title: Effect of feeding a by-product feed-based silage on nutrients intake, apparent digestibility, and nitrogen balance in sheep.
abstract: BACKGROUND
  Literature is lacking on the effects of feeding by-product feed (BF)-based silage on rumen fermentation parameters, nutrient digestion and nitrogen (N) retention in sheep. Therefore, this study was conducted to determine the effect of replacing rye straw with BF-based silage as a roughage source on ruminal parameters, total-tract apparent nutrient digestibility, and N balance in sheep.
  
  
  METHODS
  The by-product feed silage was composed of spent mushroom substrate (SMS) (45 %), recycled poultry bedding (RPB) (21 %), rye straw (11 %), rice bran (10.8 %), corn taffy residue (10 %), protected fat (1.0 %), bentonite (0.6 %), and mixed microbial additive (0.6 %). Six sheep were assigned randomly to either the control (concentrate mix + rye straw) or a treatment diet (concentrate mix + BF-based silage).
  
  
  RESULTS
  Compared with the control diet, feeding a BF-based silage diet resulted in similar ruminal characteristics (pH, acetate, propionate, and butyrate concentrations, and acetate: propionate ratio), higher (p < 0.05) ruminal NH3-N, higher (p < 0.05) ether extract digestibility, similar crude protein digestibility, lower (p < 0.05) dry matter, fiber, and crude ash digestibilities, and higher (p < 0.05) N retention (g/d).
  
  
  CONCLUSIONS
  The BF-based silage showed similar energy value, higher protein metabolism and utilization, and lower fiber digestion in sheep compared to the control diet containing rye straw.
authors: HRC, Division of Food Biosciences, College of Health and Medical Life Sciences, Konkuk University, Chung-Ju, Chung-Buk 380-701 Korea.
authors: J S
authors: JS
authors: Seok
authors: HRC, Division of Food Biosciences, College of Health and Medical Life Sciences, Konkuk University, Chung-Ju, Chung-Buk 380-701 Korea.
authors: Y I
authors: YI
authors: Kim
authors: HRC, Division of Food Biosciences, College of Health and Medical Life Sciences, Konkuk University, Chung-Ju, Chung-Buk 380-701 Korea.
authors: Y H
authors: YH
authors: Lee
authors: HRC, Division of Food Biosciences, College of Health and Medical Life Sciences, Konkuk University, Chung-Ju, Chung-Buk 380-701 Korea.
authors: D Y
authors: DY
authors: Choi
authors: HRC, Division of Food Biosciences, College of Health and Medical Life Sciences, Konkuk University, Chung-Ju, Chung-Buk 380-701 Korea.
authors: W S
authors: 0000-0002-7829-8172
authors: WS
authors: Kwak
keywords: By-product feed; Digestibility; Sheep; Silage; Spent mushroom substrate