PSI-35 Corn supplementation of beef cows and its impact on growth performance and carcass outcomes of their progeny.

To examine the impact of corn supplementation of cows on carcass outcomes of their offspring, forty-seven multiparous Angus beef cows carrying male calves were assigned randomly to two dietary treatments. Treatments were control (CON; n=23) receiving ad libitum access to a low quality, forage-based diet (57.54% TDN, 6.4% CP) TMR, and a supplemented group (SUP; n= 24) receiving corn at 0.02% BW (94.5% TDN, 7.64% CP) in addition to ad libitum access to the basal TMR. Dietary treatments started on d 110 of gestation for 22 wks. Following parturition, cows with their offspring were placed on pasture and managed as a single group. Calves were weaned (~159 d of age) and backgrounded for 250 d. Thereafter, the steers were placed in the feedlot, assigned to 4 pens (blocks) based on BW and offered a 57% corn silage/ 38% barley grain-based ration with growth performance measured at 28-day intervals. Pens 1 through 4 were fed for 69, 83, 96, and 137 d, respectively, to reach a final BW of 615 kg (~16 mo of age) and then sent to a commercial abattoir. Steers from SUP and CON cows did not differ in initial BW, final BW, and ADG, during the finishing period (P > 0.05). No significant difference in carcass quality and yield traits, including subprimal cut yields, bone, lean and fat trim, was observed between treatments (P > 0.05). In addition, differences in the frequency distribution of the Canadian quality and yield grades (P > 0.05) were not observed. Warner-Bratzler shear force values tended to be higher in steers from SUP dams than steers from CON dams (P = 0.07). Overall the results indicate that corn supplementation of cows during the mid to late gestation does not affect growth performance and carcass outcomes of their offspring.