Evaluation of Fermentation Quality, Digestive Characteristics, and Nutritive Value of Whole Crop Silage Prepared by Fine-Cutting From Rice Cultivars With Short Panicles and Fed to Dairy Cows.

Abstract

Silage fermentation and digestibility characteristics, ruminal fermentation, and chewing activity in dairy cattle fed whole-crop rice silages having short panicle cultivars "Tachisuzuka," "Tachiayaka," and "Tsukisuzuka" were evaluated. All cultivars used in this study were grown under identical conditions, harvested using a fine-cutting harvesting machine, and ensiled in a round baler for the chopped material along with Lactobacillus inoculation. Four nonlactating, nonpregnant, rumen-cannulated Holstein cows were housed in a climate-controlled room and fed one of the three silage diets in a 3 × 3 Latin square design. Every 2 weeks, the cows were housed in respiration chambers for 5 days to measure gaseous exchange, energy and nitrogen balance, apparent total-tract digestibility of nutrients, and chewing activity. All cultivars showed fermentation quality with low pH and high acetic acid content. The digestibilities of fiber and nonfibrous carbohydrates were higher in Tachisuzuka and Tachiayaka than in the other cultivars, respectively. The total digestible nutrient contents in Tachisuzuka, Tachiayaka, and Tsukisuzuka were 61.4%, 60.8%, and 59.4%, respectively. The roughage value index was 79-86. The high digestibility of these silage cultivars suggests that they could be used as feed for lactating cows; however, their high chewing stimulus also needs to be considered.