Author:
PUCHAŁA R.,ZABIELSKI R.,LEŚNIEWSKA V.,GRALAK M.,KIELA P.,BAREJ W.
Abstract
Four, 4-week old Friesian calves (BW=50±3 kg), fitted with
duodenal, portal and jugular catheters
and duodenal electrodes, were used to study the metabolism of duodenally
infused betaine (Bet) or
choline (Chol) and their effects on blood sulphur amino acids and duodenal
myoelectrical migrating
complexes (MMC). Animals were fed milk replacer at 5% BW twice daily, but
were starved overnight
prior to the experimental procedure. Animals received a saline infusion
for 2 h at 1 ml/min followed
by a 1 h infusion of 1·2 or 3·6 mmol of either Bet or Chol.
Infusion of saline was continued for another
2 h after the cessation of the amino acid infusion. Duodenal MMC were measured
with a computer-based
data acquisition system (MacLab, ADI, Australia). There were no differences
in measured
blood metabolites between the jugular and portal vein; therefore, only
average values were presented.
Plasma Met concentrations increased from 20 μm, 20 min after
initiating Bet infusion, whereas a
lower dose of Chol decreased plasma Met and a higher one had no effect.
The highest plasma
methionine (Met) concentration (29 μm) occurred 45 min after
the onset of the Bet infusion (1·2
mmol). Compared to the 3·6 mmol Bet infusion, the intraduodenal
infusion of 1·2 mmol of Bet
resulted in a greater area (P<0·001) under the plasma
Met concentration curve (281·6 v. 73·3 mmol).
A similar pattern was observed for plasma cystine concentrations. Infusion
of Bet or Chol did not
change the duration of MMC but Bet increased the number of spikes during
the phase of low spiking
activity (37·5 v. 14·6 pre-infusion, spikes/min;
P<0·01). Chol had the same effect but only after the
infusion ceased (29·3 v. 11·5 spikes/min; P<0·01).
The velocity of migration of regular spiking
activity (RSA; related to digesta transport) increased as a result of infusion
(16·4 pre-infusion v. 31·3
Bet, 25·2 Chol cm/min; P<0·01). Chol caused
an immediate increase in the velocity of migration of
RSA, whereas with the Bet infusion an increase was observed after cessation
of infusion. Increased
concentrations of sulphur amino acids during Bet infusion could indicate
that labile methyl groups
may be limited in calves. Postruminal Bet and Chol supplementation may
cause a decrease in nutrient
absorption in the small intestine by increasing digesta transport.
Publisher
Cambridge University Press (CUP)
Subject
Genetics,Agronomy and Crop Science,Animal Science and Zoology
Cited by
13 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献