The dynamic variations in nutrient and phenolic content in Sophora davidii in a Karst region of Guizhou Province

The dynamic variations of nutrient and phenolic content in Sophora davidii in a Karst region of the Guizhou Province were investigated in the study. Results showed that the content of crude protein in the vegetative, flowering, and seed set stages was higher than in the maturation stage (P < 0.05). The content of nitrogen free extract, crude ash, and ether extracts decreased with the increasing growth period (P < 0.05). The content of dry matter, crude fiber, acid detergent fiber, neutral detergent fiber, and calcium increased with the increasing growth period (P < 0.05). The content of tannin had no significant relationship with the different growth stages (P > 0.05); however, other phenolics decreased with the increasing growth period (P < 0.05). The content of tannin in the flowering and seed set stages was more suitable for feeding animals than in the vegetative stage, while higher crude protein and relative forage values were also obtained in the former. Considering all factors, we suggest that the best utilization period for feeding animals with Sophora davidii is from the flowering to seed set stages. This study can provide theoretical support for the efficient use of Sophora davidii in animal husbandry in the Karst areas of Guizhou Province.