157
The effects of feeding narasin or virginiamycin on growth and harvest performance of pigs during the grow-finish period

Tuesday, March 15, 2016: 2:15 PM
314-315 (Community Choice Credit Union Convention Center)
Roger A. Arentson , Elanco, Greenfield, IN
J. J. Chewning , Swine Research Services, Inc., Springdale, AR
Abstract Text:

The purpose of this study was to determine the effects of narasin (NAR; Skycis®, Elanco Animal Health, Greenfield, IN) or virginiamycin (VIR; Stafac®, Phibro Animal Health, Teaneck, NJ) on the growth and harvest performance of pigs during the grow-finish period. On day -7, seventy-two pens each containing 8 pigs with a BW of 23.4 kg were blocked by weight within gender and then treatments: control (CON), NAR 15 ppm, or VIR 11 ppm were randomly assigned to pens within gender of each block.  Diet treatments consisted of a sequence of five pelleted diets containing corn, soybean meal, and DDGS with the appropriate amount of antimicrobial premix added identical diets within of the five phases.  Pigs were weighed on d 0, 28, 56, 76, 97, and 108 to determine initial weight, phase weights, and ADG. Feed issuance and weigh backs were recorded in order to determine ADFI and G:F. When pigs reached a BW of 127.4 kg, they were transported to a food company for harvest.  HCW, fat depth, and loin depth were measured on each carcass.  During d 0 to 28, ADG and ADFI of pigs fed diets containing NAR or VIR was greater (P<0.05) than CON.  During d 28 to 56, pigs fed VIR had a greater ADG and ADFI than those fed CON (P<0.05, and tended to have a greater ADFI (P<0.1) than those fed NAR. Pigs fed NAR had a greater (P<0.05) G:F from d 0 to 28 than pigs fed CON or VIR .  From d 0 to 108, pigs fed NAR had a greater (P<0.05) G:F than those fed CON, and tended to be greater (P<0.10) than those fed VIR.  Pigs fed NAR and VIR (P=0.0051) had a greater (P<0.05) carcass yield than those fed CON.  In conclusion, pigs fed NAR or VIR for the entire grow-finish period have greater carcass yield than those fed control, and pigs fed NAR have a greater G:F than those fed CON.

Item

CON

NAR

VIR

SE

NAR vs CON, P<

VIR vs CON, P<

NAR vs VIR,  P<

ADG,  d 0 to 108

0.955

0.968

0.965

0.007

NS

NS

NS

ADFI,  d 0 to 108

2.340

2.345

2.374

0.02

NS

NS

NS

G:F,  d 0 to 108

0.398

0.408

0.400

0.003

0.05

NS

0.10

Keywords: Narasin, Virginiamycin, pig