When finishing pigs were fed a control diet vs. ractopamine-supplemented (Paylean from Elanco Animal Health) diet for 27 days prior to slaughter, ractopamine improved growth and feed conversion, decreased backfat and improved loin thickness.

Paylean is a feed additive that was recently approved for use in Canada. The active ingredient of Paylean is ractopamine, a beta-adrenergic agonist known to stimulate muscle growth and slow fat deposition.

In the study performed at the Prairie Swine Centre in Saskatoon, Saskatchewan, 530 animals were assigned to either a control diet or a diet supplemented with Paylean to supply 5 mg/kg or 5 ppm ractopamine.

Ractopamine improved average daily gain 12.9%, feed conversion 12.5%, decreased backfat 0.04 in. (1 mm) and improved loin thickness 0.1 in. (2.5 mm).

Paylean-fed pigs were fed a diet similar to the barn's normal gilt finisher, except lysine was increased to 1% and the ractopamine was added.

Table 1 shows the performance and carcass parameters and the feed costs associated with the use of ractopamine.

The feed additive cut age at marketing by about one week, and also reduced the number of tail-enders from 7.5% to 0.5%.

Assuming pig flow can accommodate filling the room or barn one week earlier, the net return/pig place would increase by about $5/year. The drop in the number of tail-enders would increase gross revenue by $2.17/hog under normal market conditions.

While the benefit of using ractopamine will depend on individual farm circumstances, typical farms should expect a net return of $2-3/pig sold.

Researchers: J.F. Patience, A.D. Beaulieu, J. Merrill, D.A. Gillis and G. Vessie, all of the Prairie Swine Centre. Contact Ken Engele, assistant manager, Information Services, by phone (306) 373-9922, fax (306) 955-2510 or e-mail Ken.Engele@usask.ca.

Table 1. The Effect of 5 ppm Ractopamine (RAC) on Parameters Influencing the Economics of Pork Production
Parameter Control RAC
Days on test 30.1 26.5
Tail-enders 20 2
No. of pigs condemned 0 2
No. of pigs DOA* 0 3
Overall ADG, lb./day* 2.40 2.70
Overall FCE* 0.32 0.36
lb. feed/pig started 222.0 196.2
Backfat, in. 0.72 0.68
Loin thickness, in. 2.73 2.83
Carcass index 109.96 110.57
Carcass premium, $ 1.64 1.34
Carcass value, $ 118.77 119.08
Feed cost ($/pig)
Basal cost 13.73 12.19
Extra amino acids 0.00 0.59
Extra minerals and vitamins 0.00 0.21
Ractopamine 0.00 1.72
Total feed cost, $ 13.73 14.71
*DOA=Dead on arrival; ADG=Average daily gain;
FCE= Feed conversion efficiency