no possible exit.

We have inadvertently (or negligently) stumbled down these 1-way genetic breeding and hybridization streets before.  For example:
  • Bovine leukocyte adhesion deficiency (BLAD, an autosomal recessive hereditary disease) in Holstein cattle was caused by one popular breeding bull, Osborndale Ivanhoe, that had his artificial insemination ("AI") semen sold far and wide, siring over 100,000 animals.  His semen is $4,250 a shot, and enough semen was collected for about 200,000 shots, so we have one bull's AI potential worth $850 million.  Do you see the source of this 1-way genetic road to hell?  Much later, it was discovered that this one bull had a genetic defect; BLAD.  This fatal disease started in the 1950's, but the disease wasn't identified until 1992; 29 years after the death of that bull.  Too late then, as we were already at the end of that 1-way genetic road to nowhere.  Today, there is a genetic test for BLAD.  Based on current trends of identification and prevelence reduction for BLAD carriers in Canada, it will be eradicated by Year 2167 (152 years from now).  Genetic mistakes are BIG mistakes, and take a long time to eliminate.  This Year 2167 prediction is based upon a 4.9% BLAD Canadian herd prevalence in 1992, 1% BLAD prevalence in 2006, a 272,774 Canadian registered herd size in 2004, a 550,000 herd size in 2015, steady exponential growth in herd size and BLAD prevalence.

  • The 1970 corn leaf blight outbreak was due to the widespread use of the Texas male-sterile cytoplasm in corn hybridization.
  • One type (ie. cultivar) of banana has 47% of the world's total banana production, and has 99% of the world's banana export market; the Cavandish banana cultivar.  The millions of Cavandish banana trees of today come from cuttings taken from just one mutant banana tree, discovered sometime between 1500's and 1850's.  The world's Cavandish banana monoculture is now being decimated by a new fungus that threatens to wipe out every one of those cloned banana trees.  Note that Cavendish took off as the Big Banana in the 1950's when the previous dominate banana (Big Mike) suddenly died off from Panama Disease.  We never learn.
  • Commercial chickens are controlled by just four major breeding companies (three broiler breeders and one layer breeder), which together account for ≈90% of meat-type and ≈40% of egg-type chickens supplied commercially worldwide.  Fortunately the genome mapping of the chicken (broiler, layer, silkie, and red jungle chicken, the common ancestor) was completed in 2004.  A chicken genetics study have found that there is significant in-breeding, and a loss of 50% of the prior genetic diversity in chicken.  If these lines are crossed with each other, it would somewhat improve the diversity, but not by much.  This sad state of affairs places the entire chicken industry at great risk if future shocks, emerging diseases or outbreaks, different selection criteria emerge in the future, or market trends must be responded to with chicken genetics.  Only the small flocks on the world's non-commercial farms have the required diversity and genetic pool from which to draw.
Thoroughbred racehorses have refused to use AI techniques for these very reasons.  Humans have already done much horse inbreeding before AI arrived on the scene in the 1950's.  The further down those 1-way genetic roads you go, the canyon walls become higher, steeper, and with fewer and fewer handholds, making it virtually impossible to climb out.

There were always those who warned of these potential 1-way genetic street risks that cause loss of genetic diversity.  However, the profitability for those who lead the way, and the moral hazard relief for them (ie. private profits, but the risk and its financial consequences will fall on the general public, not those who gained the profits).

These significant benefits with no risk have enticed many to turn a deaf ear to those prophetic warnings, and they have blundered ahead, driven by greed and self interest, in spite of the risk.

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