The quality of alfalfa grass meal depends on the composition ratio of alfalfa stems and leaves.

The air-dried alfalfa leaves with good storage conditions contain 25.5%±2.6% crude protein, 14.3%±2.5% crude fiber, digestive energy (pig) is (11.09±1.46) MJ/kg, metabolism energy (chicken) is (6.44±0.87) MJ/kg. according to the principle of the International Feed Classification, it belongs to the protein feed; however, the content of crude fiber in air-dried alfalfa stems is as high as 41.3%±1.8%, crude protein only contains 10.4%±0.9%, digestive energy (pig) is (4.18±0.38) MJ/kg, metabolism energy (chicken) is (0.57±0.03) MJ/kg, which belongs to roughage, so it can be seen that in the collection and storage of alfalfa should be paid attention to in the tumbling process of the loss of the leaf, as far as possible to ensure that the proportion of clover in the clover leaf is the improvement of the quality of alfalfa grass meal. It is the key to improve the quality of alfalfa hay meal.　　In the past, many scholars have studied the variation law of alfalfa nutrient composition in different growing periods. It is generally believed that the quality of alfalfa in the early flowering period is better, but according to the cooperative research of the Institute of Animal Husbandry, Chinese Academy of Agricultural Sciences and Shaanxi Provincial Animal Husbandry and Veterinary Research Institute, it is pointed out that the crude protein content of alfalfa hay meal in the bud stage, the early flowering period and the blooming period are 20.0%, 18.2% and 16.9% respectively, while the crude fiber content is 26.1%, 26.5% and 28.1% respectively, which is evident that if we don't make comprehensive research on the conditions for alfalfa storage, stem and leaf ratio, we can not make any improvement on the quality of alfalfa. It can be seen that it is difficult to judge the quality of alfalfa hay meal during the growing period without a comprehensive and careful scrutiny of alfalfa harvesting conditions, stem and leaf ratio. The nutrient content of alfalfa grass meal is directly affected by the two main factors of stem-leaf ratio and growth period of its raw materials,

To this end, according to the actual measured values of alfalfa leaves and alfalfa stems in different growth periods and the ratio of dry matter of stems and leaves, simulating and calculating the content of nutrient content of alfalfa aboveground part of the whole plant is a good way to avoid the sample error caused by the loss of leaves in the sampling time. The nutrient contents in the stems and leaves of alfalfa at different growth stages were different. The peaks of crude protein content in leaves were in the early and full flowering stage, while the crude fiber content in leaves was opposite to this law; the crude protein content in stems and leaves was the highest in the full bud stage, decreasing with the reproductive period, and the peak of crude fiber content in stems was in the full flowering stage. The quality of alfalfa meal was best at the early flowering stage, second at the full flowering stage, second at the full bud stage, and worst at the podding stage. It can be seen that the optimal mowing period of alfalfa should be combined with the stem-leaf ratio and its nutrient content projections, and then selected in the early flowering period and the full bloom period is ideal. Under the conditions of small sample size and sloppy sampling methods, the assessment of alfalfa hay meal quality is more meaningful when touching the simulation prediction than the actual sampling and measurement.