292
Growth Performance of Pigs Receiving Generic Ractopamine (Engain 9® – Zoetis)
The objective of this study was to evaluate the growth performance of market pigs receiving a generic ractopamine HCl product (Engain 9® - Zoetis; RAC) for 28 days before harvest. Animals (n=220 pigs; 44 pens; 5 pigs/pen/gender) were assigned using a split plot design, with barrows and gilts divided equally between control group (CON; no ractopamine) and treated group (RAC) receiving 10 ppm of ractopamine in the feed. Within each sex, body weight at allotment (Day -14 to allow socialization prior to Day 0) was the blocking factor, confounded with pen location. A set of two pens, forming the block within each sex, was the experimental unit for sex. Pen was the experimental unit for treatment. One animal (RAC) was removed prior to Day 28.
Initial and final body weights (BW), and total feed intake per pen were collected. Total weight gain, average daily gain (ADG), feed intake (ADFI) and gain efficiency (G:F) were calculated. Data were analyzed using a general linear mixed model with appropriate fixed and random terms. Combined results across both sexes are presented since treatment x sex interaction was not significant (p>0.05).
Results for total weight gain, ADG, ADFI & G:F are presented in the table as least squares means (LSMean), standard error (SEM) and p-value. Total weight gain over 28 days, ADG & G:F were significantly improved (P<0.0001) for the RAC pigs compared to the CP pigs with no difference (P>0.05) in feed intake.
Variable |
Control n=110 pigs |
Ractopamine n=109 pigs |
SEM |
P-Value |
Initial BW, kg |
94.37 |
93.96 |
1.014 |
0.4041 |
Final BW, kg |
124.05 |
129.38 |
1.104 |
<0.0001 |
28 d Weight Gain, kg |
29.7 |
35.4 |
0.48 |
<0.0001 |
ADG, kg |
1.06 |
1.26 |
0.02 |
<0.0001 |
ADFI, kg |
3.39 |
3.44 |
0.049 |
0.2597 |
G:F |
0.31 |
0.37 |
0.007 |
<0.0001 |
Animals remained healthy and exhibited no adverse reactions to RAC. The treatment of pigs with 10 ppm generic RAC for 28 days showed improvements in growth performance. Results were consistent with expectations for pigs treated with RAC.
Keywords: swine, ractopamine, growth performance