Effect of Inorganic Selenium Supplementation on Selenosis in Postweaning Swine

Abstract

A total of 72 pigs weaned at 4 wk of age were allotted by litter and weight to nine treatment groups and fed 20% protein cornsoybean meal diets supplemented with various levels of inorganic Se during a 37-d postweaning period. Eight groups were fed diets with 0, 2.5, 5.0, 7.5, 10, 15, 20 or 40 ppm Se provided as sodium selenite, while a ninth was offered the 0- and 40-ppm Se diets in separate feeders. Gains and feed intakes were similar during the trial for the 0- and 2.5-ppm Se diets. Both gain and feed intake declined as dietary Se levels above 5.0 ppm increased. At a dietary Se concentration of 40 ppm, feed consumption ceased within a few days of feeding and subsequent gains were negative. Pigs offered both the 0- and 40-ppm Se diets preferentially selected the basal as compared with the 40-ppm Se diet. When the feeders were switched at 28 d they refused the 40-ppm Se diet within a few hours. After a 17-d period, pigs fed the 20- or 40-ppm Se diet were not able to coordinate their walk, with many exhibiting an inability to stand. Alopecia was demonstrated in pigs fed 15 ppm Se or higher at 17 d, but was evident in the 5.0-ppm group at 37 d. At the termination of the trial, abnormal hoof formation at the coronary band was evident in pigs fed diets containing Se greater than or equal to 5 ppm.(ABSTRACT TRUNCATED AT 250 WORDS)

Intoxicação por selênio em suínos no Sul do Brasil

“…A doença ocorre, principalmente, em suínos jovens, entre um e cinco meses de idade. São descritas três apresentações clínicas distintas desta enfermidade: dificuldades locomotoras com paresia dos membros e tetraparesia, resultantes de poliomielomalácia simétrica focal (Wilson et al 1983, Carson 2006; lesões de pele e separação da borda coronária dos cascos (Mahan & Moxon 1984, Banholzer & Heinrtzi 1998, Hélie et al 1998); e perdas reprodutivas caracterizadas por diminuição da concepção e natimortos (Carson 2006). Em alguns surtos foram descritas as lesões nos cascos concomitante as lesões medulares (Harrison et al 1983, Castell et al 1985, Casteignau et al 2006.…”

Selenium Elimination in Pigs after an Outbreak of Selenium Toxicosis

“…However, the clinical presentation, necropsy findings, elimination pattern of blood selenium, and tissue selenium residues found at slaughter were consistent with those aspects of most experimental studies and field investigations of accidental selenium toxicosis. 1,2,4,[9][10][11][12][13][14][15][17][18][19]21,[23][24][25][26]28,30,[32][33][34][35][36][37] Clinical signs of selenium toxicosis (alopecia, reduced weight gain, hoof lesions) were apparent in 75% of affected pigs and were similar to signs observed in previously described experimental and accidental intoxications. 1,4,[9][10][11][12]15,[23][24][25]28,30,[34][35][36] Death of 30% (88/300) of feeder pigs accidentally exposed to feed containing a mean of 19 ppm (dry weight) sodium selenite for 42 days was previously reported.…”

“…In cases of chronic selenium toxicosis in swine where high concentrations of sodium selenite have been the cause, liver has been shown to be the organ with the highest concentration of selenium. 9,21,23,24 Although 1 liver had elevated selenium 72 days after withdrawal of contaminated feed, it is unlikely that there would have been a food safety risk to human beings. Daily dietary recommendations for selenium vary from 40 g/person/day, 20,22 which is a recommended daily allowance of 0.87 g/kg/day 6 (70 g for a 79-kg person), to a maximum acceptable intake of 500 g/person/day.…”

“…Anorexia or feed refusal in the severely affected pigs may have caused the blood selenium to decline, as exposure decreased. Feed refusal is often observed when the concentration of selenium in the ration exceeds 5 ppm, 1,10,23,24 and variable clinical responses to toxic doses of selenium are common. 36 Although the correlation between selenium concentrations in feed and blood selenium values is well documented, 9,10,37 such a correlation was not found in this outbreak.…”

“…Toxicosis has been reported in swine after repeated ingestion of feed containing Ͼ5 ppm selenium (dry weight). 4,12,[24][25][26] Signs of selenium toxicosis in swine include anorexia, alopecia, separation of hoof and skin at the coronary band, degenerative changes in the liver and kidney, and poliomyelomalacia. 16,26,27,33 In 1974, the US Food and Drug Administration (FDA) authorized the addition of a sodium salt of selenium to swine feed at a concentration of 0.1 ppm (dry weight) in the complete ration.…”