The effect of feed supplementation with organically bound selenium on reproductive performance of gilts and multiparous sows

Cytoplex-Selenit is a dried Sacharomyces cerevisiae yeast culture that cont ains 1000 mg/kg Se in the form of seleno-methionine. The feed of gilts and sows was supplemented with 300 g/metric tonne Cytople x-Selenit and was studied for its effects on the onset of breeding cycle of gilts, on the litter size of multiparous sows and viability, survival and growth r ate of the piglets and on the occurrence of periparturient disease complex of sows. The experiment carried out with 100 experimental and 100 control gilts has proven that selenium supplementation of the gilts' feed from 170 days of ag e onward has left the proportion of cyclic gilts unaltered in comparison wi th the untreated controls. Two farrowings, two nursing periods and two service periods hem weaning to service was followed up with two groups of 32 experimental and control sows . The experiment started 14 days prior to the expected parturition and conc luded when piglets of the 2(nd) farrowings had been weaned. The feed of the experimental sows was supplemented with Cytoplex-Selenit (300 g/metric ton ne) thoroughout of the experiment, It follows that at the time of the first farrowing the experimental sows had been consuming the selenium supplement ed feed only for 14 days. This short period of supplementation had no effec t on the parameters tested. Long lasting selenium supplementation, however, increased the Litter size by 0.8 piglets in the 2(nd) farrowing and the pi glets of the experimental sows produced almost 400 g more live weight by th e time of weaning at 33 days of age. No signs of periparturient disease com plex were seen in either groups. Although no differences were found between the groups in respect of e.g. proportion of cycling and silent sows and pr oportion of repeat breeders, the bigger litter size and the improved daily weight gain of suckling piglets may justify the supplementation of sows' fe eds with Cytoplex-Selenit. With regard to the legal control of selenium con tent of feed mixtures, it seems that Cytoplex-Selenit is a good source of s elenium and it is suitable for the provision of 0.4-0.5 mg/kg selenium conc entration set by the relevant law for pigs' feeds.