Effects of exogenous xylanase supplementation in plant protein‐enriched diets on growth performance, intestinal enzyme activities and microflora of juvenile Jian carp (Cyprinus carpio var. Jian)

A total of 900 juvenile Jian carp (Cyprinus carpio var. Jian) (7.99 ± 0.02 g) were fed diets containing graded levels of xylanase at 220 (unsupplemented control), 650, 1070, 1480, 1810 and 2470 U kg⁻¹ diet for 10 weeks to investigate the effects of xylanase levels on growth performance, intestinal enzyme activities and microflora. The per cent weight gain, feed efficiency, protein efficiency ratio, protein production value, lipid production value, ash production value, calcium production value and phosphorus retention ratio were significantly improved with increasing levels of xylanase up to a point, and thereafter declined (P