Natural 15N Abundance in Key Amino Acids from Lamb Muscle: Exploring a New Horizon in Diet Authentication and Assessment of Feed Efficiency in Ruminants

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• 作者：Gonzalo Cantalapiedra-Hijar ; Isabelle Ortigues-Marty ; Anne-Marie Schiphorst ; Richard J. Robins ; Illa Tea ; Sophie Prache
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2016
• 出版时间：May 25, 2016
• 年：2016
• 卷：64
• 期：20
• 页码：4058-4067
• 全文大小：427K
• 年卷期：0
• ISSN：1520-5118

文摘

Natural ¹⁵N abundance (δ¹⁵N) varies between individual amino acids (AAs). We hypothesized that δ¹⁵N of nontransaminating and essential AAs (“source” AAs, such as phenylalanine) present in animal tissues could be used as a marker of dietary origin, whereas δ¹⁵N of transaminating AAs (“trophic” AAs, such as glutamic acid) could give more detailed insights into animal feed efficiency. Two diets based on dehydrated Lucerne pellets were tested in growing lambs, which promoted different feed efficiencies. No dietary effects were noted on δ¹⁵N of any AAs analyzed in lamb muscle. In addition, δ¹⁵N of phenylalanine was unexpectedly similar to that of glutamic acid, suggesting that δ¹⁵N of AAs is significantly derived from the metabolism of the rumen microbiota and, thus, are not suited for diet authentication in ruminants. In contrast, the δ¹⁵N of transaminating AAs facilitates an improved prediction of animal feed efficiency compared to the classical isotopic bulk N analysis.