Effects of cutting number and pelletizing on vitamin content and chemical composition of alfalfa

The aim of study was to investigate the effects of cutting number and pelletizing on vitamin content, chemical composition and Escherichia coli population of alfalfa planted in the test field of Inner Mongolia Academy of Agricultural & Animal Husbandry Sciences. Three cuttings (first, second and third) were harvested at bud stage to make pellets. Then, samples were taken from the pellets to determine the vitamin content, chemical composition and E. coli population. The results showed that cutting number had significant influence on the amount of VB₂, VB₃, VB₅, VB₆ and Vc in alfalfa; the amount of VB₂, VB₃, VB₅ in the second cutting alfalfa was significantly higher than in the first and the third cuttings (P < 0.05), while the B₆ and Vc content was significantly higher in the first and second cuttings than in the third (P < 0.05). The cutting number had significant influence on the content of dry matter, organic matter, crude protein, neutral detergent fiber, and acid detergent fiber of alfalfa. Overall, the quality of the second cutting was better than the first and third cuttings (P < 0.05). The amounts of B₃ and B₅ in alfalfa were not significantly affected by pelletizing (P > 0.05), but the amounts of B₂, B₆, Vc and VK₁ were significantly reduced (P < 0.05). The interaction effect of cutting and pelletizing had significant influence on the content of B₁, B₆, organic matter, and dry matter in alfalfa (P < 0.05). The population of Escherichia coli was lowest in the first cutting and highest in the third cutting; pelletizing significantly inhibited the activity of E. coli (P < 0.05).