Sensors, Sensors Everywhere

I had a couple interesting friends in college, one of which was an Animal Science major. On one drunken night, he pulled out his phone and showed a video of him castrating a piglet. He held its hind legs in one hand, and a pair of scissors in the other. It was a little traumatic.

While our status of keystone/guardian species has been debated to death, we continue to make the choice to raise animals in ways we find repugnant. So much so, that those involved in raising animals in large scale farming have successfully pushed for laws forbidding the filming of farm operations.

I’ve tried minimizing my meat consumption, and found I am the worst possible vegetarian. I cannot muster a gram of resistance when confronted with a 14oz Ribeye at St. Elmo’s. Meat has become a part of my diet in a way I can minimize but not remove. Since my biggest qualm is the unnecessary pain caused to animals, I’m trying to only eat meats from validated sources such as farms which raise their meat with respect, an animal life I might enjoy watching before I dig into its sous vide flesh. This then poses coordination problems, who validates the treatment of individual animals? How much do you really trust all those ‘Certified Cruelty Free’ labels? This is the prophet’s solution, full of layers of trust. Interactions where you must trust the actors on the other side without being able to verify their actions. We need wizard solutions, technology and engineering built to avoid the messiness of other peoples actions.

But back to the piglets – the pain we cause them isn’t quite unnecessary, the video my friend showed me adds real value to the food chain. Castration prevents the synthesis of androstenone in male piglets. Androstenone produced by growing male pigs prevents the degradation of a second compound, skatole, with diffuses into the meat and causes boar taint; a ‘piggy’ flavor many find repellent. Most of us probably have little experience with the flavor since industrial farming deals with this problem so effectively. The compound, skatole, which contribute to this malodor are actually produced in the gut, but androstenone prevents degradation in the liver and skatole builds up in the fatty tissues (the best pig tissues in my opinion) causing the distinct taint. Here’s fun quiz since things are about to get weird. Boar taint acts as an environmental reporter for aspects of the pig’s life. The pig’s sex, hormone levels, and the presence of skatole producing gut microorganisms; but why can’t it report something else?

Environmental reporters are all the rage in synthetic biology now and this boar taint phenomenon can be adapted. Not tracking environmental conditions or atmospheric carbon, but the condition of animals through their life. Conditions like suffering, adversity, and abuse. Which could then be detected or tasted in the prepared meat.

I saw a presentation at Biotech without Boarders by Dr. Wang at Columbia. His lab invented a biological tape recorder programmed into the DNA of bacterial cells. Here is the paper, nature write up, and the lab website (since paywalls suck). During bacterial residency in the gut, this gene cassette records specific events in a DNA ‘tape recorder’. We might use the same mechanism in larger organisms to track adverse events such as stress or pain. As sequencing costs drop and speed increases, reading these adverse events in the genome would be trivial, as they could be detected easily with PCR. The sheer number of events might pose an issue, how would you differentiate between two stressful days or a lifetime of abuse in a PCR band? However, the potential mark-up on the meat might justify this yes-or-no approach.

This might be a ‘good enough’ solution for some. We use PCR screening for a lot of routine work in science and the food industry; but its not enough for me. It requires too much coordination. Too much trust between actors. We need a trust-proof mechanism that doesn’t rely on customers bringing their own PCR machines into the restaurant.

The solution is deceptively simple, combine the ability to sense adverse events with some output signal detectable to the consumer. This removes all but one layer of trust. While this might be the most difficult step mechanically it provides the greatest returns in allowing consumer choice and meat quality to drive conditions on the farm. Farmers who can raise well treated animals are rewarded with good meat, which commands a higher price, justifying the investment in animal living conditions. There are several obvious implementation hurdles, the first of which is simply finding a protein suitable for being detected. Do you produce a protein effecting taste, color, or smell? Second would be tuning; how much stress causes a detectable production of this protein? Should it degrade over time or build up as a total? Do you want a positive or negative signal for the customer? Would they detect a flavor or its absence? These design constraints require a deeper understanding of meat processing than I currently possess. Tailoring protein expression and degradation to the constraints of the current system might be the best way to prevent the gaming of this mechanism by bad actors. No matter what layer they exist at, the farm, the slaughterhouse, or the restaurant.

The final layer of trust, all but impossible to remove, is the serving and delivery of the meat. Even if you order the ‘trustworthy meat’ on a restaurant’s menu, engineered to report its lived conditions, how do you know the meat you’re being served is the engineered varietal? The strongest case I can make is property rights. Patents and trademarks allow enforcement and validation. If you want to sell the product Ethical Bacon™, you must serve the real thing otherwise you risk litigation from the producer and costumer. A situation which happened while I was preparing this post.

It might be impossible to remove all suffering from the animals we raise; a superior meat alternative might displace animal populations entirely, but sensors like the one I’ve described can provide a way to consume meat raised in a manner more fitting your and my morals.

I do so like green eggs and ham. Thank you. Thank you, synthetic biology.

-Cat in the Genetically Engineered Hat

 

Boar Taint Fun Facts:

Skatole is produced by bacteria in the gut! MICROBIOME

Skatole is found in both sexes of pig but testicular steroids prevent its degradation in the liver! WOW!

Boar taint tracks closely with color, those pink ones have low levels while pigs with darker complexions have a higher taint prevalence. FACTUAL

There is a vaccine for boar taint! It creates an autoimmune reaction to a small hormone protein; preventing the male pigs from producing hormones that prevent enzymatic degradation of skatole. VACCINES

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