全株青贮玉米品种对其发酵品质及营养价值的影响

Variety effects on fermentation quality and nutritive value of whole-plant maize silage

试验旨在比较不同品种青贮专用型玉米全株青贮发酵品质及营养价值的差异,以郑青贮1号、金岭青贮17号和京科青贮516为试验材料,于1/2~3/4乳线期刈割,使用聚乙烯发酵袋(50 cm×80 cm)在实验室条件下发酵60 d,开袋后进行感官评价,测定发酵品质,风干样粉碎后用于常规化学成分及消化率的测定。结果表明:不同品种感官评分等级均为良好级,其中,籽粒含量和总评分差异极显著(P<0.01),色泽及气味差异显著(P<0.05)。品种间各项发酵参数差异极显著(P<0.01),费氏评分≥110.00分,发酵品质均为优级。各品种青贮后干物质、粗蛋白、粗脂肪、水溶性碳水化合物、淀粉、中性洗涤纤维、酸性洗涤纤维、酸性洗涤木质素、粗灰分含量及相对饲喂价值差异极显著(P<0.01),且相对饲喂价值>121.00。品种间青贮产量及能量价值均存在极显著差异(P<0.01),郑青贮1号的奶吨指数、总可消化养分及各项能值极显著高于其他品种(P<0.01),干物质产量及奶亩指数极显著低于其他品种(P<0.01),金岭青贮17号的干物质产量显著较高(P<0.01),奶吨指数、总可消化养分及各项能值均极显著高于京科青贮516(P<0.01),奶亩指数极显著高于其他品种(P<0.01)。各品种碳水化合物组分剖分及体外干物质、中性洗涤纤维消化率均存在极显著差异(P<0.01),金岭青贮17号的体外干物质及中性洗涤纤维消化率均极显著高于京科青贮516和郑青贮1号(P<0.01),京科青贮516的体外干物质消化率极显著高于郑青贮1号(P<0.01),郑青贮1号的体外中性洗涤纤维消化率极显著高于京科青贮516(P<0.01)。综上所述,金岭青贮17号为优异的青贮专用型玉米品种,其次为京科青贮516。

This experiment was conducted to investigate the fermentation quality and nutritive value of whole-plant maize silage made from different silage-specific varieties. Zheng Silage No.1, Jinling Silage No.17 and Jingke Silage No.516 were harvested at one-half to three-fourths milk line and ensiled in plastic bags (50 cm×80 cm) for 60 days, then sensory evaluation was performed and fermentation quality analyzed. Chemical composition and in vitro digestibility were carried out after air-drying of samples. All varieties performed well in the sensory evaluations, while the grain content and total score showed significantly differences among varieties (P<0.01), color and odor also differed (P<0.05). There were significantly differences in fermentation parameters among varieties (P<0.01), and when Flieg score (FS) was ≥ 110.00 points, fermentation quality was excellent. There were significantly differences among varieties in dry matter (DM), crude protein (CP), ether extract (EE), water soluble carbohydrate (WSC), starch, neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), ash contents and relative feed value (RFV)(P<0.01), and RFV was >121.00 in all cases. There were also significantly differences in silage yield and energy values among varieties (P<0.01). The milk per ton index (MT), total digestible nutrients (TDN) and energy values of Zheng Silage No.1 were significantly higher (P<0.01), while DM yield and milk per acre index (MA) were significantly lower than other two varieties (P<0.01). The dry matter (DM) yield of Jinling Silage No.17 was significantly higher (P<0.01), MT, TDN and energy values were significantly higher than Jingke Silage No.516 (P<0.01), and milk per acre index (MA) was the highest. Carbohydrate fractions analysis, in vitro DM digestibility (IVDMD) and in vitro NDF digestibility (IVNDFD) showed significantly differences among varieties (P<0.01). The IVDMD and IVNDFD of Jinling Silage No.17 were significantly higher than other tested varieties (P<0.01). The IVDMD of Jingke Silage No.516 was significantly higher than Zheng Silage No.1 (P<0.01), while the IVNDFD of Zheng Silage No.1 was significantly higher than Jingke Silage No.516 (P<0.01). In conclusion, Jinling Silage No.17 performed better than the other two varieties in this experiment, and the second ranked performer was Jingke Silage No.516.