A total of 2,575 beef heifers (BW = 568 ± 28.1 lb; 258 ± 12.7 kg) at high-risk of developing bovine respiratory disease (BRD) were enrolled in a randomized complete-block design study at a commercial feedlot to evaluate the effect of 3 vaccine programs on health, growth performance, and carcass characteristics. Dates of arrival to the feedyard served as the blocking factor and 10, 3-pen blocks were enrolled in the study (n = 10 replications per vaccine program). Chute- order randomization was used during arrival processing to assign heifers to 1 of 3 vaccine programs that differed by vaccine products or timing of the pentavalent modified-live viral vaccination: 1) Pyramid® 5 and Presponse® SQ during arrival processing (PRE), 2) Titanium® 5 and Nuplura® PH during arrival processing (TNA), and 3) Nuplura® PH during arrival processing with Titanium® 5 delayed until 28 days- on-feed (TND). No booster vaccinations were administered. Overall mortality, BRD morbidity, and BRD treatment success risks did not differ among the vaccine programs (P>0.13). There were numerically fewer mortalities attributable to acute interstitial pneumonia in TNA heifers than the TND and PRE heifers (probability of difference = 0.99 and 1.00, respectively). Mortality attributable to BRD did not differ between vaccine programs (probability of difference < 0.48). Endotoxin concentrations were measured in the Mannheimia haemolytica vaccines, and were lower in Nuplura® PH than Presponse® SQ. An arrival vaccine program implementing Titanium® 5 and Nuplura® PH had similar efficacy on BRD- related health outcomes as vaccinating with Pyramid® 5 and Presponse® SQ. Delaying a pentavalent viral vaccine until 28 days-on-feed did not affect health or growth-performance outcomes in this study.

Mannheimia haemolytica (MH) is the primary bacterium involved with bovine respiratory disease (BRO), and there are differences between how the vaccines which confer immunity against this important pathogen are manufactured. Generally speaking, the bacterin and toxoid components of commercially available MH vaccines are harvested through propagation of whole-cell MH cultures. Nuplura® PH (NUP; Elanco Animal Health, Greenfield, IN) contains both toxoid and cell-associated antigens, but these antigens differ as they are manufactured using recombinant technology and a proprietary purification process. The relative efficacy of vaccine programs incorporating NUP versus products derived from whole-cell MH culture has not been evaluated in a large-pen feedlot setting. The objective of this study was to compare 3 vaccination programs on the health, growth performance, and carcass characteristics of feedlot heifers.

The objective of this study was to determine the relative effects of stocker-phase implant strategies on growth and carcass characteristics of beef steers. In each of 2 locations (OK and MS), steers were grazed on cool-season annual pastures in fall 2018 through spring 2019. Steers (n = 300 in MS, n = 240 in OK) were randomly assigned to one of three implant treatments, 1) a single Synovex® One Grass implant at d 0, 2) a single Component® TE-G with Tylan implant at d 0, or 3) a reimplant treatment receiving Component® TE-G with Tylan at d 0 and again at d 82 (OK) or 85 (MS). Steers from each treatment were commingled in 2 (OK) or 3 (MS) pastures for 159 (OK) or 161 d (MS). Following grazing, steers were shipped to a commercial feedyard for finishing, sorted into 3 pens based on BW with each treatment equally represented in each pen, and were managed according to that site’s BMPs. Steers from all treatments were implanted identically in the feedyard. Steers were slaughtered when the pen was visually estimated to be at 1 cm backfat. Carcass data of individuals were collected by camera grading equipment in the packing plant. Data were analyzed as a completely random design with animal as the experimental unit, treatment as a fixed effect, and pasture within location as a random effect. Marbling score tended to be greater in the single Component® TE-G with Tylan (treatment 2) vs. the other 2 treatments (425 vs 408 and 410, P = 0.07). No other production variables, including stocker-phase ADG, approached a significant difference (P &gt; 0.39). No evidence was found to recommend stocker-phase reimplanting even in relatively long stocker phases with high ADG, and producers should consider selecting the most cost-effective implant at grazing initiation.

Crossbred male beef calves (n = 259; bulls = 134, steers = 125; body weight = 250 ± 3.4 kg) approximately 6 months of age and considered high-risk for developing bovine respiratory disease arrived on 3 dates (block) and were stratified by arrival castrate status and weight to be evenly distributed across pens (8 pens/block; 9 to 12 calves/pen). The pens were randomly assigned to 1 of 2 treatments: 1) Nuplura PH (administration of a Mannheimia haemolytica leukotoxoid at processing) or 2) Control (no M. haemolytica leukotoxoid). All cattle received tilmicosin on d 0 with a 5-d post-metaphylactic interval. Body weights were recorded on d -1, 0, 14, 28, 41 and 42. Blood was collected on d -1, 14, 28, and 42 and sera were harvested to determine serum neutralization titers for bovine virus diarrhea (BVD) type I and bovine anti-M. haemolytica leukotoxin antibodies. Calves were observed daily for signs of morbidity. Body weight and average daily gain were not affected (P ≥ 0.26) by treatment. The percentage of calves administered 1, 2, or 3 antibiotic treatments for clinical bovine respiratory disease did not differ (P ≥ 0.35). There was a tendency for mortality to be greater for Control compared to Nuplura PH (1.6 vs 0.0%; P = 0.10). Calves administered Nuplura PH possessed greater antibody response against M. haemolytica leukotoxin on d 14, 28, and 42 compared to Control calves (P &lt; 0.01). There was no treatment × day interaction for antibody titers against BVD (P = 0.98). The use of a M. haemolytica leukotoxoid had no effect on growth performance and morbidity for the 42-d following receiving in this small-pen study, but reduced the incidence of mortality and did not interfere with antibody response to BVD vaccination in high-risk, newly received calves metaphylactically treated with tilmicosin on arrival.