PSV-20 The effect of differing implant strategies on the galanin receptor 2 genotype on feed intake, efficiency, and feeding behavior of crossbred Angus finishing steers

Abstract

Abstract Abstract: The objective of this study was to determine how the interaction different implant strategies with the galanin receptor 2 (GALR2) would influence intake, efficiency, and feeding behavior of finishing steers along with carcass characteristics. Angus crossbred steers (n = 93) were selected for this study based on their GALR2 genotype (GG, TT, and TG) and weaning weight with 19 GG, 36 TT, and 38 TG. Calves were blocked by initial body weight and fed a standard feedlot ration for 166 d or 202 d. Body weight data and blood samples were collected every 28 d. Steers were randomly assigned to one of two implant strategies; 1) a single Revalor-S (Merk, New Jersey) on d 77, or 2) a Revalor-S with on d 0 and another on d 77. Intake and feeding behavior data were recorded using RFID tags and Insentec feeders (Hokofarm Group, B.V., Marknesse, the Netherlands). Total DMI and feeding behavior were summarized following procedures described by (Swanson et al. 2014). Data were analyzed using the mixed procedure in SAS with a 2 x 3 factorial arrangement of treatments. The interaction of genotype x implant had a significant effect on minutes spent eating/visit (P = 0.02). The main effect of genotype had a significant effect on DMI (P = 0.05), number of meals/day (P 0.0001), and intake/minute (P = 0.002). While there was a greater DMI with the GG genotype we do not see the benefit of improved feed efficiency. The main effect of implant had a significant effect on ADG (P = 0.0008) and intake/visit (P 0.0012). Based on this data we conclude that there is no interaction between GALR2 genotype and implant strategy on efficiency or intake in finishing steers, however there may be benefit to future studies focusing on the GALR2 genotype and intake.