水稲のホールクロップサイレージによる肉用牛の肥育に関する研究.第2報 : 乳用種去勢牛の肥育試験(畜産学)  [in Japanese] Studies on Beef Cattle Production Using Rice Whole Crop Silage. II : Fattening Experiments on Japanese Holstein Steers Fed on Rice Whole Crop Silage without Supplemental Feed during Pre-fattening Period  [in Japanese]

1. 乳用種去勢牛を用い, その肥育前期(20週間), 水稲ホールクロップサイレージ(乳熟∿糊熟期刈取)のみを給与し, その後濃厚飼料を給与した(サイレージ区)場合の発育増体性及び枝肉形質について検討した。対照区には肥育前後期を通じて濃厚飼料を給与した。2. 水稲ホールクロップサイレージのみを給与した, 肥育前期20週間の平均DGは, サイレージ区は0.09kg, 対照区は1.01kgであった。また, この期間中の, TDN要求率はサイレージ区は9.5kg, 対照区は5.8kgであった。3. 肥育後期, すなわち濃厚飼料に切換えた後, サイレージ区のDGが約1kgに達するまでに16週間を要した。また, 濃厚飼料切換え後, 体重が650kgに達するまでの日数は, サイレージ区は373日, 対照区は182日であった。なお, この期間中の平均DGは, サイレージ区が0.92kg, 対照区が0.96kg, TDN要求率はサイレージ区が6.08kg, 対照区が7.42kgであった。4,枝肉形質は, ロース芯面積及びロース芯の脂肪交雑は対照区が優った。さらに, 本試験ではstore型の肥育にみられる脂肪付着の過剰はなかった。

1. Japanese Holstein steers were fed on a rice whole crop silage (harvested at milk-or dough-stage) without supplemental feed during pre-fattening period (for 20 weeks) and were fed on a concentrate mixture plus grass silage during post-fattening period (silage group). And their live weight gains and carcass characteristics were compared with those of control group fed on the concentrate mixture plus grass silage throughout the fattening period. Average initial body weight for the silage group and the control group were 301.1 and 340kg, respectively. 2. In the pre-fattening period, the daily gains for the silage group and the control group averaged 0.09 and 1.01kg, respectively. And TDN requirements during this period were 9.5kg for the silage group and 5.8kg for the control group. 3. After beginning of feeding on the concentrate mixture, it took for 16 weeks to reach about 1kg of daily gains in the silage group. 4. Days required to reach 650kg of body weight were 373 days for the silage group and 182 days for the conprol group after beginning of feeding on the concentrate mixture. In this period, the daily gains for the silage group and the control group avaraged 0.92 and 0.96kg, respectively. And TDN requirements were 6.08kg for the silage group and 7.42kg for the control group. 5. The control group had more area of rib eye and marbling than those of the silage group. In addition, there was no excess fat deposition in the silage group as seen in store type fattening of cattle.