Beef By-Product

Beef slaughter yields far more than steaks and roasts. Organs and other parts that are not sold abroad or to shoppers go raw to pet food plants, or to rendering plants that turn them into meals.^1,2,3

1. 01 // Source Cattle at slaughter Once the carcass is cut for meat, organs, blood, bone, stomachs and intestines remain.
2. 02 // Process Sorted and cleaned Stomachs and intestines are emptied of their contents. Hair, horns, teeth and hoofs are excluded by definition.
3. 03 // Process Not rendered Unlike by-product meal, these parts are not cooked, dried or ground into meal before use.
4. 04 // Output Beef by-products A wet raw material: most organs tested at 71 to 80% water, mixed into the food before cooking.

1. 01

   A low-value outlet

   Packers get the best price for offal abroad. What is not exported goes to rendering or pet food at a lower value; one export group warned liver could fall to 7 cents a pound.^6,7

2. 02

   Digests like meat

   In a 10-dog trial, liver and testicle digested like sirloin trimmings, with about 84% of their protein absorbed. Trachea came in lower, at about 73%.³

3. 03

   Uses the whole animal

   Offal made up about 7% of cold carcass weight in one study. Hide and offal together were worth about $136 per 1,400-pound steer in early 2021, and packers sell every part they can.^2,6

How much No source publishes a typical amount; a 10-dog trial mixed each tested cattle part, including organs and a muscle-meat comparison, into a reference diet only to measure digestibility.³

1. Brands say

   Organ meats are as nutritious as muscle meat

   Evidence

   1. Strong
   2. Some
   3. Thin
   4. None

   In a 10-dog trial, liver and testicle matched sirloin trimmings at about 84% protein digestibility, and red organs resemble beef cuts in composition. Trachea lagged at 73%, and the label never says which parts went in.^2,3

2. Owners say

   Beef is a common food allergen for dogs

   Evidence

   1. Strong
   2. Some
   3. Thin
   4. None

   Beef was the trigger in 102 of 297 dogs with proven food reactions, more than any other food. The authors note the ranking may partly reflect what dogs were commonly fed, not that beef is uniquely allergenic.⁴

3. Vets say

   All-meat dog foods can carry thyroid hormone

   Evidence

   1. Strong
   2. Some
   3. Thin
   4. None

   A 14-dog case series linked thyrotoxicosis to meat-based foods or treats presumably contaminated with thyroid tissue. All dogs were back in range when rechecked 4 or more weeks after the food was stopped. It gives no rate and names no part.⁵

4. Critics say

   By-products are floor sweepings and filler

   Outruns the evidence

   Evidence

   1. Strong
   2. Some
   3. Thin
   4. None

   The category covers named organs, blood and bone, and excludes hair, horns, teeth and hoofs. Liver and testicle each ran above 70% protein on a dry basis and digested as well as muscle meat in a 10-dog trial, the opposite of filler.^1,3