新疆不同草地类型天然牧草营养价值评定

Evaluation of nutritional value of natural herbage of different grassland types in Xinjiang

为研究新疆伊犁河谷不同草地类型天然放牧草场营养成分,确定不同草地类型放牧家畜的补饲量,试验采集了新疆伊犁河谷不同海拔、不同草地类型、不同区域草地上的混合牧草,同一草地类型山地草甸7种不同牧草,以及不同海拔同一种牧草伊犁绢蒿进行营养价值评定。结果显示:(1)不同草地类型牧草营养成分差异较大,山地草甸草原以上的牧草中粗蛋白质(CP)含量占干物10%以上,牧草酸性洗涤纤维(ADF)含量随着海拔的升高而降低,总体表现为随着海拔升高,天然牧草的营养价值和饲用价值也升高;(2)同一草地类型(山地草甸)上4个科7种牧草的化学成分差异较大,豆科牧草的干物质(DM)、粗蛋白质(CP)、粗灰分(Ash)、钙(Ca)含量没有显著差异(P>0.05),但中性洗涤纤维(NDF)、ADF、粗脂肪(EE)及磷(P)含量有极显著差异(P<0.01);禾本科牧草DM、CP差异不显著,其他化学成分都差异明显;(3)昭苏县、特克斯县、尼勒克县的天然牧草CP要显著高于巩留县和察布查尔县(P<0.01),且Ash、Ca、P含量较高,粗纤维含量较低。无论营养价值还是适口性,都表现为较高海拔地区的牧草饲用价值较高;(4)同一气候期高海拔生长的伊犁绢蒿,其CP和P含量高,粗纤维、EE含量低。结果表明,随着海拔升高,新疆伊犁河谷不同草地类型天然牧草的营养价值和饲用价值也有所提升,尤其是夏季放牧高寒草甸在CP含量上显著高于其他草地类型,而纤维含量显著下降;在同一草地类型上红三叶、黄花苜蓿等豆科牧草营养价值要高于其他典型草种类;特有牧草伊犁绢蒿随海拔升高营养价值有所提升。

In order to study the nutrient composition of different types of natural grazing grassland in Yili river valley of Xinjiang,determine the supplement amount of different types of grazing livestock and the sustainable development of grassland animal husbandry.In this study,we collected the mixed herbage of different altitude,different types of grassland and different regions in Yili river valley of Xinjiang,and evaluated the nutritional value of 7 different herbages of the same type of grassland in mountain meadow,and the same herbage in Yili at different altitudes.The results showed that:(1)There were significant differences in the nutritional components of different grassland types.The crude protein(CP)content accounted for more than 10%of the dry matter in the forage above the mountain meadow grassland,and acid detergent fiber(ADF)content of forage decreased with the increase of altitude,which showed that the nutritional value and feeding value of natural forage were also higher with the increase of altitude;(2)There were differences in the chemical composition of the four forage in the same grassland type(mountain meadow).There were significant differences in the contents of dry matter(DM),CP,ash and Ca in legumes(P>0.05),but there were significant differences in the contents of neutral detergent fiber(NDF),ADF,EE and P(P<0.01);there were no significant differences in the contents of DM and CP in gramineae,and there were significant differences in other chemical components;(3)The CP of natural forages in Zhaosu county,Tekesi county and Nileke county was significantly higher than that in Gongliu county and Chabuchaer county in Chal county(P<0.01),the content of Ash,Ca,P was higher,and the content of crude fiber was lower.No matter the nutritional value or palatability,the forage in higher altitude area has higher feeding value;(4)In the same phenological period,Seriphidiumt ransiliense grows at high altitude,the content of CP and P was high,but the content of crude fiber and crude fat was low.The results indicated that with the increase of altitude,the nutritional value and feeding value of different grassland types in Yili river valley of Xinjiang also increased,especially in summer,the CP content of grazing alpine meadow was significantly higher than that of other grassland types,while the fiber content was significantly lower;in the same grassland type,the nutritional value of red clover,yellow clover and other legumes was higher than that of other typical grass types.The nutritive value of the special herbage Seriphidiumt ransiliense increased with the increase of altitude.