CHEMICAL AND NUTRITIONAL CHANGES OF THE KUDZU DURING THE DRY SEASON.

Abstract

Changes in chemical and nutritional parameters in the leaf and stem fraction of the green material (F) of Kudzu (Pueraria phaseoloides) during the summer months were studied. Moreover, it was characterized the dead material that was harvested together with the green material. The plots had an average rest period at the begining of the summer time of 4.5 months of and were monthly sampled from January to April. The average precipitation was of 85 mm/month, which was in the expected rank to the area in which the research was done. precipitation was of 85 mm/month, which was in the expected rank to the area in which the research was done. The average proportion of leaf-stem, dry base, in the whole plant was 0.749, with a progressive diminution during the first months of the dry season. The content of brute protein (PC), phosphorus (CP) and tannins (CTA), the neutral detergent fraction (FDN), the true digestibility in vitro of the dry matter (DIVMS) and of the FDN (DIVFDN), and the solubility of the N in buffer of borate-phosphate (SNBF) were not significantly affected (P>0.16) by M; on the other hand, the values of these parameters in the leaf were different (P<0.03) to the stem. The content of calcium (CCa) and the solubility of the N in pepsin (SNP) were affected by M (P<0.07) and F (P<0.05). The average values during the dry season with respect to the leaf and the stem were: 19.7 and 9.2; 0.94 and 0.77; 0.16 and 0.09; 64.4 and 71.3; 1.74 and 0.0; 64.3 and 51.6; 44.4 and 33.5; 18.6 and 40.9; and 67.9 and 74.4% to CPC, CCa, CP, FDN, CTA, DIVMS, DIVFDN, SNBF and SNP, respectively. The rapidly solutive fraction (A), the no solutive fraction potentially degradable (B) and the degradation rate (K) in situ of the dry matter were not affected by M (P>0.33) and by F (P>0.19). The values for leaf, stem and whole plant during the summer season were: 6.0, 3.0 and 5.1%; 49.6, 42.0 and 45.2%; and 0.06, 0.07 and 0.065%/hour for A, B and K, respectively. In the case of brute protein, there was not effect (P>0.33) of M over A, B and K, but the values of these parameters were different (P<0.06) for the leaf and the stem. The values for leaf, stem, and whole plant during the summer were: 3.0, 21.0 and 13.3%; 63.7, 35.5 and 47.6%; and 0.064, 0.095 and 0.070/hour for A, B and K, respectively. The dead material represented the 12.0% of the harvested material with values of 7.89, 84.79, 47.70, 0.0, 39.4 and 75.8% for CPC, DIVMS, CTA, SNBF and SNP, respectively. It is concluded that the defoliation is the stage that most affected the lost of the quality of the whole plant of Kudzu during the dry season, so the leaf and the stem did not suffered appreciable changes in their quality during this season.