title: Effects of porcine circovirus type 2 vaccine and increasing standardized ileal digestible lysine:metabolizable energy ratio on growth performance and carcass composition of growing and finishing pigs.
abstract: Four experiments were conducted to examine the effect of porcine circovirus type 2 (PCV2) vaccination on the response of growing and finishing pigs (PIC 337 × 1050) to increasing dietary Lys. Experiments 1 and 2 evaluated 38- to 65-kg gilts and barrows, respectively, and Exp. 3 and 4 evaluated 100- to 120-kg gilts and barrows, respectively. Gilts and barrows were housed separately in different barns. Treatments were allotted in a completely randomized design into 2 × 4 factorials with 2 PCV2 treatments (PCV2-vaccinated and nonvaccinated) and 4 standardized ileal digestible (SID) Lys:ME ratios (2.24, 2.61, 2.99, and 3.36 g/Mcal in Exp. 1 and 2 and 1.49, 1.86, 2.23, and 2.61 g/Mcal in Exp. 3 and 4) within each experiment. There were 5 pens per treatment. At the start of Exp. 1 and 2, there were more pigs per pen (P < 0.001) in vaccinated pens because vaccinated pigs had a greater survival rate than nonvaccinated pigs, and this increase was maintained throughout the experiments. Removal rate approached 30% in nonvaccinated barrows and more than 20% in nonvaccinated gilts. Observation suggested that the removals were largely due to PCV2-associated disease. No PCV2 vaccination × SID Lys:ME ratio interactions (P > 0.10) were observed in any of the 4 studies. In Exp. 1 and 2, PCV2-vaccinated pigs had increased (P < 0.001) ADG compared with nonvaccinated pigs. The growth response was primarily due to increases in ADFI, which suggests that vaccinated pigs have a greater Lys requirement (g/d) than nonvaccinated pigs. In Exp. 1, increasing the SID Lys:ME ratio increased (quadratic; P < 0.04) ADG and G:F, with pigs fed the 2.99 g/Mcal ratio having the greatest ADG and G:F. In Exp. 2, increasing the SID Lys:ME ratio improved (linear; P < 0.001) G:F. In Exp. 3, ADG and G:F increased (P < 0.05) in a quadratic manner as the SID Lys:ME ratio fed increased. In Exp. 4, increasing the SID Lys:ME ratio increased ADG (linear; P < 0.001) and G:F (quadratic; P = 0.03). Although PCV2 vaccination improved growth, the corresponding increase in ADFI did not increase the optimal SID Lys:ME ratio for growing and finishing barrows and gilts.
authors.affiliation: Department of Animal Sciences and Industry, College of Agriculture, Kansas State University, Manhattan, Kansas 66506, USA.
authors.forename: N W
authors.initials: NW
authors.lastname: Shelton
authors.forename: M D
authors.initials: MD
authors.lastname: Tokach
authors.forename: S S
authors.initials: SS
authors.lastname: Dritz
authors.forename: R D
authors.initials: RD
authors.lastname: Goodband
authors.forename: J L
authors.initials: JL
authors.lastname: Nelssen
authors.forename: J M
authors.initials: JM
authors.lastname: DeRouchey
authors.forename: J L
authors.initials: JL
authors.lastname: Usry
mesh_terms: D000822:Animal Husbandry; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001835:Body Weight; D018173:Circoviridae Infections / Q000378:metabolism / Q000517:prevention & control / Q000662:veterinary*; D017925:Circovirus / Q000276:immunology*; D005260:Female; D016014:Linear Models; D008239:Lysine / Q000008:administration & dosage* / Q000378:metabolism; D008297:Male; D013552:Swine; D013553:Swine Diseases / Q000378:metabolism / Q000517:prevention & control*; D014611:Vaccination / Q000662:veterinary; D014765:Viral Vaccines / Q000276:immunology*
chemical_list: D014765:Viral Vaccines; D008239:Lysine