Effect Of Adding Wet Brewers’ Grains On Fermentation Quality Of Mixed Ensilage Of Rice Straw And Agro-Byproducts

It is well known that rice straw is high in crude fibre, and low in water soluble carbohydrate and crude protein. Generally, the palatability and digestibility is poor for ruminants. If rice straw is directly ensiled, it is difficult to produce quality silage due to its low water soluble carbohydrate content. However, the mixed ensilage technology and additives could improve the quality of rice straw silage. Many agro-by products are rich in nutrition and water soluble carbohydrate, and low in crude fiber. We could ensile rice straw mixed with agro-by products. On the other hand, the agro-by products are made use fully, expanding the forage sources and reducing the environmental pollution caused by the stack of agro-byproducts, and effectively improves the fermentation quality of rice straw. The rice straw, alfalfa, sweet potatoes vines, carrot and sweet potatoes peel, apple pomace and orange peel as ensilage materials, and to study the fermentation quality of mixed ensilage, and the effect of adding wet brewers’grains on fermentation quality of mixed silage. There were four experiments in this study.Experiment I:Effect of adding wet brewers’grains on the fermentation quality of mixed silages of rice straw, alfalfa, citrus peel and apple pomaceThe experiment was carried out to investigate the influence of adding wet brewers’ grains on the fermentation quality of mixed silages of rice straw, alfalfa, citrus peel and apple pomace. The proportion of rice straw, alfalfa, citrus peel and apple pomace was5:1:2:2. The adding rations of wet brewers’grains were0,10%,15%and20%, respectively. The silos were opened at1,3,5,7,14and30days. The pH decreased at the first, and then increased during the ensiling. The contents of lactic acid and total volatile fatty acids, and ammonia nitrogen/total nitrogen value increased gradually. The contents of water soluble carbohydrates and dry matter decreased gradually. Adding wet brewers’grains treatments increased the lactic acid significantly (p<0.05) and decreased the pH value (p>0.05), and improved the fermentation quality, however it increased the contents of acetic acid, propionic acid and butyric acid, and decreased the contents of water soluble carbohydrate and dry matter.Experiment Ⅱ:Effect of adding wet brewers’grains on the fermentation quality of mixed silages of rice straw, alfalfa, sweet potato peel and apple pomaceThe rice straw, alfalfa, apple pomace and sweet potato peel was used as ensilage materials and wet brewers’grains was added to give a series of different rations (0,10%,15%and20%) to investigate the effect on fermentation quality changes during ensiling. The proportion of rice straw, alfalfa, sweet potato peel and apple pomace was5:1:2:2.The silos were opened on1,3,5,7,14and30days of ensiling. Based on the result, the adding wet brewers’grains increased significantly (p<0.05) lactic acid, however, there was not different on the pH as compared with control, and increased the contents of acetic acid, propionic acid and butyric acid during ensiling. The wet brewers’grains decreased the content of water soluble carbohydrate; it indicated that the water soluble carbohydrate was used more fully than control, and because of high moisture, the wet brewers’grains decreased the content of dry matter of mixed silages.Experiment Ⅲ:Effect of adding wet brewers’grains on the fermentation quality of mixed silages of rice straw, alfalfa, sweet potato vines and apple pomaceThe mixed ensilage of rice straw, alfalfa, apple pomace and sweet potato vines was carried out, and wet brewers’grains was added to give a series of different rations (0,10%,15%and20%) to investigate the effect on dynamic changes in the fermentation process. The proportion of rice straw, alfalfa, sweet potato vines and apple pomace was5:1:2:2.The silos were opened at1,3,5,7,14and30days. Adding wet brewers’grains to the mixture silage increased significantly (p<0.05) lactic acid, and decreased the pH value, but increased acetic acid content. The contents of propionic acid and butyric acid were low; it indicated that all the treatments had fine fermentation quality.ExperimentIV:Effect of adding wet brewers’grains on the fermentation quality of mixed silages of rice straw, alfalfa, carrot and apple pomaceThe experiment was carried out to investigate the influence of adding wet brewers’ grains on the fermentation quality and water soluble carbohydrate (WSC) content of silages of rice straw, alfalfa, apple pomace and carrot. The treatments were designed as follows: control (0%),10%,15%, and20%of wet brewers’grains (fresh weight basis). The proportion of rice straw, alfalfa, carrot and apple pomace was5:1:2:2, the silos were opened at1,3,5,7,14and30days of ensiling. The results showed that adding the wet brewers’ grains decreased (p>0.05) the pH, and increased significantly (p<0.05) lactic acid, improved the fermentation quality. The wet brewers’grains increased the ammonia nitrogen/total nitrogen and volatile fatty acid as compared with control; however this content was low, and indicated that all the treatments are quality silage. The wet brewers’ grains decreased the content of water soluble carbohydrate, it indicated that the water soluble carbohydrate was made use more fully than control, and because of high content of moisture, the wet brewers’grains decreased the content of dry matter of mixed silages.