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Genomic testing of feeder cattle is reported to be beneficial in selecting cattle for the feedlot, as well as making management and marketing decisions. The objective of this study was to determine differences in performance and efficiency of finishing steers with a range of Neogen Igenity Beef scores for average daily gain (ADG) and milk. Spring born steer calves from the Oklahoma State University Range Cow Research Center (n = 83, BW = 419 ± 31.9) of Angus ancestry were placed on feed at the Willard Sparks Beef Research Center on May 5, 2022, after grazing wheat pasture for 155 d. The steers were grouped based on Igenity ADG Score [low (1-4), medium (5-6), or high (7-10)] and Milk Score [low (1-5) or high (6-10)] based on the Igenity results. Steers were allocated into pens (n = 5 steers/pen) in heavy and light BW blocks. Steers were fed a step-up diet for 30 d before being switched to a finishing ration diet (8% prairie hay, 20% Sweet Bran and 62% dry-rolled corn). Cattle were fed ractopamine for 30 d before slaughter. The heavy block were on feed for 119 d, while the light block were on feed for 148 d. Data were analyzed as a randomized complete block design using the mixed procedure of SAS (SAS Inst. Inc., Cary NC) with pen as the experimental unit. Steers with high growth (HG) scores gained weight more rapidly during finishing and weighed more at slaughter than medium growth (MG) and low growth (LG; P < 0.01); while steers with high milk (HM) gained faster (P < 0.01) and tended (P = 0.06) to be heavier at slaughter than low milk (LM). Growth score was shown to have an effect on dry matter intake (P < 0.01) with HG consuming more feed than MG or LG. Cattle with HM scores were less efficient than LM scores (P = 0.01), but there was no difference (P = 0.37) in feed efficiency due to ADG score. Those with high growth and milk scores had a higher average daily gain (P < 0.01). These data indicate that Igenity ADG scores can be used to select cattle with higher performance and bodyweight at slaughter with no adverse effect on feed efficiency. Steers with higher Igenity Milk scores were less efficient than those with LM scores. Igenity Milk scores can be used to predict efficiency, according to these data.

Our objective was to determine the effect of calf-fed or yearling finishing systems on the performance of dairy-beef crossbred steers. Dairy-beef hybrid steers were acquired from Land O’ Lakes Calf Milk Research Facility at Grey Summit, Missouri at 12-weeks of age and transported to Willard Sparks Beef Research Center (WSBRC). Upon arrival at WSBRC, steers were weighed, vaccinated, treated for parasites, and implanted with 36 mg of zeranol (Ralgro). Alternating groups of steers were placed either directly on finishing diets (FIN) or on high-quality pasture and supplementation for 5 to 6 mo before returning to WSBRC for finishing (GRW/FIN). Once GRW/FIN steers reached 312 ± 7 kg, the steers were returned to WSBRC, weighed, and processed. At WSBRC, steers within each finishing system were sorted by BW into 4 to 5 animal pens. Steers in FIN were re-implanted with Ralgro on d 56, Component TE-IS (80-mg trenbolone acetate,6-mg estradiol, and 29-mg tylosin tartrate; Elanco US, Greenfield, IN) on d 112, and Component TE-S (200-mg progesterone, 20-mg estradiol benzoate, 29-mg tylosin tartrate; Elanco) on d 224. Steers in GRW/FIN were implanted with Component TE-IS at the start of finishing, and Component TE-S on d 20. Steers in FIN were grown on successively greater energy growing diets through d 112, stepping up to a 20% roughage growing diet (18.4% CP and 2.4 Mcal NEg/kg from d 28 to 112. On d 112, FIN steers were transitioned to a finishing diet consisting of 12% roughage, 12% crude protein, and 1.3 Mcal NEg/kg. A final finishing diet (8% prairie hay, 20% Sweet Bran and 62% dry-rolled corn) was fed to FIN steers from d 224 to slaughter. Steers in GRW/FIN were stepped up to the finishing diet when they reached 407 ± 6 kg. Finishing diets for the final 28 d for FIN and GRW/FIN included ractopamine hydrochloride at a rate of 300 mg·steer-1·d-1. Initial and terminal BW were greater (P < 0.01) in steers in the GRW/FIN finishing system. Body weight at reimplant was greater (P < 0.01) for FIN. Steers in the GRW/FIN system were on feed for fewer (P < 0.01) days compared with FIN steers. Average daily gain (ADG) and DMI (kg·steer-1·d-1) were greater (P < 0.01) for GRW/FIN. Steers in GRW/FIN had a greater (P ≤ 0.02) feed:gain ratio than those placed directly into a finishing system. There were no differences (P ≥ 0.10) in USDA Yield Grade, marbling, ribeye area (REA), or back-fat thickness (BFT) between finishing systems. Steers in FIN had a greater (P < 0.01) dressing percentage (DP) and lighter (P ≤ 0.01) hot carcass weight (HCW) than those for GRW/FIN. Finishing system has an impact on performance and efficiency of dairy-beef hybrid steers, but minimal impact on carcass quality.

Two experiments (EXP1 and EXP2) evaluated the effects of NutraGen (NG) on calf health following exposure to bovine viral diarrhea virus (BVDV) on d -3 and Mannheimia haemolytica (Mh) infection on d 0. For each EXP, steers (BW = 251 ± 38.2 kg) were randomly allocated to 1 of 3 treatments (TRT). Treatments included a placebo (CON; EXP1 n = 5; EXP2 n = 5), a placebo fed from d -18 to d -3 followed by NG fed from d -3 to d 28 (CHLG; EXP1 n = 5; EXP2 n = 6), and NG fed from d -18 to d 28 (PREC; EXP1 n = 6; EXP2 n = 5). There was no treatment by time interaction (TRT×TME) or TRT effect for rectal temperatures (RT) or clinical scores (CS) in EXP1 or CS in EXP2 (P ≥ 0.26). There was a TRT×TME for respiration rates (RR) during the first 24 h following Mh infection (P = 0.04), and a tendency for a TRT effect from d -3 to d 14, and overall in EXP1 (P ≤ 0.10). There was a tendency for a TRT×TME for RT from d -3 to d 14 in EXP2 (P = 0.04). There was a TRT effect for RR from d -3 to d 14 and overall in EXP2 (P ≤ 0.05). There was a TRT×TME for leukocytes during the first 24 h following Mh infection in EXP1 (P = 0.03) and overall in both EXP (P ≤ 0.001). There was no TRT×TME or TRT effect for neutrophils (NEU), lymphocytes (LYM), or NEU:LYM in EXP1 (P ≥ 0.19); however, there were multiple TRT×TME and TRT effects for NEU, LYM, and NEU:LYM in EXP2 (P ≤ 0.05). These experiments suggest that NG has the potential to alter clinical and cellular responses during a bovine respiratory disease challenge.

Our objectives were to determine how pre-finishing plane of nutrition, season, and breed of beef sire affect performance, efficiency, and carcass attributes of dairy-beef hybrid calves. Dairy × beef hybrid steers (3 to 7 d of age) were maintained on either a moderate plane of nutrition or high plane of nutrition from 0 to 12 wk of age. Calves (n = 211, BW = 122 ± 16 kg) were then transported 689 km to the OSU Sparks Beef Research Center at an average age of 92 ± 1.6 d in four blocks. Calves from predominantly Holstein dairies in the Midwest were sired by Angus (n = 147) or Continental breed (n = 64) sires. Steers were processed on arrival and were sorted by BW within previous treatment into 4 to 5 head pens and fed receiving diets. Steers were transitioned to a grower diet from d 14 to 112. Steers were fed a 12% roughage finishing diet from d-112 to 224. A final 8% roughage finishing diet was fed from d 224 to slaughter with ractopamine hydrochloride (300 mg·steer-1·d -1) included the last 28-d before harvest. Increasing plane of nutrition during the milk replacer and starter feeding period increased (P ≤ 0.03) initial BW at arrival and through d 84, but was not affected (P ≥ 0.08) thereafter. Calves received during the winter and spring were heavier (P < 0.01) on arrival through d 168 and at harvest and gained BW faster during the growing phase and final finishing phase than steers received during the summer. Steers sired by Angus sires were heavier throughout finishing (P < 0.01) and gained BW more rapidly (P < 0.01) than steers sired by Continental breeds. Breed of sire and season have a large impact on performance of finishing dairy × beef hybrids.