PSXVI-2 - Impacts of Improvest on Primal Yields in Gilt Carcasses

Abstract: Improvest administration in gilts during the finishing phase results in heavier hot carcasses weights. The objective of this study was to determine primal cutout yields from Improvest-treated gilts compared with controls. This was a pen-fed design with 20 pens/treatment (27 gilts/pen; study d0 = 7 wk of age). The first Improvest dose was administered on d7 and the second dose administered on d67. The heaviest 8 gilts/pen were marketed 22 days post second dose (dPSD), heaviest 8 gilts/pen at 37 dPSD, and all remaining gilts marketed at 50 dPSD. All hot carcasses were weighed (HCW), and within a day and treatment, the heaviest 50 carcasses were selected for dissection. The natural fall (NF) weight was recorded, and after trimming, the finished good (FG) weight, so that primal yield could be calculated. The HCW were similar 22 dPSD, but Improvest gilts had greater HCW at 37 and 50 dPSD. Bellies (NF and FG) were increased in Improvest-treated vs. control gilts at 37 and 50 dPSD. Overall, belly yield was increased in Improvest-treated gilts. Rib weights (NF and FG) were increased in Improvest-treated gilts at 50 dPSD, but there was a decreased rib yield compared with control. There was an increased rib yield at 22 dPSD in Improvest-treated vs. control gilts. Picnic weights were greater in Improvest-treated vs control gilts, regardless of day. Loin NF and FG, butt NF, and ham NF weights were greater at 50 dPSD compared with control. When intramuscular fat was determined, the greatest (P = 0.03) amount was at 37 dPSD in Improvest-treated gilts compared with all other gilts. Even when the heaviest carcasses were selected, belly yields remain increased in Improvest-treated compared with control gilts. There were no detrimental impacts of Improvest use on any of the primal cutout yields that were observed.