天津地区窖贮苜蓿抽样检测与质量分析

Sampling Detection and Quality Analysis of Alfalfa Cellar Silage in Tianjin

为了解天津地区苜蓿青贮概况,本研究对8个奶牛场的窖贮苜蓿进行抽样检测,检测指标主要包括水分、粗蛋白、中性洗涤纤维、酸性洗涤纤维和灰分等营养指标,以及pH值、氨态氮/总氮、乙酸和丁酸等化学指标。结果表明,天津地区窖贮苜蓿平均水分含量为50.96%~74.38%,其中5个奶牛场属常规青贮,3个奶牛场属半干青贮;营养指标粗蛋白、中性洗涤纤维和酸性洗涤纤维含量分别为16.58%~21.40%,37.20%~50.87%和31.89%~44.63%,化学指标pH值、氨态氮/总氮、乙酸和丁酸含量分别为4.18%~5.29%,4.79%~19.78%,15.51%~50.75%和0.00%~34.14%;常规苜蓿青贮综合质量分级三级和未入级占比分别为20%和80%,半干苜蓿青贮综合质量分级三级和未入级占比分别为67%和33%。根据调查结果,笔者从苜蓿青贮含水量调控、适时收获及加强管理3个方面提出建议,以提升天津地区苜蓿青贮品质。

To survey the general condition of alfalfa silage in Tianjin,the nutritional and chemical indexes of alfalfa silage in 8 dairy farms were analyzed by sampling test.The results showed that the average water content of alfalfa cellar silage was 50.96%~74.38%.According to the water content,the alfalfa silage in five dairy farms were belonged to routine silage while in the other three dairy farms were belonged to semi-dried silage.The contents of crude protein,neutral detergent fiber and acid detergent fiber were 16.58%~21.40%,37.20%~50.87%and 31.89%~44.63%,respectively.The contents of pH,ammonia nitrogen/total nitrogen,acetic acid and butyric acid were 4.18%~5.29%,4.79%~19.78%,15.51%~50.75%and 0.00%~34.14%,respectively.In the comprehensive quality classification of routine alfalfa silage,the third grade and the non-grade accounted for 20%and 80%,respectively.In the comprehensive quality classification of semi-dry alfalfa silage,the third grade and the non-grade accounted for 67%and 33%,respectively.According to the survey results,the suggestions in three aspects including alfalfa silage water content controlling,optimum harvesting and reinforce the management were proposed to improve the quality of alfalfa silage in Tianjin.