Influence of nitrogen fertilization and defoliation frequency on nitrogen constituents and feeding value of annual ryegrass.
Influence of nitrogen fertilization and defoliation frequency on nitrogen constituents and feeding value of annual ryegrass.
复制标题
施氮肥和落叶频率对一年生黑麦草氮成分和饲用价值的影响
DOI：
--
复制
发表时间：
1995
影响因子：
3.3
通讯作者：
J. Hafley
中科院分区：
文献类型：
--
作者：
Y. Zhang;L. D. Bunting;L. Kappel;J. Hafley
通过两个试验，研究了氮肥（NF）和落叶间隔（DI）对一年生黑麦草（AR）中特定氮组分和生长羔羊对AR氮的总体利用率的季节效应。在Exp. 1，NF（0，112，224，和336公斤N/公顷）和DI的2，4，或6周的因子施加到AR地块。降低DI和增加NF均以依赖于收获日期的方式增加AR中的N水平（NF或DI x收获日期交互作用，P <0.05）。NF和DI对0.2%NaOH水溶性氮和可溶性蛋白氮的比例无显著影响（P > 0.05）。虽然NF对DM的原位消失没有影响（P > 0.05），但降低DI似乎降低了季节诱导的DM消失减少的严重程度（DI x收获日期相互作用，P = 0.04）。在Exp. 2、NF（0或224 kg N/ha）和DI为2或6 wk被因子地应用于AR小区。使用4 x 4拉丁方，将新鲜冷冻AR在半纯化饲料（48% DM作为AR）中饲喂给4只公绵羊羔羊（23 +/- 1.3 kg）。日粮中，包括AR有更大的瘤胃DM和植物N的消化率时，AR有2周与6周的DI与NF，但有降低消化率时，AR有2周与6周的DI没有NF。（250字处删节）
Two experiments were conducted to determine the seasonal effects of N fertilizer (NF) and defoliation interval (DI) on specific N fractions within annual ryegrass (AR) and overall usage of AR N by growing lambs. In Exp. 1, NF (0, 112, 224, and 336 kg of N/ha) and DI of 2, 4, or 6 wk were factorially applied to AR plots. Both decreasing DI and increasing NF increased N levels in AR in a manner that depended on harvest date (NF or DI x harvest date interaction, P < .05). The proportions of .2% NaOH soluble N or soluble protein N were not affected (P > .05) by NF or DI. Although NF had no effect (P > .05) on in situ disappearance of DM, decreasing the DI seemed to reduce the severity of the season-induced reduction in DM disappearance (DI x harvest date interaction, P = .04). In Exp. 2, NF (0 or 224 kg of N/ha) and a DI of 2 or 6 wk were factorially applied to AR plots. Fresh, frozen AR was fed in semipurified diets (48% of DM as AR) to four wether lambs (23 +/- 1.3 kg) using a 4 x 4 Latin square. Diets including AR had greater ruminal DM and plant N digestibilities when AR had a 2-wk vs a 6-wk DI with NF but had reduced digestibilities when AR had a 2-wk vs a 6-wk DI without NF.(ABSTRACT TRUNCATED AT 250 WORDS)