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The Green Life: Surprisingly Green: By-Products in Pet Food

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June 07, 2013

Surprisingly Green: By-Products in Pet Food

Pet foodWe need to feed another few billion mouths in the coming decades, and that's just humans. U.S. cats and dogs already account for at least 150 million more (slightly stinkier) maws, according to the U.S. Census.

So environmentally speaking, feeding animals by-products isn’t a bad way to go.

The article “Nutritional Sustainability of Pet Foods,” published in the journal Advances in Nutrition, explores the eco-aspects of providing for our companion animals.

The authors — including Kelly Swanson, associate professor of comparative animal nutrition at the University of Illinois at Urbana-Champaign, along with scientists from pet food supplier The Nutro Company — note, “Rather than competing with humans for food, pet foods based on by-products actually lighten the environmental burden of the human food system.”

The word “by-product” isn’t synonymous with pink slime. Broken kernels of rice, the authors also note, are among the hundreds of by-products used by the pet food industry. Their use lightens the carbon and water footprints of the food system at large.

Protein is the most ecologically expensive macronutrient to cultivate, the authors add, and many pet foods actually exceed the crude protein requirements for cats and dogs.

The authors also stress the difference between a nutrient and the myriad ingredients they comprise, stating that many different ingredients can meet an animal’s nutrient requirements. Sources of protein range from oats (at 1,788 tons of water to produce) to cattle (at 15,400 tons of water).

One of the article’s most palatable points is that contention reigns over what to eat, whatever the species. 


HS_Mackenzie_BLOG Mackenzie Mount is an editorial intern at Sierra. She's cleaned toilets at Yellowstone National Park and studied sustainable cooking at The Natural Epicurean Academy of Culinary Arts in Austin, Texas. 



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