Effects of yeast culture in broiler diets on performance and immunomodulatory functions

Poult Sci. 2008 Jul;87(7):1377-84. doi: 10.3382/ps.2007-00418.


A study was conducted to evaluate the effect of supplemental yeast culture (Diamond V XP Yeast Culture; YC) in broiler diets on performance, digestibility, mucosal development, and immunomodulatory functions. One-day-old Arbor Acres chicks (n = 960) were randomly assigned to 1 of 4 dietary treatments based on corn and soybean meal and containing 0, 2.5, 5.0, and 7.5 g/kg of YC in the diet for 42 d. Each treatment consisted of 12 replicates of 20 broilers each. Nutrient digestibility was determined on d 15 and 35 by total fecal collection. On d 21 and 42, 12 birds per treatment were sacrificed to evaluate gut morphology and secretory IgA. Broilers were vaccinated with Newcastle disease vaccine by eye drop on d 7 and 28 and antibody titer was determined on d 14, 21, 35, and 42. Dietary supplemental YC at 2.5 g/kg improved average daily gain and feed conversion during grower and overall periods (P <or= 0.05). Yeast culture supplementation increased digestibility of Ca (linear and quadratic, P = 0.01) and P (linear, P = 0.01) on d 35, but did not affect (P > 0.05) protein retention and energy digestibility. Villus height to crypt depth ratios in the duodenum and jejunum (d 42) and ileum (d 21) were increased (P <or= 0.05) in broilers fed 2.5 g/kg of YC. Yeast culture increased antibody titers to Newcastle disease virus (linear, P <or= 0.05), serum lysozyme activity (linear and cubic, P <or= 0.05), and IgM (linear, P <or= 0.05) and secretary IgA concentrations in the duodenum (linear, P = 0.01). Results of this study indicate that dietary supplemental YC at 2.5 g/kg improved growth performance. Dietary YC affected immune functions, digestibility of Ca and P, and intestinal mucosal morphology of broilers. Growth performance was optimized at 2.5 g/kg of YC in the present study. Immune function could be modified with dietary YC supplementation.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animal Feed
  • Animal Nutritional Physiological Phenomena
  • Animals
  • Antibodies, Viral / blood
  • Chickens / growth & development*
  • Chickens / immunology*
  • Diet / veterinary*
  • Dietary Supplements
  • Digestion / physiology
  • Female
  • Immunoglobulin A / blood
  • Immunoglobulin A, Secretory / blood
  • Immunoglobulin G / blood
  • Immunoglobulin M / blood
  • Intestines / anatomy & histology
  • Intestines / physiology
  • Male
  • Muramidase / metabolism
  • Newcastle disease virus / immunology
  • Weight Gain / drug effects
  • Yeast, Dried / pharmacology*


  • Antibodies, Viral
  • Immunoglobulin A
  • Immunoglobulin A, Secretory
  • Immunoglobulin G
  • Immunoglobulin M
  • Muramidase