Kenzi Sato’s research while affiliated with Japan International Research Center for Agricultural Sciences and other places

To evaluate the effect of feeding condensed sweet-potato distillers solubles (CSDS) on milk production and milk flavor, four Holstein lactating cows were fed ad libitum with fermented total mixed ration (TMR) containing 0%, 10% or 20% CSDS (dry matter basis ; 0%CSDS, 10%CSDS and 20%CSDS, respectively) in three 14-day sequential experimental periods. Feed intake, ruminal fermentation, plasma metabolites, and milking performance were evaluated. Milk flavor, which was determined at day 14 of each period, was assessed with a sensory evaluation and taste sensing apparatus equipped with various sensor probes made of artificial lipid polymer membrane. The dry matter intake, milk fat and solids-not-fat contents of 20%CSDS were higher than those of 0%CSDS and 10%CSDS (23.8, 21.2 and 21.2kg/day, respectively, for dry matter intake ; 5.49%, 4.88% and 4.71%, respectively, for milk fat ; 9.00%, 8.78% and 8.80%, respectively, for solids-not-fat ; P<0.05). The result of flavor assessment using taste sensing apparatus showed that the creamy flavor of milk in 20%CSDS was higher than that in 0%CSDS (P<0.05). Panel sensory evaluation showed that 5 of 6 panelists found flavor difference between milk of 0%CSDS and 20%CSDS ; but it was not significant (P＝0.109). In conclusion, any effects of 10%CSDS inclusion on milk flavor were not found, while the effect of 20%CSDS inclusion could not be clarified because of possible effect of lactation period.

Paddy weeds may spread through the manure of cattle feeding on forage rice silage that is contaminated by weed seeds. We investigated the seed viability of several different types of paddy weeds ensiled with forage rice. Weed seeds of six species [Echinochloa crus-galli (L.) Beauv. var. formosensis Ohwi, Bidens frondosa L., Eclipta prostrata (L.) L., Schoenoplectus juncoides (Roxb.) Palla, Cyperus difformis L. and Monochoria vaginalis (Burm. f.) Presl var. plantaginea (Roxb.) Solms-Laub.] mixed in forage rice died completely as a result of ensiling for approximately 90–180 days. However, the viability of Aeschynomene indica L. seeds, which have a hard coat, was not compromised even after ensiling them for approximately 180 days.Therefore, when forage rice silage is contaminated with A. indica L. seeds, there is an increased risk of the excretion of germinable seeds in cattle manure.

To provide relevant information on utilizing fodder-sugarcane for dairy cows, we investigated the chemical composition, and long-term effect of fodder-sugarcane feeding on physiological aspects in non-lactating cows and milk production in lactating cows. The CP content of fodder-sugarcane silage (KRFo93-1; harvested 4 months after regrowth) was at the lowest level, whereas NDFom content peaked in roughage fed to lactating cows on conventional dairy farms. When 6 non-lactating Holstein cows were fed fodder-sugarcane silage with soybean meal and steam-rolled corn or sudangrass hay for 106 days, there were few changes in BW, hematological parameters, and blood metabolites throughout the experimental period. Seven lactating Holstein cows were fed TMR (TDN, 69%DM; CP, 15%DM) containing 0, 3, 5, 10, 15, or 20% fodder-sugarcane silage along with commercial concentrate (1.8 kg DM/cow/day). Milk yield and milk composition were unaffected by the proportion of fodder-sugarcane silage in the TMR. Conversely, the percentage of large particles (>19 mm) in TMR and in orts rose with an increasing proportion of fodder-sugarcane silage in TMR. The BUN concentration increased when cows were fed TMR containing over 15% fodder-sugarcane silage. These results suggest that fodder-sugarcane can be fed to cows without adversely affecting their physiological condition. However, for practical feeding to lactating cows, it is necessary to observe sorting against fodder-sugarcane silage.

Most tropical grasses in the warm southwestern region of Japan are cultivated as annuals and can be sown from May to July, after the harvest of an alternating crop of Italian ryegrass. However, suboptimal thermal conditions in the region may affect the germination and growth of seedlings. The objective of this study was to compare the growth of seedlings of promising tropical grasses in a Controlled Environment Facility (CEF) and in a Field Data (FD) trial. Temperatures in the CEF averaged 17.9, 22.9 and 27.9°C for the low (LT), middle (MT) and high temperature (HT) regimes, respectively, while the temperature in the FD trial was higher in the June-sowing (average 23.7°C, with a range between MT and HT in the CEF) than in the May sowing (average 21.2°C, between LT and MT). Favorable plant growth attributes tended to increase with the increase in air temperature in both trials. The growth rates in Guinea grass and Sudan grass exhibited a linear response to the increase in temperature from LT to HT, whereas the growth rate of Rhodes grass and colored Guinea grass showed saturation between MT and HT. Thus, for early sowing in mid-May, the prominent species judged in terms of high seedling potential were Sudan grass and Rhodes grass and for the late-sowing in early July, Sudan grass and Guinea grass.

The effects of material kinds and processing time on the nutritive contents of shochu condensed distiller soluble (SCDS) were investigated. Samples were collected one time per month from four different processing plants, which process shochu made from rice, barley, sweet potato and barley plus sweet potato, respectively. The nutritive contents of SCDS were different among raw materials. There were high crude protein content in SCDS made from rice and barley, and high energy content in SCDS made from sweet potato. When raw material was one kind, the contents of crude protein and nitrogen free extract in SCDS had fewer changes all the year round, but the variation of dry matter contents was large. In this case, confirming material kind and DM content could estimate relatively correct the nutritive contents. On the other hand, when raw materials were not one kind, the crude protein content of SCDS had a large variation in year-round. In this case, it would be necessary to confirm material kinds and analyze chemical composition. When SCDS is used as a material of fermented TMR, it suggest that its low pH value will have a positive effect on the fermentation, while high buffering capacity and high pentose ratio in total sugar will have a negative effect.

The effects of planting time (early or normal), nitrogen (N) application rate (150 or 225 kg N ha-1), and N application method (early, even, and late application of extra N) on total digestible nutrient (TDN) concentration and yield of forage rice (Oryza sativa L.) in southwestern Japan were examined. For optimal forage rice production, it is important to maximize nutritional level in leaves and stems rather than panicles because the hull restricts cattle's ability to digest rice grain. In particular, it is important to maximize the TDN in leaf sheath plus stems (stems) which are the major part of the crop rather than leaf blades (leaves). Stem TDN yield was higher with early planting (340 g m-2) than with normal planting (217 g m-2) irrespective of N application rate or method. The high stem TDN yield with early planting resulted from both the high DM yield and the high TDN and organic cellular content (OCC) concentration. Stem TDN yield was not affected by the N application rate. With both early and normal plantings, stem TDN yield was higher with early N application (374 and 226 g m-2, respectively) than with late N application (305 and 208 g m-2, respectively). With early planting, the high stem TDN yield with method 1 resulted from both the high DM yield and the high TDN and OCC concentration. Thus, to obtain high stem TDN concentration and yield of forage rice, early planting and early N application are recommended.

米焼酎粕濃縮液で大豆粕を置き換えた混合飼料（TMR）の乳牛への給与が摂取量，消化性および乳生産成績に及ぼす影響を検討するため，4頭のホルスタイン種泌乳牛に大豆粕を20％（乾物ベース）含むTMR（大豆粕区）あるいは大豆粕を米焼酎粕濃縮液で置き換えたTMR（焼酎粕区）を給与し，1期14日間の反転法で試験を行った．濃厚飼料の種類や割合を変えることにより，TMRの粗濃比，可消化養分総量および窒素含量を両区でそろえた．米焼酎粕濃縮液の粗タンパク質含量は大豆粕と同程度であったが，酸性デタージェント不溶性窒素含量は高かった．摂取量，1日の反すう時間を除く咀嚼活動，乳生産量および乳成分に処理間差は見られなかったが，焼酎粕区は大豆粕区に比べ血漿中リン濃度は高く，窒素吸収率，血漿および乳中尿素態窒素濃度が低かった．以上から，窒素吸収率を考慮して飼料設計を行えば，米焼酎粕濃縮液は泌乳牛用TMR原料として有用であることが示された．

We examined the effects of cultivar (Taporuri, Mohretsu, Tachiaoba, and Hinohikari) on estimated total digestible nutrient (TDN) yield of forage rice in double harvesting. The total estimated whole-plant TDN yield (i.e., of the first crop plus second crop) of Taporuri was the highest in double harvesting. In the first crop, the estimated whole-plant TDN yield of Taporuri was the highest. In the second crop, the estimated whole-plant TDN yield of Taporuri was almost the same as those of Mohretsu and Tachiaoba but higher than that of Hinohikari. We also examined the effects of cultivation method (double harvesting or single harvesting) on estimated TDN yield of forage rice. In Taporuri and Mohretsu, the total estimated whole-plant TDN yield was similar in double harvesting and single harvesting. However, in Tachiaoba and Hinohikari, it was lower in double harvesting than in single harvesting. It is important to maximize the amount of nutrition in leaf and stem rather than panicle because the grain is not digested well by cattle. In the double harvesting, the total estimated leaf blade (leaf) TDN yield of Taporuri was higher than that of Hinohikari and almost the same as those of Tachiaoba and Mohretsu. The total estimated leaf sheath plus stem (stem) TDN yield of Taporuri was the highest. In comparison of the total TDN yield of double harvesting with that of single harvesting, the total estimated leaf and stem TDN yields were higher in double harvesting than in single harvesting in all cultivars except for Hinohikari. Thus, double harvesting of Taporuri is an effective way of reducing the overall loss of nutrition from the crop.

We tested a flail-type roll baler (FR) for wilting Italian ryegrass, oats, Guinea grass, and Sudan grass. The FR wilting system produced faster drying than the conventional system, except with Italian ryegrass. The number of times of turning did not influence a drying rate. In Italian ryegrass and oats, the increase in a lactic acid content, the content sum of butyric, caproic and valeric acid and VBN/T-N decreased in the silage which performed wilting processing compared with non-wilting silage. The fermentation quality of the silage wilted by FR were equivalent of the silage wilted by the conventional system. In Guinea grass, any processing silage had low V-Score. In FR wilting, a harvest loss rate tended to have increased compared with the conventional system except for GG. As for any forage grass, about estimated TDN and the fiber fraction, the silage made in FR wilting did not have a difference the silage made in conventional system. The FR wilting system shortened the harvesting time of Sudan grass. These results showed that the FR wilting system, which cuts the grass and then dries and harvests it without turning or with turnig once, enabled faster drying than the conventional system, and the fermentation quality of these silage is equivalent to the silage produced conventionally.