Ikuo Hattori

Early Planting and Early Nitrogen Application Increase Stem Total Digestible Nutrient Concentration and Yield of Forage Rice in Southwestern Japan

Abstract 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.

Effect of Stubble Shaving after High-Level Cutting on the Growth and Yield of Forage Sugarcane, KRFo93-1, under Multiple Ratooning Cultivation

Abstract In the production of sugarcane, stubble shaving that cuts the residual stubble of the previous crop is carried out to promote ratoon crop growth. On the other hand, in the production of feed crops, it is generally considered that high-level cutting increases the yield of the regrowth crop. In this study, the growth and yield of the forage sugarcane subjected to high-level cutting without stubble shaving (HC) were compared with those of the plants subjected to stubble shaving (Control) to clarify the necessity of stubble shaving in the cultivation of a forage sugarcane variety, KRFo93-1. The influence of high-level cutting on the growth and yield of ratoon crop was evaluated from the first ratoon crop (RC1) to sixth ratoon crop (RC6). Tiller number in the Control plot was not different from that in the HC plots in all ratoon crops from RC1 to RC6. Stem length was significantly larger in HC than in the Control plot in all ratoon crops at the initial stage of regrowth, and in RC1, RC3, RC5 and RC6 around the harvest time. Dry matter yield was significantly higher in HC than in the Control plot in RC1, RC3, RC5, RC6 and in the sum of the ratoon crops. Although no significant difference was observed in RC2 or RC4, the dry matter yield of HC exceeded that of Control plot. The increase in the dry matter yield of HC was due to an enhancement of stem growth, since the single stem dry weight were larger in HC than in Control plot. Thus, cultivation management without stubble shaving is recommended in KRFo93-1.

Effect of feeding sweet-potato condensed distillers solubles on intake and urinary excretion of minerals in Japanese Black steers

Four Japanese Black steers (16 months of age) were assigned to a 4 × 4 Latin square design to investigate the effect of graded levels of sweet-potato condensed distillers solubles (SCDS) in their diets on intake and urinary excretion of minerals. The four diets consisted of 0%, 10%, 20% and 30% (dry matter (DM) basis) SCDS, with SCDS replacing commercial concentrate (CC). Intake of K, Cl, S, P and Mg increased linearly with increasing SCDS content. Urinary pH increased linearly with increasing dietary SCDS content. SCDS feeding increased urinary K concentrations (linear and quadratic effects). Urinary concentrations of Cl increased linearly with increasing SCDS content. In contrast, urinary concentrations of Mg decreased with increasing SCDS content. Feeding of SCDS did not apparently affect urinary NH3 ,P, Na or Ca concentrations. These results suggest that high SCDS feeding is not a risk for crystallization of minerals leading to the formation of magnesium-phosphate type calculi: although SCDS contains large amounts of P and Mg, high SCDS feeding decreased the Mg concentration and did not affect the P concentration in urine. Additionally, high SCDS feeding had no apparent effects on plasma concentrations of Na, K, Cl, Ca or inorganic P.