| The objective of this study was to discuss the effect of substituting hulless barley straw for tall fescue and oat respectively at different ratios on fermentation quality?aerobic stability and in vitro digestibility of TH and OH total mixed ration silage(TMRs)after 14 days and 90 days fermentation,and to evaluate the effect of addictives on the aerobic stability of TH and OH TMRs after 90 days fermentation.In order to make full use of hulless barley straw resources in local dairy cow industry and solve the problem of pasture shortage in cold seasons,the suitable substituting ratio must be obtained to guide production.In order to improve the aerobic stability of the TMRs and decrease the loss of nutrients during the aerobic exposure,the better addictives were expected to select.1.Effect of substituting hulless barley straw for tall fescue on early fermentation quality,aerobic stability and in vitro digestibility of total mixed ration silage fermentation in TibetThe objective of this experiment was to evaluate the effects of substituting hulless barley straw for tall fescue at different ratios on early fermentation quality,aerobic stability and in vitro dry matter of TMRs in Tibet.The experiment treatments were as follows:control(THO)and three treatments(TH5,TH10 and TH15).These silos were opened on 14 days after ensiling and the fermentation quality,chemical and microbial compositions were analyzed.Meanwhile,the aerobic stability was tested by the online multi-channel data logger temperature recorder,and we took samples to estimate the aerobic stability at the 2th,5th and 8th day of exposure to air.The results showed that the pH,lactic acid,acetic acid,TVFAs and alcohol contents of TH5 had no significant(P>0.05)difference comparing with THO.The pH of TH10 was similar(P>0.05)with THO,but the lactic acid,acetic acid,TVFAs and alcohol contents had significant(P<0.05)difference comparing with THO.The lactic acid,acetic acid,propionic acid,butyric acid,total volatile fatty acids and alcohol contents of TH15 were significantly(P<0.05)lower than THO and pH of it was markedly higher(P<0.05)than that of THO.Ammonia nitrogen/total nitrogen and lactic acid/acetic acid had no significant(P>0.05)difference in all treatments and control.The lactic acid fermentation was dominant in all silages and they all had a good fermentation quality.During exposure to air,pH and ammonia nitrogen/total nitrogen in all treatments and control kept elevating after the 2th day of exposure to air,however,lactic acid,acetic acid and water soluble carbohydrates content kept decreasing;the numbers of yeast and aerobic bacteria had rising trend.Apart from TH15,other treatments temperatures began to rise at 35h after opening the silos,TH15 delayed the rising of temperature and had the smallest peak.Bringing what had been discussed into a conclusion,TH15 had the best aerobic stability.Barley straw replacement group significantly increased TMRs dry matter digestibility.Taking all aspects into account,including fermentation quality,aerobic stability and maximum using hulless barley straw,it was suggested that TH15 treatment was the most suitable choice.2.Effect of substituting hulless barley straw for oat on early fermentation quality,aerobic stability and in vitro digestibility of total mixed ration silage in TibetThe objective of this experiment was to evaluate the effects of substituting hulless barley straw for oat at different ratios on early fermentation quality,aerobic stability and in vitro dry matter of TMRs in Tibet.The experiment treatments were as follows:control(OHO)and three treatments(OH5,OHIO and OH15).These silos were opened on 14 days after ensiling and the fermentation quality,chemical and microbial compositions were analyzed.Meanwhile,the aerobic stability was tested by the online multi-channel data logger temperature recorder,and we took samples to estimate the aerobic stability at the 2th,5th and 8th day of exposure to air.The results showed that pH in four groups did not have the difference,and the lactic acid,VFAs and ethanol contents in OH5 were not different significantly with OHO,while those in OH10 and OH 15 were sharply lower than OHO.The acetic acid content,ammonia nitrogen/total nitrogen and lactic acid/acetic acid had no significant(P>0.05)difference in all groups.The ammonia nitrogen/total nitrogen and butyric acid content in all treatments were very low,which indicated that all TMRs had a good fermentation quality.During the whole period of exposure,OH 15 treatment had small change in these chemical compositions among all TMR silages.Aerobic deterioration occurred at 28 h in the control.OH15 treatment delayed the rising of temperature and had the smallest peak in all silages,which indicated OH15 had the best aerobic stability.Hulless barley straw replacement group reduced TMRs dry matter digestibility.In conclusion,the data of this study suggested that OH 15 treatment was the most suitable choice considering fermentation quality,nutritive value,aerobic stability and maximum using hulless barley straw.3.Effect of substituting hulless barley straw for tall fescue and addictives on fermentation quality,aerobic stability and in vitro digestibility of total mixed ration silage in TibetThe objective of this experiment was to study the effect of different proportions of barley straw insteading of tall fescue and 5 kinds of additives on fermentation quality?aerobic stability and in vitro dry matter digestibility of TH total mixed ration silage.After the experiment,the suitable replacement ratio and addictive can be got to improve the feeding value.There were four substituting ratio treatments including THO,TH5,TH10 and TH15 as well as addictive treatments including CK,B,A,P,E and F.These silos were-opened on 90 days after ensiling and the fermentation quality,chemical and microbial compositions were analyzed.Meanwhile,the aerobic stability was tested by the online multi-channel data logger temperature recorder,and we took samples to estimate the aerobic stability at the 3th,6th,9th and 14th day of exposure to air.The results showed that pH in TH10 and TH15 were sharply higher than that of THO,which were both below 4.6.Lactic acid,acetic acid and ethanol content in four groups significantly decreased with the increasing of replacement ratio.Ammonia nitrogen/total nitrogen and butyric acid content had no significant(P>0.05)difference in all groups.The lactic acid fermentation was dominant in all silages and they all had a good fermentation quality.pH in all addictive treatments were markedly higher than that in CK.The butyric acid contents in all groups were low(<2g/kgDM).Ammonia nitrogen/total nitrogen and ethanol contents in E and F were significantly higher than those in CK.The aerobic stability increased with the increasing of replacement ratio,which indicated that TH15 had the best aerobic stability.In all addictive treatments,A treatment had the best aerobic stability.TH15A TMR silage did not indicate the phenomenon of corruption during the exposure days.Replacement treatment reduced the in vitro dry matter digestibility of TMRs,while addictive treatment increased the in vitro dry matter digestibility of TMRs.In conclusion,the data of this study suggested that TH10 treatment and A,B and F addictive were the suitable choice considering fermentation quality,nutritive value,aerobic stability and maximum using hulless barley straw.4.Effect of substituting hulless barley straw for oat and addictives on fermentation quality,aerobic stability and in vitro digestibility of total mixed ration silage in TibetThis experiment aimed to study the effect of different proportions of barley straw insteading of oat and 5 kinds of additives on fermentation quality,aerobic stability and in vitro dry matter digestibility of OH total mixed ration silage.After the experiments,the suitable replacement ratio and addictive can be acquired to improve the feeding value.There were four substituting ratio treatments including OHO,OH5,OHIO and OH 15 as well as 6 addictive treatments including CK,B,A,P,E and F.These silos were opened on 90 days after ensiling and the fermentation quality,chemical and microbial compositions were analyzed.Meanwhile,the aerobic stability was tested by the online multi-channel data logger temperature recorder,and we took samples to estimate the aerobic stability at the 3th,6th,9th and 14th day of exposure to air.The results showed that pH in OH10 and OH 15 were significantly higher than that of OHO,and the lactic acid contents in all replacement treatments were sharply lower than that of OHO;the butyric acid content in all treatments were very low(<0.5g/kgDM).Ammonia nitrogen/total nitrogen and ethanol contents decreased with the increasing of replacement ratio,and OH15 was sharply lower than that of OHO.All treatment had good fermentation quality.The additives inhibited the lactic acid fermentation,the lactic acid contents of additive groups were lower than that of the CK group,and pH was higher than that of the CK group.Ammonia nitrogen/total nitrogen and ethanol contents in B and E were sharply lower than that of CK.The aerobic stability increased with the increasing of replacement ratio,which indicated that OH15 had the best aerobic stability.In all addictive treatments,A treatment had the best aerobic stability.Replacement treatment and addictive treatments reduced the in vitro dry matter digestibility of TMRs,while there were no difference among CK,B,A and P.Taking all aspects into account,including fermentation quality,aerobic stability and maximum using hulless barley straw,it was suggested that OHIO treatment and B,A and F treatment were the most suitable choice. |
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