The best harvesting time for drying alfalfa hay should be in bud stage, because harvesting can reach the best balance point in yield and nutrition at this time. In bud stage, there are buds at the top of alfalfa stem, but there are no purple petals. Alfalfa leaves are large, the stem is thin and soft, and the nutrient content is high. Premature harvest, although the nutrient content is guaranteed, but the yield is not high. Harvest too late, although the yield has increased, but the loss of nutrients is greater.
Judging whether alfalfa hay is harvested in bud stage depends on the size, thickness, texture and the number of leaves, in addition to whether it is rich in buds.
60% of total digestible nutrients (TDN), 70% of crude protein and 90% of vitamins in alfalfa hay exist in leaves. Alfalfa hay with high leaf content means that it has excellent technology and equipment and perfect management during harvesting, sun drying and processing. Generally speaking, it has high contents of nutrients such as minerals, vitamins, energy and crude protein. The leaf content of alfalfa hay is also closely related to the harvest time. After budding, alfalfa stems become thicker, the bottom leaves fall off, and the proportion of leaves to stems decreases, resulting in a rapid decline in hay quality.
The leaf content of alfalfa hay with good quality is generally 60% ~ 70%, and the poor is only10% ~15%. Alfalfa hay bales with high leaf content obviously have many leaves and soft stalks.
The high-quality alfalfa hay is emerald green, which means that it is properly dried and processed, has not been rained, and has no mildew and fever during storage. It should be pointed out that the alfalfa hay harvested early and rained is not green, but its nutritional value is higher than that of the emerald hay harvested late. There is no correlation between the color of grass and its digestibility. Because ungulates are color blind, they can't tell brown from green. The digestibility of grass can be determined by laboratory analysis or animal test.
Alfalfa grass is pale golden yellow after sun exposure, but it can't be compared with inferior grass that changes color due to rain or fermentation. Piles or bundles of grass placed outdoors, its outer layer is discolored by the sun, and its inner layer is still emerald green. Sunlight discolored grass has poor palatability and low carotene content. The greener the grass, the higher the carotene content.
High-quality alfalfa hay has a grassy smell, good palatability, high carotene content and high nutritional value. Hay with musty smell, rotten smell, peculiar smell, gasoline smell or chemical smell is poor in quality, and its nutritional content and palatability are reduced.