Hacker News new | ask | show | jobs
by wil421 2100 days ago
Cows do not eat 100% packaged food if they eat any at all. In fact, 80% of what cows eat cannot be eaten by humans.[1] If you could add seaweed to drastically reduce emissions not would be a win for everyone.

> They learned that most cow diets contain the following:

Grass: More than 50 percent of cow feed is actually grass (farmers call it hay and silage). While people often think dairy cows are fed a high-grain diet, in reality they eat the leaves and stems from corn, wheat and oats far more often than they are eating grain, like corn kernels.

Grain: Dairy cows do eat some grain, which usually makes up less than one-quarter of their diet. Some has been grown specifically for cows, and other types have been recycled after food or beverage production -- like barley that has been used first to brew beer.

The rest of a cow’s diet includes ingredients like almond hulls, canola meal (the leftovers from producing canola oil), citrus pulp (the leftovers from making orange juice and other beverages) and more. Here’s the cool thing: These products, which were once thrown away, are actually good for cows. Cows can “unlock” the energy and nutrients in these products that would otherwise go to waste.

[1] https://www.usdairy.com/news-articles/do-dairy-cows-eat-food...

1 comments

Source doesn't look especially reliable coming from a US Dairy website, it mentions a survey from 2008 but doesn't provide a reference.
How about this: I was on a dairy feedlot a week ago, watching them make rations. The ingredients going in included:

- Alfalfa hay (a legume crop which improves the soil)

- Corn & triticale silage (chop up the ENTIRE field, stalk, cob, and all, then ferment it a bit to improve digestibility)

- Corn cannery waste (all the leftovers after they make canned corn for people)

- Waste onions (cattle love these, they'll root through the whole ration to find them)

- Apple waste (pulp left over after squeezing apple juice)

- Potato waste (leftovers from processing potatoes for, that's right, people)

- Pea meal (broken bits of dried peas left over from processing for humans)

- Hop pellets (after breweries have used them for beer)

- Canola meal (leftover from making canola oil)

- They may have been feeding brewery waste grain, but I don't remember for sure

The first two are the only ones specifically produced for cattle. One of them improves the soil in a crop rotation, and the other is a pretty damn efficient use of plant matter vs. anything humans consume. They constitute a pretty good chunk of the ration, to be sure, but I do think HN tends to assume cattle are just fed big buckets of corn seed & wheat.

btw, I was visiting the feedlot, but they weren't just blowing smoke for the city slicker... I had worked there a decade ago, making the rations, and I fed all the same stuff then.

edit: there are effective software tools for building rations based on your particular nutrition goals, so there are dozens of different rations being made any given day. If the cannery doesn't ship any corn waste for a while, you just adjust the other ingredients until you hit your same target nutrition without it. It's impressive stuff.

Thanks for sharing your experiences, I want to take a look into it more.

> but I do think HN tends to assume cattle are just fed big buckets of corn seed & wheat

I wasn't making the assumption but I see conflicting arguments all the time on this issue both in discussions and in papers.

There's kind of a barrier to entry for the layman because feedlots are generally out of the way, and they're not usually in the business of giving tours--they're busy places with lots of heavy machinery running around. It's a fascinating business, but you have to be ready for 6.5 day work weeks :)

One way to learn a bit more is from the actual industry's magazines, like Feedstuffs, which focuses particularly on livestock feed. Here's an article picked from the top of their beef nutrition section: https://www.feedstuffs.com/nutrition-health/byproduct-feeds-...