不同生育时期紫花苜蓿和燕麦营养价值评价

Evaluation of Nutritional Value of Forage in Different Growth Stages

本试验选用紫花苜蓿(Medicago sativa)品种WL343HQ,晚熟燕麦(Avena sativa)品种燕王,这两种饲草为试验对象,利用四种改良方法(紫外分光光度--乙酰溴法、Klason法、NREL法和酸洗法)测定饲草中木质素的含量,并探讨这两种饲草在不同生育时期的基本营养成分,以及由此得出的Milk 2016指数。随着生育期的推进,这两种饲草粗蛋白的含量呈现下降的趋势,粗脂肪的含量呈先增加后减少的趋势,淀粉和中性洗涤纤维的含量随着生育期的推进呈上升的趋势。燕王的中性洗涤纤维和酸性洗涤纤维在整个生育期先增加后减少,开花期达到最高,WL343HQ的中性洗涤纤维和酸性洗涤纤维含量随着生育期推进越来越高。通过比较不同生育时期的营养成分,得出燕王在灌浆期刈割最好,而紫花苜蓿WL343HQ在现蕾期的奶吨指数和奶亩指数最高,适宜在此时期刈割。

Alfalfa(Medicago sativa)was selected as WL343HQ in this experiment.The oat(Avena sativa)variety was Yanwang,and the two forage grasses were used as test subjects.Four improved methods(UV spectrophotometry--acetyl bromide method,Klason method,NREL method and pickling method)were used to determine the content of lignin in forages.The basic nutrients of these two forages at different growth stages were investigated,and the Milk 2016 index was obtained.With the advance of the growth period,the crude protein content of these two forages showed a decreasing trend,the ether extract content increased first and then decreased,and the starch and neutral detergent fiber content showed an increasing trend with the advance of the growth period.The neutral detergent fiber and acid detergent fiber of Yanwang increased first and then decreased during the whole growth period,and reached the highest at flowering stage.The content of neutral detergent fiber and acid detergent fiber of WL343HQ increased with the growth period advancing.By comparing the nutrient composition of different growth stages,it was concluded that the best cutting time was at the milk-filling stage of Yanwang,while the milk ton index and milk mu index of alfalfa WL343HQ were the highest at the buding stage,and it was suitable for cutting at this time.