fn Partíal Fulfillnent - MSpace

PART 3.
Ðeterrnination of amino acid availabilities
by ileal sanpling from cannulated animals,
by ileal sampling from sacrificed animals,
. by removal of the caeeum and
by aid of germ-free and antibiotic treated animals.
Several approaches can be made to determine anino
acid availabilities that may or may not be partially confound.ed
by protein metabolism in the lower gut. Each approach has
its partÍcular advantages and disadvantages.
Ileal sampling by eg4nulation: liiore vaÌ.id amino
acid availability estimates wil1 be obtained. when the digesta
are collected at the end of the ileun as conpared to faecal
collections.
Continuous collection of ileat digesta at the end
of the ileum can be achieved by the use of í1eal re-entrant
cannulae (Holnes et al ., I97l+'Ì or by ii-eal-caecal re-entrant
cannulae (Easter , I97 Zl . Ileal--caecal cannulae were found to
cause fewer problems in ¡saintaining an unrestricted flow
(Easter, 1972). Use of the ileal re-entrant system will give
a closer approximation to the digestive processes in situ as
compared. to the use of the ileal-caecal re-entrant system.
The latter system bypasses the ileal-caecal valve and all
digesta passes through the caecum flrst before entering the
colon. About one-third to two-thirds of the ireal flow enters