DOI: 10.36871/vet.zoo.bio.202008008
UDC 546.56 + 547.4 + 363.03
Authors
A. A. Vikhrov
Candidate of Chemical Sciences, Researcher, Institute of Bioorganic
chemistry named after M. M. Shemyakin and Yu. A. Ovchinnikov
of the Russian Academy of Sciences,
Moscow, Russian Federation
V. P. Zubov
Doctor of Chemistry, Chief Researcher, Institute of Bioorganic chemistry
named after M. M. Shemyakin and Yu. A. Ovchinnikov
of the Russian Academy of Sciences,
Moscow, Russian Federation
S. Yu. Zaytsev
Doctor of Biological Sciences, Doctor of Chemistry, Professor,
Head of the Analytical Biochemistry Group, Leading
Researcher at the Department of Physiology and
Biochemistry of Farm Animals L.K. Ernst Federal
Science Center for Animal Husbandry,
Dubrovitsy, Russian Federation
Abstract
It is well-known, due to the geological features in a number of regions of the Russian Federation,
there may be a shortage of certain microelements and other important “nutrients” in animal
diets. The main approach to solve this problem is to use special feed additives. At present, preparations
based on organic sources, for example, metal-polymer complexes, are considered a promising
alternative. The purpose of this study is to develop an improved method for preparation of the
copper-containing polysaccharide complexes and to study their most important parameters.
Using CuCl2 as an example, it was shown that the formation of chitosan hydrogels is possible
without the usage of potentially hazardous cross-linking agents (for example, glutaraldehyde) or
polyvalent anions (for example, SO4
2–), which provide non-covalent cross-linking of chitosan due
to electrostatic interactions with NH3
+ in its composition. It was found that, upon frontal «gelation»
of a 2% chitosan solution (MM 400±100 kDa) in acetic acid (1 vol%), the formation of stable metal
gels is observed provided that the content of CuCl2 and ethanol in the precipitant solution is more
than 40 mg/ml or more than 24 vol.%, respectively (Vchitosan = Vprecipitant). The obtained complexes are
stable in aqueous-alcoholic solutions and swell in water up to destruction (pH 5,5). After additional
treatment with an aqueous 1,5% ammonia solution, complexes practically do not swell in solutions
with ≥ pH 5,5 (at least τ = 6 days) and dissolve at pH ≤ 4,2. Thus, the use of these complexes is able
to provide the release of Cu2
+ not in the rumen (pH 6,3–7,2), but in the abomasum (pH ~ 3), which
can increase the bioavailability of copper. The development of an improved method for obtaining
metal-polysaccharide complexes in a gel form that does not contain «ballast» (in terms of nutritional
value and physiology of farm animals) anions (for example, SO4
2–) opens up new opportunities for
the development of highly effective feed additives for animal husbandry.
Keywords
feed additives, copper-containing polymer complexes, ethanol, chitosan additives; analytical biochemistry.
