Toxic Effects of Supplemental Copper and Roxarsone When Fed Alone or in Combination to Young Pigs

Abstract

Three experiments were conducted to investigate the roxarsone (3-nitro-4-hydroxyphenylarsonic acid) X copper (Cu) interaction in weanling pigs. Supplemental roxarsone at 400 mg/kg diet decreased rate and efficiency of weight gain and caused visible neurological signs of toxicosis. Copper addition (CuSO4 X 5H2O) at a level of 650 mg Cu/kg diet likewise decreased weight gain and feed efficiency, and it also increased hepatic Cu deposition. The combination of these growth-depressing dosages of roxarsone and Cu resulted in a far greater reduction in gain and efficiency of feed utilization than was the case when either compound was fed alone. A growth-promoting dosage of Cu (250 mg/kg) increased weight gain by 32% in one experiment but showed no efficacy in alleviating the growth-depression resulting from feeding 400 mg/kg roxarsone. A roxarsone dosage of 100 mg/kg increased gain and feed efficiency. Surprisingly, the decreased weight gain in pigs fed 650 mg/kg Cu was ameliorated by feeding 100 mg/kg roxarsone concomitantly. This level of roxarsone also reduced liver Cu concentration substantially. It thus appears that the nature of the roxarsone X Cu interaction is dependent on the dose of each compound administered. Moreover, low-dose roxarsone administration appears to ameliorate Cu toxicity, but low-dose Cu feeding does not show efficacy against roxarsone toxicity.

Growth promotion effects and plasma changes from feeding high dietary concentrations of zinc and copper to weanling pigs (regional study).

“…For many years, Cu has been recognized as having antibacterial and antimycotic activity and the ability to stimulate growth. The addition of Cu sulfate provided at 125 to 250 ppm Cu has been shown to stimulate growth (Edmonds and Baker, 1986;Apgar et al, 1995;Cromwell et al, 1998) but its mode of action is unknown.…”

Effect of pharmacological concentrations of zinc oxide with or without the inclusion of an antibacterial agent on nursery pig performance.

“…Copper sulfate provided at dietary concentrations substantially higher (125 to 250 mg Cu/kg) than the NRC (1998) requirement (6 mg Cu/kg) has also resulted in improved nursery pig performance (Braude, 1967;Prince et al, 1979;Edmonds et al, 1986). The data from Beames and Lloyd (1965) demonstrated an additive growth response when a high dietary Cu concentration was fed in combination with an antibiotic.…”

High Performance Liquid Chromatography Determination Following Microwave Assisted Extraction of 3-Nitro-4-Hydroxyphenylarsonic Acid from Swine Liver, Kidney, and Muscle

“…Edmonds and Baker noted an improvement in the growth of young pigs (2) when raised on diet supplemented with 3-nitro. However, Akhtar et al (3,4) did not observe any beneficial effect of 3-nitro on the growth of young as well as growing-finishing pigs.…”