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pstinard · 05-07-2015, 10:38 AM

Meat or poultry by-products and meals

Some clients are concerned about the meaning, content, and source of “by-products” from meats or poultry. The lack of understanding may confuse pet owners and lead them to perceive these as poor-quality ingredients.

Meat by-products consist of edible parts and organs such as heart, lungs, stomach, or liver; meat trimmings; bone; and other tissues from mammals, such as cattle or hogs.23 As defined by AAFCO, by-products do not include hair or hide, horns or hooves, intestinal contents, or feathers from poultry.23 Compared with skeletal meat alone, by-products actually provide more essential nutrients. For example, meat is lacking in calcium and vitamin A, which are provided in by-products from the bones and liver. Although the components of by-products are not widely consumed by people in the United States, many are considered delicacies for human consumption in other cultures. These also are the same tissues consumed first by animals in the wild.

The “meals” of meat or poultry by-products are created by rendering. Rendering is a cooking process similar to what happens when you boil chicken to separate the broth, fat, and meat for chicken soup. In commercial rendering, fat is separated (and becomes animal fat), and the “soup” is dried to remove the water. The dried product is then ground into a protein-rich powder or meal.24 Meat meals and poultry meals can provide excellent sources of protein and essential amino acids and can be highly digestible.25, 26, 27 and 28 Rendering conditions, as well as the source and handling of raw materials used, can greatly influence the quality of the protein meals produced.26, 27 and 28 These variables can affect the protein digestibility of the finished pet food, so pet food companies may contract with specific suppliers to assure the consistent quality of their ingredients. Although detailed information about ingredients may be proprietary, veterinarians can contact the manufacturer to ask about the digestibility of protein in specific pet foods.

Renderers affiliated with USDA-inspected meat or poultry plants will receive animal products only from those facilities, so pet food manufacturers that work exclusively with these renderers will have greater control about the specific content and quality of the by-products that they use. One of the prevailing Internet myths about commercial pet foods states that they may contain rendered remains of pets. It is because of the ability to work with USDA-affiliated renderers that pet food companies can have confidence that their products do not contain dog or cat remains, as has been attested to by members of the Pet Food Institute and confirmed by testing conducted by the USDA’s Center for Veterinary Medicine.29

Animal Versus Vegetable Source Proteins: Determinants of Protein Quality

The quality of dietary protein is determined by the amino acid composition of the protein, its digestibility, and its ability to meet an animal’s amino acid requirements, rather than whether it comes from animal or vegetable sources. Common measures of protein quality are typically conducted on individual sources of protein (ingredients), and use laboratory assays, rodent feeding trials, or both. The associated score generally reflects the amino acid most deficient in that protein, called the “limiting amino acid”. For example, soy protein provides at least 100% of most essential amino acids, but it is deficient in methionine and thus receives a lower score based on its methionine content. Used alone, proteins with low scores would provide lower-quality nutrition. Fortunately, the limiting amino acids of different proteins often differ. Complementary proteins are those that provide excess of each other’s limiting amino acids so that the combination of ingredients provides all of the necessary amino acids.

By mixing complementary proteins in a diet, the finished product can provide excellent protein quality even though the individual components each have limitations. So although most vegetable source proteins, for example, soy protein, corn gluten meal, or wheat gluten, are incomplete proteins if used alone due to their limiting amino acids, they are highly digestible. When incorporated into a properly cooked diet with complementary proteins, they can contribute to a diet that provides complete, high-quality protein, easily digested by both dogs and cats.

05-07-2015, 10:38 AM	#4
pstinard YT 3000 Club Member Join Date: Apr 2013 Location: Urbana, IL USA Posts: 3,648	Meat or poultry by-products and meals Some clients are concerned about the meaning, content, and source of “by-products” from meats or poultry. The lack of understanding may confuse pet owners and lead them to perceive these as poor-quality ingredients. Meat by-products consist of edible parts and organs such as heart, lungs, stomach, or liver; meat trimmings; bone; and other tissues from mammals, such as cattle or hogs.23 As defined by AAFCO, by-products do not include hair or hide, horns or hooves, intestinal contents, or feathers from poultry.23 Compared with skeletal meat alone, by-products actually provide more essential nutrients. For example, meat is lacking in calcium and vitamin A, which are provided in by-products from the bones and liver. Although the components of by-products are not widely consumed by people in the United States, many are considered delicacies for human consumption in other cultures. These also are the same tissues consumed first by animals in the wild. The “meals” of meat or poultry by-products are created by rendering. Rendering is a cooking process similar to what happens when you boil chicken to separate the broth, fat, and meat for chicken soup. In commercial rendering, fat is separated (and becomes animal fat), and the “soup” is dried to remove the water. The dried product is then ground into a protein-rich powder or meal.24 Meat meals and poultry meals can provide excellent sources of protein and essential amino acids and can be highly digestible.25, 26, 27 and 28 Rendering conditions, as well as the source and handling of raw materials used, can greatly influence the quality of the protein meals produced.26, 27 and 28 These variables can affect the protein digestibility of the finished pet food, so pet food companies may contract with specific suppliers to assure the consistent quality of their ingredients. Although detailed information about ingredients may be proprietary, veterinarians can contact the manufacturer to ask about the digestibility of protein in specific pet foods. Renderers affiliated with USDA-inspected meat or poultry plants will receive animal products only from those facilities, so pet food manufacturers that work exclusively with these renderers will have greater control about the specific content and quality of the by-products that they use. One of the prevailing Internet myths about commercial pet foods states that they may contain rendered remains of pets. It is because of the ability to work with USDA-affiliated renderers that pet food companies can have confidence that their products do not contain dog or cat remains, as has been attested to by members of the Pet Food Institute and confirmed by testing conducted by the USDA’s Center for Veterinary Medicine.29 Animal Versus Vegetable Source Proteins: Determinants of Protein Quality The quality of dietary protein is determined by the amino acid composition of the protein, its digestibility, and its ability to meet an animal’s amino acid requirements, rather than whether it comes from animal or vegetable sources. Common measures of protein quality are typically conducted on individual sources of protein (ingredients), and use laboratory assays, rodent feeding trials, or both. The associated score generally reflects the amino acid most deficient in that protein, called the “limiting amino acid”. For example, soy protein provides at least 100% of most essential amino acids, but it is deficient in methionine and thus receives a lower score based on its methionine content. Used alone, proteins with low scores would provide lower-quality nutrition. Fortunately, the limiting amino acids of different proteins often differ. Complementary proteins are those that provide excess of each other’s limiting amino acids so that the combination of ingredients provides all of the necessary amino acids. By mixing complementary proteins in a diet, the finished product can provide excellent protein quality even though the individual components each have limitations. So although most vegetable source proteins, for example, soy protein, corn gluten meal, or wheat gluten, are incomplete proteins if used alone due to their limiting amino acids, they are highly digestible. When incorporated into a properly cooked diet with complementary proteins, they can contribute to a diet that provides complete, high-quality protein, easily digested by both dogs and cats. Last edited by pstinard; 05-07-2015 at 10:40 AM.