title: Fermentation Characteristics, Tannin Contents and In vitro Ruminal Degradation of Green Tea and Black Tea By-products Ensiled at Different Temperatures.
abstract: Green and black tea by-products, obtained from ready-made tea industry, were ensiled at 10°C, 20°C, and 30°C. Green tea by-product silage (GTS) and black tea by-product silage (BTS) were opened at 5, 10, 45 days after ensiling. Fermentation characteristics and nutrient composition, including tannins, were monitored and the silages on day 45 were subjected to in vitro ruminal fermentation to assess anti-nutritive effects of tannins using polyethylene glycol (PEG) as a tannin-binding agent. Results showed that the GTS and BTS silages were stable and fermented slightly when ensiled at 10°C. The GTS stored at 20°C and 30°C showed rapid pH decline and high acetic acid concentration. The BTS was fermented gradually with moderate change of pH and acid concentration. Acetic acid was the main acid product of fermentation in both GTS and BTS. The contents of total extractable phenolics and total extractable tannins in both silages were unaffected by storage temperatures, but condensed tannins in GTS were less when stored at high temperature. The GTS showed no PEG response on in vitro gas production, and revealed only a small increase by PEG on NH3-N concentration. Storage temperature of GTS did not affect the extent of PEG response to both gas production and NH3-N concentration. On the other hand, addition of PEG on BTS markedly increased both the gas production and NH3-N concentration at any ensiled temperature. It can be concluded that tannins in both GTS and BTS suppressed rumen fermentation, and tannins in GTS did more weakly than that in BTS. Ensiling temperature for both tea by-products did not affect the tannin's activity in the rumen.
authors: Department of Bioresources, Mie University, Tsu, Mie 514-8507, Japan ; Nagoya University Farm, Nagoya University, Togo, Aichi 470-0151, Japan .
authors: Makoto
authors: M
authors: Kondo
authors: Nagoya University Farm, Nagoya University, Togo, Aichi 470-0151, Japan . ; Department of Health and Nutrition, Tokai Gakuen University, Nagoya, Aichi 468-8514, Japan .
authors: Yoshiaki
authors: Y
authors: Hirano
authors: Nagoya University Farm, Nagoya University, Togo, Aichi 470-0151, Japan . ; Department of Agriculture, Iwate University, Morioka, Iwate 020-8550, Japan .
authors: Kazumi
authors: K
authors: Kita
authors: Department of Nutrition and Feed Technology, Bogor Agricultural University, Bogor 16680, West Java, Indonesia .
authors: Anuraga
authors: A
authors: Jayanegara
authors: Nagoya University Farm, Nagoya University, Togo, Aichi 470-0151, Japan .
authors: Hiro-Omi
authors: HO
authors: Yokota
keywords: In vitro Ruminal Degradation; Silage Fermentation; Tannin; Tea By-product