Getty Images
Getty Images

ScienceSeptember 14, 2021

We managed to toilet train cows, and they learned faster than a toddler

Getty Images
Getty Images

Training cows to urinate in a certain spot could make a big difference to the fight against climate change and the amount of nitrogen in our waterways, write University of Auckland researchers Douglas Elliffe and Lindsay Matthews.

Can we toilet train cattle? Would we want to?

The answer to both of these questions is yes – and doing so could help us address issues of water contamination and climate change. Cattle urine is high in nitrogen, and this contributes to a range of environmental problems.

When cows are kept mainly outdoors, as they are in New Zealand and Australia, the nitrogen from their urine breaks down in the soil. This produces two problematic substances: nitrate and nitrous oxide.

Nitrate from urine patches leaches into lakes, rivers and aquifers (underground pools of water contained by rock) where it pollutes the water and contributes to the excessive growth of weeds and algae.

Nitrous oxide is a long-lasting greenhouse gas which is 300 times more potent than carbon dioxide. It accounts for about 12% of New Zealand’s greenhouse gas emissions, and much of this comes from the agricultural sector.

When cows are kept mainly in barns, as is the case in Europe and North America, another polluting gas – ammonia – is produced when the nitrogen from urine mixes with faeces on the barn floor.

However, if some of the urine produced by cattle could be captured and treated, the nitrogen it contains could be diverted, and the environmental impacts reduced. But how might urine capture be achieved?

We worked on this problem with collaborators from Germany’s Federal Research Institute for Animal Health and Research Institute for Farm Animal Biology. Our research is published today in the journal Current Biology. It forms part of our colleague Neele Dirksen’s PhD thesis.

Toilet training (but without the nappies)

In our research project, funded by the Volkswagen Foundation, we applied principles from behavioural psychology to train young cattle to urinate in a particular place – that is, to use the “toilet”.

A calf at the start of alley, at the far end.
The calves were required to walk down an alley to enter the latrine pen. (Photo: Research Institute for Farm Animal Biology)

Behavioural psychology tells us a behaviour is likely to be repeated if followed by a reward, or “reinforcer”. That’s how we train a dog to come when called.

So if we want to encourage a particular behaviour, such as urinating in a particular place, we should reinforce that behaviour. For our project we applied this idea in much the same way as for toilet training children, using a procedure called “backward chaining”.

First, the calves were confined to the toilet area, a latrine pen, and reinforced with a preferred treat when they urinated. This established the pen as an ideal place to urinate.

Cow urinating in a latrine pen.
The cow urine could be ‘captured’ in the latrine pen. (Photo: Research Institute for Farm Animal Biology)

The calves were then placed in an alley outside the pen, and once again reinforced for entering the pen and urinating there. If urination began in the alley, it was discouraged by a mildly unpleasant spray of water.

After optimising the training, seven out of the eight calves we trained learned to urinate in the latrine pen – and they learned about as quickly as human children do.

The calves received only 15 days of training and the majority learned the full set of skills within 20 to 25 urinations, which is quicker than the toilet-training time for three- and four-year-old children.

This showed us two things that weren’t known before.

  1. Cattle can learn to attend to their own urination reflex, because they moved to the pen when ready to use it
  2. Cattle will learn to withhold urination until they’re in the right place, if they’re rewarded for doing so.

Calf consumes the reward.
Calves were given a tasty treat after using the latrine pen. (Photo: Research Institute for Farm Animal Biology)

The next stages

Our research is a proof of concept. Cattle can be toilet trained, and without much difficulty. But scaling up the method for practical application in agriculture involves two further challenges, which will be the focus in the next stage of our project.

First, we need a way both to detect urination in the latrine pen and deliver reinforcement automatically — without human intervention.

This is probably no more than a technical problem. An electronic sensor for urination wouldn’t be difficult to develop, and small amounts of attractive rewards could be provided in the pen.

The calves exited the pen through a gate. (Photo: Research Institute for Farm Animal Biology)

Apart from this, we’ll also need to determine the optimal location and number of latrine pens needed. This is a particularly challenging issue in countries such as New Zealand, where cattle spend most of their time in open paddocks rather than barns.

Part of our future research will require understanding how far cattle are willing to walk to use a pen. And more needs to be done to understand how to best use this technique with animals in both indoor and outdoor farming contexts.

What we do know is that nitrogen from cattle urine contributes to both water pollution and climate change, and these effects can be reduced by toilet training cattle.

The more urine we can capture, the less we’ll need to reduce cattle numbers to meet emissions targets – and the less we’ll have to compromise on the availability of milk, butter, cheese and meat from cattle.

Douglas Elliffe is a professor of psychology at the University of Auckland and Lindsay Matthews is an honorary academic at the Psychology Department of the University of Auckland

This article is republished from The Conversation under a Creative Commons licence. Read the original article.

Keep going!
Officers carry out an inspection with an Electronic Nose, a rapid detection tool for Covid-19 from breath, at Pasar Senen Station, Jakarta. (Photo by Dasril Roszandi/Anadolu Agency via Getty Images)
Officers carry out an inspection with an Electronic Nose, a rapid detection tool for Covid-19 from breath, at Pasar Senen Station, Jakarta. (Photo by Dasril Roszandi/Anadolu Agency via Getty Images)

ScienceSeptember 13, 2021

How electronic noses could help us sniff our way out of the Covid crisis

Officers carry out an inspection with an Electronic Nose, a rapid detection tool for Covid-19 from breath, at Pasar Senen Station, Jakarta. (Photo by Dasril Roszandi/Anadolu Agency via Getty Images)
Officers carry out an inspection with an Electronic Nose, a rapid detection tool for Covid-19 from breath, at Pasar Senen Station, Jakarta. (Photo by Dasril Roszandi/Anadolu Agency via Getty Images)

You can hear evidence of possible Covid-19, through people sneezing or coughing. You can see it, through the results of testing. But now scientists may have found a way to smell it as well. Mirjam Guesgen explains.

Electronic noses, or e-noses, are devices that can tell if someone may be infected with a disease like Covid-19 by analysing a person’s smell. Able to give a readout within a few minutes, think techy version of dog noses for sniffing out disease.

E-noses aren’t something that are about to be rolled out in New Zealand just yet, but trials to put the noses through their paces are currently under way overseas and researchers here and in Australia are pitching in on the science side to try and make Covid-sniffing machines a reality.

As borders reopen worldwide, and people flood into concerts or sports events, their advocates say they offer potential for a complement to existing systems – a fast, accurate way to detect if someone’s infected with the virus.

The devices work by analysing compounds in a person’s breath or coming off their skin. It’s not a new tech specific to the current pandemic. E-noses have been around for a while to smell for disorders like asthma or chronic obstructive pulmonary disease, infections like pneumonia, or cancers including lung and prostate cancer.

They’re able to do that because the body gives off a certain scent that comes from chemicals made as the body goes about its business of living (metabolising). These airborne compounds are called volatile organic compounds or VOCs.

“It’s an indirect detection. The assumption is that a change in the metabolic profile is uniquely associated with the presence of Covid or other disease,” explained chemist Mark Waterland from Massey University.

E-noses can look a bit like a nasal spray tube that you jam into your nostril, or like a Capri Sun pack with a straw and a bag you inflate. When an odour hits chemical sensors in the device, it triggers some physical change that’s turned into an electric signal. The electrical signal is then analysed by an artificial intelligence algorithm. All in around two to three minutes.

The algorithm works like lots of other machine learning algorithms. Give it some data to learn from, in this case the breath from people who are known to have or not have Covid-19, and then let it loose on a different set of people to test its ability to pick infected from not.

There are a bunch of e-noses floating around in the Netherlands, Israel, Indonesia and the US, among others. Even Nasa is remodelling one that was originally designed to measure air quality in space crafts.

Of those that have been trailed so far, the devices were able to pick up on people who had Covid-19 between 61% and 99.6% of the time (or missed people up to a third of the time) and correctly detected people who didn’t between 79.8% and 92% of the time. It’s a long way from perfect, but its a start, and in the broad realm of PCR tests.

In all these studies, the researchers don’t actually know what the machines are smelling or what the so-called breathprint of a Covid-19 infected person is. “Once it is trained, the algorithm is then very much like a ‘black box’,” says Waterland.

He says it’s a lot like sniffer dogs trained to detect food, bombs or drugs (side note, there are dogs trained to sniff out Covid-19 too). The dog knows it’s Covid-19 but you can’t ask them what they’re smelling, because we don’t speak dog.

That’s a problem because a breathprint for Covid-19 could be similar to a breathprint for another disease, if they cause similar changes in the body. “If there’s some other disease that causes a similar change in the metabolic profile, you’re going to get a false positive,” says Waterland.

Other research groups, like this one in France, have started work on figuring the breathprint out.

But there’s another way to programme e-noses aside from using VOCs. They could actually sniff out the virus itself, or bits of it.

Sticking with the airport drug analogy, it would be the equivalent of those machines seen on Border Patrol where border officers pop a swab into a big box that then beeps aggressively if there’s a tiny trace of the drug.

Waterland is part of a New Zealand team that developed the proof-of-concept for such a device. It uses raman spectroscopy, which has nothing to do with the noodles and everything to do with seeing how light bounces off chemicals, to detect Covid-19 spike proteins that a person breathes out.

A person breathes onto a bit of paper loaded up with aptamers, chunks of DNA that stick to the spike protein, and nano-sized globs of silver. The silver acts like an antenna to magnify the signal to the spectrometer, Waterland explains.

The neat thing about this system is that you could find different aptamers for different variants or different diseases, so the system could evolve over time as the virus does. “The phrase is aptamer, right, so it adapts,” says Waterland.

An Australian group called GreyScan is developing a similar tech, although it’s unclear what exactly their machine analyses. GreyScan could not be reached for comment.

Co-developer of the New Zealand version, Deborah Crittenden, director of the biochemistry programme at the University of Canterbury, says their device holds real promise, both for the country’s airports and the current alert level 4/2 split between Auckland and the rest of the country.

“This would absolutely be useful for rapid screening at borders if (a) it can be converted from a lab-based method to point-of-use, which would require some engineering-type work, and (b) that its [true negative rate] holds up in real world scenarios,” she told The Spinoff in an email.

The group presented their system back in February. But after an initial flurry of attention for their device, things have gone quiet. Despite the urgency around Covid-19 science, a lot of scientists are still operating on shoestring budgets, she said.

Indeed, a lot of these devices are in the early stages of development, testing and commercialisation. Despite that, a select few countries like Indonesia is ploughing ahead and deploying e-noses in airports and train stations.