title: Effects of Acid LAC and Kem-Gest acid blends on growth performance and microbial shedding in weanling pigs.
abstract: Weanling pigs with mean initial BW of 6.04 kg (Exp.1) and 5.65 kg (Exp. 2) and mean age at weaning of 18.2 d (Exp. 1) and 17.7 d (Exp. 2) were used in two 5-wk experiments (Exp. 1, n = 180; Exp. 2, n = 300) to evaluate the effects of an organic acid blend (Acid LAC, Kemin Americas Inc., Des Moines, IA) and an inorganic/organic acid blend (Kem-Gest, Kemin Americas Inc.) on weanling pig growth performance and microbial shedding. In Exp. 1, the 5 dietary treatments were 1) negative control, 2) diet 1 + 55 ppm carbadox, 3) diet 1 + 0.4% Acid LAC, 4) diet 1 + 0.2% Kem-Gest, 5) diet 1 + 0.4% Acid LAC and 0.2% Kem-Gest. In Exp. 2, the 6 dietary treatments were diets 1 through 4 corresponding to Exp. 1, plus 5) sequence 1: 0.4% Acid LAC for 7 d followed by 0.2% Kem-Gest for 28 d, and 6) sequence 2: 0.2% Kem-Gest for 7 d followed by 0.4% Acid LAC for 28 d. Pigs were housed at 6 (Exp. 1) or 10 (Exp. 2) pigs/pen. Treatments were fed throughout the experiment in 3 phases: d 0 to 7, d 7 to 21, and d 21 to 35. In Exp. 1, there were no differences (P > 0.05) in ADG, ADFI, or G:F among the dietary treatments at any time during the study. In Exp. 2, throughout the study, pigs fed carbadox (diet 2) and sequence 1 (diet 5) diets had the greatest ADG (d 0 to 35; 262, 294, 257, 257, 292, and 261 g/d, diets 1 through 6, respectively; P < 0.05), greater ADFI than all other acid treatments (P < 0.05), and tended to have greater ADFI than diet 1 (P < 0.10). Fecal pH, Escherichia coli concentrations, and Salmonella presence were determined at d 6, 20, and 34 for Exp. 1, and on d 32 for Exp. 2. For both experiments, there was no effect of treatment on the presence of fecal Salmonella (P > 0.10) at any sampling time. In Exp. 1, fecal E. coli concentrations for pigs fed the carbadox (P < 0.05) diet were greater than for pigs fed the combination diet with 0.4% Acid LAC and 0.2% Kem-Gest on d 34, and the pigs fed the negative control diet tended (P < 0.10) to have greater fecal E. coli concentrations than those fed the combination diet on d 34. In Exp. 2, fecal pH of pigs fed sequence 1 tended to be greater than fecal pH of pigs fed diet 1, diet 4, or sequence 2 (P < 0.10), but there was no dietary effect on fecal E. coli. In Exp. 1, growth performance of pigs fed the Acid LAC and Kem-Gest diets was similar to each other and to that of the carbadox-fed pigs. Adding the combination of 0.4% Acid LAC and 0.2% Kem-Gest to nursery pig diets reduced ADFI and pig growth rate. In Exp. 2, pigs fed the acid sequence of Acid LAC-Kem-Gest had similar growth performance to pigs fed carbadox, and this novel dietary acid sequence may have merit as a replacement for antibiotics in the nursery phase.
authors.affiliation: Department of Animal Science, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: M C
authors.initials: MC
authors.lastname: Walsh
authors.forename: D M
authors.initials: DM
authors.lastname: Sholly
authors.forename: R B
authors.initials: RB
authors.lastname: Hinson
authors.forename: S A
authors.initials: SA
authors.lastname: Trapp
authors.forename: A L
authors.initials: AL
authors.lastname: Sutton
authors.forename: J S
authors.initials: JS
authors.lastname: Radcliffe
authors.forename: J W
authors.initials: JW
authors.lastname: Smith
authors.forename: B T
authors.initials: BT
authors.lastname: Richert
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D002218:Carbadox / Q000008:administration & dosage / Q000494:pharmacology; D004032:Diet / Q000662:veterinary*; D004435:Eating / Q000502:physiology; D004926:Escherichia coli / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D005243:Feces / Q000737:chemistry / Q000382:microbiology; D006863:Hydrogen-Ion Concentration; D012475:Salmonella / Q000302:isolation & purification; D012481:Salmonella Infections, Animal / Q000382:microbiology*; D013552:Swine / Q000254:growth & development / Q000382:microbiology / Q000502:physiology*; D013553:Swine Diseases / Q000382:microbiology*; D013997:Time Factors; D014886:Weaning; D015430:Weight Gain / Q000187:drug effects / Q000502:physiology
chemical_list: D002218:Carbadox