Why what we feed animals matters
For those who have found their way here after reading Jayne Buxton’s excellent book The Great Plant-Based Con, the presentation on animal feed to which she refers is here. The article below is a very short summary on this topic. What we feed animals matters because it has profound consequences for them, us and the planet. And it’s not just what they eat, but how.
To understand why, we need to consider how natural systems function, how the wild ancestors of our modern domesticated animals roamed, what they ate and why the fittest survived.
Over millennia highly complex, inter-dependent ecosystems evolved with intricate food webs connecting all living things. The ecosystem in which ruminants, from whence we bred modern cows and sheep, evolved was complex: where plants developed a vital dual symbiotic relationship with the microbiome of the soil as well as the ruminants that grazed them.
The basis of life for all food webs, both above and below ground, is sunlight and carbon.
Everything living or once living, is made of carbon, and all that carbon was once carbon dioxide in the atmosphere converted via photosynthesis into the carbon-based molecules of life. Each carbon bond is a small unit of energy captured from the sun’s rays.
Photosynthesis: capturing sunlight energy
When we look at the equation for photosynthesis we see that plants use sunlight energy to transform carbon dioxide and water into glucose and oxygen:
6CO2 + 6H2O + sunlight -> C6H12O6 + 6O2
That precious glucose molecule, and the energy it holds in its carbon bonds, flows through the sap of the plant as ‘liquid carbon’. The plant uses this carbon currency to feed symbiotic soil microbes by exuding glucose through its roots, called root exudates. In return for being fed, the soil microbial lifecycle via the Poop Loop provides the plant with the mineral micro-nutrients it needs to grow.
Research has shown that through the soil food web up to 40% of the carbon absorbed by plants during photosynthesis is fed to soil microbes and ends up being sequestered (locked) in the soil, building humified soil organic matter as part of the soil lifecycle. See diagram below from how Carbon Mooooves.
Food-webs: moving sunlight energy
When we talk about food webs we are talking about how energy moves from the sun to the soil, transported via carbon-based molecules through the veins of plants, microbes, animals and humans, providing each along the food chain with the energy and nutrient-transportation system necessary to survive and thrive.
Thus, when we consider what to feed animals, we must look at how we can best mimic these natural ecosystems to maximise energy capture in photosynthesis and lubricate that liquid carbon pathway.
When done using a regenerative organic system, this will sequester carbon and re-build soils to recreate the deep, fertile soils covered in diverse flora and supporting a healthy fauna that spread around the globe before man’s intervention of chemical, industrial farming. This is of particular importance when feeding ruminants because some of the deepest, most fertile soils on the planet, like the American Prairies, were created over thousands of years by grazing herds of migrating herbivores.
Ruminants are fibre-fermenters
Ruminants are walking bio-digesters: when a cow grazes she is not feeding herself but trillions of cellulose-fermenting microbes that she carries around in a large fermentation chamber called a rumen. Cellulose, another carbon-based compound and the fibrous structural component of plants, is the most abundant organic compound on the planet. Being fibre fermenters, cows take this human-inedible substance and, through the magic of fermentation, up-cycle it into highly nutrient-dense food that we can digest: meat and milk.
However, the flavour and nutritional value of that milk and meat, as well as the health of the cow, is directly linked to what the cow eats.
This is the same for all mammals, as any mum who has ever breast-fed can attest: her baby will soon make it loudly known if she has eaten or drunk something disagreeable as it soon passes through to her milk!
And the adverse or beneficial effect on flavour and nutritional components in milk is multiplied several-fold for ruminants that rely on keeping a belly full of microbes happy. This is because, like any fermentation process, the balance of microbes and their resultant by-products directly reflect the substrate they have to ferment.
Those fibre-fermenting ruminant microbes require a natural diet of diverse pasture polycultures that include mixed hedgerows and browsing trees, known as silvo pasture. This not only provides their preferred substrate, but the diversity of plant species, each with its own array of micro-nutrients, also gives cows the ability to self-medicate and stay healthy naturally. This innate instinct is retained from times before domestication when those animals with the greatest ability to select the most nutritious plants grew the strongest, ran the fastest and passed on their genes and behaviours to their offspring.
In return, these pastoral landscapes, with their specialist ecosystems, are reliant upon being grazed: through millennia of symbiotic evolution, when a cow tears off blades of grass to eat, by wrapping her dextrous tongue around the leaves, she transfers billions of bacteria and enzymes in her saliva onto the torn edge of the leaf which stimulate the grass to grow. She also ingests billions of bacteria from the soil microbiome on the pasture plants she eats.
In this way, the microbiomes of the cow and the soil are intrinsically linked: A healthy soil microbial community, provides plants with the nutrients they need to grow and a diverse, healthy plant community growing in healthy soils provides the nutrients and microbes needed by the cows to thrive. And the cows stimulate the pastures to grow and, in turn, their meat and milk provide nourishment for humans and our own gut microbiome. Particularly for those fortunate enough to source raw milk from contented cows raised in these systems.
Rumen microbes do not like concentrated starches like grain, soya, fodder beet or maize, none of which are found in a natural system and all of which lower rumen pH. Or rather, some microbes do like these acidifying foods but these are not the microbes you want in your cow’s gut. Changes to rumen pH cause microbial populations to rapidly alter, below pH 5.4 the ‘good’ microbes die and lactic acid builds up, leading to rumen acidosis. This not only leads to poor cow health but, due to how this changes the by-products of fermentation in these acid conditions, it also adversely impacts on the flavour and reduces nutrient value of the meat or milk.
Furthermore, the perennial pasture, shrub and arboreal diet preferred by ruminants, provide incredible wildlife habitats and uses free sunlight energy and rain to grow when part of a regenerative organic system. It does not need chemicals, artificial fertilisers, sprays or require use of fossil fuels. It is replicating the natural polyculture systems of history that built fertile and functional top soils by moving carbon from the atmosphere and sequestering it in the soil via photosynthesis and microbial action.
These healthy top soils also provide essential ecosystem services which will become ever more important as we move into the impending Grand Solar Minimum, predicted by NASA to be the lowest in 200 years, and which will have an unprecedented effect on our weather as the sun cycles through this 30-year period of declining energy and magnetism. Particularly of note will be the ability of organic matter to retain water: for every extra gramme of carbon stored in the soil, the soil can hold an extra eight grammes of water, not just alleviating run-off and downstream flooding but providing to plants in times of drought.
Conversely, to grow, harvest, transport and feed concentrated feeds like grain, soya, maize, and others, requires the burning of fossil fuels and the soil-damaging and eroding practices of monoculture cropping, compaction with heavy machinery, and often sprays and chemicals, all of which oxidise carbon back from the soil to the atmosphere and reduce soil fertility and function.
It is important to note that in a regenerative organic pastoral system all the energy captured and transported is using carbon already flowing through the biosphere: it is cycling carbon. This is even true for the carbon in the CH4 molecules of methane belched by the cows, which came from the grass that obtained it from the air via photosynthesis.
The final piece to the puzzle
Having established that it is best to feed animals their natural diet of diverse perennial polyculture systems, there is one further piece to the puzzle to explain. This is a critically important piece as it is what springboards a good system into a truly regenerative one: it is the way we move the animals as they graze to replicate the beneficial impact of the great migratory herds of the world. This grazing system is referred to as mob-grazing or holistic planned grazing.
Soil science is still an emerging field but there are some very promising studies showing that cattle raised and holistically grazed as part of a regenerative organic pastoral system as outlined here, are carbon negative. That includes accounting for all emissions, including methane, and all sinks, they help sequester over three times as much carbon as weight of beef produced.
It’s not the cow, it’s the how
This shows us that blaming cattle for environmental woes is unfairly binary and simplistic. It’s not the cow, it’s the how they are kept and what they are fed.
What we feed animals matters because it impacts their health and wellbeing, and the flavour and nutritional value of their meat or milk. How animal feed is produced or grown can either create or destroy wildlife habitat, build and regenerate soil or erode soil, sequester carbon or emit it.
As Wendell Berry famously said “eating inextricably influences agriculture”. What he meant was that whenever you eat, whether you are conscious of it or not, you are directly supporting the farming methods and the industry that produced the food on your plate. For better or for worse, therefore, your food choices influence not only your own health and wellbeing but that of the farm animals and the planet too.
Choose wisely, vote with your fork by purchasing locally grown food from a regenerative organic pastoral perennial polyculture, carbon-negative system that produces delicious and nutritious food from contented animals fed their natural diet.
FIND OUT MORE:
The above article was first published in the Country Smallholding magazine in May 2020, a copy of that article can be downloaded here.
A resource-full presentation on this topic can be found here.
Paper on the forecast terrestrial cooling associated with the modern Grand Solar Minimum (2020 - 2053) can be found here.