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草业学报 ›› 2021, Vol. 30 ›› Issue (3): 110-120.DOI: 10.11686/cyxb2020340

• 研究论文 • 上一篇    下一篇

物候期对放牧牦牛瘤胃液、牧草中脂肪酸及乳脂中共轭亚油酸组成的影响及其相关性分析

潘发明1(), 常生华2(), 王国栋1, 郝生燕1, 刘佳1, 张辉元3, 徐银萍4   

  1. 1.甘肃省农业科学院畜草与绿色农业研究所,甘肃 兰州 730070
    2.兰州大学草地农业科技学院,甘肃 兰州 730020
    3.甘肃省农业科学院农产品贮藏加工研究所,甘肃 兰州 730070
    4.甘肃省农业科学院经济作物与啤酒原料研究所,甘肃 兰州 730070
  • 收稿日期:2020-07-15 修回日期:2020-10-26 出版日期:2021-03-20 发布日期:2021-03-09
  • 通讯作者: 常生华
  • 作者简介:Corresponding author. E-mail: cychangsh@lzu.edu.cn
    潘发明(1983-),男,甘肃民勤人,副研究员,硕士。 E-mail: 86975435@qq.com
  • 基金资助:
    甘肃省农业科学院重点研发计划项目(2019GAAS22);甘肃省2019年草原生态治理修复科技支撑项目(甘肃省生态草种筛选与人工繁育),甘肃省农业科学院重点研发计划项目(2020GAAS22);甘肃省现代农业科技支撑体系区域创新中心重点科技项目(2019GAAS51);甘肃省农业科学院农业科技自主创新专项现代生物育种项目(2019GAAS08)

Effects of phenological period on the composition of fatty acids and conjugated linoleic acids in rumen fluid, forage and milk fat of grazing yak and their correlation analysis

Fa-ming PAN1(), Sheng-hua CHANG2(), Guo-dong WANG1, Sheng-yan HAO1, Jia LIU1, Hui-yuan ZHANG3, Yin-ping XU4   

  1. 1.Animal Husbandry,Pasture and Green Agriculture Institute of Gansu Academy of Agricultural Science,Lanzhou 730070,China
    2.College of Pastoral Agriculture Science and Technology,Lanzhou University,Lanzhou 730020,China
    3.Agricultural Product Storage and Processing Research Institute of Gansu Academy of Agricultural Science,Lanzhou 730070,China
    4.Institute of Industrial Crops and Malting Barley of Gansu Academy of Agricultural Science,Lanzhou 730070,China
  • Received:2020-07-15 Revised:2020-10-26 Online:2021-03-20 Published:2021-03-09
  • Contact: Sheng-hua CHANG

摘要:

为研究牧草物候期对其脂肪酸组成和放牧牦牛乳中共轭亚油酸(CLA)含量的影响及其相关关系,本研究在甘肃省甘南牧区选取平均体重为(234.9±10.5) kg的10头带犊甘南牦牛作为研究对象(自然放牧),分别于牧草返青期、盛草期、枯草期采集试验牦牛采食牧草、乳和瘤胃液,分别测定瘤胃液、牧草中脂肪酸及乳脂中共轭亚油酸组成,并分析其相关关系,以期探明牧草物候期对牦牛瘤胃液和牧草中脂肪酸组成与放牧牦牛乳中共轭亚油酸含量的影响及其变化规律。结果表明:物候期显著影响了牧草中月桂酸、肉豆蔻酸、棕榈酸、硬脂酸、亚油酸、亚麻酸、总脂肪酸、多不饱和脂肪酸、多不饱和脂肪酸/总脂肪酸(P<0.05),盛草期牧草中月桂酸、肉豆蔻酸、棕榈酸、亚油酸、亚麻酸、总脂肪酸、多不饱和脂肪酸、多不饱和脂肪酸含量/总脂肪酸均显著高于返青期和枯草期(P<0.05);物候期显著影响了牦牛乳中共轭亚油酸异构体c9t11、共轭亚油酸异构体t10c12和共轭亚油酸总含量(P<0.05),盛草期放牧牦牛乳中共轭亚油酸异构体c9t11、共轭亚油酸异构体t10c12和共轭亚油酸总含量显著高于返青期和枯草期(P<0.05);物候期显著影响了牦牛瘤胃pH值、乙酸、丙酸、乙酸/丙酸、异丁酸、丁酸、异戊酸、戊酸、总挥发酸和反式11-油酸含量(P<0.05),盛草期牦牛瘤胃乙酸、丙酸、丁酸、戊酸总挥发酸和反式11-油酸含量显著高于返青期和枯黄期(P<0.05);牧草粗蛋白、粗脂肪、无氮浸出物、单宁酸、总脂肪酸和瘤胃液pH值与放牧牦牛乳中CLA含量显著正相关(P<0.05),粗纤维和粗灰分与放牧牦牛乳中CLA含量显著负相关(P<0.05),多不饱和脂肪酸(PUFAs)和瘤胃总挥发酸(TVFA)与放牧牦牛乳中CLA含量无显著相关关系(P>0.05)。

关键词: 牧草, 牦牛瘤胃液, 牦牛乳, 脂肪酸, 共轭亚油酸, 相关关系

Abstract:

The purpose of this paper was to study the effect of seasonal changes in alpine meadow herbage maturity (i.e. forage phenology) on the fatty acid composition of the forage and rumen fluid and on levels of conjugated linoleic acid (CLA) in the milk of grazing yaks. In this study, 10 Gannan yaks with calves and with an average body weight of (234.9±10.5) kg were used as the experimental subjects. The 10 yaks were naturally grazed in Gannan Pastoral Area of Gansu Province. During herbage re-greening in May, the growth flush in September, and winter herbage death in December, forage, yak milk and rumen fluid samples were collected for analysis as outlined above. The correlation between fatty acids and the composition of conjugated linoleic acid in milk fat was studied in order to find out the influence of forage phenology on the composition of fatty acid contents of forage and rumen fluid and the content of conjugated linoleic acid in milk of grazing yaks. It was found that the phenological period significantly affected the levels of lauric acid, myristic acid, palmitic acid, stearic acid, linoleic acid, linolenic acid, total fatty acids, polyunsaturated fatty acid, and polyunsaturated fatty acids/total fatty acid (P<0.05). For all except stearic acid, and for fatty acid levels in the forage, levels during the summer growth flush were significantly higher (P<0.05) than those in the re-greening and winter periods. The levels of conjugated linoleic acid isomer c9t11, conjugated linoleic acid isomer t10c12 and conjugated linoleic acid in grazing yak milk were also significantly higher (P<0.05) during the herbage growth flush than those in the re-greening and winter death periods. The pH, and contents of acetic acid, propionic acid, acetic∶propionic acid, isobutyric acid, butyric acid, isovaleric acid, valeric acid, total volatile acids and trans-11-oleic acid levels in the rumens of the yaks also differed significantly between phenological periods (P<0.05). There was a significant positive correlation (P<0.05) between the pH value of forage crude protein, ether extract, nitrogen free extract, tannic acid, total fatty acid and rumen fluid and the CLA content in grazing yak milk, a significant negative correlation (P<0.05) between crude fiber and crude ash and the CLA content in grazing yak milk, and no significant correlation (P>0.05) between polyunsaturated fatty acid levels and total volatile fatty acids and the CLA content in grazing yak milk.

Key words: forage, yak rumen fluid, yak milk, fatty acid, conjugated linoleic acid, correlation