中国畜牧兽医 ›› 2025, Vol. 52 ›› Issue (1): 121-132.doi: 10.16431/j.cnki.1671-7236.2025.01.011

• 营养与饲料 • 上一篇    

硒代蛋氨酸法和改进体外三步法测定过瘤胃蛋氨酸生物利用率及相关性研究

谭咏琪, 詹腾飞, 姚瑞芬, 郭鑫, 马露, 卜登攀   

  1. 中国农业科学院北京畜牧兽医研究所, 畜禽营养与饲养全国重点实验室, 北京 100193
  • 收稿日期:2024-06-25 发布日期:2024-12-30
  • 通讯作者: 卜登攀 E-mail:budengpan@caas.cn
  • 作者简介:谭咏琪,E-mail:renwoliu123@163.com。
  • 基金资助:
    宁夏回族自治区重点研发计划项目(2023BCF01035);中国农业科学院科技创新工程(ASTIP-IAS07-1);家畜产业技术体系北京市创新团队(BAIC05-2024)

The Bioavailability and Correlation Study of Rumen-protected Methionine Measured by Selenomethionine Method and Modified in vitro Three-step Procedure

TAN Yongqi, ZHAN Tengfei, YAO Ruifen, GUO Xin, MA Lu, BU Dengpan   

  1. State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Science of CAAS, Beijing 100193, China
  • Received:2024-06-25 Published:2024-12-30

摘要: 【目的】 本试验分别采用硒代蛋氨酸法和改进体外三步法评估3种过瘤胃蛋氨酸(A、B、C)的生物利用率,并对两种方法所得结果进行相关性分析和回归分析,旨在探究两种方法之间的关系。【方法】 ①硒代蛋氨酸法:选用33头健康泌乳奶牛,按照随机区组试验设计分为3组,试验期共32 d,分为3个阶段,其中前7 d为预饲期(第0阶段),第8~22天为第1阶段,随后10 d为第2阶段。第0阶段奶牛仅饲喂基础饲粮,第1阶段所有奶牛均按照0.3 mg Se/kg DM补充硒酵母,第2阶段继续补充相同剂量的硒酵母,同时依据相同有效蛋氨酸的量(25 g/d),3组奶牛分别补充过瘤胃蛋氨酸A(33.3 g/d,A组)、B(29.4 g/d,B组)和C(56.82 g/d,C组)。在第22和32天采集奶样,用于硒、蛋氨酸和氮浓度的测定,以硒浓度/蛋氨酸浓度(硒浓度/氮浓度)比值的变化评估3种过瘤胃蛋氨酸的生物利用率。②改进体外三步法:选用3头安装瘤胃瘘管的泌乳奶牛,3种过瘤胃蛋氨酸各设置2个平行,3个重复,通过瘤胃孵育、体外模拟胃-小肠消化测定干物质(DM)和粗蛋白质(CP)的过瘤胃率和小肠消化率以评估其生物利用率。③分析两种方法之间的相关性并建立回归方程。【结果】 硒代蛋氨酸法结果表明,过瘤胃蛋氨酸A基于牛奶硒浓度/蛋氨酸浓度和牛奶硒浓度/氮浓度比值变化计算的生物利用率分别为:83.02%和81.42%,过瘤胃蛋氨酸B的分别为:72.94%和72.47%,过瘤胃蛋氨酸C的分别为:51.77%和50.98%。改进体外三步法结果显示,过瘤胃蛋氨酸A、B和C的生物利用率分别为86.87%、75.47%和59.56%。比较两种方法的测定结果,二者无显著差异(P>0.05),且呈极显著正相关(r=0.867~0.964,P<0.01)。【结论】 在本试验条件下,硒代蛋氨酸法和改进体外三步法均能用于3种过瘤胃蛋氨酸的生物利用率的测定,且两种方法间存在较强的正相关关系。

关键词: 硒代蛋氨酸法; 改进体外三步法; 过瘤胃蛋氨酸; 生物利用率

Abstract: 【Objective】 In this experiment,the bioavailability of three types of rumen-protected methionines (A,B and C) was measured using the selenomethionine method and the modified in vitro three-step procedure,respectively,and the results obtained from the two methods were subjected to correlation and regression analyses aiming at exploring the relationship between the two methods. 【Method】 ① Selenomethionine method:Thirty-three healthy lactating dairy cows were used in the experiment,divided into three groups according to a randomised block trial design,with a total of 32 days divided into three phases,of which the first 7 days were pre-feeding (phase 0),the days 8 to 22 were phase 1,and the following 10 days were phase 2.In phase 0,cows were fed only the basal diet,and starting from phase 1,all cows were supplemented with selenium yeast at a dose of 0.3 mg Se/kg DM,in Phase 2,continued with the same dose of selenium yeast supplementation,all cows were supplemented with rumen-protected methionine supplementation A (33.3 g/d,group A),B (29.4 g/d,group B) and C (56.82 g/d,group C) based on the same amount of effective methionine (25 g/d).Milk samples were collected on days 22 and 32 for the determination of selenium,methionine and nitrogen concentrations,and the bioavailability of the three rumen-protected methionines was measured as the change in the ratio of selenium concentration/methionine concentration (selenium concentration/nitrogen concentration) in phases 1 and 2.② Modified in vitro three-step procedure:Three lactating dairy cows fitted with rumen fistulas were used in the experiment,and each of the three rumen-protected methionines (rumen-protected methionine A,B,and C) was set up in two parallels and three replicates,and the bioavailability of rumen-protected methionines were assessed by rumen incubation and in vitro simulation of gastric-small intestinal digestion of DM and CP.The correlation between the two methods was analysed and regression equations were established. 【Result】 The results of the selenomethionine method showed that the bioavailability of rumen-protected methionine A based on changes in the ratio of milk selenium concentration/methionine concentration and milk selenium concentration/nitrogen concentration were 83.02% and 81.42%,respectively,while for rumen-protected methionine B,72.94% and 72.47%,respectively,and for rumen-protected methionine C,51.77% and 50.98%,respectively.② The results of the modified in vitro three-step procedure showed that the bioavailability of rumen-protected methionine A,B and C were 86.87%,75.47% and 59.56%,respectively.The analysis of the results of the two methods showed that there was no significant difference (P>0.05),and there was a highly significant positive correlation (r=0.867-0.964,P<0.01) between the results of the two methods. 【Conclusion】 Under the conditions of this test,both the selenomethionine method and the modified in vitro three-step procedure could be used for the determination of the bioavailability of the three types of rumen-protected methionines,and a strong positive correlation existed between the two methods.

Key words: selenomethionine method; modified in vitro three-step procedure; rumen-protected methionine; bioavailability

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