Browsing by Author "Holland, Ben P."
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Item Effects of a single initial and delayed release implant on arrival compared with a non-coated initial implant and a non-coated terminal implant in heifers fed across various days on feed(2019) Smith, Zachary K.; Holland, Ben P.; Word, Alyssa B.; Crawford, Grant I.; Nichols, Wade N.; Nuttelman, Brandon L.; Streeter, Marshall N.; Hutcheson, John P.; Johnson, Bradley J.Two experiments evaluated the effect of implant number, type, and total steroidal dose on live animal performance and carcass traits in heifers fed for three different days on feed (DOF). In experiment 1, heifers (n = 3,780; 70 heifers/pen and 9 pens/treatment; initial body weight [BW] = 309 kg) were used in a 2 × 3 factorial arrangement of treatments. Factors were as follows: 1) implant (all from Merck Animal Health, De Soto, KS): 200 mg trenbolone acetate (TBA) and 20 mg estradiol-17β (E2) administered on arrival (SINGLE), or 80 mg TBA and 8 mg E2 administered on arrival followed by 200 mg TBA and 20 mg E2 after approximately 90 d (REPEATED) and 2) duration of DOF: harvested after approximately 172, 193, and 214. In experiment 2, heifers (n = 3,719; 65 to 70 heifers/pen and 9 pens/treatment; initial BW = 337 kg) were used with the same factors as experiment 1, except DOF were 150, 171, and 192. No implant × DOF interaction (P ≥ 0.06) was noted for any performance parameters in either experiment. Heifers administered REPEATED had improved (P ≤ 0.05) live gain to feed ratio (G:F) and carcass-adjusted G:F and tended (P = 0.09) to have greater hot carcass weight (HCW) in experiment 1. Increasing DOF resulted in greater (P ≤ 0.01) live and carcass-adjusted final BW and decreased (P = 0.01) live ADG in experiment 1. As DOF increased, HCW, HCW gain, and dressing% (P ≤ 0.01) increased in experiment 1. The mean carcass transfer was 79.6% across the 42 d terminal window in experiment 1. In experiment 2, REPEATED had improved (P = 0.03) carcass-adjusted G:F compared with SINGLE, but HCW was not different (P = 0.36) between treatments. Increased DOF resulted in greater (P ≤ 0.01) final live and carcass-adjusted BW, decreased (P ≤ 0.01) live and carcass-adjusted ADG, and poorer (P ≤ 0.01) live and carcass-adjusted G:F in experiment 2. In experiment 2, dressing percentage was greater (P = 0.02) in REPEATED compared with SINGLE. Heifers given SINGLE had greater (P = 0.01) back fat and estimated empty body fat (EBF), whereas REPEATED had fewer (P = 0.01) Yield Grade 4 carcasses and greater (P = 0.01) longissimus muscle (LM) area. Increased DOF resulted in greater (P ≤ 0.04) HCW, HCW gain, dressing%, back fat, LM area, marbling, EBF%, and United States Department of Agriculture (USDA) Prime-grading carcasses, Yield Grade 4 and 5, and over 454-kg carcasses in experiment 2. Carcass ADG and carcass transfer indicate a 0.70 kg carcass ADG between 150 and 192 DOF, resulting in an average carcass transfer of 72.2% in experiment 2. Although feedlot growth performance and HCW did not differ between the implant regimens tested, increasing DOF resulted in decreased live growth performance while increasing the proportion of USDA prime carcasses and HCW.Item Effects of growth-promoting implants on live performance, carcass characteristics, and mechanistic responses of beef × dairy steers(2023-05) Wesley, Kaitlyn; J. Johnson, Bradley; Ballou, Michael A.; Woerner, Dale R.; Holland, Ben P.; Hutcheson, John P.Through the use of beef semen in Holstein females, the beef production industry has found a method to accommodate beef processors at harvest while acknowledging benefits of a Holstein-type steer in the feedlot which increased incidence of beef × dairy calves in feedlots. The first study was designed to evaluate dosage and timing of trenbolone acetate administration on live and carcass outcomes of beef × dairy steers. A total of 6,895 beef × dairy steers [initial body weight (BW) = 156 kg] were allotted into 30 pens and fed an average of 329 days. Each pen was randomly assigned 1 of 3 implant treatments: 1) Revalor-IS (IS) at d0, IS at d80, and Revalor-XS (XS) at d160; 2) Ralgro at d0, IS at d80 and XS at d160; or 3) Encore at d0 and XS at d160. Pen was the experimental unit, and fixed effect of implant treatment and random effect of block were evaluated. While delayed administration or lower total dosage of TBA-containing implants may decrease buller incidence and improve Quality Grade, few differences were observed in live or carcass outcomes. The objective of the second and third studies were to evaluate the live performance, carcass characteristics, sera metabolite, and biological responses of Angus (ANG), Angus × Holstein (A×H), and Holstein (HOL) steers (n = 16 / breed; BW = 417 kg) to implant status. Data were analyzed as a 3×2 factorial, including repeated measures for sera metabolite outcomes, and main effects of breed type and implant status (no implant or Revalor-XS on d 0). Steers were fed to an average 658 kg within breed type. The A×H steers had the greatest average daily gain when fed to a similar final BW, and A×H carcasses improved ribeye area, kidney pelvic heart fat percentage, and empty body fat outcomes compared to a HOL carcass. The HOL steers had low circulating steroid hormones, possibly due to more efficient hormone clearance with a larger proportion of liver weight, and may be most responsive to administration of exogenous estrogenic compounds by increased estrogen receptor abundance. Implant administration increased steroid hormone concentrations with no effect on fiber type or myogenic outcomes. Steroid receptors with high binding affinities were unaffected by implant administration and may operate at maximum capacity at low concentrations of steroids. These results indicate beef × dairy steers may be most responsive to delayed doses of estrogen-containing implants and could be used positively in the beef production system.Item A pooled analysis of six large-pen feedlot studies: effects of a noncoated initial and terminal implant compared with a single initial and delayed-release implant on arrival in feedlot heifers(2020) Smith, Zachary K.; Renter, David G.; Holland, Ben P.; Word, Alyssa B.; Crawford, Grant I.; Nichols, Wade T.; Nuttelman, Brandon L.; Streeter, Marshall N.; Walter, Lee-Anne J.; Hutcheson, John P.; Dicke, Bill; Brandt, Robert T. Jr.; Szasz, Josh I.; Bryant, Tony C.; Pringle, Lois F.G.; Carlson, Zac E.; Erickson, Galen E.; Johnson, Bradley J.Randomized complete block design experiments (n = 6 experiments) evaluating steroidal implants (all from Merck Animal Health, Madison, NJ) were conducted in large-pen feedlot research facilities between 2015 and 2018 comparing an 80 mg trenbolone acetate (TBA) and 8 mg estradiol-17β (E2) initial implant (Revalor-IH) and reimplanted with 200 mg TBA and 20 mg E2 (Revalor-200; REPEATED) to a single 80 mg TBA and 8 mg E2 uncoated; 120 mg TBA and 12 mg E2 coated implant (Revalor-XH) at arrival (SINGLE) on growth and carcass responses in finishing heifers. Experiments occurred in Nebraska, Oklahoma, Washington, and Texas. Similar arrival processing was used across experiments where 17,675 heifers [initial body weight = 333 kg SEM (4.1)] were enrolled into 180 pens (90 pens per treatment with 65–240 heifers per pen) and fed for 145–222 d. Only REPEATED heifers were removed from their pen at reimplant. Diets contained monensin and tylosin, consisted of ingredients common to each region, and contained greater than 90% concentrate. Ractopamine hydrochloride was fed for a minimum of 28 d prior to harvest. Linear mixed models were used for all analyses; model-adjusted means for each implant group and the corresponding SEM were generated. Distributions of U.S. Department of Agriculture (USDA) quality grade (QG) and yield grade (YG) were analyzed as ordinal outcomes. No differences (P ≥ 0.11) were detected for any performance parameters except dry matter intake (DMI), where SINGLE had greater (P = 0.02) DMI (9.48 vs. 9.38 ± 0.127 kg) compared with REPEATED. Heifers implanted with REPEATED had greater (P ≤ 0.02) hot carcass weight (HCW; 384 vs. 382 ± 2.8 kg), dressing percentage (64.54 vs. 64.22 ± 0.120%), and ribeye area (91.87 vs. 89.55 ± 0.839 cm2) but less (P ≤ 0.01) rib fat (1.78 vs. 1.83 ± 0.025 cm) and calculated YG (2.82 vs. 2.97 ± 0.040) and similar (P = 0.74) marbling scores (503 vs. 505 ± 5.2) compared with SINGLE heifers. Distributions of USDA YG and QG were impacted (P ≤ 0.03) by treatment such that REPEATED had fewer USDA Prime and YG 4 and 5 carcasses. Heifer growth performance did not differ between implant regimens, but HCW and muscling did, perhaps indicating that REPEATED may be suited for grid-based marketing, and SINGLE might be suited for heifers sold on a live basis depending upon market conditions and value-based grid premiums and discounts. However, these decisions are operational dependent and also may be influenced by factors including animal and employee safety, stress on animals, processing facilities, time of year, labor availability, and marketing strategies.Item Strategies to Decrease Antimicrobial Use and Improve Health Outcomes, Growth Performance, and Carcass Characteristics of Finishing Beef Cattle Using Bunk Management, Bulk Density of Steam-Flaked Corn, and Targeted Metaphylaxis(2023-05) Smock, Taylor; Hales, Kristin E.; Ballou, Michael A.; Holland, Ben P.; Johnson, Bradley J.; Woerner, Dale R.Experiment 1: Our objectives were to evaluate effects of bunk management strategy and bulk density of steam-flaked corn on growth performance, carcass characteristics, and incidence and severity of liver abscesses in finishing beef steers fed diets without tylosin phosphate. Beef steers (n = 192; initial BW = 332 ± 8.1 kg) were used in a randomized complete block design comprised of 12 BW blocks and 12 pen replications per treatment. A 2 × 2 factorial arrangement of treatments was used: 1) slick bunk management + 335 g/L steam-flaked corn-based diets (SFC); 2) modified ad libitum bunk management + 335 g/L SFC; 3) slick bunk management + 425 g/L SFC; 4) modified ad libitum bunk management + 425 g/L SFC. Bunk management strategy did not affect growth performance, carcass characteristics, or liver abscess score (P > 0.10). The ADG of steers fed 425 g/L SFC was greater (P = 0.05) from days 35 to 105 than those fed 335 g/L SFC; however, overall ADG was not different (P = 0.36). The DMI of steers fed 425 g/L SFC was greater at each interim period (P ≤ 0.05) and overall (P ≤ 0.01) than those fed 335 g/L SFC. Gain-to-feed (G:F) of steers fed 425 g/L SFC tended (P = 0.10) to be lesser from days 0 to 35 but was not different overall (P = 0.12). Steers fed 425 g/L SFC tended to have greater backfat and calculated empty body fat percentage (P ≤ 0.07) than those fed 335 g/L SFC and greater calculated yield grade (P = 0.05). Steers fed 425 g/L SFC had 43.5% fewer (P = 0.04) liver abscesses than those fed 335 g/L SFC, but liver abscess severity did not differ (P ≥ 0.12). Bunk management did not affect growth performance, carcass characteristics, or development of liver abscesses. Steers fed 425 g/L SFC-based diets had greater DMI and 43.5% fewer liver abscesses than those fed 335 g/L SFC-based diets with similar overall G:F, but carcasses were fatter. Greater bulk density of SFC may be a useful management strategy and a viable antimicrobial alternative to decrease liver abscesses. Experiment 2: The objective was to evaluate rectal temperature and infrared thermography as qualification for targeted metaphylaxis, and effects on clinical health, growth performance, complete blood count, and serum haptoglobin in newly received beef steers during a 42-day feedlot receiving period. Crossbred beef steers (n = 240; arrival BW = 258 22.5 kg) were used. Experimental treatments were arranged as a generalized complete block design: sterile saline (NCON); conventional metaphylaxis administered to all steers (CONV); targeted metaphylaxis administered to steers with rectal temperature 39.7 C (RECT); or targeted metaphylaxis administered to steers with ocular infrared temperature 39.7 C (EYE). Body weight and blood samples for quantification of complete blood count and serum haptoglobin were collected on days 0, 14, and 42 relative to metaphylaxis. Metaphylaxis was administered to 0% of NCON, 100% of CONV, 48.9% of RECT, and 48.6% of EYE steers (P < 0.01). Therapeutic BRD treatment rate did not differ (P = 0.16), although overall BRD treatment rate was minimal. Metaphylaxis was 62.5% of total active antimicrobial compound administered to RECT and 32.1% of total active antimicrobial compound administered to EYE. Both methods of targeted metaphylaxis decreased percentage of animals administered antimicrobials relative to CONV (P < 0.01), but total mg of active drug compound administered was not different (P = 0.65). Body weight, DMI, DMI as percentage of BW, and G:F did not differ at any time point (P 0.07). A tendency (P = 0.06) was observed for ADG from day 0 to 14, where CONV was greatest, RECT and EYE were intermediate, and NCON was least. Day 0 to 42 ADG was greatest in CONV and RECT, least in NCON, and intermediate in EYE (P < 0.01). Platelet count tended (P = 0.10) to be greatest in NCON and RECT, followed by EYE and CONV. No further hematologic treatment differences were observed (P 0.22). Both methods of targeted metaphylaxis decreased the proportion of animals administered antimicrobials relative to conventional metaphylaxis, however, total mg of active drug compound administered was not different. The ADG of steers administered targeted metaphylaxis based on rectal temperature did not differ from those administered conventional metaphylaxis. Use of targeted metaphylaxis with measures of body temperature may decrease the proportion of animals administered metaphylaxis while maintaining optimal health and growth performance outcomes. Experiment 3: The objective was to provide an updated profile of the bovine acute-phase response to include recent advancements in technologies and expanded hematological, cytokine, and serum chemistry variables. Beef steers (n = 32; BW = 251 19.5 kg) were fitted with indwelling jugular catheters 1 day before lipopolysaccharide (LPS) administration to facilitate serial blood collection. Rectal temperature was measured using indwelling probes, and ocular temperature was measured using infrared thermal imaging. Blood samples were collected for subsequent analysis of serum chemistry, hematology, and cytokine concentrations. Pearson correlation of rectal temperature and ocular infrared temperature was 0.61 (P < 0.01) and the Spearman correlation coefficient was 0.56 (P < 0.01). Interactions of hour method were observed for ocular and rectal measurements of body temperature in response to endotoxin exposure. Maximum observed temperature was 39.6 C at 2.5 h for both rectal and ocular measurements. Body temperature differed by method at hours 0.5, 2.5, 4.5, 7.5, 12.5, 36.5, and 47.5 (P < 0.01), but were not different otherwise. All variables of serum chemistry and complete blood count were influenced by LPS administration, except creatinine, serum glucose, and percent basophils (P 0.02). Alanine aminotransferase and alkaline phosphatase peaked at hour 2 relative to LPS administration, returned to baseline at hour 12 and continued to decrease below the baseline value at hour 48 (P < 0.01). Total protein concentration decreased 3% in response to LPS (P = 0.01). Total white blood cell count decreased 75% after LPS administration at hour 1 (P < 0.01). Lymphocyte count recovered to baseline at hour 6; sooner than neutrophil count at hour 36. Serum cortisol concentration increased 294% relative to baseline at hour 1 followed by a sustained decrease and return to normal concentration at hour 4 (P < 0.01). Additionally, circulating cytokine concentrations changed with time in response to the LPS challenge, excluding aFGF, bFGF, IGF-1, IL-2, IL-4, MCP-1, and ANG-1 (P 0.08). Maximum observed concentration of TNF-α at hour 1 was 117% greater than the pre-challenge value (P < 0.01). Data presented herein add to existing works to understand the endocrine and immune responses of beef steers administered exogenous LPS, and incorporate recent technologies, additional biomarkers, and an expanded cytokine profile that can be used as referential data in future research.