Highlights
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Specific endogenous protein losses are significant metabolic costs to the animal, p.
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These losses are those induced by the presence of dietary components, such as fibre and anti-nutrients.
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These losses can be calculated by determining the basal and total (basal plus specific) losses and then subtracting the basal losses from total losses.
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Two techniques, namely the guanidination and isotope markers, can be used for the determination of total endogenous losses.
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Published data quantifying these losses are limited owing to the technical complexity of available methodologies.