The present situation and prospect of the processing technology of forage grass in China

Abstract

In recent years, with the rapid improvement of Chinese people’s living standards, the demand of animal products is increasing greatly, which leads to significant shortage in supply of forage especially high-quality forage. The insufficient supply of forage especially high-quality feed blocks the further promotion of animal husbandry. In China, the area of grassland accounts for 42% of the total land area, which is critical for animal husbandry. However, a gap exists between grass and livestock. Grass products such as silage and hay, are the bridge connecting grass cultivation and animal husbandry. Besides, processing technology of grass products is able to solve the question that the excess utilization of the winter-spring pasture and the imbalance of forage grass with the livestock. Therefore, we proposed that grass products processing is the key factor of promoting the development of farming and animal husbandry, it can adjust the balance of grass supply of all years, and guarantee the modern development of animal husbandry. Although great improvement has already been obtained in the processing technology of grass products, the level still is quite low compared with developed countries. Firstly, there is a lack of systematic research related to processing technology, which directly causes the low quality of grass products and weak market competition. Secondly, the machinery equipment associated with forage harvesting and processing in our country are heavily dependent on imports, its high price limits the mechanized production of grass. The physical and chemical characteristics of grass can be improved through processing modulation of grasses, contributing to the efficiency of their storage, transportation and feeding. Of the many kinds of grass products, we highlighted the importance of silage and its additives. Additives are natural or industrial products added in rather large quantities to the forage or grain mass. Additives control or prevent certain types of fermentation, thus reducing losses and improving silage stability. In order to assist in the fermentation process, various silage additives have been used to improve the nutrient and energy recovery in silage, often with subsequent improvements in animal performance. The purpose for applying additives to the silage is to ensure that the growth of lactic bacteria predominates during the fermentation process, producing lactic acid in quantities high enough to ensure good silage. Therefore, this review is made to focus on some practical aspects of the fermentation process and the uses of some common silage additives that include microbial inoculants, enzymes, and propionic acid. Overall, we summarized the current research achievements and existing issues in the processing of grass products at home and abroad regarding concepts, significances, current situations, main theories and technologies in this review. By analyzing problems, we propose the concept of grass processing especially the silage processing technique, and provide a theoretical guidance for upgrading grass products in China, which we consider an important guidance significant for forage production with high quality in the future.