| The work was to investigate the effects of different ratios of distillers’ grains and citric acid slag on the fermentation quality and aerobic stability of total mixed ration(TMR).Based on the maximum addition ratio of distillers’ grains and citric acid residues,the fermentation quality and aerobic stability were further improved by adding sodium benzoate,sodium diacetate,calcium propionate,and potassium sorbate.The TMR production technology program for the use of by-products such as distillers’ grains and citric acid slag as raw materials was proposed to open up new ways for the rational utilization of local slag residue resources and reduce resource waste and environmental pollution.1.Proportional screening of distillers’ grains on the fermented TMRThe experiment was to evaluate the effect of different proportions of distillers’ grains on the fermentation quality of TMR.The fermented TMR was prepared with distillers’grains,Napier grass and concentrates.The control and three treatments were designed as follow:Control(A1);15%Distillers’ grains(A2);25%Distillers’ grains(A3);35%Distillers’ grains(A4).The silos were opened after 60 days and the fermentation quality was analyzed.The results showed that all silages were well preserved.Compared with the control,the pH,ammonia nitrogen/total nitrogen,ethanol and butyric acid contents in the distillers’ grains treatments significantly(P<0.05)decreased,while there was no significant(P>0.05)difference in lactic acid content among treatments.The WSC content significantly(P<0.05)increased with distillers’ grains ratios increasing.There was no significant(P>0.05)difference in lactic acid bacteria counts among treatments.Aerobic bacteria and yeast counts were significantly(P<0.05)lower in the various distillers’ grains treatments than the control.In summary,to consider the maximum utilization of fermentation quality and distillers’ grains resources,TMR formula with 35%distillers’ grains mixed ratio is recommended.2.Proportional screening of citric acid slag on the fermented TMRThis experiment was to evaluate the effect of different proportions of citric acid slag on the fermentation quality of TMR.The TMR was prepared with citric acid slag and distillers grains,Napier grass and concentrates.The control and three treatments were designed as follow:Control(D1);5%Citric acid slag(D2);10%Citric acid slag(D3);15%Citric acid slag(D4).The silos were opened after 60 days and the fermentation quality was analyzed.The results showed that all the silages were well preserved.Compared with the control,the pH and dry matter significantly(P<0.05)decreased in the citric acid slag treatment,and the lactic acid,ethanol,and ammonia nitrogen/total nitrogen contents significantly(P<0.05)increased.Lactic acid,acetic acid contents in the D3 were significantly(P<0.05)higher than in others.Lactic acid bacteria,yeast counts in the D4 were significantly(P<0.05)lower than in others.There were no significant(P>0.05)differences in aerobic bacteria counts among treatments.In summary,to consider the maximum utilization of fermentation quality and citric acid slag resources,TMR formula with 10%citric acid slag mixed ratio is recommended.3.Effect of four additives on fermentation quality and aerobic stability of distiller type TMRThis experiment was to evaluate the effects of potassium sorbate,sodium benzoate,sodium diacetate and calcium propionate on the fermentation quality and aerobic stability of distiller type TMR.The treatments were as follows:Control(C);Potassium sorbate(0.1%,AK);Sodium benzoate(0.1%,AS);Calcium propionate(0.5%,AP);(5)Sodium diacetate(0.5%,AA).The silos were opened after 60 days and the fermentation quality was analyzed.The aerobic stability of silage samples on the 3,6 and 9 day of exposure to air was evaluated.The results showed that the fermentation quality of all silages were good.Compared with control,all additive silages significantly(P<0.05)decreased lactic acid content,and increased the pH excepted for AK.Additives had significantly(P<0.05)lower ammonia nitrogen/total nitrogen,aerobic bacteria and yeast counts,and significantly(P<0.05)higher water soluble carbohydrate(WSC)content.During aerobic exposure,the pH,dry matter content,ammonia nitrogen/total nitrogen,aerobic bacteria and yeast counts increased,and lactic acid,acetic acid and ethanol contents significantly(P<0.05)decreased.However,compared with control,additives improved aerobic stability,and AK performed best.In summary,AK was the most suitable to improve the fermentation quality and aerobic stability of TMR.4.Effect of four additives on fermentation quality and aerobic stability of citric acid slag type TMRThe experiment was to evaluate the effects of potassium sorbate,sodium benzoate,sodium diacetate and calcium propionate on the fermentation quality and aerobic stability of citric acid slag type TMR.The treatments were as follows:Control(C);Potassium sorbate(0.1%,DK);Sodium benzoate(0.1%,DS);Calcium propionate(0.5%,DP);Sodium diacetate(0.5%,DA).The silos were opened after 60 days of ensiling and fermentation quality was analyzed.The aerobic stability of silage samples on the 4 and 9 day of exposure to air was evaluated.The results showed that the fermentation quality of all silages were good.Compared with control,additives significantly(P<0.05)decreased the ammonia nitrogen/total nitrogen,aerobic bacteria and yeast counts,and increased the WSC,however there were no obvious effects(P>0.05)on pH and lactic acid content,and DAsilage had higher acetic acid content and ammonia nitrogen/total nitrogen than others.During the period of aerobic exposure,ammonia nitrogen/total nitrogen,aerobic bacteria and yeast counts increased,and lactic acid and acetic acid contents decreased.The pH of control rapidly increased,and DP silage had lower pH than others during the period of aerobic exposure.DA and DK silage had lower ammonia nitrogen/total nitrogen and higher WSC,respectively.After 9 day of aerobic exposure,DP and DS silage had higher lactic acid bacteria counts,and had lower aerobic bacteria in DS and yeast counts in DP.Additives somewhat improved the aerobic stability of TMR.Among them,DA performed best on enhancing fermentation quality,and DP performed best on improving aerobic stability. |
