Evaluation of different Alfalfa cultivar's hay yield and nutritional evaluation at amino acids level

The nutritional value of alfalfa protein could only be comprehensively evaluated through determination of total amino acids, essential and non-essential amino acids and ratio of essential to non-essential amino acid. Complete analysis of total amino acids, essential and non-essential amino acids and ratio of essential to non-essential amino acid of different alfalfa cultivar may provide scientific basis for effective utilization of alfalfa in feed resources. Current study was planned to evaluate the total hay yield of four Chinese alfalfa cultivars and its nutritional composition at amino acid levels. For this purpose, Golden Empress (GE), Xinjiang Daye (XD), Grassland No.3 (GR) and Zhongmu No.1 (ZM) alfalfa verities were selected. Chinese alfalfa varieties GE, XD, GR and ZM were planted in different experimental plots with an area of 3mx 8m and repeated for three times. The plots were all planted in strips with row spacing of 30cm, with sowing amount of 15 kg/hm-2 and sowing depth of 2cm. A random block design was adopted in the test sample plots. The experimental samples were alfalfas which were cut at the first flowering stage of the third stubble planted in the same year. Samples were completely dried and grinded through 60 mesh sieve before nutritional evaluation. In order to evaluate the nutritional value of alfalfa protein, 17 kinds of amino acids were determined by automatic amino acid analyzer after treated by microwave digestion hydrochloric acid hydrolysis method. Results of hay yield represents that the yield of alfalfa hay was higher for GE alfalfa variety. Results also explored that there was no significant difference in the yield of the third stubble alfalfa hay among the four alfalfa varieties. Seventeen amino acids, including aspartic acid, serine, threonine, glutamic acid, proline, glycine, alanine, cysteine, valine, methionine, isoleucine, leucine, tyrosine, phenylalanine, lysine, histidine and arginine, were determined by automatic amino acid analyzer, and the total amino acid was calculated. The total amino acid content of four alfalfas varieties was 13.18%-17.52%, the essential amino acid content was 5.70%-9.09%, and the non-essential amino acid content was 6.32%-9.36%. The total amino acid content of the second stubble was lower than that of the other two stubbles.