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ORIGINAL ARTICLE: The effect of dietary methionine levels on endogenous nitrogen and endogenous amino acids flows in growing goats
Author(s) -
Zhou C. S.,
Tan Z. L.,
Tang S. X.,
Sun Z. H.,
Han X. F.,
Wang M.,
Tayo G. O.
Publication year - 2010
Publication title -
journal of animal physiology and animal nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.651
H-Index - 56
eISSN - 1439-0396
pISSN - 0931-2439
DOI - 10.1111/j.1439-0396.2009.00944.x
Subject(s) - endogeny , latin square , ileum , duodenum , methionine , small intestine , isotope dilution , medicine , amino acid , gastrointestinal tract , zoology , biology , jejunum , chemistry , endocrinology , biochemistry , rumen , fermentation , chromatography , mass spectrometry
Summary The effect of dietary methionine (Met) levels on endogenous N and amino acids (AA) flows at different part of the digestive tract of growing goats was determined using a 15 N isotope dilution technique. Three goats (25 ± 2.5 kg) were fitted with the ruminal, duodenal and ileal cannulae and allocated to three dietary treatments in a 3 × 3 Latin square design. The dietary treatments consisted of a total mixed ration containing three levels of Met (0.15%, 0.25% and 0.35%) respectively. It was found that at 0.15% Met level, the lowest flow in endogenous N and total AA at the duodenum and ileum occurred. The endogenous N secretion contributed to 26% and 23% of the duodenal and ileal total N flows, respectively, and the proportions were not affected by the dietary Met levels. The duodenal and ileal flows of endogenous total AA were 11.1, 11.8, 11.3 g/d and 2.9, 3.9, 4.1 g/d respectively. The average real digestibility of N was 65%, 87% and 95% in the forestomach, intestine and whole digestive tract respectively.