Comprehensive evaluation on yield and silage quality of different silage corn varieties

【Objective】 To explore the effects of cultivar on biomass yield and silage quality of silage corn(Zea mays),and screen the good quality and high yield silage corn varieties suitable for planting in Chongqing,so as to provide reference for promoting the healthy and stable development of herbivorous animal husbandry in Chongqing.【Method】 Four new silage corn varieties(Yuqingyu No.3,Yuqing 386,Yuqing 385 and Yudan 58) were used as the test materials, setting Yayuqingzhu No.8 as the control(CK). The biomass yield were measured at harvest period. The conventional nutrient contents and fermentation quality were determined after the whole silage corn chopped up for 90 d. The silage quality was further comprehensively evaluated using principal component analysis and membership function analysis method,and the good variety was screened combined with biomass yield.【Result】 There were obvious differences in biomass yield among the varieties,and Yuqing 386 had the highest yield of fresh matter and dry matter,significantly increased by 9.03% and 10.56% compared to the control(P<0.05,the same below). There were differences in the nutrient contents among different varieties of whole corn silage. The highest crude protein(CP) content was in Yuqing 386 (8.43%),which was significantly higher than that of Yudan 58 and CK by 18.23% and 17.08%,respectively;and it had the lowest acid detergent fiber(ADF) content(20.33%),which was significantly lower than that of other varieties. The lowest neutral detergent fiber(NDF) content was in Yuqing 385(40.30%),which was significantly reduced than that of CK by 14.93%. The contents of starch and water-soluble carbohydrates(WSC) in Yudan 58 were the highest(37.90% and 3.12%), which were significantly higher than that of Yuqingyu No.3, Yuqing 385, and CK. There were obvious differences in fermentation quality parameters among varieties. Yuqing 386 had the lowest pH(4.06) and the highest lactic acid content(7.70%). The acetic acid content in Yuqing 385 was highest(0.56%). The propionic acid content in Yudan 58 was the lowest(0.10%). The ammonia nitrogen/total nitrogen(NH₃-N/TN) content in Yuqingyu No.3(11.45%) was significantly higher than other varieties. The butyric acid was not detected in any variety. The V-Scores of whole-plant corn silage for five varieties were all above 80 points,and the grade of fermenting quality was good level. Yuqing 386 had the highest score(93.4). Three principal components were extracted through principal component analysis,and the cumulative contribution rate reached 89.810%,reflecting most of the information of the original 14 indexes. Principal component analysis and membership function analysis showed that the silage quality of the four tested varieties was better than CK. The average membership function values of Yuqing 386 and Yuqing 385 were greater than 0.50.【Conclusion】 In summary, planting Yuqing 386 in Chongqing has the highest biomass yield and a better effect on making whole corn silage,which has higher promotion value.