G. Brunsgaard et al., THE INFLUENCE OF THE PERIOD OF ADAPTATION ON THE DIGESTIBILITY OF DIETS CONTAINING DIFFERENT TYPES OF INDIGESTIBLE POLYSACCHARIDES IN RATS, British Journal of Nutrition, 74(6), 1995, pp. 833-848
In balanced experiments with rats the influence of the period of adapt
ation on nutrient digestibility in diets containing cellulose (GEL), g
uar gum (GG), pectin (PEG) or retrograded high amylose maize starch (R
S) was studied, Inclusion level was 80 g/kg diet DM except for the ret
rograded high-amylose maize starch, where the level was 316 g/kg diet
DM, A diet containing normal maize starch only acted as a control diet
(FF), The apparent digestibilities of DM, NSP, starch and protein wer
e determined after adaptation periods of 4 d and 2, 4, 6 and 8 weeks,
The digestibility of nutrients was affected by diet (P < 0.001) as wel
l as by the period of adaptation (P < 0.001), The digestibilities of D
M, NSP and starch increased asymptotically during the course of the ex
periment. The asymptotic progress over time was most pronounced for th
e GG, PEC and RS diets, The estimated periods of adaptation required f
or stable DM digestibility were approximately 1 week for the GG, PEC a
nd RS diets and < 4 d for the FF and CEL diets, The digestibility of N
SP in the GG and PEC diets was also stable after approximately 1 week,
while it was stable from < 4 d for the CEL diet, However, PEC increas
ed the faecal content of uronic acids for at least 2 weeks, A stable s
tarch digestibility required 1 month in the case of RS and 3-10 d for
the other diets. The high faecal content of glucose for the RS diet de
creased during all 8 weeks but was still high at the close of the expe
riment, The apparent protein digestibility changed over time in a para
bolic rather than an asymptotic fashion, The GG, PEC and RS diets incr
eased the amount of N excreted by the faecal route.