168 Effects of GALR2 genotype and differing implant strategies on carcass characteristics of crossbred Angus finishing steers

Abstract

Abstract The objective of this study was to determine how the interaction of different implant strategies with the galanin receptor 2 (GALR2) genotype would affect carcass characteristics and meat quality in crossbred Angus finishing steers. Angus crossbred steers (n = 93) were selected for this study based on their GALR2c.-199T > G genotype (GG, TT, and TG) and weaning weight with 19 GG, 38 TG, and 36 TT. 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 Animal Health, NJ) on d 77 (1×), or 2) a Revalor-S on d 0 and another on d 77 (2×). Data were analyzed as a 2 × 3 factorial design of implant strategy by GALR2c.-199T > G genotype using the mixed procedure in SAS, with repeated measures used for color, and significance was set at P < 0.05. Hot carcass weight and back fat were directly affected by implant strategy where steers on the 2 implant strategy exhibited heavier hot carcass weights and increased back fat (P < 0.05). Cook loss and shear force were influenced by the interaction of genotype by implant strategy (P < 0.05). The GG steers exhibited less cook loss in comparison to all other treatments. The GG steers exhibited the highest shear force value of all treatments. The pH, water holding capacity, and color of the striploins were not affected by the genotype by implant strategy interaction or main effects of genotype and implant strategy. From this we conclude the interaction of GALR2c.-199T >G genotype implant strategy does not have a negative effect on carcass characteristics or meat quality in crossbred Angus finishing steers.