Chelated forms of microelements as swine feed additives

Abstract

Animals need microelements in small quantities which participate in almost all physiological and biochemical processes. Microelement resorption does not depend only on their content in feed, but also on the age of the animal, the electrochemical reaction in the intestines and the form of the microelement itself. The choice of the source is based on the microelement content in solid state, its solubility in the organism, availability and utilization. Oxides, chlorides and carbonates are poorly soluble, and chlorides are hygroscopic, and carbonates oxidize rapidly. Sulphates are durable salts easy to purify, and sulphate ions are easily excreted from the organism. In addition to nonorganic forms of mineral matter, so-called chelated forms are today increasinlgy being used, in fact, organically bound microelements. Minerals bound to an amino acid or peptide are better protected during their passage through the stomach, and the resorption of a chelated form of copper is considerably higher than resorption from sulphates. The resorption of organically bound microelements does not proceed in the conventional manner (carrier/diffusion), so that there is no direct homeostatic control at the level of enterocytes, and retention and the biological half-life of a chelated form are bigger than those of an anorganic form.

Životinjama su mikroelementi potrebni u malim količinama i učestvuju u skoro svim fiziološkim i biohemijskim procesima. Resorpcija mikroelemenata ne zavisi samo od sadržaja u hrani, nego i od doba životinje, elektrohemijske reakcije u crevima i oblika u kome se mikroelement nalazi. Izbor izvora zasniva se na sadržaju mikroelementa u čistom stanju, rastvorljivosti u organizmu, dostupnosti i iskoristivosti. Oksidi, hloridi i karbonati slabo rastvorljivi, a pored toga hloridi su higroskopni, a karbonati brzo oksidišu. Sulfati su postojane soli, lake za prečišćavanje, a sulfatni jon se lako izlučuje iz organizma. Pored neorganskih formi mineralnih materija, danas se sve više koriste, takozvani "helatni" oblici, odnosno organski vezani mikroelementi. Minerali vezani sa amino-kiselinom ili peptidom bolje su zaštićeni za vreme pasaže kroz želudac, a resorpcija helatne forme bakra je znatno veća od resorpcije iz sulfata. Resorpcija organski vezanih mikroelemenata se ne odvija konvencionalno (nosač/dufuzija), pa direktna homeostatska kontrola na nivou enterocita ne postoji, a retencija i biološ ki poluživot helatnog oblika su veći kod anorganske forme.