利用芳香族化合物估测反刍动物采食量的潜力

综述了芳香族化合物的发现过程、反刍动物饲草料、瘤胃和尿液中芳香族化合物的主要类型及存在形式.马尿酸是最早从家畜排泄物中发现的芳香族化合物.反刍动物的尿液中排出的苯甲酸几乎完全来源于日粮中的前体物.饲料日粮中芳香族化合物是酚酸、简单酚、香豆素、棉子酚、酚的生物碱、类黄酮、单宁酸和木质素.羟基肉桂酸和安息香酸是维管束植物中广泛存在的一类酚类化合物,其在禾本科牧草中的含量远高于豆科牧草,但禾谷类籽实中的含量却很低.瘤胃液和尿液中的芳香族代谢物主要是无酚的芳香酸、酚酸和苯酚,环己烷羧酸是惟一发现的脂环族酸.饲喂不同的日粮饲草料,反刍家畜以马尿酸形式排出的氮量大约占尿氮总量的6%,变化范围为1%～38%.测定尿中芳香族化合物特别是马尿酸对预测反刍家畜的采食量具有重要潜力和作用.

Potential use of aromatic compounds to estimate the intake of ruminants

This paper summarises the discovery of aromatic compounds and different types and existing forms in ruminant feedstuffs, rumens and urine. Hippuric acid was the earliest aromatic compound found in ruminant urine. Most benzoic acid in ruminant urine is from precursors in feedstuffs. Aromatic compounds contained in plant feeds include phenolic acids, simple phenols, coumarin, gossypol, phenolic alkaloids, flavonoids, tannins and lignin. Hydroxycinnamic and benzoic acids are phenolic compounds commonly occurring in vascular plants, and are found in much higher contents in gramineous herbage than in leguminous herbage, but the content in cereal grains is very low. The main aromatic metabolites in rumen fluid and urine are non-phenolic aromatic acids, phenolic acids and phenols, and the only alicyclic acid that has been found is cyclohexanecarboxylic acid. With feeding different feedstuffs to ruminant livestock, hippuric acid excreted in the urine accounts for about 6% of total urinary nitrogen, and ranges from 1%-38%. Measuring aromatic compounds in urine, especially hippuric acid, has an important role in predicting feed intake of ruminant livestock.