What is the appropriate crude fiber content for growing-finishing pigs

Without affecting growth, what is the appropriate crude fiber content in feed for growing-finishing pigs? How much wheat bran does everyone add?
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Fiber at around 10 percentage points, the quality of wheat bran is hard to control, it seems some feed mills are looking for substitutes.
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It is best to keep it within 8 percentage points, wheat bran has a mild diarrhea effect, so it is best to control it within 15 percent
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Generally add 10%