bluuebunny/crossref_metadata_2025 huggingface dataset:
Space charge waves in a two-dimensional electron gas
Authors: Zhang Peng , Wong Patrick , Zhou Yang , Albrecht John D. , Hodek Matt , Smithe David
Published: April 2022

This paper uses field theory to derive the exact dispersion relation of space charge waves in a two-dimensional electron gas (2DEG) located in a dielectric or a dissimilar dielectric waveguide. It is found that the dispersion of a 2DEG can be modeled accurately using the free-electron sheet model, which is further confirmed by the almost identical polarizability of a 2DEG and of a free-electron sheet with zero drift velocity. Transitions among the well-known 2DEG dispersion, the beam mode in vacuum electronics, and Gould–Trivelpiece mode in plasma physics are demonstrated by varying the 2DEG density and direct current drift velocity. The effects of waveguide dimensions are also presented. Our method is general and can be applied to find the dispersion relation of 2DEG with arbitrary drift velocity (governed by electric field and scattering) in more complex circuits. Our study provides insight into the design of electromagnetic wave devices and circuits involving a 2DEG.
‘The awesome power of yeast’
Authors: Macreadie Ian , Dhakal Sudip
Published: April 2022

Yeast is one of the most useful microorganisms in society. Aside from the well known traditional uses in beer, wine and bread making, yeast is currently providing new opportunities for our society. This article examines some of those new opportunities which include using yeast as a model organism, yeast as a cell factory for valuable proteins, including vaccines and new therapeutics, and yeast as a very convenient tool for teaching.
Bacillus Calmette-Guerin (BCG) induces superior anti-tumour responses by Vδ2+ T cells compared with the aminobisphosphonate drug zoledronic acid
Authors: Fenn J , Ridgley L A , White A , Sarfas C , Dennis M , Dalgleish A , Reljic R , Sharpe S , Bodman-Smith M
Published: April 2022

Vδ2+ T cells can recognize malignantly transformed cells as well as those infected with mycobacteria. This cross-reactivity supports the idea of using mycobacteria to manipulate Vδ2+ T cells in cancer immunotherapy. To date, therapeutic interventions using Vδ2+ T cells in cancer have involved expanding these cells in or ex vivo using zoledronic acid (ZA). Here, we show that the mycobacterium Bacillus Calmette–Guérin (BCG) also causes Vδ2+ T-cell expansion in vitro and that resulting Vδ2+ cell populations are cytotoxic toward tumour cell lines. We show that both ZA and BCG-expanded Vδ2+ cells effectively killed both Daudi and THP-1 cells. THP-1 cell killing by both ZA and BCG-expanded Vδ2+ cells was enhanced by treatment of targets cells with ZA. Although no difference in cytotoxic activity between ZA- and BCG-expanded Vδ2+ cells was observed, BCG-expanded cells degranulated more and produced a more diverse range of cytokines upon tumour cell recognition compared to ZA-expanded cells. ZA-expanded Vδ2+ cells were shown to upregulate exhaustion marker CD57 to a greater extent than BCG-expanded Vδ2+ cells. Furthermore, ZA expansion was associated with upregulation of inhibitory markers PD-1 and TIM3 in a dose-dependent manner whereas PD-1 expression was not increased following expansion using BCG. Intradermal BCG vaccination of rhesus macaques caused in vivo expansion of Vδ2+ cells. In combination with the aforementioned in vitro data, this finding suggests that BCG treatment could induce expansion of Vδ2+ T cells with enhanced anti-tumour potential compared to ZA treatment and that either ZA or BCG could be used intratumourally as a means to potentiate stronger anti-tumour Vδ2+ T-cell responses.
1 Awardee Talk: Investigation of Pain and Analgesic Strategies in Cattle Undergoing Painful Husbandry Procedures and Disease Conditions
Authors: Martin Miriam S
Published: April 2022

Negative public perception of routine husbandry practices such as dehorning and castration is growing, increasing the need for the development of practices to relieve pain and suffering in livestock. The objective was to quantify pain associated with induced bacterial pneumonia, hot-iron dehorning, surgical castration, and hot-iron branding, and to investigate analgesic effectiveness. Calves were experimentally inoculated with Mannheimia haemolytica, cautery dehorned, surgically castrated, or hot-iron branded. Outcome variables were collected at baseline and following husbandry procedures and included serum cortisol; infrared thermography (IRT); mechanical nociceptive threshold (MNT); substance P; kinematic gait analysis; a visual analog scale (VAS); chute defense and behavior scoring; clinical illness score; computerized lung score; average activity and rumination; prostaglandin E2 metabolite (PGEM); plasma serum amyloid A and rectal temperature. Reduced activity levels, decreased force on calves’ right front limb, and increased VAS scores all support that bacterial pneumonia in cattle is painful. Differences in right front force were observed in calves challenged with M. haemolytica and treated with flunixin transdermal and those given a placebo, indicating that flunixin transdermal may attenuate specific pain biomarkers in cattle with respiratory disease. Pain from cautery dehorning and surgical castration can last up to 120 h post-dehorning indicated by changes in IRT, MNT, PGEM and gait analysis. Administration of bupivacaine liposome suspension as a local anesthetic block at the time of dehorning and castration was as effective at controlling pain as a multi-modal approach of lidocaine and meloxicam. Changes in IRT, MNT, lying time, step count, visual analog scale score and wound scoring all support that hot-iron branding cattle is painful. Oral meloxicam administration reduced IRT differences from the branding and control site and reduced lying bouts. Breed and sex effects were observed across a wide range of biomarkers. The need for long-acting analgesic options for cattle that demonstrate pain alleviation across multiple biomarkers is apparent and would be beneficial to alleviating pain and suffering.
7 Awardee Talk: Muddy Environmental Conditions Increase Net Energy Requirements and Decrease Cow and Heifer Body Weight and Body Condition During Late Gestation
Authors: Nickles Kirsten , Relling Alejandro E , Garcia-Guerra Alvaro , Fluharty Francis L , Parker Anthony J
Published: April 2022

Winter and spring precipitation are expected to increase 20-30% by the end of the century in the Midwest, U.S. As a result, cows in this region are exposed to muddy conditions in pastures during late gestation. Two experiments were completed with multiparous cows and primiparous heifers to determine the energetic cost of mud during late gestation. In the first experiment, multiparous Angus cows (n = 8/treatment) were paired based on initial body weight (BW). One cow from each pair was randomly assigned to either the mud (MUD) or control (CON) treatment. Cows were housed and fed individually from d 213 to 269 of gestation. Each pair was fed to meet requirements for maintenance and gestation. In the second experiment, primiparous Angus heifers (n = 9/treatment) were paired based on initial BW. One heifer from each pair was randomly assigned to either the MUD or CON treatment. Heifers were housed and fed individually from d 196 to 266 of gestation. Each pair was fed to meet requirements for maintenance, growth, and gestation. Data in both experiments were analyzed as randomized complete block designs with repeated measurements (SAS 9.4). Although cows consumed the same amount of dry matter, cows in the MUD treatment weighed 37.4 kg less than the CON treatment (P < 0.01) and were 1.5 body condition score (BCS) units less (P < 0.01) by d 269 of gestation. Similarly, heifers in the MUD treatment weighed 43.5 kg less than the CON treatment (P < 0.01) and were 1.8 BCS units less (P < 0.01) by d 266 of gestation. In both experiments, however, calf birth weight was similar (P = 0.34). Although cows and heifers housed in mud were in a negative energy balance, they prioritized fetal growth and mobilized body tissues to meet the energetic demands of gestation.
66 Utilizing Third Generation Sequencing to Identify Pathogen Outbreaks Rapidly and Accurately
Authors: Neujahr Alison , Loy Duan , Loy J Dustin , Brodersen Bruce , Fernando Samodha
Published: April 2022

The temporal trend of novel pathogen identification has increased over the last decade, with viruses being the main contributor to the increase. Currently, the NAHLN provides veterinary surveillance and testing procedures for high consequence animal diseases, where in many cases, the detection of these diseases is based on real-time PCR assay (ASF, CSF, FMD, and IAV-S) or pathogen specific antibodies using ELISA methods (PRV). However, genetic shift and drift in virus genomes can lead to failure in detection of novel or emerging pathogens. Therefore, with the current trend of increased viral disease emergence, novel methods are needed to accurately and rapidly identify and characterize viral pathogens independent of knowing genomic information. In this study, we developed a novel diagnostic approach to identifying swine pathogens, using surrogate viruses. We implemented the use of Oxford Nanopore MinION Technology to detect long read sequences in real time. Surrogate viruses were used in place of common pathogens such as African Swine Fever, Classical Swine Fever, Pseudorabies, Foot and Mouth Disease, and Influenza A to investigate rapid detection limits. To increase the complexity of a sample, both DNA and RNA viruses were spiked into tissues were analyzed using Oxford Nanopore MinION Technology. This method can detect both DNA and RNA viruses simultaneously without prior knowledge. Additionally, as sequences can be detected real-time, we were able to confidently detect viral pathogens within a sample within 30 min. Additionally, we have established a library preparation and sequencing protocol as well as an informatic pipeline that could allow clinics and diagnostics centers to identify pathogens in less than 10 hours.
79 Determination of Optimal Timing of Marketing for Carcass Quality Measurements in Gilts Administered Improves
Authors: Vonnahme Kimberly A , Amodie Debbie , Mellencamp Martha , Pollmann Steve , Pantoja Lucina Galina
Published: April 2022

Gilts immunized against gonadotropin-releasing factor (GnRF) have reported improvements in carcass characteristics including increased belly weights and thickness, and increased loin intramuscular fat (IMF) compared with controls. The objective was to determine the optimal market timing post second dose (PSD) for anti-GNRF-treated gilts for carcass characteristics. Treatments were arranged as a 2×4 factorial: control vs anti-GnRF (d7 and 77; d0 = 8 wk of age) and marketing time PSD anti-GnRF: (first cut: 10 heaviest gilts; last cut: remaining gilts): d18 and 39 PSD; d25 and 46 PSD; d32 and 53 PSD; and d39 and 60 PSD. Pen (n=120) was the experimental unit (12-18 pens per treatment; 21 gilts per pen). Carcass data were determined from 107-188 gilts per treatment per day PSD with primal data collected from 39-54 carcasses per treatment per day PSD. At 25 wks of age, 52.5±0.05% of control gilts vs. 0.92±0.01% of anti-GnRF gilts were cycling based on ovarian structures. Regardless of cut, anti-GnRF increased (P ≤0.05) HCW, backfat, and belly depth. Loin depth and belly weights were greater (P ≤0.05) in second cut anti-GnRF gilts compared with control. Calculated percent lean was decreased in both marketing events in anti-GnRF gilts compared with control. While belly yield was similar, iodine value was decreased in anti-GnRF gilts compared with control, regardless of marketing event. Trimmed loins were lighter (P = 0.02) in second cut anti-GnRF gilts, but had greater (( P < 0.01) IMF compared with control gilts. Shear force was similar between treatments. Use of anti-GnRF in gilts results in heavier carcasses and several primal weights. The time PSD to market anti-GnRF-treated gilts does not appear to impact carcass quality indicating that it is best to focus on optimal timing based on performance traits.
74 Characterizing Pork Color Shelf Life: Foundational Visual and Biochemical Bases of Pork Discoloration
Authors: Harsh Bailey
Published: April 2022

Poor color stability limits meat shelf life, and poses an economic challenge to processors and retailers, and contributes to food waste. The US pork industry has only a limited understanding of fresh pork discoloration, with most inferences about discolored pork being extrapolated from beef discoloration studies. Despite substantial research into consumer perception, biochemical mechanisms, and economic impact of fresh beef discoloration, little is known regarding fresh pork color stability. This is problematic because of substantial differences in pork and beef myoglobin as well as discoloration traits. While discoloration in beef typically presents as a brown hue, fresh pork discoloration displays a wider range of hues, with differences in intensity and extent of discoloration. Pork-specific discoloration thresholds, as they relate to consumer acceptability, have not been defined and likely differ from beef due to the variety of discoloration hue, intensity, and extent combinations. Once discoloration in pork products has been characterized, biochemical, metabolomics, and proteomic changes between color stable and color labile products will provide information regarding a mechanistic basis for pork discoloration. Further, despite research into pre- and post-slaughter interventions to slow discoloration, it is not currently possible to predict at d 1 postmortem the inherent color persistence of pork entering the retail case 10 to 21 d later. Fundamental color stability research in pork, ranging from applied consumer perceptions to mechanistic traits, is needed to develop technologies and interventions to improve case life of color labile cuts, decrease discoloration-based profit losses, and reduce food waste.
95 Carbohydrase Mixture Supplementation to High Fiber Diets on Apparent Total Tract Digestibility of Nutrients in Diets for Gestating Sows Compared with Growing Pigs
Authors: Shipman Garrin , Perez-Palencia Jorge Y , Patterson Rob , Levesque Crystal L
Published: April 2022

The objective of this study was to compare the apparent total tract digestibility (ATTD) of nutrients and non-starch polysaccharides (NSP) between gestating sows and growing pigs fed a high fiber (NDF = 17.5%) diet with or without supplemental carbohydrase mixture (CM). Forty-five gestating sows (parity 0 to 5; BW 187 ± 28 kg) and 27 growing pigs (initial BW 35.7 ± 3.32 kg) were allotted to 3 levels of CM inclusion (‘0’ ‘0.08’ and ‘0.10’%). Sows were fed once daily at 2.2 kg/d and grower pigs provided feed at 5% of BW to reflect ad libitum feed access. Titanium (0.3%) was the indigestible marker, and feces were collected for 4 d following a 10-d adaption period. Data were analyzed in a 2 × 3 factorial arrangement with main effects of animal category (gestating sow or grower pig) and CM supplementation. Dietary CM supplementation increased (P < 0.05) ATTD of all nutrients except for NDF with tendency (P < 0.10) for increase in arabinose and glucose digestibility. There were no differences between the 0.08% and 0.1% CM inclusion levels (Table 1). Regardless of enzyme supplementation, ATTD of calcium and phosphorus were higher in the grower pigs (P < 0.01). Sows displayed increased (P < 0.05) ATTD of NDF, xylose, glucose, total NSP with tendency (P < 0.10) for ADF and arabinose in comparison to grower pigs. An interaction was detected (P = 0.036) where ATTD of phosphorus increased with 0.08 and 0.10% CM inclusion in grower pigs and only with 0.10% in sows. Dietary CM supplementation can increase ATTD of nutrients, NSP, and energy in high fibrous diets. Lastly, sows have higher digestibility of dietary fiber in comparison to grower pigs irrespective of enzyme supplementation.
101 Evaluation of Vitamin D on Performance and Bone Mineral Density in Finishing Pigs
Authors: Smith Leah , Gourley Gene , Sparks Chris , Gabler Nicholas K
Published: April 2022

The objective of this study was to evaluate the vitamin D3 (vitD) and 25-hydroxy vitamin D (25-OHD) requirements for finisher pig performance and bone density. Seventy-two pigs (62 ± 11.1 kg BW) were allotted to 36 pens (n = 2 pigs/pen) and across 4 dietary treatments (n = 9 pens/trt) for 51 d. Corn-soybean meal mash diet treatments were: 1) Diet containing 75 IU/kg vitD; 2) Diet containing 150 IU/kg vitD (NRC requirement); 3) Diet containing 750 IU/kg vitD; and 4) As 1 plus 0.0125% 25-OHD to achieve total diet equivalent of 750 IU/kg vitD. Pigs were weighed and feed disappearance recorded at the start and end of the study to calculate ADG, ADFI and G:F. Serum 25-OHD concentrations were determined on d 42. On d 51, one pig per pen was euthanized and bone mineral density determined on the rib, tibia and fibula. Data were analyzed as a complete randomized design with pen as the experimental unit. Overall, ADG did not differ between treatments 1 through 4 (1.26, 1.31, 1.34, 1.27 kg/d, respectively (P > 0.05). Further, ADFI did not differ between treatments (P > 0.05). However, G:F tended to increase as dietary vitD concentrations increased (0.34, 0.36, 0.37 and 0.35, respectively, P = 0.068). Rib, fibula and tibia bone mineral density did not differ between treatments (P > 0.05). Serum 25-OHD concentrations were 9.9, 11.9, 23.3 and 36.6 ng/mL for treatments 1-4, respectively (P < 0.001). In conclusion, vitamin D3 deficiency was not achieved with treatment 1 in finishing and all treatments had equal pig performance and bone mineral density. Further, 0.0125% 25-OHD provided equal performance and bone density to 750 IU/kg of vitamin D3.
115 Effects of a Chronic Lipopolysaccharide Challenge on Growth Performance and Immune Response of Nursery Pigs Fed Differing Sources of Dietary Zinc
Authors: Harshman Jared A , Carter Scott D , Aparachita Pornpim , Scaff Taw , van de Ligt Chris
Published: April 2022

Two experiments were conducted to determine the effects of zinc source on growth performance and immune response during a chronic lipopolysaccharide (LPS) challenge. Each study utilized 180 pigs (5.2 kg, 18-21 d) in a 42-d experiment. Pigs were allocated to pens (10 pigs/pen; 5 pens/trt) and pens were randomly assigned to 4 treatments on d 0. Three dietary treatments consisted of the addition of 100 ppm of added zinc from 3 sources (ZnHydroxyCl, ZnSO4, and ZnO). On d 29, 31, 33 and 35 of the study, challenged pigs were injected intramuscularly with LPS (10 ug/kg BW). Additionally, a control group was fed ZnHydroxyCl without receiving LPS. Pigs and feeders were weighed to determine ADG, ADFI, and G:F. Blood samples, BW, and rectal temperature (RT) were taken before the first LPS injection and 3 h post-injection on d 36. Data were analyzed using the MIXED procedure in SAS with pen as the experimental unit. There were no experiment by treatment interactions (P > 0.10). Prior to LPS challenge (d 0–28), there were no effects (P > 0.10) of treatment on ADG, ADFI, or G:F. Pigs receiving LPS had lower G:F, and greater RT and TNF-α during d 28-36 compared with non-challenged pigs (P < 0.01). Within the LPS-challenged pigs, there was no difference (P > 0.10) in ADG or ADFI among treatments (d 28-36, 0-42); however, pigs fed ZnHydroxyCl were more efficient (P < 0.02). RT and TNF-α at h 0 were similar (P > 0.10) among treatments. On d 36, 3 h following the last LPS injection, pigs fed ZnHydroxyCl had lower RT and TNF-α, followed by ZnO, then ZnSO4 (P < 0.10.) These data suggest that of the sources fed, pigs fed ZnHydroxyCl had greater performance and a lower immune response during a health challenge.
123 Superdosing Phytase Fed During Transition Phase in Sows Increased Piglet Weight Gain
Authors: Cordero Gustavo , Weber Tom , Wilcock Pete , Yague Antonio Palomo , Alonso Irene
Published: April 2022

Farrowing and lactation periods require a high demand for nutrients. Superdose (≥1500 FTU/kg) of phytase may increase the nutritive value of diets and improve litter performance. The objective of this study was to determine whether the superdosing of phytase (Quantum Blue; AB Vista) in the peripartum diet affects sow and piglet productivity and serum biomarkers (urea, cortisol, and calcium). A total of 54 sows, Topigs TN70 (27 control group, 27 superdosing group) were blocked by parity and randomly assigned to the treatments. The control lactation diet was a mixed-cereal and soybean meal-based, formulated to meet sow’s requirement with 500 FTU/kg phytase inclusion. The superdosing diet, was supplemented with a further 2,000 FTU/kg phytase to give a total of 2,500 FTU/kg. Peripartum treatment diets were provided from 10 d before farrowing until 10 d after, after which a common standard lactation was fed. Piglets were weaned at 26 d of age. Data were analyzed with ANOVA evaluating the effects of phytase dose and parity using the fit model platform in JMP15.1. Significant treatment means were separated using Student’s t-tests, with significance accepted at P ≤ 0.05. Birth weights of piglets were significantly affected by parity, with piglets born from parity 1 or 4+ sows being around 180g lighter in weight (P < 0.01) than piglets born from parity 2 or 3. The superdosing treatment increased piglet weight at weaning by 490g/weaned piglet (P < 0.01). Cortisol levels were greater (3.7 vs. 1.3 µg/dl, P < 0.01) at farrowing compared with 10d post-farrowing. Urea concentrations were 37% higher in the superdosing treatment at farrowing compared with control (P = 0.02). It can be concluded that the use of phytase at superdosing levels can be used in peripartum diets to improve piglet weight gain during lactation which is linked with greater utilization of nutrients that has been associated with greater phytate breakdown.
138 Effects of Wheat Middlings Inclusion Rate on Growth Performance of Nursery Pigs
Authors: Cemin Henrique S , Swalla Luke A , Pietig Jamie L , Hansen Sharlie A , Hansen Ernie L
Published: April 2022

An experiment was conducted to determine the effects of wheat middlings inclusion rate on growth performance of nursery pigs. A total of 1,750 pigs (initial BW = 6.0 kg), placed in pens with 35 pigs each, were used in a 39-d trial. There were 5 treatments consisting of 0, 5, 10, 15, or 20% wheat middlings. Corn and a fermented soybean meal product (ME-Pro, Prairie AquaTech, Brookings, SD) were replaced by wheat middlings to achieve the desired levels, whereas soybean meal inclusion rate was constant across treatments. Diets were not balanced for net energy. The experimental diets were fed from d 0 to 18 and a common corn-soybean meal-based diet was fed from d 18 to 39. There were 10 replicates per treatment. Pigs were weighed on d 0, 18, and 39 to calculate ADG, ADFI, and G:F. Data were analyzed with SAS MIXED procedure. From d 0 to 18, there was a linear (P = 0.041) reduction in ADG with increasing levels of wheat middlings; however, the differences were small (ranging from maximum 288 to minimum 275 g/d). This response was driven by a tendency (P = 0.096) for a linear ADFI response and a quadratic (P = 0.023) G:F response. From d 18 to 39, there was a linear (P = 0.016) G:F response, where pigs previously fed high levels of wheat middlings had improved G:F. Overall (d 0 to 39), there was no evidence (P > 0.10) for differences on growth performance. In conclusion, pigs fed high levels of wheat middlings had slightly decreased performance from d 0 to 18, but no evidence for differences were observed in the overall nursery period.
144 Effects of Increasing Dietary Standardized Ileal Digestible Lysine Levels on Growth Performance of 15- to 23-Kg Maternal Barrows
Authors: Vier Carine M , Lu Ning , Dritz Steve , Estrada Jorge , Peterson Beau , Hanson Andrea , Cast Wayne R , Wells Danielle , Orlando Uislei A
Published: April 2022

Our objective was to determine the effects of increasing dietary standardized ileal digestible (SID) lysine (Lys) on growth performance of late nursery pigs. A total of 1,125 barrows (L02 ′ L03, initially 15.4 kg ± 0.003) were used in a 14-d study. Pens of pigs were weighed, blocked by location in the barn, and randomly allotted to 1 of 6 treatments that contained 1.05, 1.16, 1.23, 1.29, 1.39, and 1.52% of dietary SID Lys. Diets were corn-soybean meal-based and contained 3,300 Kcal of ME/kg, with treatments achieved by increasing the inclusion of synthetic lysine. There were 9 pens per treatment and 25 barrows per pen. Data were analyzed using generalized linear and nonlinear mixed models with pen as the experimental unit. Competing models included linear, quadratic polynomial (QP), broken-line linear (BLL), and broken-line quadratic (BLQ). Increasing SID Lys concentration improved average daily gain (ADG; linear, P < 0.05) and gain to feed ratio (G:F; quadratic, P < 0.05). Although no model provided better fit to the ADG data compared with the linear model, the greatest improvement in growth rate was observed as SID Lys increased from 1.05 to 1.41%. The best-fitting models for G:F were QP and BLL. The QP and BLL models estimated the plateau or breakpoint at dietary SID Lys of 1.45% (95% CI: 1.21 to >1.52%) and 1.41% (95% CI: 1.40 to 1.42%), respectively. There was no evidence that increasing dietary SID Lys levels impacted average daily feed intake or the removal and mortality rate (P > 0.10). Increasing SID Lys concentration increased (linear; P < 0.05) the grams of SID Lys intake per kg of gain. In the current trial, the estimated optimum SID Lys concentration for 15- to 23-kg maternal barrows ranged from 1.41 to 1.46%, depending on the statistical model.
162 Investigating Strategies to Manage Feed Supply Chain Disruptions on Grow-Finish Pigs
Authors: Miller Kayla A , Johnson Erika M , Matchan Stacie , Goehring Devin , Ross Jason W , Gabler Nicholas K
Published: April 2022

In the likelihood of a foreign animal disease outbreak, the U.S. pork industry may face supply chain disruptions, including those to feed delivery. Therefore, our objective was to evaluate feeding strategies to prolonged feed availability in group housed finishing pigs and assess impacts on pig performance. 1,407 mixed sex pigs (92±11 kg BW) were blocked by initial average BW to pens and assigned to 1 of 5 treatments (n =12 pens/treatment, 22 pigs/pen) over a 21-d test period. Treatments were fed for 14 d (P1) and thereafter all pens returned to ad libitum access to a standard commercial diet for 7 d (P2). Treatments included: 1) Pens fed ad libitum (CON); 2) Pens fed at 1.45x ME maintenance requirement daily (1.45x); 3) Pens fed 2x ME maintenance requirement daily (2x); 4) Tightened feeders to lowest setting, fed ad libitum (Closed); and 5) Whole corn kernels, fed ad libitum (Corn). The P1 and P2 BW and feed disappearance were recorded to calculate ADG, ADFI, and G:F. Data were analyzed with pen as the experimental unit and least squares means values reported by treatment. Compared with CON, 1.45x, 2x, Closed and Corn treatments significantly reduced P1 ADG (1.09 vs 0.02, 0.34, 0.72, 0.41 kg/d, respectively), ADFI (3.21 vs. 1.42, 1.90, 2.49, 2.40 kg/d, respectively) and G:F (P < 0.05). During P2, ADG and G:F were both increased (P < 0.05) compared with CON across all treatments. However, ADFI increased only from the CON in the 2x, Closed and Corn diets (P < 0.05). Overall (d 0-21), all strategies attenuated BW, ADG and ADFI (P < 0.0001) compared with CON. However, G:F was only reduced (P < 0.01) in 1.45x and Corn, but not 2x and Closed (P > 0.05) from the CON. In conclusion, implementing management strategies to conserve feed maintained marginal pig growth.
158 Effects of Increasing Dietary Standardized Ileal Digestible Lysine Levels on Growth Performance of Grow-Finish Pigs That Were Sired by PIC 800 Boars
Authors: Xue Pengcheng , Lu Ning , Pilcher Chad M , Frederick Brent , McGhee Molly L , Li Qingyun , Vier Carine M , Cast Wayne R , Orlando Uislei A
Published: April 2022

A total of 1,092 pigs (PIC 800 × Camborough) were used to investigate the effects of increasing dietary standardized ileal digestible (SID) Lys on growth performance in 4 experiments covering body weight ranges of 25-45 kg (Exp. 1), 45-73 kg (Exp. 2), 74-91 kg (Exp. 3), and 98-120 kg (Exp. 4). Pigs were placed in 1 room and divided into 2 groups with 42 pens/group and 13 pigs/pen (6 or 7 gilts and 7 or 6 barrows, balanced among treatments). Group 1 was used in Exp. 1 and 3; group 2 was used in Exp. 2 and 4. At the beginning of each trial, on-trial pens were blocked by body weight and randomly allotted to one of 6 treatments (85.0, 90.0, 95.0, 100.0, 107.5, or 115.0% of PIC SID Lys recommendations) in a randomized complete block design. Data were analyzed using generalized linear and nonlinear mixed models with pen as the experimental unit. In Exp. 2 to 4, the competing nonlinear models did not fit the data or improve the fitness compared with the linear models. Greater SID Lys linearly increased (P < 0.05) average daily gain in Exp. 1 and 3 (Table 1). Increasing SID Lys tended to increase gain to feed ratio (G:F; quadratic, P < 0.10) in Exp. 1, and broken-line linear and broken-line quadratic models estimated the maximum G:F at 99.9 and 98.5% SID Lys, respectively. In Exp. 2 and 3, increasing SID Lys also increased G:F (linear, P < 0.10). Growth performance did not differ among treatments in Exp. 4. Results indicated that the optimum SID Lys concentration for 25 to 45 kg PIC 800 pigs was between 98.5 and 99.9% of PIC SID Lys recommendations. More research is needed to validate the optimum SID Lys concentrations for pigs above 45 kg.
159 Effects of Dietary Energy and Standardized Ileal Digestible Lysine Levels on Growth Performance of Grow-Finish Maternal Barrows
Authors: Estrada Jorge , Hanson Andrea , Vier Carine M , Lu Ning , Navales Ron A , Cast Wayne R , Peterson Beau , Parr Eric , Orlando Uislei A
Published: April 2022

Our objective was to determine the effects of dietary energy and standardized ileal digestible (SID) lysine (Lys) on growth performance of grow-finish maternal barrows. A total of 1,056 barrows (L02 ′ L03, initially 35.2 kg±0.29) were used in a 107-d study. Pens of pigs were weighed, blocked by body weight (BW), and randomly allotted to treatments in a 2×2 factorial design in a randomized complete block design structure. Treatments consisted of 2 energy concentrations: 3,175 and 3,300 kcal ME/kg, and 2 levels of SID Lys: 93 or 105% of PIC recommendations. Diets were corn-soybean-meal-DDGS-based, and energy treatments were achieved increasing corn oil and lysine treatments were achieved increasing soybean meal levels. There were 11 pens per treatment and 24 barrows per pen. Data were analyzed using linear mixed models in SAS with pen as the experimental unit. Overall, there was no evidence for a significant interaction between energy and lysine for average daily gain (ADG, P >0.10, Table 1) and average daily feed intake (ADFI, P >0.10). Pigs fed 3,175 kcal ME/kg had significantly greater ADFI compared with those fed 3,300 kcal ME/kg. Pigs fed SID Lys at 105% of PIC recommendations had improved gain to feed (G:F, Lys×ME, P = 0.002) and marginally greater final BW (Lys×ME, P = 0.09) compared with those fed at 93% when dietary ME was 3,300 kcal ME/kg, but not when dietary ME was 3,175 kcal ME/kg. There was no evidence for dietary SID Lys or ME levels impact on ADG or removal and mortality (P >0.10). Under the conditions of the current experiment, feeding PIC maternal barrows with increased SID Lys levels (105% vs. 93% of PIC recommendations) improved G:F and final BW only when dietary ME level was at 3,300 kcal/kg but not at 3,175 kcal/kg.
169 The Effect of Increasing Valine, Isoleucine, and Tryptophan:Lysine Ratios on Growth Performance and Carcass Characteristics of Pigs Fed Diets with High Leucine:Lysine
Authors: Williams Hadley , Tokach Mike D , Woodworth Jason C , DeRouchey Joel M , Goodband Robert D , Gebhardt Jordan T , Hastad Chad W , Post Zach , Haydon Keith D
Published: April 2022

A total of 4,076 pigs (initially 39.3 kg) were used across 2 experiments to evaluate the effect of increasing ratios of Val, Ile, and Trp:Lys in corn-soybean meal-DDGS-based diets on pig growth performance and carcass characteristics. In both experiments, the 4 dietary treatments were: 1) high soybean meal and low feed grade amino acids (control), 2) low soybean meal and high feed grade amino acids, with Val:Lys, Ile:Lys, and Trp:Lys at 67, 55, and 18, respectively, (low ratio) 3) diet 2 except Val:Lys, Ile:Lys, and Trp:Lys increased to 72, 60, and 21, respectively, (medium ratio), and 4) diet 2 except Val:Lys, Ile:Lys, and Trp:Lys at 80, 65, and 23, respectively (high ratio). The Leu:lys levels for the diets with increased synthetic amino acids ranged from 135 to 146 for the 4 phases. All diets contained 30% DDGS until 100 kg BW, and then 20% DDGS until trial completion. Because there was no experiment × treatment interactions, data from both experiments were combined. Overall, ADG and ADFI increased (AA ratio; linear, P < 0.05) as Val, Ile, and Trp:Lys ratios increased from low to high. Pigs fed the control diet exhibited increased ADG compared with pigs fed low ratio diets, while pigs fed medium and high ratio diets performed intermediate. For carcass characteristics, pigs fed the control had increased (P < 0.05) percentage lean and loin depth compared with pigs fed the medium ratio diet, with pigs fed low and high ratio intermediate. Pigs fed the medium ratio diet had increased backfat depth compared with pigs fed the control, with pigs fed the low and high ratio intermediate (P < 0.05). In summary, the soybean meal level can be reduced, and synthetic amino acid levels increased in high DDGS diets as long as ratios of Val, Ile, and Trp to Lys are increased.
168 Evaluation of Increasing Dietary Threonine to Lysine Ratio in Corn-Soybean Meal Diets with and Without Dried Distillers Grains with Solubles (DDGS) on Growth Performance of Grow-Finish Pigs
Authors: Tolosa Russi Andres F , Tokach Mike D , Goodband Robert D , Gebhardt Jordan T , Woodworth Jason C , DeRouchey Joel M
Published: April 2022

A total of 2,160 pigs (PIC 337×1050; initial BW 35.1 kg) were used in a 112-d growth trial to evaluate the effects of normal or high SID Thr:Lys ratio in diets with and without DDGS on growth performance. Pigs were assigned to pens (27 pigs per pen) in a randomized complete block design by BW with 20 replications per treatment. Pens of pigs were allotted to 1 of 4 dietary treatments arranged in a 2×2 factorial with main effects of dietary Thr level (Normal vs High) and DDGS (with or without). Treatment diets were formulated in 4 phases from 35 to 57, 57 to 82, 82 to 105, and 105 to 136 kg BW. Diets with high DDGS were formulated to include 40% DDGS in phase 1 and 2, 30% in phase 3, and 15% in phase 4. Normal Thr diets were formulated to contain 61, 62, 63, and 65% SID Thr:Lys ratios for the 4 dietary phases, respectively. High Thr diets had SID Thr:Lys ratios of 67, 68, 69 and 72%, respectively. There were no (P>0.10) DDGS×Thr interactions. For the overall period (d 0 to 112), pigs fed diets without DDGS had increased (P < 0.001) ADG and BW, and reduced (P < 0.001) ADFI leading to improved (P < 0.001) G:F. There was no evidence for difference (P > 0.10) between diets with normal or high SID Thr:Lys ratio regardless of DDGS inclusion. In summary, the addition of high levels of DDGS reduced ADG and increased ADFI, which resulted in poorer G:F and lighter final BW, regardless of the dietary SID Thr:Lys ratio. These results indicate that addition of an insoluble fiber source, such as corn DDGS, does not increase the Thr:Lys requirement of finishing pigs.
124 Early Microbiome Development for Gut Health: Intrinsic and Extrinsic Drivers
Authors: Gomez Andres , Law Kayla
Published: April 2022

The gut microbiome, the collection of bacteria, fungi, virus and protozoa that inhabit the pig gastrointestinal tract, is promptly acquired at birth. During this seeding process, maternal and environmental microbial sources have a fundamental role, further modulated by nutritional and management interventions applied to both sow and piglet. Simultaneously, early microbiome seeding has significant impacts on the physiological landscape of the piglet gastrointestinal tract. In this talk, we will address the importance of diverse intrinsic and extrinsic factors, including nutrition, environment and sow physiology, in shaping early microbiome colonization and specific gut health traits in young pigs. Specifically, we propose that early microbiome development, including strategies for its manipulation, could potentially impact piglet survivability, immune function, pathogen susceptibility, digestion, absorption and overall well-being. We propose that, although some of these microbiome-mediated effects may be transient, others can be long lasting, possibly affecting health and productive performance along the life course. We propose that a microbiome lens could potentially contribute to better understanding health and performance in young pigs, by bridging basic and applied nutrition research.
179 Sire Distribution of Calves in a Herd with use of Fixed Time Artificial Insemination Followed by Immediate Bull Exposure for Natural Service
Authors: Hartman Ashley R , McCabe Esther D , Jacobs Devin , Grieger David M , Fike Karol E
Published: April 2022

Use of fixed time AI followed by immediate exposure of females to bulls for natural service can be a useful management strategy for commercial cow-calf producers to limit labor and time related to bull turnout as well as increase pregnancy rates earlier in the breeding season. Considering potential influence of factors such as bull fertility and time to and length of estrus in females, expectations for outcomes in natural service sire versus AI sire parentage is relatively unknown. We hypothesized that of calves born in the first 14 d of the calving season, less than 5% would be sired by natural service bulls exposed to females immediately following fixed time AI. Heifers (n = 191) and cows (n = 156) were synchronized and inseminated using the 7-d CO-Synch + CIDR fixed time AI protocol. All females were inseminated by the same AI technician using a single sire for heifers and a different single sire for cows. All females were exposed to bulls immediately following insemination. DNA was collected from a random subset of calves (Calves born from heifers n = 59; Calves born from cows n = 89) born in the first 14 d of the calving season for parentage analysis to estimate the overall percentage of calves sired by AI and natural service. Chi-Square tests were used to determine if the percentage of calves actually sired by natural service differed from the hypothesized 5% or less. Among calves born from heifers, the actual percentage sired by natural service (5.1%; n = 3/59) was similar (P = 0.98) to our hypothesized percentage. Among calves born from cows, the actual percentage sired by natural service (14.6%; n = 13/89) was greater (P < 0.001) than our hypothesized percentage of 5%. If commercial producers use fixed time AI followed by immediate bull exposure in cows, natural service bulls may sire more calves early in the calving season than expected.
176 Are Ovarian Reserve Parameters Related to Reproductive Tract Development and Fertility in Ewes?
Authors: Cushman Robert , Yake Hannah K , Snider Alexandria P , Murphy Thomas , Freking Bradley
Published: April 2022

There are differences between cows and ewes in ovarian reserve parameters. No major genes influencing follicle numbers have been identified in cows, whereas several genes have variants reported to influence follicle numbers in ewes. In contrast, antral follicle count is associated with fertility in cows, and we reported that beef cows that failed to conceive in 2 consecutive years had fewer antral follicles and smaller reproductive tracts than cows that had never failed to conceive. In the current study, we tested the hypothesis that ewes that had failed to lamb (BARREN) in 4 consecutive annual breeding seasons of 21– 35 d with rams that had passed a breeding soundness exam have fewer follicles and smaller reproductive tracts than ewes that consistently produced lambs (FERTILE) under the same breeding protocols. BARREN ewes (n = 19) were paired by breed, age, and sire to a FERTILE control ewe (n = 19) and reproductive tracts were recovered at necropsy. All visible antral follicles in both ovaries were counted and a representative cross section of one ovary was embedded for histological evaluation of primordial follicle numbers. The reproductive tract was weighed, and ovulatory status was evaluated. Paired t-tests indicated that BARREN ewes had 25.6 ± 5.0 fewer antral follicles per pair of ovaries, 17.3 ± 4.4 fewer primordial follicles per histological section, and 54.5 ± 18.7 g lighter reproductive tracts than FERTILE ewes (P ≤ 0.01). The odds of FERTILE ewes being ovulatory at necropsy were 2.25 that of BARREN ewes, but this did not differ from expectation by McNemar’s test (P = 0.13). The results indicate that size of the ovarian reserve influences fertility in ewes as it does in cows. USDA is an equal opportunity provider and employer.
194 Evaluation of Dietary Roughage Inclusion in a Single or Two-Diet System for Backgrounding and Finishing Steers
Authors: Hamilton Thomas G , Rusche Warren C , Smith Zachary K
Published: April 2022

The objective of this experiment was to determine the influence that equal cumulative roughage inclusion in a single diet or two-diet system during a 210-d growing-finishing period has on growth performance responses, efficiency of dietary net energy (NE) utilization, and carcass traits in beef steers. Pre-conditioned beef steers (n = 46; initial shrunk [4%] BW = 281 ± 40.4 kgs) were fed once daily, and bunks were managed according to a slick bunk management system at the Ruminant Nutrition Center in Brookings, SD. Treatments included: 1) A single diet program (targeted a 1.30 Mcal/kg NEg diet fed for 210-d; 1D) or 2) two diet program (targeted a 1.21 Mcal/kg NEg diet fed for 98-d, a 1.30 Mcal/kg NEg diet fed for 14-d, and a 1.39 Mcal/kg NEg diet fed for 98-d; 2D). All steers were implanted on d 1 with a 100 mg trenbolone acetate (TBA) and 14 mg estradiol benzoate (EB) implant and re-implanted with a 200 mg TBA and 28 mg EB implant on d 112. Average daily gain tended (P = 0.06) to be 9.5% greater for 1D compared with 2D during the backgrounding portion and ADG was increased (P = 0.01) for 2D compared with 1D by 11.3% during the finishing phase of the experiment. Cumulative ADG did not differ between treatments (1.61 vs. 1.62 ± 0.046 kgs) for 1D and 2D, respectively. Cumulative observed dietary NEm and NEg did not differ (P ≥ 0.96) between treatments. There were no differences (P ≥ 0.18) detected between treatments for HCW, DP, REA, RF, USDA marbling score, KPH, yield grade, retail yield, EBF, or body weight at 28% estimated EBF. In conclusion, Northern Plains feedlot producers can feed a single growing-finishing diet to preconditioned beef steers with minimal effects on overall growth performance or carcass traits.
205 Evaluation of a Direct Fed Microbial and/or an Enzymatically Hydrolyzed Cell Wall + Yeast Culture Product on Growth Performance, Dietary Net Energy Utilization, and Carcass Traits in Beef Steers
Authors: Gubbels Erin , Rusche Warren C , Rehberger Tom G , Block Elliot , Smith Zachary K
Published: April 2022

This research determined the influence a direct fed microbial (DFM) and/or enzymatically hydrolyzed yeast (EHY) product (both from Arm & Hammer Animal and Food Production, Princeton, NJ) have on growth performance and carcass characteristics in beef steers fed in the Northern Plains (NP). Single-sourced, newly weaned steers (n = 256; initial BW = 246 ± 1.7 kg; n = 8 pens/treatment with 8 steers/pen) were blocked by location in a 2×2 factorial treatment arrangement of DFM (Certillus CP B1801 dry; Bacillus subtilis, Lactobacillus plantarum; 28 g/steer·d-1) and EHY (Celmanax; 18 g/steer·d-1). Steers were individually weighed on d 1, 14, 42 (end of receiving phase; implant with 200 mg progesterone and 20 mg estradiol benzoate), 77, 105 (end of growing phase), 133, 161 (implant with 200 mg trenbolone acetate and 28 mg estradiol benzoate), 182, 230 (start ractopamine HCl at 300 mg/steer·d-1) and 258. No DFM × EHY interactions (P ≥ 0.05) were observed for cumulative growth performance. No health parameters were influenced by treatment (P ≥ 0.08). EHY steers had reduced (P = 0.04) dry matter intake compared with DFM and had a tendency (P < 0.08) for improved applied energetics measures. A DFM × EHY interaction (P = 0.02) was noted for the distribution of USDA yield grade (YG) 1 carcasses. Control steers had a greater proportion (P < 0.05) of YG1 carcasses compared with other treatments. A DFM × EHY interaction (P = 0.04) was noted for the distribution of USDA Prime carcasses. Steers from DFM × EHY had a greater proportion (P < 0.05) of USDA Prime carcasses compared with DFM or EHY, but did not differ from control, which were similar to DFM and EHY. Use of DFM and EHY alone or in combination had minimal effects on growth performance and carcass traits in NP steers.
206 Effects of a Direct Fed Microbial and/or an Enzymatically Hydrolyzed Yeast Product Fed to Beef Steers Provided Ractopamine Hydrochloride 28 d Before Harvest During Summer Months in the Northern Plains
Authors: Gubbels Erin , Rusche Warren C , Rehberger Tom G , Block Elliot , Smith Zachary K
Published: April 2022

This research determined the influence a direct fed microbial (DFM) and/or enzymatically hydrolyzed yeast (EHY) product (Arm & Hammer Animal and Food Production, Princeton, NJ) have on heat stress measures in beef steers administered ractopamine hydrochloride (RH; 300 mg/steer·d-1) the final 28-d on feed, during summer months in the Northern Plains (NP). At weaning, single-sourced steers (n = 256; initial BW = 246 ± 1.7 kg; n = 64 steers/treatment; 8 steers/pen) were blocked by location in a 2×2 factorial arrangement of DFM (Certillus CP B1801 dry; Bacillus subtilis, Lactobacillus plantarum; 28 g/steer·d-1) and EHY (Celmanax; 18 g/steer·d-1). The final diet provided 1.44 Mcal/kg of NEg and 30 g/907kg of monensin sodium. Temperature-humidity index (THI) was calculated from: 0.81 × ambient temperature + [relative humidity × (ambient temperature - 14.40)] + 46.40. On d 1 and 2 and d 21 and 22 on RH, respiration rate (RR) and panting scores (PS) were determined before and after AM and PM feedings (0700h, 1100h, 1400h, 1700h). RR (n = 3 steers/pen) was calculated from: 600/seconds required for 10 flank movements. PS was determined from: 0 (not distressed) to 4.5 (severely distressed). Two separate heat events occurred and average THI was greater than 75 for 10-d of the 28-d period. A DFM×EHY interaction was noted for the proportion of steers categorized as PS 2.0 at 1100h on d21 (P = 0.03) and RR on d21 at 1400h (P = 0.02). Control steers had a greater proportion of PS 2.0 at 1100h on d21 compared with DFM or EHY steers (P ≤ 0.05), while DFM×EHY steers did not differ from others (P ≥ 0.10). On d21 DFM×EHY steers had greater (P < 0.05) RR compared with DFM steers, control and EHY steers did not differ from others (P ≥ 0.10). DFM and EHY used alone or in combination had minimal effects on heat stress measures in steers fed RH in the NP under minimal heat stress conditions.