Motohiko Ishida

Diversity in VP3, NSP3, and NSP4 of rotavirus B detected from Japanese cattle

Bovine rotavirus B (RVB) is an etiological agent of diarrhea mostly in adult cattle. Currently, a few sequences of viral protein (VP)1, 2, 4, 6, and 7 and nonstructural protein (NSP)1, 2, and 5 of bovine RVB are available in the DDBJ/EMBL/GenBank databases, and none have been reported for VP3, NSP3, and NSP4. In order to fill this gap in the genetic characterization of bovine RVB strains, we used a metagenomics approach and sequenced and analyzed the complete coding sequences (CDS) of VP3, NSP3, and NSP4 genes, as well as the partial or complete CDS of other genes of RVBs detected from Japanese cattle. VP3, NSP3, and NSP4 of bovine RVBs shared low nucleotide sequence identities (63.3-64.9% for VP3, 65.9-68.2% for NSP3, and 52.6-56.2% for NSP4) with those of murine, human, and porcine RVBs, suggesting that bovine RVBs belong to a novel genotype. Furthermore, significantly low amino acid sequence identities were observed for NSP4 (36.1-39.3%) between bovine RVBs and the RVBs of other species. In contrast, hydrophobic plot analysis of NSP4 revealed profiles similar to those of RVBs of other species and rotavirus A (RVA) strains. Phylogenetic analyses of all gene segments revealed that bovine RVB strains formed a cluster that branched distantly from other RVBs. These results suggest that bovine RVBs have evolved independently from other RVBs but in a similar manner to other rotaviruses. These findings provide insights into the evolution and diversity of RVB strains.

Improving quality of common reed ( Phragmites communis Trin.) silage with additives

Objective Common reed (Phragmites communis Trin.) could potentially provide an alternative resource for silage; however, its silage quality is poor. The aim of this study was to investigate the factors in reed that contribute to poor quality and determine how the use of additives at ensiling could improve fermentation quality. Methods In Experiment 1, we determined the chemical composition and the presence of indigenous lactic acid bacteria (LAB) in reed. We further examined fermentation quality of reed silage under conditions without additives (NA) and treated glucose (G), lactic acid bacteria (L), and their combination (G+L). In Experiment 2, silage of NA, and with an addition of cellulase and lactic acid bacteria (CL) were prepared from harvested reed. The harvested reeds were fertilized at nitrogen concentrations of 0, 4, 8, and 12 g N/m2 and were harvested thrice within one year. Results The indigenous LAB and fermentable carbohydrates are at extremely low concentrations in reed. Reed silage, to which we added G+L, provided the highest quality silage among treatments in Experiment 1. In Experiment 2, N fertilization had no negative effect on silage quality of reed. The harvest times decreased fermentable carbohydrate content in reed. The CL treatment provided a higher lactic acid content compared to the NA treatment. However, the quality of CL treated silage at the second and third harvests was significantly lower than at the first harvest, due to a reduction in carbohydrates caused by frequent harvesting. Conclusion The causes of poor quality in reed silage are its lack of indigenous LAB and fermentable carbohydrates and its high moisture content. In addition, reed managed by frequent harvesting reduces carbohydrate content. Although the silage quality could be improved by adding CL, higher-quality silage could be prepared by adding fermentable carbohydrates, such as glucose (rather than adding cellulases).

Effects of inclusion levels of pelleted silvergrass (Miscanthus sinensis Andress.) in the diet on digestibility, chewing activity, ruminal fermentation and blood metabolites in breeding Japanese Black cows.

To examine the effects of inclusion levels of pelleted silvergrass (PS) in the diet on digestibility, ruminal fermentation and nutrient status of breeding Japanese Black cows, four cows were allotted to a 4 × 4 Latin square design experiment. Treatments were control fed a diet consisting of 89.4% Sudangrass hay and 10.6% soybean meal on a dry matter (DM) basis, and PS18, PS27 and PS45 fed the diet replaced with 18%, 27% and 45% of control with PS, respectively. The total digestible nutrients (TDN) content of PS was 45.6% on a DM basis. The TDN intakes were significantly decreased by increasing PS level in the diet (P < 0.05), but were higher than the TDN requirement of maintenance cows in all treatments. The total chewing time was decreased significantly by increasing PS level in the diets (P < 0.05). However, the pH and concentration of volatile fatty acid in the ruminal fluid and serum metabolite concentrations were not significantly different among the treatments. The results suggested that including PS up to 45% in the diet did not have adverse effects on the ruminal fermentation and nutrient status in breeding Japanese Black cows at the maintenance stage.