The objective of this study was to determine the effect of beet pulp (BP) and lactic acid bacteria (LAB) on silage fermentation quality and in vitro ruminal dry matter (DM) digestion of vegetable residues, including white cabbage, Chinese cabbage, red cabbage, and lettuce. Silage was prepared using a small-scale fermentation system, and treatments were designed as control silage without additive or with BP (30% fresh matter basis), LAB inoculant Chikuso-1 (Lactobacillus plantarum, 5mg/kg, fresh matter basis), and BP+LAB. In vitro incubation was performed using rumen fluid mixed with McDougall's artificial saliva (at a ratio of 1:4, vol/vol) at 39°C for 6h to determine the ruminal fermentability of the vegetable residue silages. These vegetable residues contained high levels of crude protein (20.6-22.8% of DM) and moderate levels of neutral detergent fiber (22.7-33.6% of DM). In all silages, the pH sharply decreased and lactic acid increased, and the growth of bacilli, coliform bacteria, molds, and yeasts was inhibited by the low pH at the early stage of ensiling. The silage treated with BP or LAB had a lower pH and a higher lactic acid content than the control silage. After 6h of incubation, all silages had relatively high DM digestibility (38.6-44.9%); in particular, the LAB-inoculated silage had the highest DM digestibility and the lowest methane production. The vegetable residues had high nutritional content and high in vitro DM digestibility. Also, both the addition of a LAB inoculant and moisture adjustment with BP improved the fermentation quality of the vegetable residue silages. In addition, LAB increased DM digestibility and decreased ruminal methane production.

Nitrification, the microbial oxidation of ammonia to nitrate via nitrite, occurs in a wide range of acidic soils. However, the ammonia-oxidizing bacteria (AOB) that have been isolated from soil to date are acid-sensitive. Here we report the isolation and characterization of an acid-adapted AOB from an acidic agricultural soil. The isolated AOB, strain TAO100, is classified within the Gammaproteobacteria based on phylogenetic characteristics. TAO100 can grow in the pH range of 5-7.5 and survive in highly acidic conditions until pH 2 by forming cell aggregates. Whereas all known gammaproteobacterial AOB (γ-AOB) species, which have been isolated from marine and saline aquatic environments, are halophiles, TAO100 is not phenotypically halophilic. Thus, TAO100 represents the first soil-originated and non-halophilic γ-AOB. The TAO100 genome is considerably smaller than those of other γ-AOB and lacks several genes associated with salt tolerance which are unnecessary for survival in soil. The ammonia monooxygenase subunit A gene of TAO100 and its transcript are higher in abundance than those of ammonia-oxidizing archaea and betaproteobacterial AOB in the strongly acidic soil. These results indicate that TAO100 plays an important role in the nitrification of acidic soils. Based on these results, we propose TAO100 as a novel species of a new genus, Candidatus Nitrosoglobus terrae.

Nine multiparous Holstein cows were used in a replicated 3 × 3 Latin square design to determine the effects of substituting corn grain with brown rice (BR) grain in total mixed ration (TMR) silage on milk yield, ruminal fermentation and nitrogen (N) balance. The TMR silages were made from the ensiling of TMR containing (dry matter basis) 50.1% forage in rice silage and corn silage combination, and 49.9% concentrate. The grain portion of the diets contained 31.2% steam-flaked corn, 31.2% steam-flaked BR or an equal mixture of corn and BR. Dietary treatments did not affect dry matter intake, milk yield and milk fat, protein and lactose yields. The ruminal pH and total volatile fatty acid concentrations were not affected by dietary treatment. The urinary N excretion decreased linearly (P < 0.01) in response to increased levels of BR, with no dietary effect on N intake, N secretion in milk and fecal N excretion. Our results indicate that steam-flaked BR is a suitable replacement for steam-flaked corn in dairy cow diets, and that it can be included in rations to a level of at least 31.2% of dry matter without adverse effects on milk production, when cows were fed rice silage and corn silage-based diets.

Data of 46 water balance measurements were collected from dry and lactating Holstein cows in the controlled climatic chamber, which maintained at 20°C and 60% relative humidity, to evaluate between drinking water intake (DWI), feed water intake (FWI), total water intake (TWI) and some variables in cows. Orchardgrass silage, alfalfa silage and corn silage were offered in dry cows, and alfalfa or orchardgrass silage and concentrates were given as a TMR in ratio of 60:40 in lactating cows. DMI and milk production were highly related to DWI and TWI of lactating cows. DWI in dry and lactating cows increased and FWI decreased as dietary DM increased, but there was a very weak correlation between dietary DM and TWI. In both dry and lactating cows, positive correlations were obtained between dietary CP or K and TWI, especially highly correlations between dietary K and TWI. There were strong positive correlations between N intake, K intake or urine volume and TWI rather than DWI in dry and lactating cows. These results suggest that dry and lactating cows accelerate DWI to excrete large amounts of K or N into urine in excess of their needs, but TWI is more suitable to evaluate the effects of dietary CP or K on water intake and urine volume in dairy cows.

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The objective of this study was to evaluate the effect of substituting brown rice grain for corn grain in total mixed ration (TMR) silage containing food by-products on the milk production, whole-tract nutrient digestibility and nitrogen balance in dairy cows. Six multiparous Holstein cows were used in a crossover design with two dietary treatments: a diet containing 30.9% steam-flaked corn (corn TMR) or 30.9% steam-flaked brown rice (rice TMR) with wet soybean curd residue and wet soy sauce cake. Dietary treatment did not affect the dry matter intake, milk yield and compositions in dairy cows. The dry matter and starch digestibility were higher, and the neutral detergent fiber digestibility was lower for rice TMR than for corn TMR. The urinary nitrogen (N) excretion as a proportion of the N intake was lower for rice TMR than for corn TMR with no dietary effect on N secretion in milk and fecal N excretion. These results indicated that the replacement of corn with brown rice in TMR silage relatively reduced urinary N loss without adverse effects on feed intake and milk production, when food by-products such as soybean curd residue were included in the TMR silage as dietary crude protein sources.

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In the cultivation of tea in Japan, compared with other crops, large amounts of nitrogen have been applied as fertilizer, resulting in an increase in nitrate-nitrogen (NO 3 -N) concentrations in the groundwater around intensive tea-growing areas. To address this problem, the amounts of nitrogen fertilizer applied to tea fields have been reduced in recent years. It has been reported that the amount of fertilizer used in 1993 was more than 1,000 kg N ha, but had decreased to 600 kg N ha )1 in 2002 in Shizuoka Prefecture. In the present study, the effect of a reduction in nitrogen fertilizer use in an intensive tea-growing area in Shizuoka Prefecture on surrounding water systems was assessed. A seasonal Mann-Kendall test, one of the most widely used non-parametric tests, was applied to 10-year datasets of monthly pH and NO 3 -N concentrations from 16 sites, including drainages, springwater, groundwater and streams, for trend analysis. The results showed that there were significant downward trends (two-sided test at a 5% level) in NO 3 -N concentrations at most of the sites, and the seasonal Kendall slope estimator b, which represents the magnitude of the trend, ranged from )2.9 to )0.8 in drainages, from )2.6 to )1.8 in springwater and from )0.6 to )0.3 mg N L )1 year )1 in streams. The results of the present study suggested that the efforts made by farmers and authorities to reduce nitrogen fertilizer use in tea fields have resulted in improvements in NO 3 -N concentrations in the surrounding water systems in the study area. In contrast, for pH, significant downward trends were observed at nine of the 16 sites, indicating that water systems in this area have been acidifying, despite a reduction in nitrogen fertilizer use.