摘要
为探究藏北高原天然草地放牧系统牦牛鲜奶品质及其影响因素,本研究于2021年8月在高寒草甸、高寒草原和荒漠草原3个类型放牧草地上选择12个样地及其周边36个牧户,采集测定牧草和牦牛鲜奶的营养品质指标,采用单因素方差分析法比较不同草地类型牦牛鲜奶营养品质的差异,利用结构方程和混合线性模型定量揭示牧草营养品质对牦牛鲜奶营养品质的调控路径和影响强度。结果表明:1)荒漠草原区牦牛鲜奶蛋白质含量(4.36%)最高,显著高于高寒草原(4.05%)和高寒草甸(3.59%)(P<0.05);高寒草甸区牦牛鲜奶的乳糖(5.45%)和矿物质含量(0.82%)均最高,显著高于高寒草原(4.31%和0.71%)和荒漠草原区(4.24%和0.73%)(P<0.05)。2)牧草粗蛋白含量和粗脂肪含量对牦牛鲜奶蛋白质含量影响显著(P<0.05),分别可以单独解释其53.58%和26.07%的变异;牧草粗蛋白和中性洗涤纤维含量对牦牛鲜奶乳糖含量影响显著(P<0.05),分别可单独解释其49.88%、40.92%的变异;牧草中性洗涤纤维含量对牦牛鲜奶矿物质含量影响显著(P<0.05),单独解释了其53.33%的变异。3)结构方程模型显示,植物生长季温度和降水可通过调控土壤全氮和有机碳含量间接或直接地影响牧草粗蛋白、粗脂肪、中性洗涤纤维含量,进而影响牦牛鲜奶乳糖、蛋白质、脂肪、矿物质等指标含量。综上所述,牦牛鲜奶营养品质受气候条件、土壤养分和牧草品质多重因素的调控。
To explore the relationship between the nutritional quality of fresh yak milk and forage plant species across the northern Tibetan Plateau,12 sites and 36 adjacent herder families were selected from alpine meadow,alpine steppe,and desert steppe zones to sample fresh yak milk and forage plants in August 2021.The differences in nutritional quality indicators of fresh yak milk samples were compared among different grassland zones using a one-way analysis of variance.The influence of the nutritional quality of forage plant species on fresh yak milk was quantitatively evaluated using structural equation modeling and generalized mixed linear models.The results showed that:1)The protein content of fresh yak milk from alpine deserts was the highest(4.36%),significantly higher than that from alpine steppes and alpine meadows(4.05%,3.59%)(P<0.05).The lactose and mineral content of fresh yak milk from alpine meadows were the highest(5.45%,0.82%),significantly higher than that from alpine steppes(4.31%,0.71%)(P<0.05)and alpine deserts(4.24%,0.73%)(P<0.05).2)The crude protein and crude fat content of forage plant species had significant impacts on the protein content of fresh yak milk,explaining 53.58%and 26.07%of the total variance in protein content,respectively(P<0.05).The crude protein and neutral detergent fiber content of forage plants had significant impacts on the lactose content of fresh yak milk(P<0.05),explaining 49.88%and 40.92%of the total variance in lactose content(P<0.05).The effect of neutral detergent fiber content on the mineral content of fresh yak milk was also significant(P<0.05),explaining 53.33%of the total variance in mineral content.3)The structural equation model showed that temperature and precipitation during the plant growth season indirectly or directly affected the crude protein,crude fat,and neutral detergent fiber content of forage by controlling soil total nitrogen and organic carbon content,which in turn affected the lactose,protein,fat,and mineral content in fresh yak milk.In summary,the nutritional quality of fresh yak milk on the northern Tibetan Plateau is regulated by multiple factors,including climatic conditions,soil nutrients,and forage together.
作者
张新永
李少伟
刘增辉
陈林耀
武建双
ZHANG Xinyong;LI Shaowei;LIU Zenghui;CHEN Linyao;WU Jianshuang(Institute of Environment and Sustainable Development in Agriculture,Chinese Academy of Agricultural Sciences,Beijing 100081,China;Institute of Geographic Science and Natural Resource Research,Chinese Academy of Sciences,Beijing 100101,China)
出处
《草业科学》
北大核心
2025年第1期209-224,共16页
Pratacultural Science
基金
第二次青藏高原综合科学考察项目(2019QZKK1002)
阿里地区区域科技协同创新专项(QYXTZX-AL2022-02)
阿里措勤农业科技园区人工草地提质增效技术研究与集成示范项目(QYXTZX-AL2022-03)。
关键词
牧草营养品质
牦牛鲜奶
高寒草地
高寒牧区
藏北高原
畜牧业
品质指标
forage nutritional quality
fresh yak milk
alpine pastures
alpine pastoral areas
northern Tibetan Plateau
grazier
quality indicators
作者简介
第一作者:张新永(1996-),男,甘肃定西人,在读硕士生,主要从事草地资源管理研究。E-mail:zhang.xinyong@outlook.com;通信作者:武建双(1983-),男,河北宁晋人,研究员,博导,博士,主要从事青藏高原气候变化和草地资源可持续性研究。E-mail:wujianshuang@caas.cn。
