Abstract: Thai Nguyen is located in the subtropical region, some regions are strongly influenced by the northeast monsoon, so the chilling unit is higher than some other regions. Temperate fruit trees (pears, persimmons, plums), annual trees that need a certain degree of chilling unit in the winter to differentiate flower buds, this requirement makes the above fruit tree species only suitable for growing in cold climates. high mountain areas in Vietnam. Zoning the accumulated chilling unit is a decisive step in determining areas to develop temperate fruit trees in highland communes, Thai Nguyen, Vietnam. Total area with chilling unit > 150 cu where temperate fruit tree varieties can be grown in highland communes: 75,312.37 hectares (accounting for 46.53% of total natural area): Very little cold region: 44,710, 7 hectares (accounting for 59.3%), it is recommended to test pear, persimmon, and plum; Less cold region: 20,687.83 hectares (accounting for 27.47%), it is recommended to grow pears, persimmons,

Straw is considered as a resource that can be used as an input material for many industries such as mushroom farming, animal feed, paper making, energy, organic fertilizer production ... In our country, these by-products have not been used thoroughly, causing waste of resources and environmental pollution. According to the General Statistics Office, the country's rice production in 2017 reached 42.7 million tons. Such rice output produced a huge amount of rice straw, equivalent to about 42.7 million tons of rice straw, if there is no effective treatment measures, it will pollute the environment, especially in localities having strengths in rice production. Also according to the General Statistics Office, Vietnam's corn production in 2017 reached 5.132 million tons, down 15,000 tons compared to 2015 due to decrease in cultivated area. If calculating the corn cob coefficient, which accounts for 25%, in 2017 alone, the amount of corn cob discharged into the environment was about 1.28 million tons. According to

Abstract This review provides an overview of the availability, nutritive value and possible strategies to improve the utilisation of rice straw as a ruminant feed. Although, rice straw is the most abundant agricultural by-product and can consider as a sustainable source for ruminant feed in Vietnam, only a small proportion of rice straw is fed to ruminants. Rice straw is rich in polysaccharides and has the high levels of lignin and silica, limiting voluntary intake and reducing degradability by ruminal microorganisms. Some physical treatments are not practical because they require machinery application or are not economically feasible for the farmers. Chemical treatments, such as urea, ammonia or lime, currently seem to be more practical for on-farm use. The application of chemical agents can be hard to handle, harmful to the habitat. The use of white-rot fungi, exogenous enzymes and lactic acid bacteria to enhance the nutritive value and digestibility of rice straw are expected to be a practical and