Fermentative quality of purple rice (Oryza sativa L.) silage and its effects on digestibility, ruminal fermentation and oxidative status markers in sheep: A preliminary study

Some anthocyanins have been reported to exhibit antioxidant activity and to enhance antioxidant enzyme activity. The aim of this study was to determine the fermentative quality of purple rice, which is abundant in anthocyanin, and its effects on digestibility, ruminal fermentation and oxidative status markers in sheep. The whole crop silages of purple and control rice were prepared in drum silos after the materials were chopped and lactic acid bacteria was inoculated. These were followed by a feeding trial using eight wethers in a 2 x 2 crossover design. Both the purple and control rice silages showed excellent fermentative qualities. Although the purple rice silage contained abundant anthocyanin, it had inadequate nutritional values in comparison to the control rice silage, including higher levels of fiber fractions, lower nutrient digestibility and lower production of ruminal volatile fatty acids. The feeding of the purple rice silages led to an elevation in plasma activity of superoxide dismutase, which is an important antioxidant enzyme. The results of this study suggest that purple rice may become a source of anthocyanin to improve oxidative status in ruminants. To achieve that, however, a new variety of purple rice with good nutritional value is needed for practical use as a ruminant feed.