Tolerance of pigs to sorghum ergot (Claviceps africana) during growth and finishing, and effect on conception of replacement gilts

Abstract

Two batches of sorghum infected with ergot were incorporated into nutritionally balanced grower and finisher diets that contained 0, 5 or 10 mg alkaloid/kg (0, 4 or 8 mg dihydroergosine/kg), or 10 mg alkaloid/kg (8 mg dihydroergosine/kg) plus 1% zeolite. The contents of ergot sclerotia in the 10 mg/kg diets were ~2% in one batch and 4% in the other; the latter batch had a heavy secondary fungal infection of Cerebella sp., which tends to limit alkaloid accumulation. These diets were each fed to four male and four female pigs as they grew from 20 to 90 kg. There were no deleterious effects on growth, feed intake and conversion even with lower plasma prolactin of 0.1 µg/L in ergot-fed pigs compared with ~1 µg/L in the control pigs. Zeolite did not counteract the ergot reduction of prolactin and had no effect on performance. Male pigs were then slaughtered, but females continued to be fed the diets for a further 3 months, when they were brought into oestrus and artificially inseminated. One month after pregnancy was confirmed, they were slaughtered and fertility was assessed. There were no significant differences in the numbers of corpora lutea or embryos between pigs fed ergot and control diets.