Effect of dietary supplementation with Yarrowia lipolytica or Saccharomyces cerevisiae yeast and probiotic additives on growth performance, basic nutrients digestibility and biochemical blood profile in piglets.

The objective of the study was to compare the efficiency of dietary supplementation of two species of yeast, Yarrowia lipolytica (YL) and Saccharomyces cerevisiae (SC), with or without the addition of a probiotic, on growth performance, basic nutrients digestibility and blood profile in piglets. The experiment was conducted on 360 weaned piglets (180 barrows and 180 gilts). Each treatment comprised 60 piglets. The piglets (27-day-old) were assigned to the following dietary treatments: (a) basal control (C) diet, (b) C diet + probiotic (Bacillus licheniformis and Bacillus subtilis-2 × 109  CFU/kg of feed), (c) C diet + 3% Y. lipolytica (YL-2 × 1010  CFU/g), (d) C diet + 3%YL + probiotic, (e) C diet + 3% S. cerevisiae (SC-3 × 1010  CFU/g) and (f) C diet + 3% SC + probiotic. Blood for analysis was collected from a total of 36 piglets at the end of the experiment, that is, 56 days after weaning. During the entire experiment, significantly greater weight gain was observed in the piglets receiving YL. The addition of the probiotic supplement and SC yeast reduced the daily feed intake during day 16-56 and from day 0 to 56 of the experiment. A better feed conversion ratio (FCR) during day 0-56 of the experiment was noted after addition of the probiotic and yeast. The use of YL yeast in diets for piglets had a more beneficial effect on weight gain and FCR than SC. Moreover, the addition of YL modulates lipid metabolism in piglets, as indicated by the reduced levels of TCH, LDL and TG and increased level of HDL in the plasma. The combined use of either YL or SC with a probiotic is not recommended in piglet rearing, as it does not substantially improve growth performance and health in comparison with yeast alone.