An experiment was carried out to test the effects of generic ractopamine (Engain; Zoetis Inc., Kalamazoo, Michigan) on growth, carcass characteristics, meat quality and fat quality of finishing pigs. Lead author was A.C. Dilger of the University of Illinois-Urbana and the paper was published in Professional Animal Scientist.

A total of 220 pigs were fed no (CON) or 10mg per kg of generic ractopamine (gRAC) for 28 days before slaughter.

Barrows fed gRAC were 5.22kg (4.13 per cent) heavier (P<0.0001) than CON barrows. Gilts fed gRAC were 5.44kg (4.47 per cent) heavier (P<0.0001) than CON gilts.

Barrows fed gRAC gained 0.21kg per day (18.75 per cent) more weight (P<0.0001) than CON barrows. Gilts fed gRAC gained 0.20kg per day (20 per cent) more weight (P<0.0001) than CON gilts.

Generic RAC-fed barrows were 20 per cent more (P<0.0001) feed-efficient than CON barrows. Generic RAC-fed gilts were 15.62 per cent more feed-efficient (P<0.0001) than CON gilts.

Longissimus muscle area (LM; 11.9 per cent) and loin depth (8.6 per cent) were greater (P<0.0001) in gRAC-fed barrows than CON barrows, whereas LM area (7.7 per cent) and loin depth (6.4 per cent) were greater (P<0.001) in gRAC-fed gilts than CON gilts.

Boneless cutting yields - 1.77 per cent units in barrows and 2.20 per cent units in gilts - of gRAC-fed pigs were greater (P≤0.02) than cutting yields of CON.

Feeding gRAC did not affect (P≥0.24) subjective LM quality characteristics.

Fresh belly firmness was not (P≥0.66) affected by gRAC but gRAC-fed gilts had greater (P≤0.01) proportions of all PUFA, particularly linoleic and linolenic acids, than CON gilts.

Although shear force values did not differ (P=0.24) between gRAC and CON barrows, gilts fed gRAC had 0.46kg (13.7 per cent) greater (P=0.04) shear force values than CON gilts.

Feeding 10mg per kg of generic ractopamine to finishing pigs improved production efficiency and increased cutability but did not affect meat or fat quality.

Reference

Boler D.D., F.K. McKeith, C.L. Puls, M. Ellis, S.L. Wood-Follis, R.W. Miller, H.B. Vanimisetti, W.M. Moseley, A.L. Schroeder and A.C. Dilger. 2014. Effects of generic ractopamine (Engain) on the growth performance, carcass characteristics, meat quality, and cutability of finishing barrows and gilts. Professional Animal Scientist. 30: 625-636. doi: 10.15232/pas.2014-01320

Further Reading

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January 2015