Common Mistakes in Waste Transformation, and in Food and Fuel Production

Type 1 waste should not be fed to larvae and worms at Level 2, unless it has spoiled and can no longer be preserved as feed. Why make a feed out of a feed, especially when there is no shortage of Type 2 waste?

For example, BSF larvae grow exceptionally well on fresh coffee pulp, but fresh coffee pulp can be easily fermented into feed for pigs, chickens and cows. BSF larvae also grow well on peanut press cake, spent brewery grain and rice wine distiller’s byproduct. But all three can be easily fermented into great animal feeds.

When Vor Sina of Laos fed only 4% fermented spent brewery grain (dry matter basis) to goats fed a basal diet of cassava foliage, this more than doubled their rate of growth

and greatly improved the dry matter feed conversion rate

In a study conducted by Inthapanya (2016), we see that when cattle were fed 5% brewers’ grain as a supplement to their fermented basal diet, N retention increased by almost 50%. When rice wine distiller’s by-product was added to the basal diet of “Yellow” cattle (4% DM intake), live weight gain improved by 37%. When biochar was added to the mix, live weight gain increased to 60% (Effect of rice-wine distillers’ byproduct and biochar on growth performance and methane emissions in local “Yellow” cattle fed ensiled cassava root, urea, cassava foliage and rice straw). A lot more to come on the benefits of incorporating biochar into fermented feed.

In Effect of a 4% dietary concentration of rice distillers’ byproduct, or of brewers’ grains, on growth rate and feed conversion during pregnancy and lactation of native Moo Lath gilts and their progeny, we see that “DM feed conversion, expressed as (total feed DM consumed during pregnancy and lactation/weight of piglets) weaned, was improved by 60%, when the diet of Moo Lath gilts was supplemented with 4% rice distillers’ byproduct.” Also see: A low concentration of rice distillers’ byproduct, or of brewers’ grains, increased diet digestibility and nitrogen retention in native Moo Lath pigs fed ensiled banana pseudo-stem (Musa spp) and ensiled taro foliage (Colocasia esculenta). In Rice distillers’ byproduct improved growth performance and reduced enteric methane emissions from “Yellow” cattle fed a fattening diet based on cassava root and foliage (Manihot esculenta Cranz), we see that the “growth rate and feed conversion in cattle were improved by 40% and 17% respectively when the diet of fermented cassava root and cassava foliage was supplemented with 4% (in DM) of rice distillers’ byproduct. Rice distillers’ byproduct supplementation increased the concentration of propionic acid in the rumen VFA and reduced the calculated methane production by 28%.”

One should not make feed out of food: for example, feeding soybean or corn to insects, pigs, chickens, cows or fish. “Feeding grain to farm animals is a particularly egregious practice, argued Stevenson. It is inherently wasteful of calories: for every 100 calories of human edible cereals fed to farm animals, just 17-30 calories enter the human food chain as milk or meat. Using publicly available and peer-reviewed data Stevenson calculated that, in terms of wasted food and calories, this single practice will cost $1.32 trillion a year by 2050” (Hidden cost of feeding grain to farm animals to hit $1.32tn a year).

One should not make feed out of food: for example, feeding soybean or corn to insects, pigs, chickens, cows or fish. “Feeding grain to farm animals is a particularly egregious practice, argued Stevenson. It is inherently wasteful of calories: for every 100 calories of human edible cereals fed to farm animals, just 17-30 calories enter the human food chain as milk or meat. Using publicly available and peer-reviewed data Stevenson calculated that, in terms of wasted food and calories, this single practice will cost $1.32 trillion a year by 2050” (Hidden cost of feeding grain to farm animals to hit $1.32tn a year).

One should not make fertilizer out of food: for example, using fresh milk and eggs to fertilize vegetables. Yes, this actually takes place in Vietnam. Minimizing the number of trophic levels involved in waste transformation or food production generally leads to greater overall efficiency. Finally there is the total nonsense of making fuel out of food: for example, making ethanol out of corn, or making biodiesel out of palm oil, soybean oil or larval fats (Understanding the climate implications of palm oil biodiesel consumption). More than one third of the entire corn crop in the United States is devoted to ethanol production.

“For every megajoule of energy used, the study finds that palm oil emits 231g of COequivalent and soybean oil 150g/CO2e, far higher than the UN climate science panel’s estimates for any fossil fuel” (EU green transport target ‘may have increased greenhouse gas emissions’). One would even caution against making biodiesel out of used cooking oil, since used cooking oil can be used in fry-cooking food waste.

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