姜苗茎剪切力研究

Correlations among shearing force and feed characteristics of ginger stems

研究姜苗茎的剪切力与其形态学指标、化学组成和瘤胃降解率之间的关系。样品采集后,去叶,将茎按其长度平均分为上部茎段和下部茎段,试验选用G-LM3型肌肉嫩度仪测定茎剪切力,同时测定姜苗茎的长轴、短轴,化学组成采用尼龙袋法测定干物质(DM)、中性洗涤纤维(NDF)48h瘤胃降解率。通过数据分析、线性拟合探讨剪切力与各项指标之间的关系。试验结果表明:姜苗上部茎段和下部茎段试验结果一致,茎的粗细是影响剪切力的重要因素,木质素含量与剪切力之间有正相关关系,茎DM、NDF降解率随着其剪切力的增加而降低,并呈显著负相关关系,回归效果显著。剪切力与其形态学指标、化学组成及养分降解率均有一定的相关性,同时,由于剪切力测定易于操作,因此,剪切力可以用于作物秸秆营养价值的初步估计。

The objectives of this study were to investigate the effects of morphological characteristic on shearing force, the relationship between shearing force and chemical compositions; and the relationship between shearing force and in situ digestibility of ginger stems. Ginger stems were harvested and all leaves were removed from the main stems. Each stem was cut into two segments. Shearing force was measured with a C-LM3 meat shear. Meanwhile, long axis, minor axis, and chemical composition were measured. Three Xiao Wei sheep were used to determine in situ digestibility of DM and NDF in 48 h for ginger stems. The results showed that long axis was more important than chemical composition in affecting shearing force of ginger stem. There was positive relationship between lignin content and shearing force ginger stems. Correlations were also found between shearing force and other chemical components, such as ADF, cellulose and hemicelluloses in ginger stems. Negative correlations were found between shearing force and DM digestibility, NDF digestibility in ginger stem. These indicats that the variance in stern shearing force was related to chemical composition and morphological characteristics. In situ digestibility of ginger stems had a negative relationship with shearing force. Shearing force was easy to measure and it can be used as an indicator of forage nutritive value.