Study On The Relationship Between Fermentation Accumulated Temperature And Nutrition Loss Of Whole Plant Corn Silage

In animal husbandry,the production and management of whole-plant corn silage is a core work of silage production technology.in the process of silage fermentation,the normal dry matter loss is 13%-15%.The higher the silage temperature is,the longer the duration is,the more energy is consumed,and the greater the dry matter and nutrition loss is.Therefore,this experiment puts forward the following ideas:after the whole plant corn silage is sealed,from the beginning of fermentation to the stable stage of silage,during which the silage consumes nutrients and produces heat through aerobic respiration,and whether the amount of nutrient loss in silage can be estimated by measuring heat production.Previous studies have shown that compared with normal fermentation,high-temperature fermentation of silage will lose more nutrients.Based on this experimental background,combined with the concept of the accumulated temperature of crop fermentation,the concept of the accumulated temperature of fermentation was put forward,which was defined as the sum of temperature produced after the whole plant corn silage was fermented into a stable stage,and the consumed energy was converted into heat energy.Studies at home and abroad have shown that it takes 60 days for silage to complete fermentation and enter the stable stage.In this experiment,considering the great difference of air temperature in different regions,to reduce the difference of accumulated temperature of silage fermentation in different regions,the fermentation days are set at 70 days.In 2018,8 silage pits were selected in 2 dairy farms and 17dynamic thermometers were used to monitor the accumulated temperature of silage fermentation.the results showed that the fermentation temperature of whole plant corn silage in the Chabei alpine area was below 28℃,and the accumulated temperature of fermentation was 1700℃.However,the highest fermentation temperature of whole plant corn silage in North China Plain was 32℃and the accumulated fermentation temperature was 2200℃.Based on the above experiments,focusing on the four factors affecting fermentation accumulated temperature,this study explored whether the nutrient loss of whole plant corn silage could be estimated by measuring the fermentation accumulated temperature of whole plant corn silage,and the following results were obtained.136 silage pits were selected from 29 dairy farms in 10 provinces to determine the accumulated fermentation temperature of whole plant corn silage.meteorological data of 29 dairy farms at the same time were collected to explore the effect of air temperature on fermentation accumulated temperature.The results showed that the accumulated fermentation temperature of whole plant corn silage varied greatly among provinces in China,the lowest was 1842.45℃and the highest was 3048.25℃,the highest in East China was 2805.55℃,and the highest in subtropical zone was 2776.44℃.The accumulated temperature of whole-plant corn silage fermentation in each region was significantly correlated with the local air temperature,and the correlation coefficient was 0.53-0.81,indicating that the external temperature would have an effect on the accumulated temperature of whole-plant corn silage fermentation.On the premise of controlling the fermentation days and ambient temperature of whole plant corn silage,four silage compaction densities were designed,which were 300,450,600 and700kg/m~3 respectively,with 3 repeats in each group.The results showed that there was a significant non-linear relationship between whole-plant corn silage compaction density and fermentation accumulated temperature,and the correlation coefficient was 0.9996.Under the condition of different densities,the establishment of a multiple linear regression model between fermentation accumulated temperature and nutrition loss is very significant.The fitting degree of each index loss linear regression model is 90.5%-92.5%,and the correlation coefficient is 0.819-0.856,which shows a high correlation.It shows that increasing the compaction density of whole plant corn silage can reduce the fermentation accumulated temperature,and the accumulated temperature and nutrition loss of silage can be predicted by compaction density.On the premise of controlling the compaction density and ambient temperature of whole plant corn silage,five silage fermentation days were designed,which were 7,15,30,45 and 70 days respectively,with 3 repeats in each group.The accumulated fermentation temperature of whole plant corn silage was detected after measuring the accumulated fermentation temperature of different fermentation days.The results showed that there was a significant non-linear relationship between fermentation days and fermentation accumulated temperature of whole plant corn silage,and the correlation coefficient was 0.9677.Under the condition of different fermentation days,the establishment of a multiple linear regression model of fermentation accumulated temperature and nutrition loss is extremely significant.The fitting degree of each index loss linear regression model is 96.6%-99.1%,and the correlation coefficient is 0.933-0.981,which shows a high correlation.It shows that the accumulated temperature and nutrient loss of silage fermentation can be predicted by fermentation days.To study the effect of fermentation accumulated temperature on nutrition loss under the condition of different additives,single lactic acid bacteria starter and lactic acid bacteria starter+antistaling agent silage pits were selected in 5 areas,respectively.The accumulated temperature of silage fermentation with different silage additives was measured,and the silage samples were buried in the cellar.The samples were recovered when the cellar was opened,and the amount of nutrition loss before and after silage was compared.The results showed that the simultaneous use of lactic acid bacteria starter and antistaling agent in Hebei could significantly reduce the accumulated fermentation temperature of whole-plant corn silage by 13.66%.Low fermentation accumulated temperature in the Hebei area retained DM content better,but CF,ADF,and NDF content increased significantly,which may be due to the limitation of cellulase activity due to low fermentation accumulated temperature.There was no significant difference in silage fermentation accumulated temperature in other areas.To sum up,the external temperature can affect the fermentation accumulated temperature of whole-plant corn silage.through the compaction density and fermentation days,the accumulated fermentation temperature of whole-plant corn silage can be predicted and the nutrient loss of whole-plant corn silage can be estimated.The use of different silage additives in Hebei will have an effect on the accumulated temperature of fermentation but has no significant effect in other areas.