ARTIFICIAL REARING OF COLOSTRUM-DEPRIVED PIGLETS USING IRON CHELATORS: IN VITRO AND IN VIVO COMPARISONS OF EDDHA AND HBED WITH AND WITHOUT PORCINE IMMUNOGLOBULINS

Abstract

Two iron chelators, ethylene diamine-di-orthohydroxyphenyl acetic acid (EDDHA) and N,N′-Bis(o-hydroxybenzyl)-ethylenediamine diacetic acid (HBED), were investigated as possible substitutes for lactoferrin in sow milk replacers. The antibacterial properties of lactoferrin, EDDHA and HBED, with and without porcine immunoglobulins, were compared in vitro using E. coli 0 157 K88. Lactoferrin and EDDHA inhibited the growth of E. coli over a 12-h incubation period, while HBED had no effect on bacterial growth. Porcine immunoglobulins inhibited the growth of E. coli after 6, but not after 12 h of incubation. Ethylene diamine-di-orthohydroxyphenyl acetic acid and HBED were further compared as substitutes for lactoferrin in sow milk replacers fed to colostrum-deprived piglets. All piglets received porcine immunoglobulins for 24 h following birth. They then received EDDHA, HBED or no chelator with or without porcine immunoglobulins on days 2–14. Piglets that received HBED had lower survival rates and weight gains than piglets that received EDDHA or no chelator. Weight gains were equal for piglets receiving either EDDHA or immunoglobulins alone and there was no additive effect on piglet weight gains when EDDHA and immunoglobulins were fed together. Ethylene diamine-di-orthohydroxyphenyl acetic acid may be a practical substitute for lactoferrin in sow milk replacers. Key words: Immunoglobulins, piglet, lactoferrin, iron chelators, E. coli