レンゲの飼料価値に関する研究 (第1報) レンゲの化学威分並びにそのエンシレージ調製と品質について

The chinese milk-vetch. Astragalus sinicus L., is cultivated in paddy-fields as the winter crop from late September (or early October) to late May. This crop develops very vigorously under suitable conditions. The crop heretofore has mostly been cultivated for the purpose of utilizing it as the green manure, but its full utilization as the fodder is very important since the crop is rich in nutrients. The authors are at present investigating the feeding value of this plant from the nutritional viewpoint; in this paper, however, the results obtained on the variations of the chemical composition and of the yield of nutrients in various growing stage and on the silage-making from the chinese milk-vetch, will be reported. The following are some of the results obtained: (1) The chinese milk-vetch cultivated in paddy-fields as the winter crop was reaped eight times at intervals of approximately a week from April 16 (before the bloom stage) to June 3 (the early stage of the seed maturity). These eight samples of chinese milk-vetch reaped at different times were analyzed. It was inferred that the yields of solid substance and of crude protein per 10 a. were about the maximum in the stage of full bloom. (2) The crude protein content of chinese milk-vetch in the stage of full bloom was 40.5 % in leaves, 12.4 % in stems and 28.6 % in floweres. The distribution of crude protein was as follows: 47.3 % in the portion of leaves, 44.7 % in the portion of stems and 8.0 % in the portion of flowers. The artificial digestibility of crude protein of leaves, of stems and of flowers was respectively 64.4, 64.8 and 71.3 per cent. The crude protein content of pods in the early stage of the seed maturity was 29 per cent on the dry matter basis and nearly equal to that of flowers. (3) Chinese milk-vetch was ensiled according to the following scheme: The quality of resulted silages was excellent or good m the wilted- and semiairtight-lot. The silage of the wilted-lot was found to have the following properties: pH 3.99, lactic acid content 2.58, acetic acid content 0.66 and butyric acid content 0 per cent. (4) The results of digestion experiment on rabbits are shown in the Tables 13 and 14. The digestibility of organic matter of silage in semiairtight-lot, wilted-lot, cut on June 3-lot, and in no chopping-lot was respectively 64.2, 58.2, 26. 8 and 38.9 per cent. (5) The ratio of water soluble nitrogen to the total nitrogen was higher in good silage than in poor silage. (6) In good silage the results of calculation of the digestibility of silage protein by WATSON'S formula practically agreed with the results of digestion experiments on rabbits. (7) The ratio of amino nitrogen to the total nitrogen in the silage of low pH vallues was higher than that in the silage of high pH values.