Changes

The term “protein quality” is used to describe the ability of a given plant or animal protein to provide adequate levels of [[Nutrition Glossary#Essential Amino Acids|essential amino acid(s)]] in order to support biological functions, such as growth or reproduction. Protein quality is determined by the composition of amino acids, and the [[Nutrition Glossary#Digestibility|digestibility]] and [[Nutrition Glossary#Bioavailability|bioavailability]] of amino acids within a given protein type. Protein digestibility can be adversely affected by dysfunction in any of the organs responsible for protein digestion and absorption (e.g. disorders of the stomach, [[Pancreas - Anatomy & Physiology|pancreas]], small intestine). In healthy animals protein digestibility is influenced by size in dogs<ref>Hannah SS, et al. Digestibility of diet in small and large breed dogs. Vet Clin Nutr 1995;2:145.</ref><ref>Nery J, et al. Influence of dietary protein content and source on fecal quality, electrolyte concentrations, and [[Nutrition Glossary#Osmolarity|osmolarity]], and digestibility in dogs differing in body size. J Anim Sci 2010;88:159-169.</ref> and decreases with age<ref>Teshima E, et al. Nutrient digestibility, but not mineral absorption, is age-dependent in cats. JAPAN (Berl) 2010;94:e251-258.</ref>. Additionally, cats protein digestibility of certain protein sources is lower compared to dogs<ref>de-Oliveira DL, et al. Digestibility for dogs and cats of meat and bone meal processed at two different temperature and pressure levels. JAPAN(Berl) 2012;96:1136-1146.</ref>. Dietary factors known to influence protein digestibility include:  

The term “protein quality” is used to describe the ability of a given plant or animal protein to provide adequate levels of [[Nutrition Glossary#Essential Amino Acids|essential amino acid(s)]] in order to support biological functions, such as growth or reproduction. Protein quality is determined by the composition of amino acids, and the [[Nutrition Glossary#Digestibility|digestibility]] and [[Nutrition Glossary#Bioavailability|bioavailability]] of amino acids within a given protein type. Protein digestibility can be adversely affected by dysfunction in any of the organs responsible for protein digestion and absorption (e.g. disorders of the stomach, [[Pancreas - Anatomy & Physiology|pancreas]], small intestine). In healthy animals protein digestibility is influenced by size in dogs<ref>Hannah SS, et al. Digestibility of diet in small and large breed dogs. Vet Clin Nutr 1995;2:145.</ref><ref>Nery J, et al. Influence of dietary protein content and source on fecal quality, electrolyte concentrations, and [[Nutrition Glossary#Osmolarity|osmolarity]], and digestibility in dogs differing in body size. J Anim Sci 2010;88:159-169.</ref> and decreases with age<ref>Teshima E, et al. Nutrient digestibility, but not mineral absorption, is age-dependent in cats. JAPAN (Berl) 2010;94:e251-258.</ref>. Additionally, cats protein digestibility of certain protein sources is lower compared to dogs<ref>de-Oliveira DL, et al. Digestibility for dogs and cats of meat and bone meal processed at two different temperature and pressure levels. JAPAN(Berl) 2012;96:1136-1146.</ref>. Dietary factors known to influence protein digestibility include:  

#The presence of anti-nutritive properties within certain ingredients (e.g., trypsin inhibitors found in uncooked legumes)<ref>Gilani GS, et al. Impact of antinutritional factors in food proteins on the digestibility of protein and the bioavailability of amino acids and on protein quality. B J Nutr 2012;108:S315-S332.</ref>;  

#The presence of anti-nutritive properties within certain ingredients (e.g. trypsin inhibitors found in uncooked legumes)<ref>Gilani GS, et al. Impact of antinutritional factors in food proteins on the digestibility of protein and the bioavailability of amino acids and on protein quality. B J Nutr 2012;108:S315-S332.</ref>;  

#The formation of [[Nutrition Glossary#Maillard Reaction|Maillard reaction]] products (cross-linkages between sugars and amino acids)<ref>van Rooijen C, et al. The Maillard reaction and pet food processing: effects on nutritive value and pet health. Nutr Res Rev 2013;26:130-148.</ref>; and  

#The formation of [[Nutrition Glossary#Maillard Reaction|Maillard reaction]] products (cross-linkages between sugars and amino acids)<ref>van Rooijen C, et al. The Maillard reaction and pet food processing: effects on nutritive value and pet health. Nutr Res Rev 2013;26:130-148.</ref>; and  

#High temperature and pressure effects on protein structures<ref>Johnson ML, et al. Effects of species raw material source, ash content, and processing temperature on amino acid digestibility of animal by-product meals by cecectomized roosters and ileally cannulated dogs. J Anim Sci 1998;76:1112-1122.</ref><ref>Larsen JA, et al. 2010 Bioavailability of lysine for kittens in overheated casein is underestimated by the rat growth assay method. JAPAN (Berl) 2010;94:e102-108.</ref><ref>Kerr KR, et al. Apparent total tract energy and macronutrient digestibility and fecal fermentative end-product concentrations of domestic cats fed extruded, raw beef-based, and cooked beef-based diets. J Anim Sci 2012;90:515-522.</ref>. The digestibility of protein is typically lower in plant-compared to animal-derived proteins<ref>Neirinck K, et al. Amino acid composition and digestibility of four protein sources for dogs. J Nutr 1991;121:S64-S65.</ref>. Feeding diets with a high soluble fiber content<ref>Muir HE, et al. Nutrient digestion by ileal cannulated dogs as affected by dietary fibers with various fermentation characteristics. J Anim Sci 1996;74:1641-1648.</ref><ref>Silvio J, et al. Influences of fiber fermentation on nutrient digestion in the dog. Nutr 2000;16:289-295.</ref><ref>Harper EJ. The effect of fiber on nutrient availability in cats of different ages. Vet Clin Nutr 1995;3:114.</ref> or with larger volumes of poorly digestible carbohydrate<ref name="NRC"/> will also result in a lower apparent protein digestibility in both dogs and cats.

#High temperature and pressure effects on protein structures<ref>Johnson ML, et al. Effects of species raw material source, ash content, and processing temperature on amino acid digestibility of animal by-product meals by cecectomized roosters and ileally cannulated dogs. J Anim Sci 1998;76:1112-1122.</ref><ref>Larsen JA, et al. 2010 Bioavailability of lysine for kittens in overheated casein is underestimated by the rat growth assay method. JAPAN (Berl) 2010;94:e102-108.</ref><ref>Kerr KR, et al. Apparent total tract energy and macronutrient digestibility and fecal fermentative end-product concentrations of domestic cats fed extruded, raw beef-based, and cooked beef-based diets. J Anim Sci 2012;90:515-522.</ref>. The digestibility of protein is typically lower in plant-compared to animal-derived proteins<ref>Neirinck K, et al. Amino acid composition and digestibility of four protein sources for dogs. J Nutr 1991;121:S64-S65.</ref>. Feeding diets with a high soluble fiber content<ref>Muir HE, et al. Nutrient digestion by ileal cannulated dogs as affected by dietary fibers with various fermentation characteristics. J Anim Sci 1996;74:1641-1648.</ref><ref>Silvio J, et al. Influences of fiber fermentation on nutrient digestion in the dog. Nutr 2000;16:289-295.</ref><ref>Harper EJ. The effect of fiber on nutrient availability in cats of different ages. Vet Clin Nutr 1995;3:114.</ref> or with larger volumes of poorly digestible carbohydrate<ref name="NRC"/> will also result in a lower apparent protein digestibility in both dogs and cats.