1. Conventional ingredients and effective energy value

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

The air-dried alfalfa leaves with better storage conditions contained crude protein 25.5%±2.6%, crude fiber 14.3%±2.5%, digestible energy (pig) was (11.09±1.46) MJ/kg, metabolizable energy (chicken) was (6.44 ±0.87) MJ/kg. According to 

the principle of international feed classification, it belongs to protein feed; however, the crude fiber content in air-dried alfalfa stems is as high as 41.3%±1.8%, the crude protein only contains 10.4%±0.9%, and the digestible energy (pig) is (4.18±0.38) MJ/kg. The energy (chicken) is (0.57±0.03) MJ/kg, which belongs to roughage. It can be seen that when collecting and storing alfalfa, attention should be paid to the loss of leaves in the process of tanning, and try to ensure the proportion of alfalfa leaves in alfalfa, which is the key to improving the quality of alfalfa meal. .

In the past, many scholars have studied the variation law of alfalfa nutrients in different growth periods. It is generally believed that the quality of alfalfa at the early flowering stage is better, but according to the cooperative research of the Institute of Animal Husbandry, Chinese Academy of Agricultural Sciences and the Shaanxi Provincial Institute of Animal Husbandry and Veterinary Medicine, the crude protein content of alfalfa meal at the budding stage, the early flowering stage and the full flowering stage is 20.0%, respectively. , 18.2% and 16.9%; and the crude fiber content was 26.1%, 26.5% and 28.1%, respectively. It can be seen that it is difficult to judge the quality of alfalfa grass powder by the growth period if the harvesting and storage conditions of alfalfa and the proportion of stems and leaves are not comprehensively and carefully considered.

2. Amino acid content of alfalfa

According to the statistics of China Feed Database, the artificially dried alfalfa meal harvested in full bloom period contains 0.74%~0.78% of lysine, and the total essential amino acid content is relatively balanced. grass meal feed ingredients.

3. Mineral and trace element content

The calcium and phosphorus contents in alfalfa leaves were about 150% and 50% higher than those in stems, respectively, and tended to decrease with the growth period. Calcium and phosphorus deficiency, but no phytate phosphorus.

Alfalfa meal is rich in iron and selenium content is high, which is 5 to 10 times higher than that of general livestock and poultry. It is a good source of iron and selenium. However, copper, zinc and manganese are all within the range of livestock and poultry requirements or are lacking, and should be added as appropriate.

4. Nutrient composition prediction and optimal harvesting period

The nutrient composition of alfalfa powder is directly restricted by two main factors: the ratio of stems and leaves of its raw materials and the growth period. For this reason, according to the actual measured values of alfalfa leaves and stems in different growth periods and the dry matter ratio of stems and leaves, the simulated alfalfa is calculated. It is a good way to avoid sample errors caused by the loss of leaves during sampling. The contents of nutrients in the stems and leaves of alfalfa at different growth stages were different. The peak value of crude protein content in leaves is in the early flowering period and full flowering period, while the crude fiber content in leaves is the opposite. The peak is in full bloom. The quality of alfalfa grass powder was the best in the early flowering stage, followed by the full flowering stage, followed by the full bud stage, and the worst in the pod setting stage. It can be seen that the optimal mowing period of alfalfa should be calculated based on the ratio of stem to leaf and its nutrient content, and it is ideal to select it in the early flowering period and the full flowering period. The simulation prediction of quality time is more practical than the actual sampling and measurement.