全株玉米与紫花苜蓿拉伸膜裹包混合青贮的研究

Study on Mixed Ensiling of Whole-crop Maize and Alfalfa by Stretch Film Wrapping

试验以全株玉米和紫花苜蓿为原料,探讨不同混合比例青贮效果,确定最佳混合比例.试验设5个处理组:全株玉米单贮(Y组)、紫花苜蓿单贮(Z组)、75%全株玉米+25%紫花苜蓿(Y75Z25组)、67%全株玉米+33%紫花苜蓿(Y67Z33组)、50%全株玉米+50%紫花苜蓿(Y50Z50组).结果表明,全株玉米与紫花苜蓿混合青贮的粗蛋白、酸性洗涤纤维、粗灰分含量介于全株玉米单贮和紫花苜蓿单贮之间.表现为,青贮饲料粗蛋白(CP)、粗灰分(CA)含量随着紫花苜蓿比例的提高,而显著提高(P<0.05);酸性洗涤纤维(ADF)含量随着紫花苜蓿比例的降低,而显著降低(P<0.05).紫花苜蓿单贮,发酵品质较差.与紫花苜蓿单贮相比,混合青贮饲料随着全株玉米比例的提高,青贮效果逐步改善,当比例达到67%时,显著降低了青贮饲料的pH值、氨态氮/总氮值(P<0.05),显著提高了乳酸含量、乳酸/总酸值(P<0.05),并使丁酸含量低于检测水平,获得优质青贮饲料.综合各项指标,以67%全株玉米+33%紫花苜蓿与75%全株玉米+25%紫花苜蓿混合青贮效果较为理想.

This study carried out to evaluate the fermentation effect of mixed silages of wholecrop maize and alfalfa.There are 5 treatments which are silage of whole-crop maize(Y),ensiling of alfalfa(Z),mixed ensiling of 75%whole-crop maize+25%alfalfa(Y75Z25),mixed ensiling of 67%whole-crop maize+33%alfalfa(Y67Z33)and mixed ensiling of 50%whole-crop maize+50%alfalfa(Y50Z50).The results showed that CP,ADF and Ash contents of maize-alfalfa silages mixtures ranged between those of maize silage and alfalfa silage.CP content,CA content of silages significantly increased with increasing proportion of alfalfa(P<0.05),ADF content of silages significantly decreased with decreasing proportion of alfalfa(P<0.05).Fermentation quality of alfalfa silage was poor.The fermentation qualities of mixed silages improved gradually with the increasing proportion of whole-crop maize compared with alfalfa silage.When the proportion of whole-crop maize reached 67%,the values of pH and NH3-N/TN significantly reduced(P<0.05),Lactic acid(LC)contents and LC/TA values significantly increased(P<0.05),the butyric acid contents were lower than detection level.Taking nutrient contents and fermentation qualities of silage into account,mixed silages with 67%whole-crop maize+33%alfalfa and 75%whole-crop maize+25%alfalfa got the desired results.