新疆沙尔套山四季放牧草地主要牧草营养价值变化特征研究

以新疆昭苏县域内沙尔套山分布的12种主要牧草为研究对象,对其营养物质和瘤胃体外消化率特征进行分析,以期揭示各牧草营养物质和消化率的季节性变化规律。结果表明,各牧草的营养物质含量和消化率特征指标均存在明显的季节性变化规律。通过模糊相似优先比分析,综合营养物质(干物质、粗蛋白、中/酸性洗涤纤维、粗脂肪、粗灰分)和瘤胃体外消化率特征(有机物消化率、代谢能)的8项指标进行综合营养价值评价,主要结论为:1)研究区放牧草地12种主要牧草中针茅、芨芨草、紫花鸢尾综合营养价值最佳季节在春季营养生长期(6月),其余牧草均为夏季开花期(7月)。2)春季营养生长期(6月)和秋季果后营养期(9月),综合营养价值最好的均为鸭茅;夏季开花期(7月),综合价值最好的牧草为西伯利亚羽衣草;秋季结实期(8月),综合营养价值最好的牧草为红花车轴草;冬季停止生长(10月)和枯草期(11月),综合营养价值最好的分别为针茅和紫花鸢尾。

Seasonal variation in nutritive value of twelve main forage plant species of grazed grassland in Shaertao mountain,Xinjiang

Twelve of the main forage plant species contributing to livestock diets in grazed grassland of Shaertao mountain in Zhaosu county, Xinjiang, were assessed for nutritive value and in vitro digestibility in order to define the seasonal variation in these traits for each forage. Large seasonal changes were observed for each forage species. Data for six indicators offorage quality (dry matter, crude protein, neutral detergent fiber, acid detergent fiber, ether extract, crude ash), together with rumen in vitro digestibility of organic matter and herbage metabolic energy were analyzed using a “Fuzzy similar priority ratio” method. The main conclusions were:1) For the three species Stipa capillata, Achnatherum splendens and Iris ruthenica, the best comprehensive nutritive value score occurred in the spring vegetative growth period (June), while the best season for utilization of the remaining 9 species was summer flowering period (July). 2) Dactylis glomerata had the best nutritional value in spring (June) and post-flowering (September), while Alchemilla sibirica had the best nutritional value at summer flowering (July). During autumn (August), Trifolium pratense with the highest comprehensive nutritional value score. 3) In the hay season (November), species with the best nutritional value were S. capillata and I. ruthenica. All species ceased growth in winter.