Effects of porcine circovirus type 2 and mycoplasma hyopneumoniae vaccines on nursery pig performance

A total of 360 weanling barrows (PIC 1050, 21 d of age and 13.0 lb) were used in a 35-d study to evaluate the effects of porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae (M. hyo) vaccines on nursery pig growth performance. Two commercial PCV2 vaccines were evaluated in this study: (1) a 2-dose product, Circumvent PCV (Circumvent; Intervet/Schering-Plough Animal Health, Millsboro, DE) and (2) a 1-dose product, Ingelvac CircoFLEX (CircoFLEX; Boehringer Ingelheim Vetmedica, Inc, St. Joseph, MO). For the M. hyo vaccine, RespiSure (Pfizer Animal Health, New York, NY), a single 2-dose product, was used. At weaning (d 0), pens of pigs were blocked by average pig weight and randomly allotted to 1 of 6 treatments in a 3 × 2 factorial arrangement composed of a combination of PCV2 vaccine (Circumvent, CircoFLEX, or non-PCV2-vaccinated control) and M. hyo vaccine (RespiSure or non-M. hyo-vaccinated control). There were 5 pigs per pen and 12 pens per PCV2 × M. hyo vaccine treatment. All vaccines were administered according to label directions— CircoFLEX at weaning and Circumvent and RespiSure at weaning and 21 d later. Common diets were fed by phase to all pigs. There were no PCV2 × M. hyo vaccine interactions for any response criteria. Overall, pigs vaccinated with Circumvent had decreased ADG (P < 0.02) and ADFI (P ≤ 0.01) compared with CircoFLEX-vaccinated and control pigs, respectively. On d 35, Circumvent- vaccinated pigs weighed less (42.9 lb, P < 0.01) than pigs vaccinated with CircoFLEX (44.4 lb) or control pigs (44.4 lb). Pigs vaccinated with RespiSure had decreased ADG compared with control pigs (P ≤ 0.05) from d 14 to 21 and d 21 to 25. On d 35, RespiSure-vaccinated pigs tended to weigh less (43.5 lb, P = 0.06) and have lower ADFI (P = 0.06) than controls (wt = 44.3 lb). These data indicate that PCV2 and M. hyo vaccination can independently reduce feed intake and performance of nursery pigs and that the PCV2 vaccine effect is product dependent. Although PCV2 and M. hyo vaccines are known to improve finishing performance, their negative impact on nursery performance must be considered when implementing vaccine strategies.