TY - JOUR
T1 - Assessment of duodenal amino acid profile in dairy cows by the in situ method
AU - Tagari, H.
AU - Arieli, A.
AU - Mabjeesh, S.
AU - Bruckental, I.
AU - Zamwell, S.
AU - Aharoni, Y.
PY - 1995/4
Y1 - 1995/4
N2 - In situ evaluation of the duodenal amino acid (AA) profile was attempted in a 4 × 4 Latin square study using four lactating Holstein cows fitted with ruminal and duodenal cannulas. Dietary supplemental crude protein (CP) sources, making up 40% of the dietary CP, were: soybean meal, cottonseed meal, corn gluten meal or urea. Duodenal flow of organic matter (OM) and CP was determined in vivo by means of constant infusion of ytterbium and chromium, and predicted in situ from rumen degradation. Purines were used as microbial markers. In situ calculation of the AA profile, expressed as g AA in 100 g of total AAs, was based on the composition of AA in feed and in isolated bacteria as well as on in situ rumen degradation of OM and CP. The AA profile in the duodenum when assessed in vivo was affected by the nature of the supplemental protein; in situ assessment of the AA profile resulted in comparable profiles. The data are interpreted to suggest that the in situ method enables prediction of the profile of AA (g AA/100 g total AA) flowing to the duodenum, and that the undegraded portion of supplemented protein affects that profile.
AB - In situ evaluation of the duodenal amino acid (AA) profile was attempted in a 4 × 4 Latin square study using four lactating Holstein cows fitted with ruminal and duodenal cannulas. Dietary supplemental crude protein (CP) sources, making up 40% of the dietary CP, were: soybean meal, cottonseed meal, corn gluten meal or urea. Duodenal flow of organic matter (OM) and CP was determined in vivo by means of constant infusion of ytterbium and chromium, and predicted in situ from rumen degradation. Purines were used as microbial markers. In situ calculation of the AA profile, expressed as g AA in 100 g of total AAs, was based on the composition of AA in feed and in isolated bacteria as well as on in situ rumen degradation of OM and CP. The AA profile in the duodenum when assessed in vivo was affected by the nature of the supplemental protein; in situ assessment of the AA profile resulted in comparable profiles. The data are interpreted to suggest that the in situ method enables prediction of the profile of AA (g AA/100 g total AA) flowing to the duodenum, and that the undegraded portion of supplemented protein affects that profile.
KW - Dacron bag
KW - Dairy cow
KW - Duodenal amino acid
UR - http://www.scopus.com/inward/record.url?scp=0006107519&partnerID=8YFLogxK
U2 - 10.1016/0301-6226(94)00061-B
DO - 10.1016/0301-6226(94)00061-B
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AN - SCOPUS:0006107519
SN - 0301-6226
VL - 42
SP - 13
EP - 22
JO - Livestock Production Science
JF - Livestock Production Science
IS - 1
ER -