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The effects of feeding narasin on growth and harvest performance of pigs during the grow-finish period
The purpose of this study was to determine the effects of narasin (NAR; Skycis®, Elanco Animal Health, Greenfield, IN) on the growth and harvest performance of pigs during the grow-finish period. On d -8 or -9, seventy-four pens each containing 8 pigs were blocked by gender and weight within each of 4 barns resulting in 18 blocks containing 2 pens of gilts and 2 pens of barrows and 1 block containing 2 pens of gilts. On d 0 (initial BW 26.34 kg), diet treatments control (CON) or NAR 15 ppm were randomly assigned to pens within gender of each block. Pigs were fed a series of 5 corn–soybean meal diet phases with or without NAR premix. Pigs were weighed on d 0, 26, 54, 74, 95 or 96, and 109 or 110 to determine initial weight, phase weights, and ADG. Feed issuance and weigh backs were recorded in order to determine ADFI and G:F. On d 95 or 96, the heaviest 3 barrows and 1 gilt from appropriate pens and on d 109 or 110 the remaining pigs were transported to a food company for harvest. HCW, fat depth, and loin depth were measured on each carcass. Data were analyzed using the PROC MIXED procedure of SAS. Pigs fed NAR had a greater BW on d 54 (P<0.01), 74 (P<0.001), and 95.5 (P<0.001) and tended to be greater at the end of the study (P<0.1) than pigs fed CON. Pigs fed NAR had a faster ADG during d 0 to 26 (P<0.05), 26 to 54 (P<0.01), and 54 to 74 (P<0.001), and tended to be faster during d 0 to d 109.5 (P<0.10) than pigs fed CON. Feed intake by pigs fed NAR was greater during d 26 to 54 (P<0.05) and d 54 to 74 (P<0.05), but was less than CON from d 95.5 to 109.5 (P<0.05). G:F of pigs fed NAR was greater than CON on d 54 to 74 (P<0.01) and d 0 to 109.5 (P<0.05). On d 95.5 and 109.5, HCW (P<0.01) and loin depth (P<0.01) of pigs fed NAR was greater than pigs fed CON. Data from this study demonstrates that NAR improves growth performance and carcass characteristics of grow-finish pigs.
Item |
CON |
NAR |
SE |
P |
Overall ADG, kg |
0.950 |
0.967 |
0.010 |
<0.1 |
Overall ADFI, kg |
2.440 |
2.455 |
0.018 |
>0.1 |
Overall G:F |
0.404 |
0.410 |
0.004 |
<0.05 |
Carcass wt., kg |
96.46 |
98.25 |
0.542 |
<0.01 |
Loin depth, mm |
65.82 |
67.40 |
0.408 |
<0.01 |
Keywords: pig, narasin, grow-finish