白羊草灌丛草地优势种牧草营养物质及瘤胃降解动态研究

Study on Nutrients of Dominant Species of Forage and Dynamics of the Rumen Degradability in Old World Bluestem Shrub Rangeland

对白羊草灌丛草地优势种牧草白羊草、达乌里胡枝子、尖叶铁扫帚、铁杆蒿和隐子草的营养动态进行了研究,结果表明:随着生育期的延续,牧草粗蛋白质和粗灰分含量逐渐降低,而酸性洗涤纤维和中性洗涤纤维则呈相反的趋势;豆科牧草与铁杆蒿的粗蛋白质含量以现蕾期为转折点,禾本科牧草则以开花初期粗蛋白质含量较高。同时,对白羊草和达乌里胡枝子在绵羊瘤胃内的降解动态的研究表明:粗蛋白质含量高的其粗蛋白质降解率高,白羊草在开花期的粗蛋白质降解率高于抽穗期,但稍低于拔节期,达乌里胡枝子在现蕾期的粗蛋白质降解率高于分枝期;瘤胃降解率在前24h迅速上升,之后则较平缓;8月份白羊草处于开花期,为地上生物量的高峰期,对放牧极为有利。

The dynamics of nutrients of dominant species of forage such as old world bluestem(Bothriochloa ischaemum),dahurian bushclover(Lespedeza davurica),rush lespedeza(Lespedeza inschanica),Russian wormwood(Artemisia vestita),cepitose cleistogenes(Cleistogenes caespitosa) were studied,results showed that the contents of crude protein,ash declined gradually,with the passing of growth stage,but contrary result appeared with acid detergent fiber and neutral detergent fiber.The contents of crude protein in Legume changed markedly at bud stage.It happened in grasses at early blooming stage.The dynamics of the rumen degradability of old world bluestem and dahurian bushclover showed that the more crude protein,the higher degradability of crude protein.Crude protein degradability of old world bluestem at blooming stage were higher than that in heading stage,but lower in jointing stage.crude protein degradability of dahurian bushclover at bud were higher than that in other stages.The degradability is going up rapidly before 24 times,then declined slowly.It is beneficial to grazing that the peak of biomass(aboveground biomass) at blooming stage in old world bluestem appeared in august.