Changes

==Dietary Sources==

==Dietary Sources==

Protein is found in animal and plant protein sources, such as muscle and organ meats, eggs, dairy protein (e.g. casein), cereal grains, and pulses (i.e. legumes). Animal sourced proteins are generally more highly digestible than plant sourced proteins for both dogs and cats<ref>Neirinck K, et al. Amino acid composition and digestibility of four protein sources for dogs. J Nutr 1991;121:S64-S65.</ref><ref>Funaba M, et al. Evaluation of meat meal, chicken meal, and corn gluten meal as dietary sources of protein in dry cat food. Can J Vet Res 2005;69:299-304.</ref>. Processing of proteins can affect their digestibility; heat processing can increase digestibility for some proteins, while rendering and drying can decrease digestibility<ref>Murray SM, et al. Raw and rendered animal by-products as ingredients in dog diets. J Anim Sci 1997;75:2497-2505.</ref><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>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>. Presence of soluble fibres and carbohydrates within a diet can also decrease protein digestibility<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>. In dogs, digestibility varies with size, breed, and age, with older dogs experiencing a decrease in digestive capacity<ref name="Wannemacher"/><ref>Hannah SS, et al. Digestibility of diet in small and large breed dogs. Vet Clin Nutr 1995;2:145.</ref>. '''Cats have a shorter small intestinal length to body size ratio which may limit their ability to digest protein, and may explain why protein digestibility is lower in cats compared to dogs'''<ref name="NRC"/>.

Protein is found in animal and plant protein sources, such as muscle and organ meats, eggs, dairy protein (e.g. casein), cereal grains, and pulses (i.e. legumes). Animal sourced proteins are generally more highly digestible than plant sourced proteins for both dogs and cats<ref>Neirinck K, et al. Amino acid composition and digestibility of four protein sources for dogs. J Nutr 1991;121:S64-S65.</ref><ref>Funaba M, et al. Evaluation of meat meal, chicken meal, and corn gluten meal as dietary sources of protein in dry cat food. Can J Vet Res 2005;69:299-304.</ref>. Processing of proteins can affect their digestibility; heat processing can increase digestibility for some proteins, while rendering and drying can decrease digestibility<ref>Murray SM, et al. Raw and rendered animal by-products as ingredients in dog diets. J Anim Sci 1997;75:2497-2505.</ref><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>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>. Presence of soluble fibres and carbohydrates within a diet can also decrease protein digestibility<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>. In dogs, digestibility varies with size, breed, and age, with older dogs experiencing a decrease in digestive capacity<ref name="Wannemacher"/><ref>Hannah SS, et al. Digestibility of diet in small and large breed dogs. Vet Clin Nutr 1995;2:145.</ref>. '''Cats have a shorter small intestinal length to body size ratio which may limit their ability to digest protein, and may explain why [[Digestibility of Protein|protein digestibility]] is lower in cats compared to dogs'''<ref name="NRC"/>.

Crude protein as listed on a pet food label is a measure of dietary nitrogen and does not reflect the source or quality of protein in a commercial diet.

Crude protein as listed on a pet food label is a measure of dietary nitrogen and does not reflect the source or quality of protein in a commercial diet.