| The informations of whole plant silage corn varieties,harvesting and procduction in large-scale pastures in Heilongjiang were investigated,and silage samples were collected.The quality of the samples was evaluated by sensory evaluation,nutritional value,fermentation quality and rumen degradation characteristics.Then the analysis of the key points of silage production were conducted by the grey correlation degree analysing to calculate the weight of each index in the evaluation of silage quality.The key points of were further analyzed.This shudy provided a theoretical basis for the production of higher quality and rational utilization of whole plant corn silage.Experiment 1:Quality evaluation of whole plant corn silage from 2016 to 2017 in large-scale pastures of Heilongjiang provinceThe informations of whole plant silage corn varieties,harvesting and procduction in large-scale pastures in Heilongjiang were investigated,and silage samples were collected.The number of samples were 27 and 24 in 2016 and 2017,respectively.Samples were collected from pastures in Harbin,Qiqihar,Daqing,Anda,Suihua,Shangzhi,Heihe,Meishan and other places in Heilongjiang province.The quality of the samples was evaluated by sensory evaluation,nutritional value,fermentation quality and rumen degradation characteristics.Then the analysis of the key points of silage production were conducted by the grey correlation degree analysing to calculate the weight of each index in the evaluation of silage quality.The key points of were further analyzed.The results showed that the sensory evaluation and grain fragmentation of silage in 2017 were better than those in 2016,dry matter(DM)content decreased significantly(P<0.05),but starch content,dry matter degradation rate(DMD)and neutral detergent fiber degradation rate(NDFD)of silage increased significantly in 2017(P<0.05).The results of grey correlation method showed that the weight coefficient of DM,NDF and starch were higher in evaluating silage quality.In summary,the comprehensive evaluation quality of whole plant silage produced by large-scale pastures in Heilongjiang in 2017 was better than that in 2016.The key points of silage production were corn varieties,compactness,cutting length and stubble height.Experiment 2:Effects of varieties and stubble height on the quality of whole plant corn silageThree corn varieties widely cultivated in Heilongjiang province including high starch variety of Yangguang No.1,high protein variety of Zhongyuandan 32 and high biology yield variety of Longfu 208 were studied in this experiment.Using a single factor design,two cutting heights of 19 and 49 cm were set.The conventional nutritional value,fermentation quality and rumen degradation rate of 6 different treatments were determined.The results showed that with the increase of stubble height,the contents of DM,CP and starch increased significantly before and after fermentation(P<0.05),while the contents of NDF,ADF and ammoniacal nitrogen/total nitrogen(VBN/TN)decreased(P<0.05).For rumen degradation rate,DMD and CPD increased significantly with the increase of stubble height in high protein variety Zhongyuandan 32 and high yield variety Longfu 208(P<0.05),but the NDFD of high starch quality Yangguang No.1 and high protein variety of Zhongyuandan 32 decreased significantly(P<0.05).Therefore,the increase of stubble height could increase the content of DM,CP and starch in whole plant corn silage,but it would reduce the buffer of fermentation process and had little effect on the fermentation index.Therefore,stubble height coud be appropriately reduced for high starch and low fiber silage corn varieties such as Yangguang No.1,while high protein variety of Zhongyuandan 32 and high biology yield variety of Longfu 208,stubble height could be properly increased in order to maximize the quality and yield of silage.Experiment 3: Effect of cutting length on the quality of whole plant corn silageSingle factor design was applied to this experiment,whole plant corn silage samples were collected from large-scale pasture(n=3)in Daqing City,Heilongjiang Province,of which cutting lengths were 1 cm,1.5 cm and 2.5 cm,respectively.The crushing degree of gr ains,physical effective factor,routine nutritional value,fermentation quality and rumen degradation rate of each sample were measured.The results showed that with the increase of cutting length,physical effective factors and the number of intact grains increased significantly(P<0.05),lactic acid content decreased significantly(P<0.05);DM content decreased significantly when cutting length was 1 cm(P<0.05);DMD and starch degradation rate decreased significantly when cutting length was 2.5 cm(P<0.05).In summary,the silage quality of the whole plant was the best when the cutting length was 1.5 cm.With the decrease of cutting length,the loss of soluble nutrients and physical effective factor increased.In contrast,with the increase of cutting length,the degree of grain breakage and DMD and starch degradation rate decreased.Experiment 4: Effect of moisture and compaction on the quality of whole plant corn silageIt is difficult to quantify moisture content and compactness in the process of filling and cellar pressing in large-scale pasture silage production.Therefore,a single factor experiment design was adopted to comprehensively analyze the effects of different water moisture and compactness on silage quality.In this experiment,nine-point sampling method was used to collect the upper,middle and lower layers of silage in large-scale pasture(n=6).The routine nutritional value,fermentation quality and rumen degradation rate of the samples were determined.The fermentation quality was evaluated comprehensively by the membership function value method of fuzzy mathematics.The results showed that the moisture content and compa ctness of silage increased with the increase of depth.DM content in lower layer was significantly lower than that in upper layer(P<0.05).The DMD and NDFD in middle and lower silage were significantly higher than those in upper silage(P<0.05),but there was no significant difference between middle and lower silage(P>0.05).The evaluation results of subordinate function method showed that the comprehensive evaluation value of middle silage in silage silo is the highest,followed by lower sample.In summary,the nutrient loss of DM and starch increased with the increase of the depth of silage,but the p H and organic acid was better,and the rumen degradation rate was increased.However,after reaching a certain depth,the fermentation quality tended to be sta ble.The comprehensive evaluation results showed that the quality of middle silage was the best.In conclusion,the following conclusions could be drawn from this study:The comprehensive quality of corn silage in Heilongjiang area in 2017 was better tha n that in 2016.The main factors affecting the quality of corn silage were corn varieties,compactness,cutting length and stubble height.Among the corn varieties with different characteristics widely planted in Heilongjiang area,the high starch and low fiber variety Yangguang No.1 showed the best quality.The suitable stubble height for whole plant corn silage was 19 cm,for high starch and low fibre varieties,the stubble height could be reduced appropriately,for high protein or high yield varieties,the stubble height could be increased appropriately to maximize the quality and yield.The best quality of whole plant corn silage was obtained,when the cutting length of 1.5 cm.In addition,the fermentation quality tends to be stable after the silage re acheed a certain depth.Therefore,attention should be paid to the layer-by-layer pressure cellar and top sealing in process of silage production. |
PDF Full Text Request