Food systems in the 21st Century Assignment | Online Assignment

Description

Answer the three questions below. Write up to 250 words per each question. Spacing 1.5, font size 12 of your choosing. Hebrew submissions are possible. Please Note: your answers should be anchored in knowledge you have gained from the videos. However, you are expected to build upon it, research further, expand and develop these core frames, as well as present an original argument, providing adequate reasoning and examples. What are the known main factors responsible for CCD? Please explain the differences in the approaches taken in the EU vs. the United States. In your answer please address both environmental legislation as well as conventional and biodynamic beekeeping methods. What is organic matter and why is it important for soil fertility? Please relate to micro and macro organisms, the nutrient cycle and improvement of crop yields. What is a Dietary Shift Potential? In your answer please explain why a plant based diet or the substitution of beef with chicken is more efficient than a diet which includes beef. Please refer to the environmental burdens of animal farming
Food Systems – Unit 5
Chapter 1
Hi there. In the previous units we talked about how the green revolution introduced two practices that stand at the core of intensive industrial agriculture: plant breeding and chemical fertilizers. As we know, these practices are accompanied by significant use of pesticides. These are mainly regarded as the “bad boys” of agriculture, and for a good reason, but today we will learn that they are not the only villains in this story. As it turns out, chemical fertilizers also have considerable negative effects on the environment, soil fertility and more. We will soon find out that scientific studies determined that the current use of chemical fertilizers – get this – hinders the ability of a crop to tolerate insect, pests and disease, and that the plant’s immune system is tied to optimal soil quality properties. It turns out that organic fertilizing, so quickly replaced in the green revolution, is not that far-fetched. Contrary to what Liebig and co. believed, organic substances in the soil are crucial for plants and soil fertility. Let’s begin.
Chapter 2
Hi there. In order to understand the problem with chemical fertilizers, we first have to learn about the differences between them and organic fertilizers. Why does it matter to the plant where it gets its nutrients from? As a girl scout, I remember plenty of hiking in nature. The general rule was to burn toilet paper, so as not to leave anything behind, but if someone was to finish an apple or a banana, throwing it on the ground was perfectly fine, because it’s organic and good for the soil. But before you set off fertilizing the earth with apples and banana peels, take a sec. In most places in the world, we simply can’t allow ourselves to toss organic waste, not even in the forest. Why? Because there are too many people and not enough natural spaces. If everyone leaves behind a “fertilizer”, we will knock the natural system out of balance and advance the reproduction of one species over another. We see this problem in cities: leftover food in open trash cans lead to more cats, crows and rats. Now, people don’t like rats and crows, and surely understand that having more of them is undesirable. But cats? They’re cute! So yeah, cats are cute, a lot of people think they are the greatest animal in the world, even though others hate them. Cat person or not, you still understand that it is important to keep the system balanced. Cats are predators. Too many cats harm different species, including reptiles, birds, waterfowl, small predators and small mammals. Why are they so important? Watch this video and we’ll talk about it in just a bit.
So we saw what wolves, plants and the entire Yellowstone ecosystem have in common. We saw how the park deteriorated and the return of the wolves resurrected it and even changed its physical geography. This is a tangible example of a system that managed to regain balance after nearly collapsing. I want you to remember what you saw, because soon we will talk about the earth and the microorganisms that live in it, and those cannot really be seen at all. But despite not being able to see them, they are also a part of a complex ecosystem which without them may go off balance and even collapse. A significant part of this ecosystem is the soil’s natural nutrient cycle. We mentioned it in the first unit when we talked about the agricultural revolution. Remember we said that agriculture is not “natural” for the soil, and that cucumbers cannot be repeatedly sown in the same soil without fertilizing it? In order to make a better sense of this and truly understand organic fertilizing, let’s take a walk into the woods – a source of food for the human race for hundreds of thousands of years. An apple that falls off a tree in the forest will probably end up in the belly of some nice animal. But what happens to the twigs and leaves that fall? It might seem like a terrible waste for a tree to put all its energy into growing leaves, only to shed them in the fall. But don’t worry, the tree knows what it’s doing. When the leaves fall, they are decomposed by microorganisms such as fungus and bacteria, and macro organisms such as worms and insects. The result is valuable fertilizer for the tree, which regains nutrients through its root system. Animals that have ended their lives also become food for various organisms which decompose them and fertilize the soil. Now back from the woods to the field – how does one reintroduce into agricultural soil the nutrients that were taken by the plant? The answer is simple – compost! Someone over the past years must have tried to get you to toss your organic waste into a designated bin, or create your own compost pile for your home garden So compost is a fertilizer that originates in organic matter that had been processed in a manner designed to speed up natural processes through controlled conditions of humidity, heat and ventilation. Inside the compost pile there is magic, just like in nature. All that junk we throw in there – eggshells, old vegetables and weeds from our lawn – creates a substance that smells like moist forest soil, and crumbles easily. Another term you should be familiar with is Humus. Not the hummus we eat. Humus is an exceptionally sturdy form of organic matter. It stays in the ground for years and carries no signs of the origin from which the organic matter was taken. You can learn more about the process here. But before you run off to make compost at home, you have to know that meat and fish are not on the menu and require special treatment, since they take longer to decompose. Additionally, when they rot, they become an odor nuisance and attract various animals, and they also raise the risk of pathogens – disease producers – in the compost. If you want to learn about making your own compost, click here. Composting is an ancient practice that held on quite well until Liebig, the German chemist, undermined the concept of organic fertilizing. He claimed that the nutrients most necessary for the plant are potassium, nitrogen and phosphorus, which can be found in chemical compounds and not only in organic components found in the soil. The chemical fertilizing we know from intensive agriculture is based on these notions. But now, it turns out that the organic way is not so out there. After decades of intensive chemical fertilizing, more and more cracks appeared in Liebig’s chemical fertilizing notion. We will talk about this in the next chapter.
Chapter 3
Hi there. Over the past several years, organic fertilizing has enjoyed a rise in popularity. Why is it making a comeback after so many years of chemical fertilizer domination? Today we will begin to uncover the reasons for this and crack the magic, using the fascinating example of Mycorrhizal fungi. Mycorrhizal fungi are one of nature’s most wonderful creations. Science has known about them for years. But lately they’ve risen to superstardom in the agricultural sphere. Let’s find out why. Fertile grounds in nature experience symbiosis, a reciprocal relationship between plants and fungi Mycorrhizal fungi can be categorized into two groups: Endomycorrhizae, which embed themselves within the root tissue, and Ectomycorrhizae, that form an extensive dense sheath around roots. This description might sound like a hostile takeover, but the symbiosis is a win-win deal for both parties. Let’s start with the Endomycorrhizae. Turns out that when a plant needs phosphorus, it signals to the Endomycorrhizae. The fungus reaches the root cell walls. The plant initially identifies it as an intruder and prevents it from penetrating, but eventually it coaxes its way in. Don’t worry, the fungus doesn’t harm the plant – it helps it by breaking down the phosphorus molecules in the earth that the plant cannot break down on its own. What does the fungus get out of it? The greatest treat in the world – sugar! Yup, the same sugar created by plants through photosynthesis, out of carbon dioxide, water and sun. The Ectomycorrhizae helps the plant too: it settles onto the roots and suppresses their growth. Again, it sounds like a bum deal for the plant, but we already know this story has a happy ending. The fungus suppresses root growth, but in exchange provides the plant with a longer root system, helping it reach water and nutrients. By this point you should be raising an eyebrow and asking, “what do we need these fungi for?” Liebig created synthetic phosphorus and plants receive readily available phosphorus via the irrigation system. The answer is interesting: First, turns out that in many instances in agriculture, the plant only absorbs a small amount of chemical phosphorus – even less than 50%, with the rest washed off into our water sources, contaminating them. This excess of nutrients feeds blue seaweeds, which loves phosphorus, overtake entire water sources and destroy their ecosystems. Second, the mining of phosphate, from which phosphorus is made, pollutes the environment, damages the ecosystem and is energy-consuming. And just as important – readily available phosphate is dwindling! The phosphorus in our planet is being depleted at an alarming rate. At current consumption levels, we will deplete known phosphorus reserves in around 80 years, but consumption will not stay at current levels. Nearly 90% of phosphorus is used in the global food supply chain, most of it in crop fertilizers – and the demand for food is not shrinking, as we all know. Now comes the obvious question: what happened to the Mycorrhizal fungi? Why did they stop providing phosphorus to plants in intensive agriculture? Well, there are three main reasons: first, many agricultural lands simply do not have Mycorrhizal fungi. Intensive processing and plowing damage the fungi as well as other micro and macroorganisms in the soil. Studies show that natural, unplowed soil exhibits a greater presence of fungi, both in the soil and in the plant. Second, even if the ground does contain some Mycorrhizal fungi, it still needs to be rich in organic matter in order for the fungus to provide the plant with phosphorus, and we’ve already learned that this is hardly the case in intensive agriculture. Lastly, we saw that plants receive large quantities of chemical phosphorus. As soon as it gets all that it needs, the mechanism that signals fungi about a deficit simply doesn’t get triggered. Mycorrhizal fungi are of course but one example and just the tip of the iceberg. In the next chapter we will introduce another example, just as cute: earthworms!
Chapter 4
Hi there. In the previous chapter, we began to see how the organic fertilizing method, according to which plants need live components in their soil, is not an absurd idea. We began to discover that soil is much more than a receptacle for plants, and today we will continue to understand the use for organic matter in the soil – the very thing Liebig dismissed offhand and is lacking in intensive agriculture. In the previous chapter, we saw that organic matter enriches the soil with vital elements for the plant. One of these is phosphorus. We saw that Mycorrhizal fungi are necessary for breaking down the phosphorus in the soil and transport it to the plant, and saw that they do it very efficiently. Let’s take a closer look at another example of nutrient recycling in nature: earthworms. Earthworms are known for their important role in aerating the soil, but we’re going to learn about some other important roles they have. Worms feed on plant debris, dead roots, leaves, grasses, manure, and soil. Their digestive system concentrates the organic and mineral constituents in the food they eat, so their casts are richer in available nutrients than the soil around them. Nitrogen in the casts is readily available to plants. Worm bodies decompose rapidly, further contributing to the nitrogen content of soil. Earthworms don’t stop at providing the plant with nutrients and aerating the soil. They also help create aggregates that absorb water and prevent its evaporation. Earthworms’ casts cement soil particles together in water-stable aggregates. These are able to store moisture without dispersing. You may already have guessed how important it is for soil to retain moisture. First, it has a clear economic significance for arid countries, because the plants require less watering. Additionally, absorbent soil enables plants to better cope with water scarcity. It’s important to note that both Mycorrhizal fungi and earthworms are merely examples of the complex processes that occur in the soil, working in harmony thanks to the earth’s biodiversity. At the base of this hard work in the soil lies organic matter. Organic matter is the backbone of the soil’s food chain. Organic matter is the primal component that allows the existence of microorganisms such as soil bacteria and the fungi we mentioned earlier, as well as macroorganisms such as earthworms and beetles, all of which serve crucial roles. Modern science acknowledges the importance of organic matter and biodiversity in the soil. Popular opinion states that chemical fertilizing is still necessary to provide plants with their basic nutrients, but it’s recommended to enrich the soil with organic matter, based on the knowledge of its importance in increasing crop yields. Alongside recognition of the importance of organic matter in the soil, there is also a clear understanding that chemical fertilizers also have to be used in a more measured and precise manner. The Indian example, we’ll soon see, proves that. Remember that we talked about the time India decided to adopt the American green revolution? Well, it did. Since 1950, chemical fertilizing in India rose from 66,000 tons to 26 million tons. The state subsidized use of chemical fertilizers and farmers used them… a bit too much! Overuse of chemical fertilizing with phosphorus, potassium and nitrogen damaged soil fertility, reducing crop yields. To address the issue, the Indian government has invested in an expensive, large-scale program of individualized soil testing. The program aims to provide 145 million farmers with individualized laboratory tests of their land’s soil composition, providing a detailed analysis of the availability of various nutrients and other compounds along with recommendations for fertilizer application based on a target yield. I’m going to skip ahead and reveal that the plan didn’t go as expected. Despite incredible investments in soil testing, farmers did not implement the conclusions. Why? Why did farmers decide to overlook government decisions? For a number of reasons: mistrust of government representatives, misunderstanding the recommendations, and of course, force of habit. To sum, with all due respect to the magic of chemistry and Liebig, science recognizes the benefits of organic matter in the soil and understands the damages of uncontrolled use of chemical fertilizers – both to the crops and the environment. Now that the problem is known, we will see in the next chapter what we can do to cope with it.
Chapter 5
Hi there. In the previous chapter, we talked about the shift from Liebig’s notion of chemical fertilizing firmly adopted by intensive agriculture, and the clear-as-day understanding of the importance of organic matter to the soil. Science recognizes the dangers of chemical fertilizing to the environment, crops and the farmer’s bottom line. So where do we stand today? Right beside information technology: With big data, Artificial intelligence and machine learning in agriculture, too! Technology has slowly been taking over our lives. We witness IT and AI take over complex decision making, for instance, which route to take to work, or what TV show to watch. You can’t argue with its efficiency. Agriculture too embraced the revolution, and over the past years, information technology has been gradually integrated into intensive agriculture, primarily in developed countries. The buzzword is Precision Agriculture. Precision agriculture aggregates the world of information technology. The world of agriculture utilizes it in dealing with water crises, as well as overuse of pesticides and chemical fertilizers, which are harmful to us and the environment. Precision agriculture aspires to improve crops and motivate more efficient use of resources, using highly advanced technology that includes sensors, high-resolution satellite photos, smart algorithms and the analysis of mountains of information from various sources. All this technology is used to provide recommendations for precise watering, fertilizing and use of pesticides, tailored to specific crops. You know, just like Waze gives a suggested route and ETA, as well as the best time to leave – the various systems of precision agriculture can perform preliminary strategic planning to save valuable resources. Just like Waze recognizes and alerts of road hazards, so do precision agriculture systems provide real-time indication of problems in the field, from water shortage through pest infestation in a specific plot or any other woe, and of course offer solutions. We have to remember that even today, large-scale farmers follow very clear protocols of fertilizing and pest-control dictated by large chemical corporations. Nevertheless, this trend of precision agriculture, designed to reduce water, fertilizer and pesticide consumption, is a welcome one. Side by side with precision agriculture are also developments that mirror the newfound understanding of nature’s brilliance. Companies offer mycorrhizal fungi by the bag, recognizing the importance of biodiversity in the field. Yup! Lab-grown mycorrhizae are sold to farmers involved in precision agriculture alongside chemical fertilizers and pesticides. This comprehension of nature’s complexity also affects pesticides treatment. We now understand the importance of integrated pest-control – using chemical pesticides as well as biological pest-control in the form of spiders, owls and more. We’ll get more specific later when we talk about pesticides. But there’s also another approach, truly revolutionary, which shows the clear link between chemical fertilizing in intensive agriculture and an increase in pests and diseases. Basically, it states that plants grown in soil rich in organic matter and microorganisms are more immune, not just to root disease, but also different insects, pests and diseases. This approach reintroduces the old organic paradigm: for the first time, scientific tools make possible what our forefathers probably knew. This is still an unpopular opinion and considered innovative and revolutionary. We’ll talk about it in the next chapter.
Chapter 6
Hello. In the last chapter, we talked about precision agriculture, designed to reduce the use of water, fertilizers and pesticides. Among the supporters of precision agriculture, one can also find those in the scientific community who claim there is no need to praise precision agriculture for trying to right wrongs – since there was no need for the warping created by intensive agriculture. These scientists emphasize the importance of live, fertile soil, rich in organic matter and microbial activity. As early as 1967, French researcher Chaboussou published studies that prove plants that grow in healthy soil, rich in organic matter and biodiverse activity, are more resistant to disease and pests. It is a critical statement, so let’s talk about it for a minute. Chaboussou actually said that pests tend to attack plants grown in a chemically enhanced soil, more so than those grown in soil rich in organic matter and microorganisms. His ideas seemed far-fetched at the time, and were dismissed. Now, 50 years later, he has gained the recognition he deserves. A number of research studies have emerged, supporting Chaboussou’s assertion, showing that the ability of a plant to tolerate insect pest and disease is tied to optimal soil quality properties. Soils with high organic matter content and rich biological activity exhibit good soil fertility as well as complex food webs with many beneficial microorganisms that prevent infection. In a series of controlled greenhouse experiments, when given a choice of maize grown on organic versus chemically fertilized soils, European corn borer females significantly laid more eggs in the plants grown on chemically fertilized soils. Although there was significant variation in egg laying among plants grown on conventionally managed soil, in plants grown in organic managed soil, egg laying was uniformly low. Pooling results across all sampled farms showed that variation in egg laying was 18 times higher among plants grown in conventionally managed soil than among plants grown on organic soils. In similar studies conducted in China, it was indicated that butterflies preferred to lay eggs on foliage of chemically fertilized cabbage plants and that the larvae grew faster on plants fertilized with synthetic fertilizers. The results of this study suggested that a proper organic treatment can increase plant’s biomass production and exhibit a lower pest occurrence. So how can this be? I’ll try to demonstrate using mycorrhizal fungi as an example. We learned about the magical symbiosis between them and plants, in which plants gain phosphorus in return for sugar. Today we understand this symbiosis is much more complex, and the picture gets clearer. Remember the Endo-mycorrhizae? The fungi that penetrates the plant’s roots? It is claimed that once the fungi try to penetrate the plant, the latter attempts to prevent it by secreting certain substances. Eventually, as we know, the fungus outsmarts the plant and penetrates its cells, without harming them, of course. It seems that when the plant tries to prevent the fungi from entering, it becomes healthier, because it develops what we might call a stronger immune system. It’s just like how kids who grow up in too sterile an environment tend to get sick more often than kids who are exposed to germs. The brilliance of nature in all of its glory. See you in the next and final chapter.
Chapter 7
Hi there! Let’s sum up. In this unit we learned about the nutrient cycle in nature. We understand that organic matter disintegrates and enriches the soil with nutrients. we saw the nutrient cycle in the forest and saw how to use compost to return lost nutrients into the soil. We saw how the needle of science now points to organic, and studies determine that organic matter in the soil increases the activity of micro and macroorganisms in the soil and increases their biomass. Consensus states that organic matter in the soil contributes to improving soil structure, moisture absorption capability, an increase in nourishing matter, protection from disease, and improvement of crop yields. We gave two nice examples to demonstrate: mycorrhizal fungi and earthworms, but they are of course only a fragment of a greater whole we are still far from understanding. On the other hand, we know that overuse of chemical fertilizers contaminates water reservoirs and phosphorus is dwindling. We saw what happened in India – where the government subsidized chemical fertilizers, and the farmers indeed used it, and the result was a distinct decline in soil fertility. The scientific needle today is at an interesting median stage. We understand that chemical fertilizing is necessary for feeding humanity, but should be used in measure and in addition to organic matter. One response was by way of information technology, aggregated under the popular name “precision agriculture”. This approach is favored by many farmers, who enjoy the fruits of the information revolution in the form of sensors and smart algorithms and strategic planning. Many start-ups enter the field of agritech and force agrochemistry giants to buckle up and integrate information technologies in their value propositions to the farmers. Ministries of agriculture also profit from technological innovation that introduces new tools for improving crop yields. We also talked about the emerging trend of commercial developments that attempt to mimic nature, and returning beneficial fungi and natural predators as part of intensive agriculture. Lastly, we presented theories by researchers who attempt to continue moving the needle, challenging intensive agriculture. We learned that studies from 50 years ago, mocked in their time, are turning out to be correct. Still a minority opinion, researchers from the heart of academia present studies on how plants are more resistant to disease and pests when grown in healthy soil, rich in organic matter and biodiverse activity. The question remains: what’s the problem? Why don’t we just move to organic fertilizing? That’s a good question. Can you think of some reasons? We’ll talk about it more, later in this course.

Food Systems – Unit 6
Chapter 1
Hi there. In the previous unit we mainly talked about the plants we eat. Now it’s time to talk a little bit about animals. In this unit we’ll talk about husbandry, rather than aquafarming. Many animals share our modern lives: cows, goats, chickens, pigs and many others. For most of us city-folk, these animals are a rare sight and no longer roam beside us. But that doesn’t mean they’re not present in our lives – this era of abundance brings animals and their produce right to our plate. There is a variety of animals in the modern food industry, and each has its own story. We’ll explore this reality from a cow’s perspective, which best demonstrates the processes we’ve gone through on the way to intensive animal farming. But before we pop over to the cowshed, a few words on husbandry. Hunters-gatherers didn’t walk around with a cow, goat, pig and chickens, so when and how did farm animals enter our lives? In the previous units we talked about how 10,000 years ago, the agricultural revolution led a significant change in the lives of humans. From hunters-gatherers, they became farmers who domesticate wild plants according to their needs. Well, apart from a selection of crops that feed us to this day, a small number of animals were also domesticated. Just like plants, each global region is suited to specific animals, which have been domesticated in different places and different periods. For instance, in Southwest Asia, sheep, goats, pigs and cattle were domesticated between ten and eight thousand years ago. On the other hand, in South America, llamas, alpacas and guinea pigs were domesticated between six and two thousand years ago. Much like the questions surrounding plant domestication, the story of animal domestication still has some gaps in it. Did it start as a rational, premeditated human decision? Did man understand, right from the start, the potential value of commanding the animals surrounding him? Or was it a random, Darwinist process that developed gradually and evolutionarily? It remains to be decided, and many questions remain unanswered. In particular, we don’t know how a specific set of animals and plants, out of the immense selection available in the wild, was selected to sustain humanity to this day. If you want to read more about the controversy surrounding animal domestication, please look at the recommended reading list. Much like domesticated plants, domesticated animals have different qualities than wild ones – qualities that benefit man. For example: high milk productivity, calm demeanor, certain physical size, lack of dangerous horns, etc. Like their plant counterparts, most domesticated animals won’t usually survive in the wild without human help. Remember we talked about plant cultivation and grafting, designed to create plants with desired qualities? Natural breeding has been occurring in animals for thousands of years, through sexual reproduction between animals of the same species. The goal is to cultivate desired qualities over generations. And if you thought horses and donkeys are related, now’s the time to set the record straight! Animals are considered to be of the same species if they can bear fertile offspring that can continue to reproduce. Take the mule, the horse-donkey offspring. Mules are infertile, and cannot breed, whereas both donkeys and horses can. Horses and donkeys are therefore considered different species. Over the years, mankind has improved animal qualities through careful selection and breeding of animals with desired qualities. But only around 1700 was animal breeding professionally systemized. This isn’t the first time we mention the 17th and 18th centuries as crucial turning points: the industrial revolution, the second agricultural revolution, groundbreaking scientific discoveries, and the start of modern chemistry. In the next chapters we’ll discover what happens to the cow along these stations, up until today.
Chapter 2
Hi there. When we talked about domestication in the previous units, we focused on crops, but that doesn’t mean our cow wasn’t part of the story. Over the years, food from plants and food from domesticated animals complemented each other, nutritionally and agriculturally. Remember the closed economy model of traditional farming? Let’s go back to the important role farm animals had in it. Cows provided farmers with milk and cow dung for manure. Cows grazed legumes such as clover in natural pastures, planted in order to retain nitrogen and return minerals to the soil as well to be used as feed. This limited the number of animals that could be sustained by the farm, creating a certain balance. When the boundaries of closed farming were breeched, traditional, sustaining agriculture was abandoned in favor of profitable agriculture. Organic fertilizing was gradually abandoned, and chemical fertilization took over. Livestock experienced similar turmoil. With the shift to for-profit crops, this balance began to turn. The way animals were raised had changed, as did their nutrition. We’ll soon demonstrate on the cow. In terms of traditional agriculture, the cow served an important role in the context of the soil’s nutrient cycle. But the cow’s efficiency had another manifestation as well: cows graze on grass that humans can’t digest, and produce calories rich in protein for human consumption: meat and dairy. With the shift to industrial agriculture, two processes took place: the first was the removal of the cow from the nutrient cycle, and as if that wasn’t enough, the cow started “wasting” human food. Our cow that used to feed on grass and clover now feeds on soy, corn and wheat – just like us. Is that efficient? We’ll talk about it later in this unit. Now, we’ve been talking a lot about the clash between science-based modern farming and nature’s basic principles. We talked about it in the context of chemical fertilization as opposed to mycorrhiza, and in the context of bees. In the next chapter, we’ll talk about precisely such a case from a cow’s point of view, and learn how when we choose to butt heads with the principles of nature – sparks fly!
Chapter 3
Hi there. In this chapter, we’ll talk about one of the side effects of intensive animal farming – Mad Cow Disease, which broke out in England in the 1980s. But what does that have to do with our cow’s diet? Let’s find out. The official name of the mad cow disease is bovine spongiform encephalopathy, or BSE. It is a progressive neurological disorder in cattle. Its symptoms are similar to a disease in sheep, and include abnormal behavior, trouble walking, and weight loss. Terminally, the cow becomes unable to move. As of January 2004, more than 180,000 cases of BSE were confirmed in Great Britain in more than 35,000 herds of cattle. The epidemic peaked in January 1993 at almost 1,000 new cases per week. It wasn’t just entire herds that were annihilated. The disease, it seemed, could be passed on to humans who ate tainted meat, and give them a variant of Creutzfeldt–Jakob disease. What does that disease have to do with Mad Cow? For instance, all cases of confirmed Creutzfeldt–Jakob have occurred in people who have lived in geographic areas which had BSE cases. The majority of Creutzfeldt–Jakob cases have occurred in the UK, which has had the largest number of cases of BSE in cattle. So what’s the source of this disease? The cow’s nutrition, apparently. In the previous chapter we talked about how cows are grass-grazing herbivores. Science today believes that the disease broke out among claves who were fed tainted tissue of cows and sheep, who had the disease due to a rare mutation. But how did cows turn to cannibalism? And why did the disease spread in Britain of the 1980s? Well, since the 18th century, farmers would feed cows with meat left over after the slaughter. It was a good – and free – source of protein. One notion is that after WWII, when times were dire, farmers noticed that cows that were fed animal protein exhibited improved milk production. And when something works, you keep it going. They increased the amount of animal protein in the cows’ diet, up to a point when cows were eating cows and sheep as their main diet. So, what do you think? Is it still ok to feed cows with cow-leftovers? A controversial speculation is that the Mad Cow did not erupt because cows were fed meat tainted from a rare mutation, but rather because eating animal protein simply isn’t in the cow’s nature. We have supporting evidence for the first claim, but no scientific basis for the latter. Nevertheless, we are still a long way from showing that the mutation is caused by the cow’s diet. Either way, we understand that cows aren’t supposed to eat animal proteins, if only because of the threat of spreading this disease.
Chapter 4
Hi there. In the previous chapter we talked about the cow’s diet and how it relates to the outbreak of the Mad Cow Disease in the 1980s. Now we’ll see that nutrition is only one of the changes that took place in the animal food industry. Thousands of years had passed since animals were domesticated. Thousands of years of natural and artificial selection that affected the qualities and characteristics of domesticated animals. From the 1950s onwards, this process was expedited through controlled, mass-raising of animals. Those with the most commercially desirable characteristics are chosen and bred among themselves, and the cycle continues. Within a few generations, a new animal is created, quite different from its ancestors. Humans in the 20th century produce much more from each animal. We’ll talk about the toll this takes in just a minute. For example, we know that a wild chicken lays 10-15 eggs each year. 2,000 years ago, Roman researcher Pliny reported that the most fertile domesticated chickens produce 60 eggs each year. 100 years ago, following decades upon decades of domestication and breeding, chickens produced 120 eggs per year, and modern chickens in industrial farms lay 300 eggs per year, or more. This high rate is made possible, among others, through decades of breeding and use of artificial coop lighting which disrupts natural processes and encourages egg production. And what about the cows? Pretty similar. Milk production has increased significantly over the years, through breeding and adapting of food, water and even shed temperature. Within a few decades, milk production rose from 8 to 40 liters per day. Moral repercussions of the animal food industry aside, it all sounds pretty good. More food for humans, and dietary security for humanity. But is that really the case? Let’s talk about crops and what they have to do with the meat we eat: if at the beginning of the course, anyone still thought crops have nothing to do with the burgers they eat, things are about to clear up. Think that the cows of industrial farming still feed solely on clover and grass? Think again. For one, there aren’t enough pastures for the amount of cows in demand by the meat industry. Second, in order to reach the desired milk production, eating grass simply isn’t enough. Their diet must be varied and rich, primarily in protein. We’ve given up on stuffing cows with meat, as we saw in the previous chapter. Modern cows eat a mix of soy, corn and wheat, in addition to animal-sourced supplements, and – get this! – chicken feces. Legislation changes from one country to the next, and the cow’s legally-approved diet is also affected by the cow’s intended use (whether meat or dairy), as well as age. And so, since the second half of the 20th century, we have been experiencing a steep increase in crops destined for animal consumption, such as corn and soy. Today, over one third of the world’s soy production is designated for animal consumption. While in the days of traditional farming, cows kept out of our plates and settled for grass and clover, modern cows are very much into human food. But maybe it has its merits? Let’s see. Someone’s already done the math for us. International data shows that the area required for producing one gram of protein from beef is 100 times greater than that needed for producing the same gram of plant-based protein, such as soy and lentils. As a result, we can see that manufacturing food from animals requires increased water consumption. It’s simple math. Cattle farming is inefficient in terms of land and water use. And we already know that intensive farming that uses chemical fertilizers and pesticides pollutes and harms the environment and biodiversity. And this is before we even mentioned the health repercussions of eating meat. Now, meat and protein lovers can rightly claim that with all due respect to the massive resource consumption of the livestock industry, they need protein. And plenty of it. They’re not going to eat two cups of lentils per day to get it. I bet I can find parents to young children who claim it’s easier to convince kids to eat a hamburger than lentils. It’s a cultural thing, of course, and it’ll take time until healthy, plant-based food will replace animal consumption. But even in the world of animal-based food, there’s a hierarchy. Chickens requires much less resources than beef, which is the least efficient of all animal-based foods. We’ll talk about it in the next chapter.
Chapter 5A
Hi. We’re at the Weizmann Institute. Remember that I promised you that after this course, you might think twice before eating your steak or burger? So today we are going to understand exactly why we should cut our meat consumption. But there are good news: if you’re a chicken lover, so you are fine with respect to our planned boundaries, put aside moral issues. We are going to hear a fascinating lecture by Dr. Alon Shepon, who will tell us all about it. Join me. My name is Alon Shepon and I’m a postdoc at Harvard Chan School of Public Health, at the department of nutrition. Today I’ll be talking about the environmental burdens of animal based foods. You know that in the Anthropocene we have transformed earth, and the food that we grow and what we eat and the way we produce it, have also changed dramatically. In the past, we used to hunt for our meat and then grow it on a regional and local scale, but in the last hundred years, our food system has turned into an industrial and global food production system. If we look, for example, on mammals, on terrestrial mammals, today about 96% of the biomass is us and the livestock that we got produce our food. The wild mammals are only 4% of that biomass. Is this sustainable? How much food are we producing? Are there large or small environmental burdens associated with that? We’ll explore a little bit of that in the next lecture and try to see if there are any alternatives to that, in terms of consumption, diets and environmental burdens.
Chapter 5B
So what are the environmental burdens associated with animal production? Here you see a global map of where animals are reared around the world, in various different systems. The orange is grazing lands which are the largest portion of land. Here you can see a more detailed picture of where pastoral lands occur in the world, and going back again, you can see again the various different systems. In green you see the mixed systems, these are agricultural production systems where animals and crops are produced simultaneously and in the red you see industrial systems. So livestock production is actually the single largest land user sector, occupying 80% of all agricultural lands, with implications to habitat fragmentation and biodiversity loss. It disrupts nitrogen and phosphorus, biochemical cycles, air pollution, soil acidification and ecosystem alteration and it’s a key reason for tropical deforestation, especially in the Amazon region, eutrophication, soil erosion and antibiotic overuse. It roughly emits about 20% of all global greenhouse gas emissions and it is estimated 20% of total global water use, which is about a third of agricultural use. Let’s look at little bit on the united states, which my research focused on in the last 10 years. Here you see a map of the United States with the various different crafts that are cultivated there. If you look at the east and west coasts you will see agricultural lands that produce mostly vegetables, nuts, fruit. But if you kind of focus on the center of the continent, you’ll see large regions of crops of soy and corn, which about 40% of it is produced for animal feed. If you look at the regions of yellow, these are regions of hay production and silage also, for animal production. In the green you see wheat, which only a small portion of it goes to feeding animals. But again, if you look at the entire agricultural system you see that a lot of it is actually geared towards producing feed for animal production.

Chapter 5C
This are the results that we came up with and these are resources or pollution that are associated with consuming about a 1000 calories of these animal based products. These are the five categories produced in the American mean diet: dairy, beef, poultry, pork and eggs. If you look at the land resources that are needed to produce a 1000 calories, you see that the scale ends at around 20 square meter, but you see that for beef, the range goes to about a 150, which is considerably higher than the other animal based products. Most of it is in the form of pastures, which are the diagonal white lines that are there to differentiate between crop lands and grazing lands. But even if we take that out, you see that beef crop lands are higher than the others. The same is true for the other environmental metrics. Beef is… the resources needed to produce a 1000 calories is considerably higher than the other animal based products. What you can also see, on the top of each of the panels are comparisons to plant-based products. We have “rice” for R, P for “potato” and W for “wheat”. Except water, plants are doing better, but in the… For water, because a lot of the feed in the United States is produced via rain, what we call “green water”, When it comes to blue water, irrigation water, they are very… Animal based products are very close to plant based products in the United States and you can see that in this slide. Finally, what we can also see is that dairy and eggs are very very similar to pork and poultry, so the other animal based products are not that different from each other, and we can see, when we compare it to what Americans are actually consuming, that there is a mismatch between the environmental burdens of foods and what Americans are actually consuming. Another way of looking at the results is through what we call “feed to food conversion ratio”. It’s a unitless number that actually tells us how much feed we need in a certain amount of weight unit to produce one weight of live animals. So 14 for beef actually means that we need 14kg of concentrates, roughage and pasture feed to produce one unit, one kilogram of beef and for pork that number is 3 and for poultry it’s 2, and this actually mirrors the previous slide because if we need more feed, we need more lands, we need more irrigation, we need more fertilizers. The next step is actually taking all the feed that is produced in the United States, dividing it between the 3 different types: concentrates, which is mostly corn, processed roughage, hay, and then pasture, and then assigning it, seeing how much of it goes to each one of the five categories of animal based products. And then, eventually, to your right you’ll see what ends up on the plates of consumers in the United States. So you get a snapshot of the entire animal portion of the American food system, starting from the left of the field, production of feed, all the way to the animals and then to the consumers on the right. The values on your right, the conversion efficiency, tell you how much of that feed is converted into food. So 3% for beef actually tells you that for a 100 calories of feed, we only get 3 calories of beef on the plate. That’s a very low efficiency and it stems from various different reasons. The first one is because of the biological, physiological constraints, limitations of animals. Not all the feed that they eat eventually turns into meat, or the products that we are looking at. The reproduction is also limited. A cow will give birth to only one calf per year. The second reason is of course choices, food choices. Americans choose to eat only a certain portion of the animals. And the last reason is food loss, which is, implicitly here in this calculation, where food loss is actually lost across the supply chain. When we do this calculus also for protein, we see that the numbers don’t change for beef and for pork, but there’s a higher conversion efficiency for poultry and eggs, because they have higher protein content, but the same picture, the same pattern emerges and that is that around 7-8% of the protein that goes into the system or calories, only results in 7% or 8% of consumed calories and proteins.
Chapter 5D
So let’s try to understand what that means, what are these dietary shifts? This is one of the pioneering, I would say, research that came out several years ago, trying to understand what is the potential of dietary shifts. Here you see the global food system, production of calories, on top, and then the different amounts that go into the various different demands. So about 55% of all calories produced in the world go to direct consumption, 10% go to biofuel and about 36% go to producing feed for animals. But as we’ve seen in the research that I’ve showed about the United States, that is converted to about 10%, so only 4% of food actually makes it to the plate and the authors conclude that all in all, only 60% of calories from this 100% production actually goes to feeding people. If we would divert the arrows of production towards direct consumption, we could be actually feeding an additional 4 billion people and that’s a very large number. It means that the food system is inefficient in the way it’s structured, and if we divert more food into direct consumption, we could actually be feeding more people. There are some, I would say, limitations to this research, one of it is that it’s focused only on calories and… diets should be also looking at other important micronutrients and macronutrients, and also that this research assumes that all the different calories that are produced are edible, which we know is not the case, for example, hay. But I think it gives us a very soon kind of first order approximation of understanding that there is a lot more food that could be produced in this kind of system. So we came up with a different metric, which we call “the dietary shift potential” and it actually says what are the amounts of additional people we can feed on spared lands resulting from dietary shifts. So what this means is, if we have a certain food, type a, let’s call it, and this is the amount of land that is needed to produce it and we move the entire population from eating food a into eating food b, and we have to think that… what is this “food b”? It should be very close to food a if we don’t want to have any other repercussions in terms of health. But let’s assume that food b is very close nutritionally to food a, but it uses less land. so on the spared lands that occurred because of that shift, we could be actually producing food for more people and the amount of people that we could actually feed on those lands is the dietary shift potential. So we’re going back to the United States where we did our research and we looked at substituting beef to poultry. So what would that mean? If the entire population in the United States would consume poultry instead of beef, so all the feed lands, agricultural lands that are producing beef would be diverted to producing poultry. But we actually have a better feed to food conversion ratio So we need less lands to do that and the result, the spared lands could actually be feeding 120-140 million people in addition to the current population in the United States. Now, it’s important to know that beef and poultry are quite similar in terms of their nutritional quality. Not identical but very similar. So when we did that for beef and plants we hand to think of an assemblage of plants that are very similar, close to beef in their nutritional quality, but could also give us a very large benefit in terms of land. Here you see the assemblage of plants that would replace beef. It’s mostly consumed of legumes, but when we do the dietary shift potential, we see that these spared lands could actually produce food to feed an additional 190 million Americans. So here, again, production of beef, starting off on a certain arbitrary land, producing feed, plants, in green. This is converted to producing feed in a smaller arrow, as we’ve seen before. There’s also conventional food loss across the supply chain, which is there, and at the end, it results in the arrow that goes straight to your right/ This is the amount of protein of beef produced. If we take the same amount of land and produce the substitute of the plant based product that have the same nutritional quality as beef, this is what we’ll get, using the same amount of land and putting conventional food loss in there again, you’ll see that we get a very larger arrow of production. It tells you the difference in terms of production of protein. The difference is… in breadth of the arrow actually tells you the large differences in production by these 2 paths. So what that means is, by Americans choosing to eat the left side, of beef, instead of eating the plant based alternatives, there’s actually what economists call an “opportunity cost” and we call it an “opportunity food loss”. What it means is that 96% means that if the right… pathway of production produces a 100 grams of protein, the left one, of beef, only produces 4 grams. And what’s interesting is that by shifting from beef production to the alternative plant based production, we could actually be salvaging more food, or, producing more food. That amount, this 96% percent loss that we can salvage, is actually greater than the conventional food loss of beef. This is true for all the other animal based products. By shifting from the left to the right, and moving towards a plants based diet, we could actually be producing more food than is actually lost through the conventional food loss. In fact, when we deploy the dietary shift potential, by changing the consumption of all Americans from animal based products to plant based products, with a very similar nutritional quality, we could be sparing lands to produce food for additional 350 million Americans, that’s actually double the population. That amount of food is larger than all the supply chain food wasted in the United States.
Chapter 5E
So what kind of future prospects and ideas that we have, when it comes to dietary shifts? So, there is no one silver bullet that solves the problems that we are… are faced with with the current food system. I talked about only several of the ideas and paths that we can take. I talked a little bit about animal based foods moving from the more resource intensive towards the more benign meat of poultry, for example, in terms of environmental performance. There’s a lot of talk nowadays about fish, in terms of having a very high quality of nutrition, but on the other hand, fish have been over exploited in most fisheries around the world and aquaculture production has its share of environmental burdens. So it’s a very complicated picture as well. There’s a lot of interest nowadays with insects. and then we explored a little bit about plant based substitutes. Today there is a very strong and important market of veggie burgers and all these kinds of substitutes that give you the feel of meat without having to actually eat meat. There’s cultured foods, There’s cellular foods, these are foods… these are single cells that are produced in laboratories to produce protein for our consumption and they have a very… They have a better environmental performance than current production of animal based protein. There’s also mushrooms, which are, I think, are very important to explore, to explore in terms of their nutritional quality and environmental performance.
Chapter 5F
To wrap up this talk, I just wanted to give kind of the last points of what we discussed today. We really need a system level approach. This is a food system approach to understanding the challenges that we are faced with producing and consuming food. We’ve seen a little bit that the global, terrestrial and marine food systems are very intertwined systems that form a very large, complex food network. Climate change and degradation of habitats and other human activities pose large threats to the functionality of the food system. We’ve more explored the demand side but we would also need to make very large changes on the supply side, but both of them are crucial to really meet the challenges that we are facing with food production in the future. We’ve seen that in the United States, animal based products incur a large and disproportionate environmental toll and this is something that has been replicated in other research, in other places around the world. It’s true that in other countries there are various different food systems, sometimes animals are reared on pastoral lands and it has a different environmental burden, but all in all, in developed countries, the over-consumption and production of animal based products incur very high environmental costs. Dietary shifts could be a very important and potential strategy to mitigate some of these costs and produce more food in the world, or actually, spare lands that could be maybe used in other ways, more efficient or rewilded for nature conservation. But I think we’re kind of left with this very important question: How do we get people to change their diets on a very large population level? Thank you very much for your attention.
Chapter 5G
Thank you for a fascinating talk, obviously I have some questions. So can you please explain… you were talking about 40% of terrestrial land that is directed towards agricultural lands. So could you explain what is agricultural land, what is 40%? A little bit… -Sure. -More details. So if we take out the polar, the ice regions and the deserts, 40% of land is devoted to producing the food that we eat. -Okay. That 40% is mostly grazing land. About 2/3 of it is grazing land which is called “agricultural land”, and a 1/3 of that is crop lands. -Okay. Crop land – which is everything we grow. -Right, feed. -Okay. That crop land, that 1/3, a third of that is devoted to producing feed crops that go to feeding animals. Two thirds of that is to producing vegetables and all the other things, staple crops that we eat. -Grains… -Right. -Okay. Fruit. -Right. It’s very important that you made this distinguishment in terms of the various different production, grazing vs. crop lands. In the dietary shift potential that I showed, we were only focusing on crop lands. So when we move from producing beef to producing poultry for example, we are only looking at the crop lands. Obviously, this dietary shift entails sparing all pastoral lands, because poultry does not need pastoral lands. Okay. -So that big chunk of grazing land in the United States that is devoted to producing beef, we spare that land. We could rewild it, we could do a lot of other things, but it’s out of the equation. Now we’re only focusing on the crop land. We chose a metric that actually says how much food… how many people can we actually feed on those lands, people who eat the mean American diet. This is the metric that we chose, we could have chosen other things to produce on that land, but we wanted to show that we can feed more people and that amount of people is really large. -What is the number? So, only this substitution on a population level, of moving from beef to poultry could actually spare lands to produce food for 120-140 million Americans. That’s about a third of the population. It’s a lot. -Just if all people in the United States decided to move from eating beef, to poultry. Okay. -And that number even grows when we actually exchange meat with plant based diets. Okay, can you explain? -Sure. So I showed that, in the opportunity food cost slide, so let’s look again at beef, and now substitute that with a plant based diet. -Okay. Which lentils, lettuce, vegetables… -Right, it’s a sort of an assemblage of plants that has a very similar nutritional quality than beef. So I’m not losing proteins… -A lot of soy beans, actually. -Okay. Which is also quite funny because we… in the United States, a soybean is used to feeding animals but soybeans are very very nutritious and also are very environmental in some aspects of… in terms of yields, because we’re only looking at the land area now, and not in other metrics. There’s this farm, and now you produce corn and soy to feed the beef. You take the same plot of land now and you produce that assemblage of plant based diets you could be producing 20 times more protein than beef. That number goes to 2 times for eggs, but for beef, it’s a very large potential to produce more food. I still get all the proteins, all the vitamins, it is a balanced food, it’s not just carbohydrates. Right, so, in those calculations that we did what I say as a plant based substitute, I don’t only look… I don’t focus only on calories and protein. I look at the entire assemblage of nutrients and I want to bring a package that is very close to the beef. Plant based diets have an environmental benefit and also today, in terms of health. Most authoritative reports, WHO, The EAT-Lancet, they talk about moving back into plant based diets because in developing countries like the United States, like in Israel, we consume more meat than we actually need. So we’re also getting a very… getting a health benefit with this dietary shift. So there’s an environmental, there’s a health benefit to that, and also a planetary health benefit. That ties… that goes together. Thank you so much. You’re welcome.
Chapter 6
Hi there. In the previous chapter we learned that beef is inefficient in comparison to other animal-sourced food. We saw that researchers point to the inefficiency of the amount of land and water required to raise cattle for consumption, but also other parameters such as greenhouse gas emission and chemical fertilizing. In this chapter, we’ll discuss these parameters and raise some moral questions. One of the greatest challenges of the human race is climate change and global warming. Researchers assume that the livestock industry is responsible for 18% of greenhouse gasses, more than global transportation which is responsible for 13%. Greenhouse gas emission as a result of animal-sourced food manufacturing greatly surpasses emissions from plant-sourced food manufacturing. For example, greenhouse gas emission from manufacturing one gram of cattle-sourced protein is hundreds of times greater than emissions from manufacturing the same amount of protein from legumes. So what is the source for these emissions? The answer is threefold: one, emissions from animal feed production, the result of the energy used to produce chemical fertilizer for the crops. Two, natural methane emissions produced by animals during digestion, which increase when animals are fed soy and corn instead of grass. Third, we have to account for the forests, cleared to make land for growing crops to feed the animals. When forests and grassland are cleared for feed crops, carbon stored in soil, roots, stems and branches is released into the atmosphere. One proposal concerning the environmental aspect is that consuming beef from cattle fed in natural pastures is likely to be less environmentally harmful than the industrial option. A comprehensive 2017 report from, found in this link, examined these notions. It found that this is only true in certain conditions, dependent on factors such as soil quality, plants and climate, as well as the way the pasture is managed, in a way that guarantees both the soil and crops can renew. The report stresses that a natural pasture which meets these conditions for environment efficiency cannot meet the current demand for beef. So if you happen to have a natural pasture that meets these strict criteria by your house, and cows just so happen to graze there, enough to maintain the quality of the soil and plants – you can enjoy beef without the guilt of harming the environment. Controversy surrounding the animal-sourced food industry is not only environmental, but also moral. Despite local and international legislation concerning animal welfare, we still raise them in industrial conditions. The main question is, to what extent can humans use farm animals to our benefit. Well, there are three main approaches: the first is the common one that goes hand in hand with industrial agriculture, according to which animals are a product like any other, and humans can use them as they please. This approach creates a race for livestock industry efficiency, just like any other industry. For instance, in attempt to maximize land use, chickens are kept in battery cages, unable to move, while cows – special breeds with high milk production – are often kept in closed cowsheds. Remember what happens when plants grow in close confines without biodiversity? Disease. And so the livestock industry also uses immunizations, antibiotics and other chemicals to fight off disease and parasites in animals. On the other end of spectrum is the approach that fits the vegan philosophy, which states that man has no right to use animals, and any use of their bodies or secretions for human benefit is wrong. According to this approach, Cow’s milk is solely for the calf, honey for bees, wool belongs to sheep, feathers to the geese… the list goes on. The third approach fits in with traditional agriculture, in which each farm kept a small number of naturally fed livestock (grass and hay). Animals were mostly kept in good conditions and open spaces, and use of milk, eggs and chickens was kept to a minimum. In terms of cows, for example, this approach states that we can enjoy the gifts given to us by cows – their milk while they are alive, and their hides when their time on earth ends – as long as they lead a good life and treated with respect. I visited several of these small, communal farms, who sport commercial, moral and environmental logic. Sadly, this approach cannot supply the demand for animal-sourced food. Cows in camped industrial sheds are fed food that isn’t natural to them, designed to increase milk production, and the conditions in which they are used are more machine-like than those fitting living animals. Another issue we hadn’t discussed is the separation of the cow from her calf, who feeds on the valuable milk. This issue raises more questions than answers, and the number of opinions and practices is as great as the number of farmers I asked – which is a lot. It’s interesting to see this discussion, and there’s an attempt to understand how cows can be treated better and manufacture smaller quantities of milk, which fits the current nutritional recommendations to reduce dairy consumption. I admit I’ve been struggling with this issue for several years, researching and trying to understand each side. What I concluded is that industrial animal farming is a barbarian practice I hope to see eradicated sooner than later. As a complementary solution, the past few years have seen technological developments designed to provide meat lovers with the same experience, minus the environmental, moral and health issues. Some start-up companies develop lab-grown meat from beef tissue, while others try to manufacture plant-based hamburgers and probiotic yogurt. Plant cultivators, too, step up to the challenge and attempt to breed seeds such as peas to be richer in protein. This is only the beginning, and there are many surprises ahead.
Chapter 7
Hi there. In this unit, we followed the cow from its domestication to industrial farming. We mentioned that hunters-gatherers did not walk around with cows and chickens, and saw that much like plant domestication, animal domestication evokes numerous controversies: was animal domestication an intentional process of man, or did it start as a random, Darwinist occurrence, a gradual evolutionary process? We learned that over many years, plant-based and animal-based foods have complemented each other, nutritionally and agriculturally. Cows provided farmers with meat and dairy, and cow dung provided fertilizer for crops. This was all done efficiently, since cows grazed on grass unfit for human consumption, and produced protein-rich calories for man. We then talked about intentional breeding which led to increased livestock production, and about nutritional change, also designed to increase production and respond to the growing demand for animal-sourced food. We saw that the cow’s nutrition was enriched with animal protein – other cows, sheep, etc. – which led to the Mad Cow disease in 1980s UK, and the cow’s eventual return to a plant-based diet. But on who’s expense? We learned that today, in order for us to eat cows, the latter eat mostly vegetarian food off our plates: corn, soy and wheat. We also saw that the cow was removed from the nutrient cycle. a deal that turned out to be environmentally inefficient. We said that environmentally, it is indisputably better to consume plant-based protein, and if we eat animals, it’s better to consume eggs, poultry, even dairy – anything but beef. Still, if someone has a natural pasture that adheres to very strict criteria, they can go ahead and eat, no environmental guilt. We also touched upon some moral aspects of consuming animals, and mentioned new solutions for solving environmental and moral issues – such as cultured meat, plant-based substitutes. See you in the next unit.