不同生长时期构树叶营养成分动态变化的研究.

The purpose of this paper was to study the dynamic changes of conventional nutrients and available energy in the Broussonetia papyrifera leaves at different growth stages. According to the growth cycle of conformation trees in Yangling area of Shaanxi Province, Broussonetia papyrifera leaves with no pests and diseases and normal plants were picked for one year. Starting from April 19th, tree leaf collection was conducted every three weeks, with a total of 10 groups until October 25th. Nutrient composition was determined after sample collection. The results showed that: the crude protein, total fatty acid, unsaturated fatty acid, amino acid, P, S, K, available energy value, relative feeding value, milk yield per ton of feed and relative forage quality from May 10th to May 31th collected Broussonetia papyrifera leaves were significantly higher than other growth stages (P<0.05); the lignin and ADF of collected Brous⁃ sonetia papyrifera leaves in the middle growth stage were significantly higher than other growth stages (P< 0.05); the crude fat, NDF, water-soluble carbohydrate, Ca and Mg of collected Broussonetia papyrifera leaves in late growth stage were significantly higher than other growth stages (P<0.05). According to the results of this experiment, as a high-quality protein feed, the Broussonetia papyrifera leaves can be harvested from May 10th to May 31th as feed materials for most animals. [ABSTRACT FROM AUTHOR]