A total of 1680 pig allocated in 84 pens were distributed in three diets differing in RAC concentration (0. 5, and 7.4 mg/kg), 2 duration periods (the final 21 or 28 d). After the slaughter, carcass characteristics, meat quality traits, and sensory attributes were evaluated in late-finishing pigs, weighing between 100 to 130 kg of BW. For the carcass evaluation, all primal cuts from the right sides of the carcass corresponding to two pigs from each pen (a total of 168 pigs) were collected in order to calculate primal yields as a percentage of the hot carcass weight. Subjective colour, firmness, and marbling scores were determined on the LM of each loin and the semimembranosus muscle (SM) of the ham, whereas moisture, extractable lipid, texture, and trained sensory evaluations (juiciness, tenderness, and pork flavour) were measured on the LM samples only.
It was observed that animals fed with the supplemented RAC diet had higher hot carcass weight than those animals fed the control diet (P<0.05). However, pork quality was neither affected by feeding 5 or 7.4 mg/kg of RAC, nor by the duration of RAC supplementation. Carcass composition, pork quality, or cooked pork palatability were neither affected by RAC supplementation. Dietary supplementation of 5 mg/kg of RAC increased (P<0.05) boneless cut and lean cut yield compared to pigs fed 0 or 7.4 mg/kg of RAC. The use of RAC in the last-finishing diets for 21 or 28 days did not affect sensory evaluation based on percentage of moisture and intramuscular lipid. It is concluded that the addition of RAC in the late-finishing diet improved carcass and primal cut yields when it was fed at 5 and 7.4 mg/kg without altering pork quality traits regardless de duration of RAC supplementation in feed.
DM Fernández-Dueñas, AJ Myers, SM Scramlin, CW Parks, SN Carr, J Killefer, and FK McKeith. 2008. Journal of Animal Science. 86:3544-3550.