From Trash to Nutritional Treasure; Part 1

Cattle are fascinating animals. Not only do they provide beef, milk, and by-products, but they also are fantastic recyclers and convert feed that is most-times not suitable for human consumption.

The bovine digestive system is not like the human monogastric (single-chambered) stomach. Cattle are ruminants, meaning their stomach has four unique compartments.

These forage-consuming species, along with sheep, goats, buffalo, elk, giraffes and camels, rely on a microbe-based process to digest feed to convert it to energy. The fourth compartment, the rumen, contains millions of microbes (microscopic bugs) that help cattle digest feed.

Thanks to this super-powered digestion process, cattle can eat forages that humans can’t digest. In addition to grass, hay and grains (which are both technically grasses), cattle can be fed leftovers from other industries that would otherwise be trashed in a landfill.

What are some interesting feed ingredients fed in Arizona?

There are lots! Wes Kerr, of Kerr Family Dairy in Buckeye, Arizona, shared that his dairy cows are currently eating a feed mix of alfalfa, oats and sorghum silage, steam-flaked corn, cotton seed, almond hulls, whey, vitamins and minerals. Cotton seeds, almond hulls, and whey are all by-products of other agricultural crops. “We are diligent to provide our dairy cows with the nutrition they need, and sometimes we are able to utilize feed products from other Arizona businesses that one might see as ‘trash’ but, to my cows, they are nutritional ‘treasures,’” Wes explained.

Processed with Snapseed.
Wes and Lauren Kerr with their children Madelyn, Caroline and Evan. 

Seasonal variability does affect the by-products available. For example, right now, cotton seed is readily available as a feed ingredient because Arizona’s cotton farmers have just completed cotton harvest. Cotton seed is high in fat, fiber and vitamins – all important for cattle. When cotton goes to gin for cleaning, the seeds, dirty lint and debris are removed. Interestingly, the dairy also uses the “gin trash” as bedding for cows.

Weather, global markets and geopolitical events also affect pricing and availability of different feed products. For example, Wes shared that “2016 was the largest almond harvest* in California’s history, therefore there were lots of almond hulls available at an affordable price.” *California grows 100% of the U.S. domestic supply of almonds.

Though these feed by-products and others are unique, hay, silage and grains are vital. “We consult with a dairy cattle nutritionist to help formulate the proper mix to keep our cows healthy,” Wes explained. “We also regularly send feed samples to a lab to determine the nutrient value of each crop and commodity to monitor protein, carbohydrates, fiber, vitamins and minerals.”

From upper left: cotton seeds; steam-flaked corn; pelletized vitamins and minerals; the chopped, mixed and finished feed. 

The Kerrs (and most dairy farmers) grow most of their own forage including corn, sorghum, alfalfa and oats. In recent years, they have switched more to sorghum over corn for silage because sorghum is more drought tolerant (doesn’t use as much water) and is resistant to crop disease.

Wes offered an enlightening perspective that even vegetarians and vegans benefit from animal agriculture: “If one only consumes plant-based foods, like soy products or almond milk, or wears cotton, they are also contributing to the sustainability of all of agriculture. Soy and almond hulls are fed to cattle or they would otherwise go to into a landfill. Everyone wears cotton and we can even utilize the cotton waste.”

The old saying, “one man’s trash is another man’s treasure” is fitting. Or, in this case, “one man’s trash is a dairy cow’s power smoothie.”

Tune in next week for a visit to a cattle ranch and feed yard.

Arizona grows and feeds a lot of alfalfa. It is high in protein, fiber and calcium. Arizona averages 9-10 cuttings of alfalfa from the same crop per year (the national average is 4-5). This is due to Arizona’s warm and temperate climate and summer and winter rains.

Corn Silage
Silage is fermented corn and corn stalks that can be easily chopped and is high in energy and digestibility.

Sorghum Silage
Like corn silage, but from the sorghum plant.

Cotton Seeds
When cotton is harvested (for clothing, textiles, paper…) the seeds are discarded and can be fed to cattle. They are a good source of energy (from fat), fiber, protein and vitamins (vitamin B6, folate, calcium, iron and potassium, protein, thiamin, magnesium, phosphorus, zinc and manganese).

Gin Trash
The “dirty” lint, seeds and other plant material can be composted or used for bedding for cattle.

Almond Hulls
When almonds are harvested from the tree, the nut (kernel) is inside a shell which is inside the hull. Hulls provide fiber to cattle.

A grain that is high in energy, protein and fiber.

Soy beans and hulls, the shell around the bean that gets discarded before human consumption, is high in fiber.

The byproduct of cheese making, whey by-products. Human athletes use whey protein for workout recovery. Dairy cattle can be fed the liquid form leftovers, helping cheese makers to waste less, while providing carbohydrates, minerals (calcium, phosphorus, zinc, potassium and magnesium), vitamins (riboflavin, vitamins B-6 and B-12), protein and fat.


Other interesting feed products, some of which we will cover in the series: molasses, beet pulp, citrus pulp, cull products from vegetable production, bakery waste, distillers grains, brewers grains

6 thoughts on “From Trash to Nutritional Treasure; Part 1

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s