Effects Of Replacement Of Whole-Plant Corn With Oat And Common Vetch On The Fermentation Quality And Aerobic Stability Of Total Mixed Ration

The objective of this study was to evaluate the effects of replacement of whole-plant corn with oat and common vetch at different rates on the fermentation quality and aerobic stability of total mixed ration (TMR) silage in Tibet, then screening the appropriate ratio and applying molasses, lactic acid bacteria and propionic acid to further improve fermentation quality and aerobic stability. That supply theoretical evidences for the development and utilization of forage and additives in Tibet.1. Study on the effects of replacement of whole-plant corn with oat and common vetch on the fermentation quality and chemical composition and aerobic stability of TMR silage.1.1. The effects of replacement of whole-plant corn with oat and common vetch on the. fermentation quality and chemical composition of TMR silage.The objective of this experiment was to evaluate the effects of replacement of whole-plant corn with oat and common vetch on the fermentation quality and chemical composition of TMR silage in Tibet. Four TMR that was varied in the forage sources on dry matter basis:(1) 52% whole-plant corn (Control), (2) 43% oat+12% common vetch (OC3.6), (3) 38% oat+18% common vetch (OC2.2), (4) 33% oat+23% common vetch (OC1.5). Silos were opened on day 45. The results showed that all silages were well preserved with low pH and NH3-N contents, and high lactic acid contents and V-scores. With the increasing proportion of common vetch, dry matter, crude protein, ether extract contents in treated silages increased significantly (P<0.05) as compared with the control silage, and neutral detergent fiber and acid detergent fiber contents decreased (P<0.05) as compared with the control silage.1.2-The effects of replacement of whole-plant corn with oat and common vetch on the aerobic stability of TMR silage.All silos were opened after 45 days of ensiling, and then sampled on 6,9 and 12 day in which TMR silages were subjected to an aerobic stability evaluation. Each treatment was 3 replicates at each time point. The results showed that treated silages improved aerobic stability. During the whole aerobic exposure period, yeast numbers were>107 cfu/g-FM after aerobic exposure for 12 days in the control and OC1.5 silages. While yeast numbers were still<105 cfu/g-FM in OC2.2 silages, and>105 cfu/g-FM in OC3.6 silage. With the time of aerobic exposure, the pH raised from 3.90 to 7.07 in the control silage at 12 days. At 9 days, the pH in the control silage had already raised to 5.1, it had aerobic spoiled. Similar with the control silage, the pH raised from 4.14 to 4.77, it had aerobic spoiled at 12 days. OC3.6 and OC2.2 silages did not spoiled through the whole aerobic exposure period. OC2.2 silage prolonged the longest time of aerobic stability.2. Study on the effect of additives on the fermentation quality and aerobic stability of TMR silage.2.1. The effects of adding molasses and propionic acid on the fermentation quality of TMR silage.The objective of this study was to evaluate the effects of molasses and propionic acid on the fermentation quality of TMR silage prepared in Tibet. The treatments were as follow: no additives (Control), molasses (M) or propionic acid (P) and moasses+propionic acid (MP). All silos were opened after 45 days of ensiling, and then determined the fermentation quality. The result showed that the four TMR silages were of good quality with low pH value and NH3-N contents, and high lactic acid contents and V-scores. There were no differences in pH and lactic acid contents between the control and M silage, while adding molasses decreased the crude protein contents of TMR silage, which indicated that adding molasses could not improve the fermentation quality of TMR silage. Although adding propionic and molasses+propionic inhibited proteolysis by undesirable microorganisms, it also inhibited lactic acid bacteria ativity and decreased lactic acid contents of TMR silage.2.2.The effects of adding molasses and propionic acid on the aerobic stability of TMR silage.The objective of this study was to evaluate the effects of molasses and propionic acid on the aerobic stability of TMR silage prepared in Tibet. All silos were opened after 45 days of ensiling, and then sampled on 6,9 and 12 day in which TMR silages were subjected to an aerobic stability evaluation. During the whole aerobic exposure period, yeast numbers were less than 1×105 cfu/g·FM, lactic acid content changed unsignificantly and pH was low in the control silage, which indicated the control silage had good aerobic stability. In contrast, the yeast numbers and pH increased gradually in TMR silage treated with molasses, lactic acid content decreased gradually in TMR silage treated with molasses. At 9 days of aerobic exposure, the yeast numbers were more than 1×105 cfu/g·FM and had raised to 5.08, which indicated that adding molasses promoted aerobic deterioration of TMR silage. Lactic acid contents in propionic acid and molasses + propionic acid treatments increased during the first 9 days of aerobic exposure, and then significantly (P<0.05) decreased, the pH value maintained unchanged and the number of yeast were significantly (P<0.05)lower than the control and lactic acid bacteria addition. Adding propionic acid and molasses + propionic acid improved the aerobic stability of TMR silage.2.3.The effects of adding lactic acid bacteria and propionic acid on the fermentation quality of TMR silage.The objective of this study was to evaluate the effects of lactic acid bacteria and propionic acid on the fermentation quality of TMR silage prepared in Tibet. The treatments were as follow:no additives (Control), lactic acid bacteria (L) or propionic acid (P) and lactic acid bacteria + propionic acid (LP). All silos were opened after 45 days of ensiling, and then determined the fermentation quality determination. The result showed that adding lactic acid bacteria and lactic acid bacteria + propionic effectively improved the, fermentation quality of TMR silage, significantly increased lactic acid contents and decreased pH, acetic acid and NH3-N contents. Although adding propionic inhibited lactic acid bacteria ativity and decreased lactic acid content of TMR silage, pH, acetic acid and ammonia nitrogen content were relatively low. Thus, the fermentation quality was still good.2.4. The effects of adding lactic acid bacteria and propionic acid on the aerobic stability of TMR silage.The objective of this study was to evaluate the effects of lactic acid bacteria and propionic acid on the aerobic stability of TMR silage prepared in Tibet. All silos were opened after 45 days, and then sampled on 6,9 and 12 day in which TMR silages were subjected to an aerobic stability evaluation. During the whole aerobic exposure period, yeast numbers were less than 1×105 cfu/g·FM, lactic acid changed unsignificantly and pH was low in the control silage, which indicated the control silage had good aerobic stability. At 12 days of aerobic exposure, the yeast numbers were more than 1×105 cfu/g-FM and pH had raised to 6.03, which indicated that TMR silage treated with lactic acid bacteria was aerobic deterioration. Adding lactic acid bacteria shorted the aerobic stable time of TMR silage. Lactic acid content in TMR silage treated with propionic acid and lactic acid bacteria+propionic acid significantly (P<0.05) decreased at 12 days of aerobic exposure, while the pH value maintained unchanged and the number of yeast were less than 1×105 cfu/g-FM. Thus, adding propionic and lactic acid bacteria+propionic acid improved aerobic stability of TMR silage.