عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Introduction: Forage drying has long been used as a traditional method of storage of forage feedstuffs. However, the need to postpone forage harvest until maturity in order to obtain more dry matter reduces its digestibility. Also, adverse weather conditions can lead to loss of nutrients and overall decline in the nutritional value of dried fodder. One of the methods that is somewhat less dependent on climate conditions and used by ranchers to maintain plants. The product of fermentation under anoxic and acidic conditions is called silage (Khorvash et al., 2014). During forage ensiling due to the activity of lactic acid producing bacteria and in anaerobic conditions, water soluble carbohydrates in forage are converted to predominantly lactic acid acids predominantly, which reduce the pH and protect the forage against microbial spoilage. Corn as a plant with high production capacity and adaptability in most parts of the country can play an important role in providing forage to livestock, especially in winter. One of the main concerns in the preparation of a good silage is the rapid decrease in silage pH in the shortest time. Hay pH at harvest time is between 6 and 7 and after the incubation period with proper fermentation, pH can be equal to or less than 4, which this reduction in pH is due to production of lactic acid and other organic acids by bacteria. Accelerate the reduction of pH by adding lactic acid bacteria in food is very important to minimize depreciation. Recent studies have shown that inoculation with Lactobacillus buchneri inhibits yeast growth and reduces the susceptibility to aerobic spoilage of various ensiled forages. This study was conducted to determine the effect of EM (containing yeast an lactobacillus) and lalsil (containing lactobacillus buchneri) inoculants on chemical composition, fermentation profile and degradability of corn silage.
Materials and methods: This research was carried out to investigate the Effects of Different Biological Additives on Fermentation and Chemical composition of corn silage by using 3 experiments (Chemical composition assay, gas production and in vitro degradability) in a completely randomized design. This experiment was performed in a completely randomized design with 4 different treatments in three replications. The corn was harvested at the dough stage and then crushed by a chaper with an average length of 5 cm. The silos were kept at room temperature for 90 days. Dry matter, organic matter, crude protein, insoluble fiber in acidic and neutral detergent, lactic acid content, water soluble carbohydrate, ammonia nitrogen concentration and total volatile fatty acids, pH were measured with 3 replicates. The four various treatments in the running order incorporated as: 1. control (without any inoculant), 2. Corn silage treated with bacterial additive lalsil 1.8×106 CFU/g fresh forage (include lactobacillus buchneri), 3. Corn silage treated with bacterial additive at 0.02 percent, and 4. Corn silage treated with bacterial additive at 0.04 percent (at fresh weight). Crops were ensiled in triplicate laboratory mini soils for 90 days at room temperature. The results were analyze using SAS (2002) software with GLM procedure and using of Duncan’s test for comparing the averages (at 5% level).
Results and Discussion: The results showed that the additive of the different Biological Additives used had the potential to positively change the chemical composition of corn silage. Treating corn silage with lalsil and EM caused a significant decline in pH in comparison to control treatment (P<0.001). Supplementation of additives significantly increased dry matter content of corn silage (P <0.05). Statistical analysis of data from this experiment on corn silage pH showed that addition of lalisil and EM significantly decreased corn silage pH (P <0.05). Also the addition of EM to corn silage in 0.02 percent of supplementation had no significant difference with a control treatment. The EM treatments caused a significant decline in lactobacillus population in relation to lalsil treatments (P<0.05). Experimental treatments in relation to control and the other treatments. Addition of Lalsil and EM to corn silage had no significant effect on neutral detergent fiber (NDF). Treating corn silage with lalsil and EM caused a significant decline in pH in relation to control treatment (P<0.05). The lowest pH is related to inoculated bacterial treatment. Addition of lacillus and EM had no significant effect on insoluble fiber in neutral detergent and acid detergent fiber. Lalisil additive reduced the amount of crude protein in the silage. The EM treatments caused a significant decline in lactobacillus population in relation to lalsil treatments (P<0.05). DM disappearance was lower in EM treatments in at any level of supplementation in the early hours of incubation in relation to control treatment (P<0.05) as well as adding of lalsil significantly reduced the DM disappearance (P<0.05).
Conclusion: Adding different biological additives to corn silage reduces pH and can improve the aerobic stability, quality of corn silage in laboratory silos by altering the availability of WSC.