Eggnog. Cream-covered pavlova. A traditional Aussie barbeque.

All these Christmas feast foods require one very important contributor.

Cows.

Here are our five favourite cow science stories that cropped up in 2021.

Spotting cows from space

When looking down upon the Earth through the eyes of a satellite, what would you choose to look at? For students at the University of California Santa Barbara, they watched cows from space.

In a recent paper published in Biological Conservation, a team of students, along with ecologist Doug McCauley, scrutinised satellite images of cattle herds around Point Reyes National Seashore, USA, to track how wildlife and livestock interact.

Their rigorous cow spotting showed that wild elk had learned to avoid cattle in the area, choosing different places to forage in order to coexist. 

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Investing in water quality could fatten up cattle

Renovating dams and improving water quality could fatten up cattle and reap long-term financial rewards, according to a new study by the Australian National University (ANU).

Aussie researchers, led by Leo Dobes, conducted a cost-benefit analysis of renovating dams to promote weight gain for cattle on farms in south-eastern Australia. They found that there was a strong likelihood that per-farm financial benefits would outweigh the costs of renovating, with an increase of 1.5 times for NSW and up to 3 times for Victoria.

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The new solution to climate change: Potty-training cows

Cows contribute massively to global emissions because of the greenhouse gases they produce. We’re not talking hot air here. It’s the No. 1s and No. 2s. Which is why potty training can be part of the solution.

On farms, cows graze freely, but that also means they poo and pee freely too. Unfortunately, this waste often contaminates the soil and waterways. 

On the other hand, keeping cows in barns causes their urine and faeces to combine. This releases ammonia, which leaches into the soil where microbes convert it to nitrous oxide – the third most impactful greenhouse gas after methane and carbon dioxide.

To get around this, researchers from the Research Institute for Farm Animal Biology (FBN), Germany, and the University of Auckland, came up with a novel solution: a potty-training program for cows.

“It’s usually assumed that cattle are not capable of controlling defecation or urination,” says co-author Jan Langbein from FBN.

“[But] cattle, like many other animals or farm animals, are quite clever and they can learn a lot. So why shouldn’t they be able to learn how to use a toilet?”

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Stomach that: Liquid from cow stomachs digests plastic

Bacteria from the stomach of a cow can digest some plastic, removing it from the environment, according to a team of Austrian researchers.

The polymers that plastics are made of usually aren’t digestible by ordinary organisms – be they animal, plant or bacteria – meaning the molecules accumulate in the environment very easily. While there has been some success in recent years finding microbes that can digest plastic polymers, the idea has so far been focussed on individual organisms, usually breaking down individual plastics.

This new research, published in Frontiers in Bioengineering and Biotechnology, has found a combination of bacteria from cow stomachs to be more effective at digesting three different polyesters, including the common and long-lasting polyethylene terephthalate, or PET.

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Seaweed stops cattle burps

A small amount of seaweed could get rid of a lot of agricultural emissions.

Livestock are responsible for around 15% of annual greenhouse gas emissions worldwide. A large part of that is methane, burped from cattle.

These emissions are damaging to the environment, and they’re also problematic for farming efficiency: animals’ digestive systems spend a lot of energy making useless methane. But new research, published in PLOS ONE, has found that a particular genus of seaweed could play a big role in reducing methane made by beef cattle.

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