bluuebunny/crossref_metadata_2025_split huggingface dataset:
259 Evaluation of Methane and Carbon Dioxide Production from Cattle on Different Diet Adaptation Strategies
Authors: Mansfield Cindy , Sjostrand Rebecca L , Troyer Braden C , Heil Holly A , Norman Mitchell M , Youngers Maggie , Watson Andrea K , Erickson Galen E 
Published: October 2023

Abstract
An experiment was conducted to evaluate impacts of RAMP (Cargill Corn Milling, Blair, NE) on methane (CH4) and carbon dioxide (CO2) emissions, performance, and carcass characteristics of beef cattle during the grain adaptation phase and finishing phase. Crossbred steers [n = 64; initial body weight (BW) = 347 ±7 kg] were utilized in two treatments; RAMP, fed 100% RAMP during step one and then stepped up to a common finisher diet consisting of 65.5% steam-flaked corn (SFC), 22.5% Sweet Bran (SB), 8% wheat straw, and 4% supplement. The second treatment was control (CON) fed 30.5% SFC, 22.5% SB, 8% wheat straw 35% alfalfa hay, and 4% supplement during step one and then stepped up to the common finisher diet. There were 8 steers per pen and 4 paired replications. Replications were stepped up together and rotated through a two-chamber emissions barn in 5-day cycles to measure CH4 and CO2 emissions at three time points: step one of step-up phase, early feeding phase (one week after starting the finishing diet), and later finishing phase (13 weeks after starting the finishing diet). Performance data were analyzed using the MIXED procedure of SAS with treatment and BW block as fixed effects and emissions data analyzed with BW block and treatment as fixed effects and barn chamber as a covariate. Feeding RAMP during step one of the step-up phase led to a decrease in CH4, as g/d (P = 0.03) and a decrease in the CH4:CO2 ratio (P = 0.02). However, CH4 as g/kg of dry matter intake (DMI) was not affected by treatment (P = 0.25). Control steers had a decrease in CO2 as g/day (P = 0.03), but not as CO2 g/kg of DMI (P = 0.31). There were no differences in DMI (P = 1.00) during the step-up phase, averaging 10.3 kg/d for both treatments. For measures taken while all cattle were on the common finishing diet, RAMP did not reduce CH4, as g/d or g/kg DMI (P ≥ 0.27), CO2 as g/d or g/kg DMI (P ≥ 0.37), or CH4:CO2 (P = 0.12). There were no significant differences in DMI (P = 0.49) whole cattle were in the emissions barn during the feeding phase. There were no significant differences for interim (d 66) cattle performance including BW (mean 504 kg; P = 0.84), DMI (mean 9.7 kg; P = 0.27), ADG (mean 2.33 kg/d; P = 0.88), or G: F (mean 0.246; P = 0.30). Feeding RAMP to cattle during the grain adaptation phase resulted in a 12% decrease in methane emissions on a g per day basis without affecting cattle performance. This reduction in emissions didn’t carry over into the finishing phase when a common diet was fed.
263 Effects of Programmed Compensatory Gain on Feedlot Steer Performance
Authors: Buessing Zachary , Schwager Jebadiah , Murphy Michael , Hannon Bruce , Shike Daniel W , McCann Joshua C 
Published: October 2023

Abstract
The objective was to determine the effects of programmed compensatory gain on feedlot steer growth performance. After a period of growth restriction, a return to ad libitum intake will result in compensatory gain as cattle convert feed more efficiently due to reduced maintenance costs. Simmental × Angus steers (n = 159; BW = 278 ± 49 kg) were blocked by BW, stratified by sire, and allotted to 10 pens. Each pen contained a 3.0 m-long bunk to allow 19 cm of linear bunk space per steer. Pens were randomly assigned to one of two treatments on d 0: control (CON) or programmed compensatory gain (PCG). To achieve programmed compensatory gain, previously growing animals were maintained at a constant BW by reducing the amount of feed offered by 3.29% daily for 10 consecutive d. Thus, on d 54, PCG steers were consuming 72% of original dry matter intake (DMI) and subsequently returned to ad libitum intake to facilitate a period of compensatory gain. Feed intake for CON pens was managed using slick bunk management for the entire experiment. Steers were fed a common diet consisting of 20% corn silage, 20% modified wet distillers grains, 25% high moisture corn, 25% dry rolled corn, and 10% supplement inclusion on a dry matter basis. Steers were feed twice daily at 0800 h and 1200 h. Data were analyzed using MIXED procedure of SAS 9.4 using a beta distribution. The model included fixed effects of treatment and block. From d 39 to 63, average daily gain (ADG) was greater (P = 0.03) for PCG steers compared with CON steers. No treatment effect (P = 0.36) for dry matter intake was observed from d 39 to 63 as PCG and CON steers were consuming 9.49 and 9.67 kg, respectively. Thus, PCG steers had a greater (P = 0.01) gain:feed (G:F) than CON steers from d 39 to 63. Body weight was not different (P = 0.38) on d 148. Also, ADG from d 0 to 148 was not different (P = 0.54) as PCG and CON steers gained 1.92 and 1.91 kg, respectively. From d 0 to 148, overall dry matter intake was not affected (P = 0.91) by treatment. However, programmed compensatory gain steers had a greater G:F (P = 0.01) compared with CON steers for the overall feeding period (0.216 vs 0.210, respectively). In conclusion, programmed compensatory gain improved G:F of feedlot steers over a 148 d-finishing phase without affecting final body weight. Effects of programmed compensatory gain should be further evaluated in a commercial setting with large feedlot pens.
309 Evaluation of Encapsulated Megasphaera Elsdenii Ncimb 41125 in an Accelerated Beef Step-up Program and an Acidosis Challenge Model
Authors: Mansfield Cindy , Sjostrand Rebecca L , Troyer Braden C , Norman Mitchell M , Spore Tyler , Corrigan Mark , Erickson Galen E , MacDonald Jim C 
Published: October 2023

Abstract
A metabolism experiment was conducted to evaluate the effects of daily feeding of encapsulated Megasphaera elsdenii (M. elsdenii) NCIMB 41125 along with a one-time dose of Lactipro NXT (MS Biotec) on dry matter intake (DMI), rumen pH, in vitro lactate disappearance, volatile fatty acid (VFA) concentration, and lactate concentration. Ruminally cannulated crossbred steers (n = 40, initial BW 437 ± 98 kg) were individually fed a finisher diet consisting of 70% steam-flaked corn, 18% modified distillers grain plus soluble, and 7% alfalfa hay. Treatments were control (Con) steers which were given no M. elsdenii and four treatments that received LactiproNXT on day 1 and were given 0 (Drench), 1×106 (Low), 1×107 (Medium), or 1×108 (High) CFU of encapsulated M. elsdenii daily throughout the experiment fed as a top-dress. Adaptation to the finishing diet was accomplished in 19 days for Con steers and 9 days for steers in the Drench, Low, Medium, and High treatments. The experiment included five continuous periods: step-up (d 1-19); finishing (d 20-88); feed restriction (d 89, 24-h full feed restriction); challenge (d 90, cattle were fed at 150% of max DMI from finishing period); and recovery (d 91-94). Data were analyzed using the MIXED procedure of SAS with linear and quadratic effects of dose with drench as the intercept. There were no significant differences for DMI in the step-up, finishing, or challenge period. In the recovery period, DMI was greater for Low, Med, and High compared with Drench (P = 0.07) and there was a tendency for a linear increase in DMI with increasing the dose of M. elsdenii (P = 0.11). Recovery period DMI, expressed as a percentage of pre-challenge intake, was greater (P = 0.05) in steers fed M. elsdenii daily compared with Drench steers, and increased linearly (P = 0.06) as dose of M. elsdenii increased. Rumen pH in steers fed M. elsdenii daily was greater (P &lt; 0.01) during the feeding period and tended to be greater during the challenge (P = 0.14) and recovery (P = 0.11) periods when compared with the Drench treatment. In vitro lactate disappearance tended to be greater (P = 0.13) in steers given M. elsdenii daily when compared with Con and Drench on d 88. For days 90, 91, and 92 combined, a treatment effect was observed for in vitro lactate disappearance with steers in the Low, Med, and High treatments having greater (P &lt; 0.05) disappearance than Con steers, and Med steers having greater (P &lt; 0.05) disappearance than all other treatments. An accelerated step up is possible with the drench and daily feeding of M. elsdenii. Daily feeding of M. elsdenii has a positive effect on cattle during and after an acidosis challenge event.
308 Zinc Supplementation and Implant Abscess Effects on Growth Performance and Immune System of Growing Beef Steers
Authors: Rients Emma L , Franco Carlos , Diaz Fabian , McGill Jodi , Hansen Stephanie L 
Published: October 2023

Abstract
Zinc is beneficial in growth and immune system function in cattle. Angus-cross steers (n = 72; initial BW = 261 ± 14 kg) were used in this 58-day study to determine the effects of supplemental Zn on growth, trace mineral status, and circulating immune cell populations. On d 0, steers received a Component E-S with Tylan implant (Elanco Animal Health, Greenfield, IN) and were stratified by BW into twelve GrowSafe-equipped pens. Dietary treatments included: control (CON; no supplemental Zn), Zn100 (100 mg supplemental Zn/kg DM), and Zn150 (150 mg supplemental Zn/kg DM). Supplemental Zn was provided as Zn sulfate, and other trace minerals were supplemented at NASEM (2016) recommendations. Individual BW was recorded on days -1, 0, 12, 13, 27, 28, 56, and 57. Blood was collected from 9 steers per treatment on d 13 for immune cell population and function assays. Liver biopsies were conducted on 18 steers per treatment on d 14. On d 16, implant abscesses (ABSC) were evaluated, and all steers were treated with meloxicam (285 mg). Data were analyzed using the Mixed procedure of SAS (Cary, NC) with fixed effects of treatment and ABSC prevalence using steer as the experimental unit. Abscess prevalence among treatments was analyzed using Proc Glimmix. Sixty percent of steers had ABSC; ABSC prevalence was similar by treatment (P = 0.67). Steers without ABSC had greater (P = 0.04) ADG d 0 to 13 and tended to have greater (P = 0.09) ADG d 0 to 57. There was also a tendency (Trt × ABSC; P ≤ 0.09) for steers without ABSC to have greater ADG and G:F from d 14 to 27 in CON and Zn100 while within Zn150 steers without ABSC tended to have lesser ADG and G:F than ABSC steers. No other treatment by ABSC or treatment effects (P ≥ 0.14) for growth performance were observed. There were no treatment by ABSC effects for immune cell populations on d 13 (P ≥ 0.26). In Zn150 steers, activated natural killer and gamma delta T cells were increased (P ≤ 0.03) on d 13. Similarly, CD21+ MHC IIhi B cells tended to be increased in Zn150 steers (P = 0.08). Steers with ABSC had increased relative frequency of CD5+ and CD21+ B cells (P ≤ 0.05) and tended to have increased natural killer and CD21+ MHC IIhi B cells (P ≤ 0.09). In addition, steers without ABSC had greater liver Mn on d 14 than ABSC steers (P = 0.05). There were no other effects on liver trace mineral concentrations (P ≥ 0.17). These observations suggest Zn supplementation has greater impact on the cellular immune system, while ABSC have a greater effect on B cells and the adaptive immune system.
310 Evaluation of Orally Administered Megasphaera Elsdenii in Preconditioned Calves Abruptly Transitioned from a Receiving Diet with 4% Dietary Starch to a Growing Diet with 37% Dietary Starch
Authors: Francis Forest L , Gubbels Erin R , Hanson Santana , Norman Thomas , Ribeiro Thiago Lauro Maia , Rusche Warren C , Smith Zachary K 
Published: October 2023

Abstract
The objective of this study was to evaluate the effects of orally administered Megasphaera elsdenii NCIMB 41125 (ME) in preconditioned calves abruptly transitioned from a receiving diet with 4% dietary starch [dry matter (DM) basis] to a growing diet with 37% dietary starch (DM basis). Preconditioned steers [n = 192; initial shrunk body weight (SBW) = 309 kg ± 20.6 kg] were assigned to microbial supplement treatment in a randomized complete block design. Treatments were CON: no ME; and LP: orally administered 20 mL of microbial supplement (2 × 1010 colony forming units ME/mL) immediately before diet change. Steers were abruptly changed from a receiving diet based upon soybean hulls and wheatlage with 4% dietary starch (DM basis) to a growing diet based upon high-moisture ear corn, dry-rolled corn, and wheatlage with 37% dietary starch (DM basis). Diets were switched on an equal DM basis to achieve abrupt change and steers were fed treatment diet for 49 d until study completion. Prior to study initiation, steers (n = 72; n = 3/pen) were fitted with wireless rumination tags to track daily activity and rumination time. Growth performance data and efficiency of dietary net energy utilization were analyzed with pen as the experimental unit, fixed effect of treatment, and random effect of block (location in the feedlot). Activity and rumination data were analyzed in a repeated measures analysis of covariance with individual animal as experimental unit, fixed effects of treatment, week, and their interaction, block (location in feedlot) as a random effect, and baseline activity and rumination as a covariate in the model. If no interaction was observed, main effect means of treatment and week were evaluated independently. For all statistical analysis, P ≤ 0.05 was declared significant and P ≤ 0.10 was declared a tendency. No difference (P ≥ 0.20) was observed between treatments for final SBW, average daily gain, dry matter intake, feed efficiency, calculated net energy (NE) for maintenance and gain or observed-to-expected ratio of NE for maintenance and gain. Additionally, no treatment × day differences (P ≥ 0.27) were observed for activity or rumination measures. Treatment effects (P &lt; 0.01) were observed for both activity and rumination where LP steers had a 2% increase and 2% decrease in minutes per day active and ruminating respectively. Additionally, a positive linear effect (P &lt; 0.01) of week was observed for minutes ruminating and quadratic effects (P &lt; 0.01) of week were observed for minutes active and ruminating. Oral administration of ME had no effects on growth performance or efficiency of dietary net energy utilization in steers transitioned from a receiving diet containing 4% starch (DM basis) to a growing diet containing 37% starch (DM basis).
307 Effect of Calcium Magnesium Carbonate and/or Tylosin Phosphate Supplementation on Receiving Period Growth Performance in Yearling Beef Steers
Authors: Grimes Becca , Francis Forest L , Gubbels Erin R , Rusche Warren C , Smith Zachary K , Paulus Devan 
Published: October 2023

Abstract
The objective of this study was to evaluate the effects of CaMg(CO3)2 (MIN-AD, Papillon Agricultural Company, Easton, MD; MA) and/or tylosin phosphate (Tylan, Elanco, Indianapolis, IN; TY) supplementation on growth performance of yearling beef steers during transition to a finishing diet during the first 28 days on feed. Treatments were arranged in a 2 × 2 factorial arrangement including MA and TY. Beef steers (n = 156; initial BW = 469 ± 18.0 kg) were randomly assigned to dietary treatments pens (7 to 8 steers/pen) with pen (n = 20 pens total, 10 pens/main effect mean, and 5 pens/simple effect mean) serving as the experimental unit. Cattle were transitioned from a 30 % roughage receiving diet to a 7 % roughage finishing diet based on dry-rolled corn, dried distillers grains plus solubles, a liquid supplement, and oat silage over the initial 20 d period. Monensin sodium was included in the diet at 30 mg/kg (DM basis). The MA was included at 1.5 % of the diet (DM basis) in replacement of dry-rolled corn and TY was provided at 90 mg/animal·d-1. Data were analyzed according to a randomized complete block design with the fixed effects of MA, TY, or their interaction; block was considered a random effect. No interaction was noted between MA or TY (P ≥ 0.68) for any variables measured. The main effect of TY did not influence d 28 BW, ADG, DMI, or G:F (P ≥ 0.43). The main effect of MA reduced DMI by 1.9 % (P = 0.01), but did not appreciably influence d 28 BW, ADG, or G:F (P ≥ 0.42). MA may decrease DMI while maintaining similar BW gain and efficiency compared with non-supplemented calves.
15 Industry Perspective on the Value and Challenges of Amino Acid Feeding in Ruminants
Authors: Wertz-Lutz Aimee 
Published: October 2023

Abstract
The focus of this presentation is to provide a perspective on the value and challenges to meeting the amino acid needs of ruminant livestock based on experiences in the feed manufacturing and ruminant feeding industries. Monogastric nutritionists have demonstrated extensively the value of having an ideal amino acid profile from the point of growth, efficiency, and environmental stewardship. For the ruminant animal, the challenges of protein fractionation, deamination and re-synthesis of amino acids in the rumen create greater complexity both for research advancement as well as practical application to delivery of amino acid technology. In this presentation, amino acid supplies, protein synthesis, the impact of overlaid growth-promoting technologies, and return relative to investment of amino acid-feeding technology will be discussed. In addition to discussing the biological and economic aspects of amino acid feeding, thoughts on the means of delivering amino acid technology within the constraints of feed manufacturing and feeding practices common to ruminant livestock will be discussed. As genetics for improved lean growth in cattle continue to evolve, amino acid nutrition should be at the forefront of investigation of nutritional technologies which allow the improvement in genetic potential to be fully expressed. In addition to the potential value that amino acid feeding brings to ruminant livestock growth and efficiency, it also stands to merit environmental stewardship within this industry.
14 Predicting Performance Responses of Growing Cattle to Amino Acid Supplementation
Authors: Titgemeyer Evan C 
Published: October 2023

Abstract
Amino acid utilization by cattle can be studied by: 1) assessing amino acid requirements with foundational research and using the resultant information to predict animal performance, or 2) evaluating changes in animal performance in response to changes in amino acid supply and subsequently using those measures to predict amino acid requirements. Neither approach has yielded definitive results, and our ability to predict responses of cattle to amino acid supplementation is still quite limited after many years of research. Most supplementation studies have focused on methionine and lysine, amino acids for which ruminally protected products are commercially available. Most finishing cattle fed diets typical of the U.S. feedlot industry are not responsive to methionine or lysine supplementation, although little research is available for cattle fed beta-agonists. In some cases, growing cattle fed corn-based diets have demonstrated performance responses to lysine supplementation. Growing cattle fed forage-based diets, particularly those based on grass silages, appear responsive to supplemental amino acids. Numerous studies with Holstein steers (150 to 250 kg) maintained in a research model to make amino acids the most limiting nutrient have demonstrated linear increases in nitrogen retention, followed by a plateau, when limiting amino acids were supplemented. From those studies, maintenance requirements for amino acids appear to be small, and efficiencies of amino acid utilization for growth are less than predicted by NASEM (2016). Some factors that would be expected to increase the likelihood that amino acids are the most limiting nutrient include: decreased body weight, greater mature body weight, environments that minimize maintenance energy requirements, and diets that lead to redued amounts of microbial protein synthesis (energy sources such as fat and ruminally resistant starch). Despite the many unknowns associated with amino acid requirements of cattle for growth, potential exists to use amino acid supplementation to improve economics of cattle performance or reduce environmental impacts of cattle production.
13 Considerations When Rumen Protected Amino Acids are fed to Dairy Cows
Authors: Lee Chanhee 
Published: October 2023

Abstract
The modern concept of diet formulation for protein is to balance for amino acids (AA). The expectation of feeding a diet with balanced AA is better dietary N utilization, leading to decreased protein content in a diet and less N excretion. Feeding rumen protected (RP) AA can be a good option to increase some of AA that are short in supply. RP-Met and -Lys have been largely studied with early- and mid-lactation cows, and meta-analyses are available. Although studies that showed no responses to RP-AA exist, results of meta-analyses were consistent that RP-Met is effective to increase milk protein and fat yield. When RP-Met and -Lys were fed together, positive effects on milk yield and composition were also shown. If a diet adequate or slightly deficient in protein is fed especially at commercial farms, RP-His has large potential to increase production of high producing cows. Although cows have the ability to utilize digestible His efficiently for milk protein when the supply is short, studies consistently showed that additional supply of His increased milk yield and milk protein yield when His supply is insufficient. However, RP-His is not commercially available yet. Studies about transition cows with RP-AA are relatively limited, and results are variable. The inclusion of RP-Met and Lys in prepartum and postpartum diets were determined assuming that the requirements of AA are the same as early- or mid-lactating cows. In the transition cow studies, if positive production effects (e.g., milk and milk protein yield) were observed, DMI was often increased with RP-AA. If DMI was not affected, then production was not affected by RP-AA or milk fat yield was sometimes increased. The inconsistent results likely indicate potential differences in AA requirements between transition cows and early lactation cows. Because of the negative energy and protein balance postpartum, studies showed positive production responses consistently to increased dietary protein concentration. One study compared production responses between a postpartum diet with increased protein without considering AA profile and diet with increased protein with considering AA profile (casein AA). No difference in milk yield and composition was found, suggesting that the quantity of protein supply is more important than quality, or digestible AA mimicking casein AA is not ideal for transition cows. There are key components to consider when RP-AA are fed to cows to potentially increase responses. Because utilization efficiency of AA for protein synthesis decreases as the supply increases, excessive supply of AA should be avoided. To adequately supply certain AA via RP-AA, knowing accurate bioavailability of RP-AA is essential. However, recent studies questioned in vitro and in situ methods about its accuracy. Development of a gold standard in vivo method to calibrate in vitro or in situ methods is necessary.