(59) A. Kułakowska - K. Burlikowska - R. Szymeczko - M. Bogusławska-Tryk - D. Pietruszyńska - A.
Brudnicki - A. Piotrowska - M. Trojan
Ileal and total digestibility of protein and amino acids in polar foxes (Alopex lagopus L. ) fed
diets with different levels of inulin.
a.kulakowska@utp.edu.pl
Department of Animal Physiology , Faculty of Animal Breeding and Biology, University of Technology and Life Sciences,
Bydgoszcz, Poland
Introduction: Inulin plays an important role i.a. in the absorption of minerals and vitamins, in the
stimulation of the immune system as well as in bioavailability of nutrients. The results obtained by
other authors from the studies on the effects of prebiotics on the nutrients digestibility are
characterized by a diversity. Thus, the objective of the present study was to determine whether
dietary supplementation with inulin affects the ileal and total digestibility of protein and amino
acids in polar foxes.
Materials and Methods: 24 foxes (6 animals in each group) were fed diets with 0 (control group),
0.25, 0.5 and 1% inulin additive (experimental groups). In the digestibility experiment, testing each
diet was divided into two 4-day periods: preliminary (adaptation to the diets) and appropriate
(feces collection). Chromic oxide was used as a digestible marker. In the final day of the
experiment, foxes were euthanized to collect the contents of the distal segment of the small
intestine. After freeze-drying, diets, feces and ileal digesta samples were analyzed for nitrogen
(Kjeldalh method) and amino acids (amino acid analyzer AAA 400). The results were verified
statistically. The level of significance was set at P<0.01 and P<0.05.
Results and Discussion: Higher ileal digestibility (P<0.01) of protein and amino acids (LEU, LYS,
PHE, ASP, and PRO) were found in 0,5% inulin group in comparison to the control group without
inulin. There were no statistically significant differences in the total protein digestibility. However,
there was a significant increase in the total digestibility of methionine in foxes from 0,25% inulin
group (P<0.05) and 0,5% inulin group (P<0.01) compared to the control group without inulin.
Conclusions: Supplementation of the diet of polar foxes with 0.5% inulin significantly influenced
the ileal digestibility of protein and both indispensable (LEU, LYS, PHE) and dispensable amino
acids (ASP, PRO). Moreover, it caused a significant improvement in the total digestibility of
methionine which is a first limiting amino acid for polar foxes.
443