title: Effects of yeast culture in broiler diets on performance and immunomodulatory functions.
abstract: 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.
authors.affiliation: Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: J
authors.initials: J
authors.lastname: Gao
authors.forename: H J
authors.initials: HJ
authors.lastname: Zhang
authors.forename: S H
authors.initials: SH
authors.lastname: Yu
authors.forename: S G
authors.initials: SG
authors.lastname: Wu
authors.forename: I
authors.initials: I
authors.lastname: Yoon
authors.forename: J
authors.initials: J
authors.lastname: Quigley
authors.forename: Y P
authors.initials: YP
authors.lastname: Gao
authors.forename: G H
authors.initials: GH
authors.lastname: Qi
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002645:Chickens / Q000254:growth & development* / Q000276:immunology*; D004032:Diet / Q000662:veterinary*; D019587:Dietary Supplements; D004063:Digestion / Q000502:physiology; D005260:Female; D007070:Immunoglobulin A / Q000097:blood; D007071:Immunoglobulin A, Secretory / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007422:Intestines / Q000033:anatomy & histology / Q000502:physiology; D008297:Male; D009113:Muramidase / Q000378:metabolism; D009522:Newcastle disease virus / Q000276:immunology; D015430:Weight Gain / Q000187:drug effects; D015002:Yeast, Dried / Q000494:pharmacology*
chemical_list: D000914:Antibodies, Viral; D007070:Immunoglobulin A; D007071:Immunoglobulin A, Secretory; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D009113:Muramidase