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Effects of supplement feeding order on lactation, diurnal variation of ruminal ammonia and urea in the blood and milk of dairy cows
Author(s) -
IKUTA Kentarou,
SASAKURA Kazumi,
NISHIMORI Kazuhiro,
HANKANGA Careen,
OKADA Keiji,
YASUDA Jun
Publication year - 2005
Publication title -
animal science journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.606
H-Index - 38
eISSN - 1740-0929
pISSN - 1344-3941
DOI - 10.1111/j.1740-0929.2005.00234.x
Subject(s) - latin square , urea , lactation , zoology , rumen , ammonia , chemistry , biology , diurnal temperature variation , food science , biochemistry , fermentation , pregnancy , genetics , atmospheric sciences , geology
The present study examined the effects of feeding order of grain and protein supplements on ruminal nitrogen (N) loss through the diurnal variation of ruminal ammonia N and urea N in the blood and milk of dairy cows. Three ruminally fistulated cows were used in a 3 × 3 Latin square arrangement of treatments; that is, grain supplement fed at the first feed and then the protein supplement at the second (GS‐1st), protein supplement fed first and then the grain supplement (PS‐1st), and the grain and protein supplements mixed and divided into equal portions fed at each supplement feeding time (GP‐mix). No differences in the lactation parameters were observed among the treatments. In GS‐1st treatment, the increase in the concentration of ruminal ammonia N was inhibited after feeding, and the concentration was lower ( P < 0.05) than with the other treatments 1–2 h after basal feeding. The concentrations of urea N in the blood and milk with the GS‐1st treatment were the lowest of all treatments throughout the sampling times, and were lower ( P < 0.05) than with the GP‐mix treatment except for blood levels 1 h after basal feeding. The results suggest that grain feeding before protein feeding can reduce ruminal N loss.