体外法评价青海省泽库县高寒草甸草场不同物候期牧草的营养价值  

Evaluation of Forage Nutritional Value of Alpine Meadow Grassland in Different Phenological Periods in Zeku County of Qinghai Province by in Vitro Method

作　　者：张群英[1,2] 李捷 郝力壮 刘书杰[1,2] 柴沙驼[1,2] 牛建章[1,2] 张晓卫[1,2] 王迅[1,2] 孙璐[1,2] 多吉欧珠[3] ZHANG Qunying;LI Jie;HAO Lizhuang;LIU Shujie;CHAI Shatuo;NIU Jianzhang;ZHANG Xiaowei;WANG Xun;SUN Lu;DUOJI Ouzhu(Qinghai University,Xining 810016,China;Academy of Science and Veterinary Medicine of Qinghai University,State Key Laboratory of Plateau Ecology and Agriculture,Key Laboratory of Plateau Grazing Animal Nutrition and Feed Science of Qinghai Province,Qinghai Plateau Yak Research Center,Xining 810016,China;Yadong County Pastoral Service Centers of Tibet Autonomous Region Shigatse,Shigatse 857600,China)

机构地区：[1]青海大学,西宁810016 [2]青海大学畜牧兽医科学院,青海省高原放牧家畜动物营养与饲料科学重点实验室,省部共建三江源生态与高原农牧业国家重点实验室,青海高原牦牛研究中心,西宁810016 [3]西藏自治区日喀则市亚东县农牧综合服务中心,日喀则857600

出　　处：《动物营养学报》2020年第3期1415-1423,共9页CHINESE JOURNAL OF ANIMAL NUTRITION

基　　金：国家重点研发计划(2016YFD0500504);国家自然科学基金项目(31660673);中国科学院“西部之光”人才培养引进计划(1-7);青海省高原放牧家畜动物营养与饲料科学重点实验室奖励项目(14);国家重点基础研究发展计划(973前期项目)(2012CB722906)

摘　　要：本试验旨在探讨青海省泽库县高寒草甸草场不同物候期[1~4月份(枯草期)和5~6月份(返青期)]牧草营养价值的动态变化,以期为当地放牧家畜的精准补饲提供基础数据。选取青海省泽库县典型的高寒草甸草场,从2018年枯草期的1月份至返青期的6月份,每月中旬跟踪放牧牦牛模拟采集可食性牧草,并采用常规营养成分分析方法测定牧草的常规营养成分含量,体外发酵法测定牧草体外发酵不同时间点的产气量(GP)和体外干物质消失率(IVDMD)以及体外发酵48 h时发酵液pH、氨态氮(NH 3-N)浓度、挥发性脂肪酸(VFA)含量。结果表明:牧草中粗蛋白质(CP)、粗脂肪(EE)含量及48 h IVDMD均在5、6月份极显著高于其他月份(P<0.01),且上述指标在1月份均处于最低值。72 h GP以及发酵液pH与NH 3-N浓度、VFA含量均随着牧草营养品质的变化而变化,72 h GP与发酵液NH 3-N浓度在5、6月份均显著高于其他月份(P<0.05),在1~3月份则均显著或极显著低于其他月份(P<0.05或P<0.01)。在发酵液总VFA含量上,5、6月份之间没有显著差异(P>0.05),但二者均极显著高于其他月份(P<0.01),同时1月份极显著低于其他月份(P<0.01)。综上所述,青海省泽库县高寒草甸草场的牧草在返青期营养品质优良,在枯草期营养品质偏低,不能满足牦牛的营养需要,故建议牧民进行精准补饲,合理利用草场资源,促进当地畜牧业的发展。The aim of this experiment was to explore the dynamic changes of forage nutritional value of alpine meadow grassland in different phenological periods[January to April(hay period)and May to June(returning green period)]in Zeku county of Qinghai province in order to provide some basic data for accurate supplementary feeding of local grazing livestock.Local typical grazing pastures were chosen to collect edible forage in the middle of each month by tracking grazing yak from January of hay period to June of turning green period,2018.The conventional nutrient contents of pasture were determined by common nutrient composition analysis method,and the in vitro fermentation method was used to measure the gas production(GP)and in vitro dry matter digestibility(IVDMD)at different fermentation time points,and the pH,ammonia nitrogen(NH 3-N)concentration and volatile fatty acid(VFA)contents in fermentation broth at fermentation 48 h.The results showed that the conventional nutrient contents and IVDMD of forage in May and June were significantly higher than those in other months(P<0.01),and the lowest values of them in January.With the nutritional quality of forage changed,72 h GP and pH,NH 3-N concentration and VFA contents in fermentation broth also changed,the 72 h GP and NH 3-N concentration in May and June were significantly higher than those in other months(P<0.05),and those in January to March were significantly lower than those in other months(P<0.05 or P<0.01).On the total VFA content in fermentation broth,there was no significant difference between May and June(P>0.05),but they were significantly higher than other months(P<0.01),and the January was significantly lower than other months(P<0.01).In summary,the forage of alpine meadow grassland in Zeku county of Qinghai province has good nutritional quality in turning green period,but it in hay period has lower nutritional quality and can not meet the nutritional needs of grazing yaks.It is recommended for accurate feeding herders,rational use of grassland resources ca

关 键 词：体外发酵 牧草 营养价值 体外干物质消失率 

分 类 号：S823[农业科学—畜牧学] S54[农业科学—畜牧兽医]