三江源区高寒草场不同物候期牧草对放牧牦牛产奶量及乳中矿物质元素含量的影响  

Milk Yield and Milk Mineral Element Contents of Grazing Yaks in Different Phenological Periods in Alpine Pastures in the Source Area of Three Rivers

作　　者：周义秀 郝力壮[1] 刘书杰[1] ZHOU Yixiu;HAO Lizhuang;LIU Shujie(Qinghai Plateau Yak Research Center,State Key Laboratory of Plateau Ecology and Agriculture,Key Laboratory of Plateau Grazing Animal Nutrition and Feed Science of Qinghai Province,Academy of Animal Science and Veterinary Medicine,Qinghai University,Xining 810016,China)

机构地区：[1]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

出　　处：《动物营养学报》2020年第8期3742-3749,共8页CHINESE JOURNAL OF ANIMAL NUTRITION

基　　金：中科院“西部之光”人才培养引进计划“西部青年学者”A类项目(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(2020-ZJ-Y08);国家重点基础研究发展计划(973前期项目)(2012CB722906)。

摘　　要：本试验旨在探讨三江源区高寒草场不同物候期牧草对放牧牦牛产奶量及乳中矿物质元素含量的影响。选取自然放牧状态下胎次和体况一致的健康泌乳牦牛10头为研究对象,记录放牧母牦牛在枯草期(12—4月)、返青期(5月)、青草期(6—8月)和枯黄期(9—11月)的产奶量,通过火焰原子吸收法分别对4期牧草样品和采集的乳样品进行矿物质元素[钾(K)、钠(Na)、钙(Ca)、镁(Mg)、铁(Fe)、锰(Mn)、锌(Zn)、钴(Co)、铜(Cu)]含量的测定。结果表明:1)青草期牧草的Na、Mg、Fe、Mn和Cu含量显著高于其他物候期(P<0.05),而枯草期牧草的K、Ca和Co含量显著高于其他物候期(P<0.05),牧草的Zn含量随物候期推移呈现增加趋势。2)青草期牦牛的产奶量显著高于其他物候期(P<0.05);青草期牦牛乳中K、Na、Ca、Mg、Mn和Cu含量显著高于其他物候期(P<0.05),枯草期乳中Co含量显著高于其他物候期(P<0.05),而乳中Fe和Zn含量在枯黄期较高(P<0.05)。3)不同物候期牧草与牦牛乳中Na、Mg、Mn、Co、Cu含量的相关性显著,相关值分别为0.723(P<0.01)、0.996(P<0.01)、0.975(P<0.05)、0.981(P<0.05)、0.967(P<0.01)。由此可知,牦牛产奶量和乳中矿物质元素含量随着不同物候期牧草中矿物质元素含量变化而变化,从枯草期到青草期,牦牛产奶量呈现逐渐增高趋势,而后产奶量随牧草枯黄逐渐降低,乳中Na、Mg、Mn、Co、Cu含量会随着牧草中相应矿物质元素含量的升高而升高。This experiment was to explore the effects of different phenological periods of pasture on alpine natural grassland on the milk yield and mineral element contents of grazing yak in the source area of Three Rivers.Ten healthy lactating yaks with the same parity and physical condition were selected as the research objects,and the milk yield was recorded of grazing female yaks in the withered period(from December to April),regreen period(May),grassy period(from June to August)and withering period(from September to November).The collected milk samples were subjected to the determination of mineral element(K,Na,Ca,Mg,Fe,Mn,Zn,Co and Cu)contents.The results showed that:1)the contents of Na,Mg,Fe,Mn and Cu of the grass were significantly higher than those in other phenological periods(P<0.05),while the contents of K,Ca and Co of grass in the withered periods were significantly higher than those in other phenological periods(P<0.05),the content of Zn increased with the phenological period turning.2)The milk yield of grazing yak in the grassy period was significantly higher than that in other phenological periods(P<0.05).The contents of K,Na,Ca,Mg,Mn and Cu in yak milk in the grassy period were significantly higher than those in other phenological periods(P<0.05),and the Co content of yak milk in the withered periods was significantly higher than that in other phenological periods(P<0.05).The contents of Fe and Zn in yak milk were significantly higher than those in other phonological period(P<0.05).3)The correlations of Na,Mg,Mn,Co,and Cu between forage and yak milk were significant in different phenological periods.The correlation values were 0.723(P<0.01),0.996(P<0.01),0.975(P<0.05),0.981(P<0.05)and 0.967(P<0.01),respectively.It can be concluded that the yak milk yield and the contents of mineral elements in milk will change as the contents of mineral elements in forage in different phenological periods.From the withered periods to the grassy periods,the yak milk yield show a gradually increasing trend.Then it gradually

关 键 词：放牧牦牛 物候期 牦牛乳 产奶量 矿物质 

分 类 号：S823[农业科学—畜牧学]