|
|
||||||||
Journal of Animal Science, Vol 72, Issue 1 229-235, Copyright © 1994 by American Society of Animal Science
JOURNAL ARTICLE |
S. Rahnema, Z. Wu, O. A. Ohajuruka, W. P. Weiss and D. L. Palmquist
Department of Dairy Science, Ohio State University, Wooster 44691.
Five lactating Holstein cows with ruminal and duodenal cannulas were used in a 5 x 5 Latin square to determine the site of mineral absorption and effects of sources and amount of dietary fat on apparent absorption. Cows were fed (DM, 17.4 +/- .8 kg/d) chopped alfalfa hay, alfalfa haylage, corn silage, and concentrate at 1:1:1:2 (DM) at 12-h intervals. Calcium salts of palm fatty acid distillate (CS) or animal-vegetable (AV) fat were 0% (control), 2.5% (low, L), or 5.0% (high, H) of the diet DM. After 2 wk of adaptation, duodenal and fecal grab samples were collected at 7-h intervals for 5 d and composited by animal. Calcium intake increased (P < .05) with high-fat diets (195 vs 170 g/d), whereas Mg intake remained unchanged (54.3 +/- 9.0 g/d). Apparent absorption, estimated by Cr2O3, was regressed on Ca or Mg intake (grams/day) and fatty acid (FA) intake (grams/day). Total absorption of Ca (grams/day) = -37.4 + .264 Ca (P = .07, R2 = .14). Ruminal absorption of Mg was independent of FA intake, and magnesium was secreted posterior to the duodenum. Total tract Mg absorption (grams/day) was described by -7.685 + .464 Mg -.0044 FA (P < .0005, R2 = .46). Fat intake decreased (P < .05) total tract Mg absorption, and Ca absorption was decreased by high fat compared with low fat intake (P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)
This article has been cited by other articles:
![]() |
J. T. Schonewille, H. Everts, S. Jittakhot, and A. C. Beynen Quantitative Prediction of Magnesium Absorption in Dairy Cows J Dairy Sci, January 1, 2008; 91(1): 271 - 278. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. P. Weiss Macromineral Digestion by Lactating Dairy Cows: Factors Affecting Digestibility of Magnesium J Dairy Sci, July 1, 2004; 87(7): 2167 - 2171. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |