bluuebunny/crossref_metadata_2025 huggingface dataset:
156 Effects of Standardized Ileal Digestible Lysine Level on Growth Performance in 35 to 80 Kg DNA Finishing Pigs
Authors: Royall Rafe Q , Goodband Robert D , Tokach Mike D , DeRouchey Joel M , Gebhardt Jordan T , Woodworth Jason C
Published: April 2022

Two studies were conducted to estimate the SID Lys requirement for growth and feed efficiency of 35-80-kg DNA finishing pigs. In Exp. 1, 608 pigs (600 × 241, DNA; initially 36.3±0.91kg) were used to estimate the SID Lys requirement from 35-55-kg. In Exp. 2, 700 pigs (DNA 600×241; initial BW of 53.2±0.86kg) were used to estimate the SID Lys requirement form 50-80-kg. Pens of pigs were blocked by BW and randomly allotted to 1 of 6 dietary treatments with 7-10 pigs/pen in a randomized complete block design with 12 replications per treatment. Diets were corn-soybean meal-based and SID Lys increased by increasing soybean meal and feed-grade amino acids while maintaining minimum ratios for other amino acids. Increasing SID Lys increased (linear, P < 0.05) ADG in both studies. From 50-80-kg, ADFI decreased, then increased (quadratic, P = 0.004) with increasing SID Lys. Feed efficiency improved, while Lys intake/d, and Lys intake/kg of gain increased (linear, P < 0.05, 35-55-kg; quadratic, P < 0.05, 50-80-kg) with increasing SID Lys. At current ingredient and pig prices, there were no statistical differences in income over feed cost (IOFC) from 35-55 kg. From 50-80-kg, increasing SID Lys increased (linear, P < 0.001) IOFC. Linear models resulted in the best fit for ADG, G:F and IOFC from 35-55-kg, with optimum performance at 1.20% SID Lys or greater. A quadratic polynomial model predicted a requirement of 0.97% SID Lys for optimum G:F from 50-80-kg. Meanwhile, a broken-line linear model predicted optimal IOFC at 0.76% SID Lys from 50-80-kg. In summary, these results suggest that the optimal SID Lys level for 35-55-kg DNA finishing pigs is at least 1.20%. The optimal SID Lys level for 50-80-kg DNA finishing pigs depends on the response criteria, with growth performance optimized at or above 0.97% SID Lys and IOFC maximized at 0.76% SID Lys.
157 Effects of Standardized Ileal Digestible Lysine Level on Growth Performance in 75 to 130 Kg DNA Finishing Pigs
Authors: Royall Rafe Q , Goodband Robert D , Tokach Mike D , DeRouchey Joel M , Gebhardt Jordan T , Woodworth Jason C
Published: April 2022

Two studies were conducted to estimate the SID Lys requirement for growth and feed efficiency of 70-130-kg DNA finishing pigs. In Exp. 1, 616 pigs (600×241, DNA; initially 76.4±1.25 kg) were used from 70-100-kg and in Exp. 2, 679 pigs (600×241, DNA; initially 103.8±1.32 kg) were used from 100-130 kg. Pens of pigs were blocked by BW and randomly allotted to dietary treatments with 8-10 pigs/pen in a randomized complete block design. Diets were corn-soybean meal based and SID Lys increased by increasing soybean meal and feed-grade amino acids while maintaining minimum ratios for other amino acids. From 70-100 kg, ADG, G:F, Lys intake/d, and Lys intake/kg of gain all increased, (linear, P < 0.05) with increasing SID Lys. From 100-130 kg, ADG, Lys intake/d, and Lys intake/kg of gain increased (linear, P < 0.05) with increasing SID Lys, while G:F increased (quadratic, P = 0.032). At current ingredient and pig prices, there were no statistical differences in income over feed cost (IOFC) from 70-100 kg. From 100-130 kg, increasing SID Lys increased (quadratic, P = 0.001) IOFC. A broken-line linear (BLL) model predicted optimal ADG at 0.83% SID Lys, while a quadratic polynomial (QP) model predicted a requirement of 0.90% for G:F from 75-100 kg. A QP model predicted maximum IOFC at 0.78% SID Lys from 75-100 kg. From 100-130 kg, BLL models predicted optimal ADG and G:F at 0.64 and 0.59% SID Lys, respectively. A QP model predicted maximum IOFC at 0.64% SID Lys. In summary, these results suggest the optimal SID Lys level for 75-100 kg DNA finishing pigs for growth performance is between 0.83 and 0.90% SID Lys, and 0.78% SID Lys for maximum IOFC. The optimal SID Lys level in 100-130 kg DNA finishing pigs depends upon the response criteria, with growth performance and IOFC maximized between 0.59 and 0.64% SID Lys.
161 The Impact of Sex, Birth Weight, and Nutrient Density on the Growth Restriction and Compensatory Gain of Finishing Hogs After a Three- or Six-Week Period of Nutrient Restriction
Authors: Hagen Chloe S , Greiner Laura L , Humphrey Dalton C , Krahn Gregory , Spencer Joel
Published: April 2022

The objective of this analysis was to investigate the effect of pig phenotype on growth restriction and compensatory ability after receiving a nutrient-deficient (97% corn) diet for 3 or 6 weeks. Sixteen hundred and sixty mixed-sex pigs (DNA Genetics, Columbus, NE) were tagged with radio frequency identification tags (LeeO, Prairie Systems, Spencer, IA) at birth with litter information and body weight (BW) measured at birth, weaning, and the end of the nursery phase. At a starting BW of 73.5 ± 2.2 kg, pigs were blocked by BW to 140 pens and assigned to a 2:3:1 factorial. The seven treatments were comprised of a combination of 2 restriction lengths (3 weeks vs. 6 weeks) and 3 lysine inclusion levels at re-alimentation (Lys:ME of 100%, 110%, or 120% of the genetic margin over feed curve), and a control that remained nutrient unrestricted. Individual BW was measured on trial d 0, 21, 41, and market to calculate individual average daily gain (ADG) for each phase. Percent change in ADG between each phase was calculated using the previous ADG of each pig. Observational analysis was conducted in SAS 9.4 (Cary, NC) with pig as the observational unit. When fed the restrictive diet, gilts had a greater reduction in ADG (P < 0.01) than barrows (64 vs. 59 % decrease in ADG from previous period). Furthermore, pigs with lower birth weight, thus lighter starting trial weight, had a greater decrease (P < 0.01) in growth in response to nutrient restriction. Validating the biological requirements of finishing pigs, animals with a greater lysine requirement, gilts, and lighter weight pigs had a more severe reduction in growth than those with a decreased lysine requirement.
175 Evaluation of Electrical Impedance Spectroscopy to Determine Swine Herd Reproductive Status Using the Accuracy of Ultrasound and Hormonal Assays as Diagnostic Tools
Authors: Vinas Raquel Fernandez , Arend Lidia S , Silva Gustavo , Lower Aaron , Connor Joseph F , Furugen Cesar de Andrade Andre F , Kaustubh Bhalerao , Knox Robert V
Published: April 2022

Management of fertility determines production efficiency. Important fertility measures include detection of estrus (DE), early pregnancy confirmation (EPC), and day of farrowing (DF) with few tools available to diagnose or predict. Electrical impedance spectroscopy (EIS) uses an array of frequencies to determine tissue resistance in relation to change. Our objective was to determine if EIS can predict reproductive events. The study was conducted for DE using weaned sows (n = 135) scanned on D 1-7; EPC used inseminated sows (n = 135) scanned on D 18-20; DF used pregnant sows on D 113 to farrowing. The EIS device used a four-electrode transducer with an internal processor and was connected to a mobile device for operation, reading, and data storage. The device obtained impedance (Ω) and phase data for analysis from 42 frequencies between 1,000 and 29,000 Hz. The device was disinfected and inserted into the vagina with scans requiring ~20 s. Data were uploaded to a server and stored on a website for labeling and analysis. Accuracy was based on DE, EPC on D 30, and DF. Data were analyzed in RStudio using GLM with logistic regression to generate log-likelihood estimates for r2 and associated P values. Predictive models for DE, EPC, and DF included EIS, day of measure, and parity. For DE, prediction was greatest 1 d before and on estrus (r2 = 0.98), moderate 3 to 4 d before estrus (r2 = 0.59), and not predictive ≥4 d before estrus. For EPC, the measures for EIS were not predictive due to limited numbers of non-pregnant sows (3%). For DF, prediction for 1 d before was (r2 = 0.98), for 2 d (r2 = 0.89), and for 3 d (r2 = 0.51). Our preliminary results suggest impedance of the sow vagina can be used to predict events, but more data for failures and days will be needed to improve prediction.
188 Prospects of Swine Production in the Context of Climate Change
Authors: Rauw Wendy M
Published: April 2022

Pig production systems provide multiple benefits to humans. However, the global increase in meat consumption has profound consequences for our earth, including the use of finite natural resources (land, water, and energy), pollution of watercourses, loss of biodiversity, and contribution to climate change. Pig production practices contribute to climate change through greenhouse gas production associated with manure management and feed production. Novel feed resources that provide a wide range of ecosystem services in mixed cropping, crop rotation, circular agriculture, or circular economy can improve sustainability of pig production practices. Vice versa, global warming has profound consequences for pig production through the negative consequences of heat stress on production efficiency, growth rates, and increased health care costs. Research suggests that pigs that are better adapted to heat stress are better able to maintain growth when intake becomes restricted. These appear to be animals with lower growth rates during thermoneutral conditions. During heat stress, pigs become more feed efficient; however, reduced growth rates result in decreased slaughter weights or increased days on farm, thus reducing production efficiency. Furthermore, heat stress is found to alter the growth trajectory (maturation rate and mature body weight), tissue accretion rates, and carcass composition, and negatively impacts animal health and welfare. The impact of heat stress can be mediated through control strategies of the thermal environment using precision livestock techniques. In addition, because response to heat stress shows variation, these results emphasize the necessity to review breed choice and genetic selection objectives for improved heat tolerance to climate change. Pigs of interest as selection candidates may be those that are able to maintain high growth rates under heat stress, and these may not be the genetics with highest growth potential under environmentally neutral or favorable conditions.
201 Impact of Steam-Flaked Rye Fed in Combination with Steam-Flaked Corn on Performance and Carcass Characteristics of Yearling Steers
Authors: Wagner Samantha K , Erickson Galen E , Troyer Braden , McPhillips Levi J , Brattain Rebecca S
Published: April 2022

The objective of this study was to evaluate the effects of increasing inclusions of steam-flaked hybrid rye (SFR) replacing steam-flaked corn (SFC) in finishing diets on cattle performance and carcass quality. Rye was grown as one hybrid and processed at a single feedyard in eastern Nebraska (14.5 kg/bu for SFR, 2.55 ± 0.94 mm average particle size). Crossbred yearling steers (n = 400, initial BW = 400 ± 24 kg) were used in a randomized block design (blocked by BW and source), stratified, and assigned randomly to pen (n = 40), and pen assigned randomly to treatment. Four treatments were evaluated, a control with no SFR (0%), and 3 inclusions of SFR where the rye replaced 25%, 50%, or 100% of the SFC in the diet (0%, 15.4%, 30.8%, and 60% SFR respectively). A linear decrease in carcass weight, dry matter intake, average daily gain (ADG), and gain:feed (G:F) was observed as SFR inclusion increased in the diet (P ≤ 0.01). Intake decreased by 1.2 kg/d as SFR increased from 0 to 100% of the grain inclusion. A 14.5% reduction in ADG and 6.2% decrease in G:F was observed as SFR replaced SFC, which lead to decreases in calculated NEm and NEg dietary energy values based on performance. Longissimus muscle area (P ≤ 0.01), 12th rib fat (P ≤ 0.03), and marbling score (P ≤ 0.01) decreased linearly with increasing rye inclusion. Calculated yield grade did not differ among treatments (P = 0.16). These data suggest no evidence of an associative effect for blending SFR with SFC. Based on dietary energy calculated using performance, SFR has approximately 92% the energy value of steam-flaked corn. Feeding flaked rye grain decreased intake, gain and feed efficiency suggesting SFR contains less energy than steam-flaked corn.
195 Interaction of Urea with Frequency and Amount of Distillers Grains Supplementation for Growing Steers on a High Forage Diet
Authors: Linder Haley , Sebade Josh , Drewnoski Mary E , MacDonald Jim C
Published: April 2022

Two studies determined the interactions of urea inclusion to a dried distillers grains plus solubles (DDGS; 29.4% CP, 5.48% ether extract) supplement fed at 2 amounts and 2 frequencies to steers consuming ad libitum Smooth Bromegrass hay (6.8% CP). In Exp. 1, 120 (247 kg; SD = 20) steers were fed individually for 84 d with treatments arranged in a 2 x 2 x 2 factorial. Supplement was fed every day (D) or 3x/week (ALT), amount of supplement fed was 6.36 kg/week (LO) or 12.73 kg/week (HI) and contained either no urea (-U) or 1.3% urea (+U). In Exp. 2, 8 ruminally cannulated steers (310 kg; SD = 25) were used in an 8 x 6 row-column design with 8 steers and 6, 14-d periods. Treatment design was the same as Exp. 1, except that supplement was fed at a rate of 0.4% (LO) or 0.8% of BW (HI) and supplement was fed either daily (D) or every other day (ALT). In Exp. 1, ADG was 0.30 kg/d greater, and hay DMI was reduced by 0.39 kg/d for HI vs. LO (P < 0.01). Hay DMI was reduced by 0.54 kg/d for ALT vs. D (P < 0.01). In Exp. 2, hay DMI was also reduced HI vs. LO (P < 0.01). Rumen pH was decreased on the day of feeding for steers on ALT (P < 0.01) and was reduced for steers fed HI vs. LO. A reduction in in situ NDF disappearance was observed on the day ALT received supplement between HI and LO (P < 0.01). However, there was no difference between NDF digestibility between D and ALT (P > 0.05). Urea had no effect on digestion or ADG, suggesting RDP was not deficient. Dried distillers grains can be supplemented infrequently without reducing animal performance.
197 Effects of Sorghum Grain as a Replacement for Corn on Lamb Growth Performance, Economics, and Total Tract Digestibility
Authors: Scotten Skyler S , Buessing Zachary T , Zumbaugh Charles A , Jones Cassandra K
Published: April 2022

The objective of this experiment was to evaluate the effect of substituting grain sorghum in place of corn in growing lamb diets on their growth performance, nutrient digestibility, and economics. A total of 72 Rambouillet wethers (33.9 ± 3.10 kg) were utilized in a completely randomized design and allotted to 1 of 4 dietary treatments. Each pen contained 3 wethers , with 6 replicate pens per treatment. Dietary treatments included: 1) Control (basal diet with 0% inclusion of sorghum); 2) Sorg10(basal diet with 10% of corn substituted for sorghum); 3) Sorg20(basal diet with 20% of corn substituted for sorghum); and 4) Sorg30(basal diet with 30% of corn substituted for sorghum). Feed additions were recorded, and lamb and feeder weights were recorded weekly to determine average daily gain (ADG), average daily feed intake (ADFI) and gain to feed (G:F). Data were analyzed using the GLIMMIX procedure of SAS v9.4 (SAS Inst., Cary, NC) with pen as the experimental unit. There was no evidence that sorghum inclusion level affected ADG (P = 0.88), ADFI (P = 0.19), or G:F (P = 0.92). Due to the high price of sorghum, lambs fedSorg30 had greater (P < 0.05) total feed cost per lamb, but there was no evidence of differences in cost/kg of gain (P = 0.63) or value of gain (P = 0.88). At the conclusion of the growth experiment, 24 of the initial 72 lambs (46.1 ± 3.9 kg) were fed an additional 14 d to evaluate total-tract digestibility of the 4 diets. Organic matter digestibility linearly increased (P < 0.05) with sorghum inclusion. In conclusion, there was no evidence that feedings up to 30% sorghum in place of corn substantially affected lamb growth. Future research is necessary to investigate the efficiency of these diets.
196 Interaction of Corn Processing Method and Sweet Bran Inclusion in Finishing Diets
Authors: Sjostrand Rebecca , Troyer Braden , McPhillips Levi J , Youngers Maggie , Stock Rick , MacDonald Jim C , Erickson Galen E
Published: April 2022

Two studies were conducted to evaluate the effect of corn processing method and wet corn gluten feed [Sweet Bran (SB); Cargill] concentration on feedlot performance and nutrient digestion. Treatments were arranged as a 2 × 3 factorial, consisting of two corn processing methods [steam-flaked corn (SFC) or a high-moisture corn (HMC) dry-rolled corn (DRC) blend] and 3 inclusions of SB (0, 20, or 40% of diet dry matter). In Exp. 1, yearling steers (n = 480; initial body weight = 363 ± 15.1 kg) were utilized in a randomized block design. A linear interaction was observed for average daily gain (ADG), feed efficiency (G:F), and hot carcass weight (HCW; P < 0.01). At 0% SB, cattle fed SFC had greater ADG and HCW than cattle fed HMC/DRC. As SB increased, ADG and HCW increased at a greater rate for HMC/DRC cattle than SFC cattle resulting in similar ADG and HCW at 40% SB. At 0% SB, cattle fed SFC were 12.4% more efficient than cattle fed HMC/DRC, but as SB increased the improvement declined to 5.3%. In Exp. 2, 6 fistulated steers were utilized in a 6 × 6 Latin square design. Cattle fed SFC had greater starch digestibility (P < 0.01); HMC/DRC cattle tended to have greater neutral detergent fiber digestibility (P = 0.08). As SB increased, cattle fed SFC and HMC/DRC had greater dry matter intakes (DMI) in both studies (P > 0.01), and as a result, greater digestible energy (DE) intakes (P > 0.01). Increased DE intake improved ADG and G:F when feeding SB in Exp. 1 as explained by greater DMI and increased DE observed in Exp. 2. Feeding up to 40% SB in SFC diets doesn't affect feedlot performance and feeding SB in HMC/DRC based finishing diets linearly improves performance at inclusions up to 40%.
193 Impact of Corn Silage Moisture And/Or Kernel Processing at Harvest on Finishing Steer Growth Performance, Efficiency of Dietary Net Energy Utilization and Carcass Traits
Authors: Hamilton Thomas G , Rusche Warren C , Walker Julie , Smith Zachary K
Published: April 2022

Steers (n = 192; initial shrunk BW = 446 ± 28.3 kgs) were used in a 112-d finishing experiment Treatments were arranged in a 2 x 2 factorial (24 pens total; 8 steers/pen) to evaluate corn silage moisture [1/2 to 2/3 milk line (ML) and black line (BL)] and kernel processing at harvest on finishing steer growth performance and carcass traits. Steers were blocked by batch fraction (n = 6) and pen as the experimental unit. The model included the effects of harvest time, processing, and their interaction. Block was included as a random factor. No harvest time x KP interaction was detected (P ≥ 0.28) for any growth performance related parameters. No Harvest time × KP interaction was detected (P ≥ 0.26) for any parameters related to the efficiency of dietary NE utilization. Comparative NEm for harvest time indicates that delayed harvest enhanced corn silage NEm by 6% and KP decreased apparent NEm value of corn silage by 9% compared with current feeding standards. No harvest time × KP interaction (P ≥ 0.08) was detected for any carcass traits except the distribution of USDA Prime carcasses (P = 0.04). Steers from ML/KP- had the fewer (P = 0.05) USDA Prime carcasses compared with ML/KP+, BL/KP-, and BL/KP+. Harvest time (P ≥ 0.07) and KP (P ≥ 0.07) had no appreciable influence on any carcass trait parameters. These data indicate that corn silage harvest can be delayed without detriment to growth performance and kernel processing does not enhance the apparent feeding value of corn silage when corn silage is fed as the sole roughage component of a feedlot finishing diet (i.e., 20% inclusion DM basis).
210 Evaluation of the Effects of Wood-Sourced Biochar as a Feedlot Pen Surface Amendment on Manure Nutrient Capture
Authors: Sperber Jessica L , Troyer Braden , Norman Mitch , McPhillips Levi J , Watson Andrea K , Erickson Galen E
Published: April 2022

Two nutrient mass balance experiments were conducted during winter and summer seasons to evaluate the effects of spreading unprocessed Eastern red cedar biochar onto the feedlot pen surface on manure nutrient capture and cattle performance. A 186-d feedlot finishing experiment was conducted from December to June (WINTER) and a subsequent 153-d feedlot finishing experiment was conducted from June to November (SUMMER). The WINTER experiment evaluated 3 treatments, including biochar spread to the pen surface during the feeding period (24 kg/steer; 10 steers per pen), hydrated lime spread to pen surface at end of feeding period (31 kg/steer), and control (no treatment applied). The SUMMER experiment evaluated biochar treatment (31 kg/steer; 8 steers per pen) against control. There was no difference in N and P intake, retention, or excretion (P ≥ 0.38) between WINTER treatments. Steer performance (P ≥ 0.10) and carcass characteristics (P ≥ 0.50) were not impacted by pen treatment in WINTER. Nitrogen and P intake and excretion (P ≥ 0.35) were similar between treatments in SUMMER and retention of N and P was significantly greater for the biochar treatment (P = 0.04) due to greater ADG. There was no difference in DMI (P = 0.48) in SUMMER, steers on biochar pen treatment had heavier HCW and increased ADG (P = 0.05), resulting in improved feed efficiency (P = 0.08). In both experiments, biochar addition to the pen surface tended (P = 0.07) to increase manure N as a percent of manure DM, but this increase in N concentration did not impact kg of N removed from the feedlot pens (P ≥ 0.15) or N losses (P ≥ 0.68). The addition of unprocessed red cedar biochar to the feedlot pen surface did not improve manure nutrient capture of N or P and did not reduce N losses associated with soil-based feedlot pens.
204 Effect of Breed Type on Maintenance Energy Requirements and Partial Efficiency of Metabolizable Energy use in Growing/Finishing Cattle
Authors: Lancaster Phillip A
Published: April 2022

Consensus is lacking on whether genetic differences exist in the partial efficiency of metabolizable energy use. Genetic differences in net energy required for maintenance have been reported, but independence of body composition was not addressed. The objective was to determine contribution of genetic differences to net energy for maintenance and partial efficiency of metabolizable energy use in growing/finishing cattle independent of body composition. A literature search was performed to compile data (31 studies, 214 treatment means) on metabolizable energy intake (MEI) and composition of empty body gain in growing steers. Dietary roughage concentration and breed were recorded. Data analyses were performed using R statistical package for linear models. For analysis, breeds were categorized as British (Angus, Hereford, English crosses), Continental (Charolais, Simmental, Limousin), Crossbred (British x Continental breeds), Dairy (Holstein), Double-muscled (Belgian Blue, Piedmontese), and Heat-tolerant (Boran, Brahman, Tuli). The base regression model of log10 of heat production on MEI had R2 of 0.8830 and intercept of 1.912 (81.6 kcal/kg.75). Inclusion of breed type significantly (P < 0.0001) affected the intercept and slope of the model. Dietary roughage concentration, empty body fat percentage, and energy retained as protein or fat, but not empty body protein percentage, explained a significant amount of variation (P < 0.01) resulting in R2 of 0.9851. In this final model, Heat-tolerant breeds had 12% lesser (P < 0.05) net energy for maintenance than British with Continental, Crossbred, and Double-muscle being intermediate, and Dairy had 27% greater (P < 0.05) net energy for maintenance than other breed types. Also, breed type by MEI interaction was significant (P < 0.0001) with Dairy having lesser (P < 0.05) slope than other breeds, and Heat-tolerant having greater slope than British. In conclusion, breed type affected net energy for maintenance and partial efficiency of metabolizable energy use after accounting for body composition and dietary roughage concentration suggesting that genetic variation exists.
212 The Effects of Propionibacterium Acidipropionici P169 in an in Vitro Ruminal Acidosis Model
Authors: McNelis Jenna , Gaffney Bree , Linder Haley , Buessing Zachary , Earing Jennifer E , Shike Daniel W , Bernardeau Marion , McCann Joshua C
Published: April 2022

The objective was to evaluate the effect of Propionibacterium acidipropionici P169 (PA) concentration on fermentation characteristics in a ruminal acidosis in vitro model. Ruminal acidosis is a common metabolic disorder in feedlot cattle characterized by a low rumen pH. The experiment included 5 treatments in a completely randomized design. Treatments included a negative control (NCON), 5 × 105 colony forming units (CFU) PA (PA5), 5 × 106 CFU PA (PA6), 5 × 107 CFU PA (PA7), and a positive control with greater forage inclusion (PCON). Flasks for NCON, PA5, PA6, and PA7 contained 8.75 g of substrate (70% corn, 15% DDG, 15% silage) while substrate for PCON flasks contain additional silage (40% corn, 15% DDG, 45% silage). Treatments were run in duplicate and the experiment was replicated 3 times. All flasks included 175 mL of inoculum (4 McDougall’s buffer:1 rumen fluid). Flasks were incubated at 39◦C for 36 hours and sample aliquots were collected every 4 hours. The MIXED procedure of SAS 9.4 was used for statistical analysis with a repeated measures analysis. A treatment by hour interaction (P < 0.01) was observed for pH; at hour 8, PCON was the least and PA5 was the greatest. From 20 to 36 h, PCON had the greatest pH. There was no treatment by hour interaction (P = 0.99) observed for redox potential. However, treatment affected (P < 0.01) redox potential with PCON being greater than PA6, PA7, and NCON, with PA5 being intermediate. In vitro dry matter disappearance (IVDMD) tended (P = 0.09) to be affected by treatment; PA5, PA6, and PA7 were greater than PCON. In conclusion, Propionibacterium acidipropionici P169 concentrations affected IVDMD, pH, and redox in a ruminal acidosis in vitro model.
213 Assessment of Equations Relating Shrunk, Empty Body, and Carcass Weight in Growing/Finishing Cattle
Authors: Lancaster Phillip A
Published: April 2022

Existing equations to estimate empty body weight of cattle from live or carcass weight were developed over 40 years ago using different cattle genetics. The objective of this analysis was to evaluate existing equations using cattle genetics from that time to today. A literature search was performed to identify experiments measuring shrunk body weight (SBW), empty body weight (EBW), and carcass weight (HCW) resulting in 269 treatment means from 32 experiments since 1976. Two equations were used to compute EBW from SBW: 1) NASEM (2016) and 2) Gil et al. (1970: 10.2527/jas1970.313459x). Eight equations were used to compute HCW from EBW: 1) Lofgreen et al. (1962; 10.2527/jas1962.21120x), 2) Garrett and Hinman (1969; 10.2527/jas1969.2811), 3) Holzer and Levy Eq. 1 (1969; Isr. J. Agric. Res. 19:195), 4) Holzer and Levy Eq. 2, 5) Gil et al. (1970: 10.2527/jas1970.313459x), 6) Alhassan et al. (1975; 10.4141/cjas75-045), 7) Ferrell et al. (1976; 10.2527/jas1976.4251158x), and 8) Fox et al. (1976; 10.2527/jas1976.433566x). Mean (SD) shrunk, empty, and carcass weight were 359 (145), 322 (134), and 210 (92) kg, respectively, and were strongly correlated (> 0.990). For all equations, simultaneous testing of intercept equal to zero and slope equal to 1 indicated that the intercept and slope for EBW and HCW were different than zero and one, respectively. For EBW, the CCC was high (> 0.95) for all equations and mean bias was -1.69 and -4.75% for Eq. 1 and 2, respectively, but became a greater underprediction in more recent publication years for Eq. 1. For HCW, CCC was high (> 0.95) and similar for all equations, but Eq. 7 had the MB nearest to zero (-0.10%) and Eq. 4 furthest from zero (10.74%). For Eq. 2, 4, 6, and 8 there was greater overprediction in more recent publication years. In conclusion, existing equations provide similar precision, but differ in accuracy to predict weight with some equations significantly influenced by year of publication.
215 Assessment of Equations Relating Carcass Chemical Components in Growing/Finishing Cattle
Authors: Lancaster Phillip A
Published: April 2022

Existing equations to estimate chemical composition of cattle were developed over 40 years ago using different cattle genetics. The objective of this analysis was to evaluate existing equations using cattle genetics from then to today. A literature search was performed to identify experiments measuring carcass chemical composition by proximate analysis resulting in 106 treatment means from 10 experiments since 1976. Four sets of equations were used to compute carcass chemical composition assuming carcass water was known: 1) Garrett and Hinman (1969; 10.2527/jas1969.2811), 2) Gil et al. (1970: 10.2527/jas1970.313459x), 3) Preston et al. (1974; 10.2527/jas1974.38147x), and 4) Ferrell et al. (1976; 10.2527/jas1976.4251158x). Mean (SD) carcass water, fat and protein were 57.19 (7.20), 20.49 (8.87), and 17.80 (2.90) % of HCW, respectively. For all equations, simultaneous testing of intercept equal to zero and slope equal to 1 indicated that the intercept and slope for fat, protein, ash and energy were different than zero and one, respectively. The concordance correlation coefficient (CCC) was high (> 0.85) for fat and energy, but low (< 0.40) for protein and ash for all equations. Mean bias for fat, protein, ash, and energy ranged from -8.84 to -0.09%, 2.02 to 8.68%, -13.35 to 12.35%, and -3.50 to 0.79%, respectively, with Eq. 1 having the MB closest to zero for ash, Eq. 3 having the MB closest to zero for fat and protein, and Eq. 4 having the MB closest to zero for energy. Publication year as a continuous variable was a significant (P < 0.05) predictor of the difference between observed and predicted values for all components using all equations. Fat and energy had greater overprediction whereas, protein and ash had greater underprediction in more recent publications. In conclusion, existing equations provide similar precision, but differ in accuracy to predict carcass chemical composition. The trend for greater bias in more recent publication years indicates the need to reevaluate relationships among carcass chemical components using current cattle genetics.
214 Assessment of Equations Relating Empty Body Chemical Components in Growing/Finishing Cattle
Authors: Lancaster Phillip A
Published: April 2022

Existing equations to estimate empty body chemical composition were developed over 40 years ago using different cattle genetics. The objective of this analysis was to evaluate existing equations using cattle genetics from then to today. A literature search was performed to identify experiments measuring empty body chemical composition by proximate analysis resulting in 198 treatment means from 25 experiments since 1976. Three sets of equations were used to compute empty body chemical composition assuming empty body water was known: 1) Garrett and Hinman (1969; 10.2527/jas1969.2811), 2) Gil et al. (1970: 10.2527/jas1970.313459x), and 3) Ferrell et al. (1976; 10.2527/jas1976.4251158x). Mean (SD) empty body water, fat and protein were 59.91 (6.32), 17.58 (7.89), and 18.24 (2.02) % of EBW, respectively. For all equations, simultaneous testing of intercept equal to zero and slope equal to 1 indicated that the intercept and slope for fat, protein, ash and energy were different than zero and one, respectively. The concordance correlation coefficient (CCC) was high (> 0.85) for fat and energy, but low (< 0.50) for protein and ash for all equations. Mean bias for fat, protein, ash, and energy ranged from -19.58 to -3.50%, 1.62 to 15.84%, -2.22 to 14.15%, and -6.09 to -0.63%, respectively, with Eq. 1 having the MB closest to 0 for protein, and Eq. 3 having the MB closest to 0 for fat, ash, and energy. Publication year as a continuous variable was a significant predictor of the difference between observed and predicted values for all components. Fat and energy had greater overpredicted whereas, protein and ash had greater underprediction in more recent publications. In conclusion, existing equations provide similar precision, but differ in accuracy to predict empty body chemical composition. The trend for greater bias in more recent publication years indicates the need to reevaluate relationships among empty body chemical components using current cattle genetics.
218 Evaluation of a Direct-Fed Microbial Product (DIRECTä) on Fecal Shedding of Shiga Toxin-Producing Escherichia Coli in Finishing Cattle in a Commercial Feedlot
Authors: Amachawadi Raghavendra G , Nagaraja T G , Goodall S Richard
Published: April 2022

Shiga toxin-producing Escherichia coli (STEC), particularly seven serogroups O26, O45, O103, O111, O121, O145, and O157, are major food borne pathogens. Cattle are a major reservoir in which STEC colonize the hindgut and are shed in the feces. Most cattle shed the organisms at low concentrations and a small proportion, called super shedders, shed at high concentrations (≥ 104 per g). Our objective was to evaluate the effect of a commercial DFM product containing lactic acid and propionic acid bacteria (Microbios Direct LA = 1 x 107 CFU and Direct PRO = 5 x 107 CFU/animal/d). The study was conducted in a commercial feedlot and a total of 16 pens were randomly assigned to control or DFM-treated group. Twenty pen-floor fecal samples were collected from each pen on 3 occasions, at 2-week intervals, approximately 100 d after DFM supplementation. Fecal samples were subjected to culture and PCR methods to quantify E. coli O157 and determine prevalence of the 6 non-O157 serogroups and 4 major virulence genes, Shiga toxins 1 and 2, intimin (an adhesin) and enterohemolysin. Data were analyzed using PROC MIXED procedure with pen as the experimental unit. The treatment means comparison within sampling day were carried out for variables that showed significant treatment and sampling day interaction. The overall fecal shedding of E. coli O157 was higher in the control group than in the DFM group, and the difference was significant in the third sampling day. Among the top-6 STEC, O26 and O103 were the dominant serogroups. The prevalence of the 4 major STEC virulence genes and the non-O157 STEC serogroups were not affected by inclusion of the DFM in the diet. In conclusion, DFM supplementation appeared to reduce fecal shedding E. coli O157, but prevalence of the 6 non-O157 serogroups and virulence genes were not affected.
220 Evaluation of Forage Quality of Crested Wheat Grass
Authors: Adair Kelton , Watson Andrea K , MacDonald Jim C , Wilke Karla
Published: April 2022

An experiment evaluated forage value of crested wheat grass (CWG) harvested from Western Nebraska over a 2-year period (2019-2020). Two large pastures, comprised of 95% CWG, were divided into 13 paddocks (34.4 ha, 3 paddocks and 42.5 ha, 10 paddocks). Within each pasture, 2 paddocks were assigned at random for sampling. Forage samples were collected twice each month from 2 random locations within assigned paddocks by hand clipping forage within a 0.25m2 quadrant at ground level. For each year, samples were composited by pasture and month. Samples from 2019 (n = 10) were harvested in May, June, July, August, and September while 2020 samples (n = 8) were harvested in May, June, July, and August due to drought conditions. Local precipitation from May 1st to September 30th was 552.7 mm for 2019 and 150.1 mm for 2020 with a 10-yr average precipitation of 350.0 mm. Cattle were stocked at 4.2 hectares per steer using a rotational grazing system. Samples were freeze dried and ground to a 1mm particle size to evaluate in-vitro dry matter disappearance (IVDMD, % of DM), and in-vitro organic matter disappearance (IVOMD, % of OM). Orthogonal contrasts were used to analyze changes in forage quality over time with month and pasture as fixed effects (glimmix procedure of SAS). Forage quality quadratically decreased over the growing season in 2019 (IVDMD, P = 0.02 and IVOMD, P < 0.01). In May, 2019 CWG averaged 54.0% IVDMD and 60.4% IVOMD and decreased to 37.0% IVDMD and 43.3% IVOMD by September 30th. No significant differences in IVDMD (P = 0.57) or IVOMD (P = 0.53) between months were detected for samples collected in 2020 averaging 43.1% IVDMD and 46.8% IVOMD. When precipitation is not limiting CWG, forage quality is greatest early in the growing season and decreases as it matures.
224 Net Nutrient Conversion of Human-Edible Nutrients in the Beef Supply Chain
Authors: Lancaster Phillip A , Presley DeAnn , Fick Walt , Pendell Dustin , Ahlers Adam , Ricketts Andrew , Tang Minfeng
Published: April 2022

Beef is a good source of several vitamins and minerals but data on the net contribution to the human diet is lacking. The objective was to quantify the net nutrient contribution of the beef supply chain to Fe, Zn, Se, P, B12, B6, riboflavin, niacin, and choline in the human diet. Beef cattle production parameters for the beef supply chain were as described by Baber et al. (2018; 10.1093/tas/txy086) with the red meat and liver yield from each production segment estimated using literature values of serially harvested beef cattle. Nutrient concentration of feeds was acquired from feed composition tables in beef, swine, poultry, and equine nutrient requirement texts, and the nutrient concentration of beef and liver was based on 2018 USDA Food and Nutrient Database for Dietary Studies. Nutrient absorption values of feeds, red meat, and liver were acquired from the literature for humans or swine if human studies were unavailable. The human-edible conversion ratio was < 1.0 for all nutrients except for P and B12 when only red meat yield was considered indicating that the beef supply chain consumed more human-edible nutrients than it produced. Results were similar when liver yield was added although the ratios were closer to 1 for other nutrients. After adjusting for the absorptability of nutrients, the beef supply chain was a net contributor of niacin, P, and B12 in the human diet with or without liver. The net nutrient contribution is driven primarily by the ratio of nutrient concentration and absorbability of nutrients in beef relative to corn. In the current production scenario, the combined ratio of nutrient concentration multiplied by the ratio of absorbability must equal 15.17 or 12.45 to achieve equilibrium between nutrient consumed and produced for red meat or red meat plus liver yield, respectively. In conclusion, current beef production system is a net contributor of human-absorbable P, B12, and niacin to the human diet.
222 Awardee Talk: What we Know Now: Strategic Zinc Supplementation for Cattle Utilizing Growth Promoting Technologies
Authors: Messersmith Elizabeth M , Smerchek Dathan , Hansen Stephanie L
Published: April 2022

A 98-d study examined the effects of increasing supplemental Zn on cattle performance, plasma Zn concentrations, and nitrogen metabolism using 92 Angus-crossbred steers (424 ± 28 kg) administered growth-promoting technologies. Steers were implanted with Component TE-200 (Elanco, Greenfield, IN) on d 0 and fed 300 mg‧steer-1‧d-1 of ractopamine hydrochloride (Zoetis, Parsippany, NJ) from d 70-98. Pens were equipped with GrowSafe bunks (GrowSafe Systems Ltd., Airdrie, AB, Canada), and steer served as the experimental unit (n = 22 or 23 steers/treatment). Dietary Zn treatments included 0, 100, 150, and 180 mg Zn/kg dry matter from ZnSO4 (Zn0, Zn100, Zn150, and Zn180, respectively). Data were analyzed via the Mixed and Corr procedures of SAS. Contrast statements tested linear, quadratic, and cubic effects of Zn supplementation and Zn0 vs. Zn supplementation. Day 10 and 70 body weights and d 0-10 and 0-70 average daily gain were linearly increased with increasing Zn supplementation (P ≤ 0.05), and greater for Zn supplemented steers (P ≤ 0.03). Concurrently, d 10 and 69 plasma Zn concentrations linearly increased (P ≤ 0.03). Final body weight, dressing percentage, ribeye area, 12th rib fat, and marbling were not influenced by Zn supplementation (P ≥ 0.11). Hot carcass weight tended to be 7 kg greater for Zn supplemented steers than Zn0 (P = 0.07). Day 10 liver Mn tended to be positively correlated with d 10 liver arginase activity (r = 0.27; P = 0.07) and was positively correlated with d 10 serum urea nitrogen (r = 0.55; P < 0.0001). Neither d 79 liver arginase activity nor serum urea nitrogen were correlated with d 79 liver Mn (P ≥ 0.21). These data suggest increased supplemental Zn is beneficial to growth directly following implant administration and that implants and beta agonists differentially influence nitrogen metabolism.
228 Hind Leg Angle and Stride Length Measured by 3-D Imaging Account for Variance of Locomotion Score and Growth Performance of Cattle in Slatted Feeding Facilities
Authors: Dawson Cody , Shike Daniel W , Condotta Isabella , McCann Joshua C
Published: April 2022

The objective was to determine the variance of locomotion score (LS) and growth performance attributable to hind leg angle and stride length (SL) measured by 3-D image analysis for cattle in slatted feeding facilities. Inherent individual differences in structural conformation may be related to cattle mobility and growth performance in indoor slatted facilities. Angus × Simmental steers (n = 189; BW = 352 ± 43 kg) were blocked by initial BW and assigned to 21 pens. Pens were randomly assigned to 1 of 3 treatments (TRT): concrete slats with no matting, 15-year-old Animat Pebble matting, and new Animat Pebble matting. Steers were fed for 152 d. Individual steers videos were recorded on d 0 using an Intel RealSense depth camera and processed using MATLAB to estimate hind leg angle, SL, and body length (BL). Locomotion scores were assigned using a 0-3 scale (Zinpro Step-Up Locomotion Scoring System) throughout the finishing phase. The MIVQUE0 option of the MIXED procedure of SAS 9.4 was utilized to estimate the proportion of variance in average LS, overall ADG, and final BW. Variance of average LS was attributed to SL and SL × BL × TRT at 64% and 28%, respectively. For overall ADG, variance was attributable to SL × BL, SL × BL × TRT, and TRT at 38%, 35%, and 25%, respectively. Variables of SL, BL, SL × BL × TRT, and TRT accounted for 38%, 23%, 23%, and 15% of the variance in final BW, respectively. Hind leg angle did not account for variance in average LS, ADG, or final BW. Overall, variance of average LS, overall ADG, and final BW were primarily attributed to stride length, body length, flooring type, and their interactions. Individual animal differences in structural conformation are related to cattle mobility and growth performance in slatted indoor facilities.
259 Effects of Late Gestation Energy and Protein Restriction in Beef Cows on Offspring Growth and Carcass Characteristics
Authors: Waldon Naomi , Nickles Kirsten , Parker Anthony J , Swanson Kendall C , Relling Alejandro E
Published: April 2022

Our objective was to conduct a systematic literature review and collate data to run a meta-regression on the effect of protein and energy restriction during the last third of gestation on offspring growth and carcass characteristics. The literature search was restricted to only using data from the last third of gestation in spring calving herds such that the last trimester coincided with winter months. Additionally, the search was limited to Bos taurus beef cattle and peer reviewed research articles; review articles and proceeding abstracts/papers were excluded. The search was conducted using the Web of Science. During this process we found contradictory results. As an example, some manuscripts indicate that energy and/or protein restriction during late gestation has a negative impact on offspring growth and/or carcass characteristics; however, there are also manuscripts that report no differences in similar growth and carcass variables (Table 1). Also, most of the studies reported no differences with maternal restriction on offspring body weight at calving and at weaning. One of the limitations in the data set is that most articles did not measure or report dry matter, net energy, or crude protein intake on the dam; therefore, making it difficult to predict the severity of maternal nutrient restriction and the effects on the offspring. Because of this gap in the literature, we suggest that net energy and crude protein intake should be reported in future studies to better determine the effects of maternal restriction during late gestation on offspring growth and carcass characteristics.
232 State of the Art: Zinc and Copper Nutrition for Feedlot Cattle
Authors: Hansen Stephanie L , Messersmith Elizabeth M , Deters Erin L
Published: April 2022

Beef cattle require several trace minerals for optimal function, but of these, zinc (Zn) and copper (Cu) are arguably the most widely studied. Zinc and Cu both have essential roles in feedlot cattle growth, health, and carcass merit, yet they could not be more different. Ruminants are tolerant of quite high dietary Zn concentrations but will readily absorb and store Cu to the point of eventual toxicity. Zinc is ubiquitous in the body, needed for countless bodily processes, while Cu is more specialized, essential for a handful of biochemical processes. Because Zn is involved in so many proteins, a Zn biomarker in cattle (or any species) has remained elusive. In contrast, liver Cu is a well-accepted status index in ruminants, though reference ranges for adequacy are wide and non-specific. In addition, because of a shared affinity for the storage protein metallothionein, Zn and Cu may prove antagonistic to one another. Differences in bioavailability of Zn and Cu sources add further complexity to designing an optimal trace mineral supplementation program. This presentation will cover a review of the Zn and Cu feedlot literature from the past several years, in addition to pooled analysis of in-house data from our laboratory, with the goal of offering recommendations for best practices for Zn and Cu nutrition of feedlot cattle.