bluuebunny/crossref_metadata_2025 huggingface dataset:
166 The Impact of Dietary Crude Protein Level on Growth Performance of Growing-Finishing Pigs
Authors: Xue Pengcheng , McGhee Molly L , Pilcher Chad M , Li Qingyun , Frederick Brent
Published: April 2022

Two experiments were conducted to evaluate the impact of dietary crude protein (CP) levels on growth performance of growing-finishing pigs. In experiment 1, a total of 1,035 pigs (47.53 kg ± 1.12 kg) were allotted to a randomized complete block design with 5 dietary treatments (9 pens/treatment; 23 split sex pigs/pen) and fed experimental diets for 5 wk. The concentration of CP in each diet was 13.35, 14.10, 14.85, 15.60, and 16.35%, respectively, and CP was manipulated by soybean meal and crystalline amino acid inclusion. Diets were formulated to be isocaloric and contained equal provisions of standardized ileal digestible Lys, Met+Cys, Thr, and Trp. Diets met or exceeded NRC (2012) estimated nutrient requirements. In experiment 2, the same pigs as used in experiment 1 were randomly reallotted (initial body weight = 107.56 ± 1.77 kg) by pen following a washout period to 5 dietary treatments containing 10.70, 11.45, 12.20, 12.95, or 13.70% CP, respectively. Experimental diets were fed for 3 wk. Results of both experiments were analyzed using the lme4 package of R 4.0.2, and the statistical models included the fixed effect of CP and the random effect of body weight block. Orthogonal contrasts were used to test linear and quadratic effects of increasing dietary CP. Results of experiment 1 indicated final body weight, average daily gain (ADG), and gain:feed (G:F) linearly increased (P < 0.05) as CP in the diet increased (Table 1). Average daily feed intake (ADFI) did not differ among treatments. In experiment 2, dietary CP did not affect body weight, ADG, nor ADFI. As dietary CP increased, however, G:F tended (P < 0.10) to increase. In summary, greater dietary CP improved the performance of growing-finishing pigs by increasing ADG and G:F in the grower phase and tended to increase G:F in the finishing phase.
126 Maxwell Lectureship: Large Scale Practical Nutrition Research Sharing: Feeding the E. Coli Challenged Pig: What we Have Learned to Date
Authors: Gerhart Mandy J , Carrender Brittany , Coble Kyle
Published: April 2022

Over the past couple of years there has been a marked increase in the amount of E. coli outbreaks observed during the nursery phase of production. This is a multi-disciplinary issue and requires a holistic understanding of all possible contributing factors and input from production, vet, and nutrition teams. For the purposes of this presentation, we will focus on what potential impacts nutrition may have on E. coli. Within our production system we have made numerous modifications to our nursery diets to try and reduce mortality and help ameliorate scours associated with E. coli. To better understand what impacts our diet modifications have made on performance, fecal consistency, and mortality we have used a combination of monitoring closeouts, field trials, and challenge studies conducted at our research facility. In the field we have investigated the effects of reducing SID lysine, increasing oats, various feed additives and medication strategies. We took these questions to our research barn where we looked at IDF:SDF ratios, crude protein by oat, lactose by SBM, and lactose level by phase. To ensure the answers from our research barn aligned with field conditions, each trial utilized multiple sow sources and a challenge protocol where pigs were inoculated with E. coli. This challenge model has been successful in eliciting an E. coli outbreak in each trial where it was applied, providing us with a robust tool to mimic field scenarios in a typical high-health, low mortality, research facility. To complement what we were learning with controlled research we have also completed numerous validation experiments in the field, using an 8-week, two-treatment approach. To date, we have not found the silver bullet when it comes to eliminating E. coli issues in the nursery; however, we have learned some valuable lessons as to what does and doesn’t work for our genetics, facilities, and producers.
174 Effects of Nursing a Large Litter and Ovarian Response to Gonadotropins at Weaning on Subsequent Fertility in First Parity Sows
Authors: Arend Lidia S , Vinas Raquel Fernandez , Silva Gustavo , Lower Aaron , Connor Joseph F , Knox Robert V
Published: April 2022

Post-weaning fertility failures occur more often in parity 1 (P1) sows due to increased metabolic demands for lactation and inability to meet energy requirements for maintenance, growth, and reproduction. We hypothesized that body condition loss occurs more frequently in P1 sows nursing a large litter, resulting in impairment of ovarian follicle development during lactation and post-weaning. At 24 h post-farrowing, P1 sows (n = 123) were assigned to treatment (TRT) based on body weight and the number of functional teats to receive High Number (HN, 15 to 16) or Low Number (LN, 12) of nursing pigs. At weaning, sows in each TRT were assigned to receive PG600 or None (Control). During lactation, sow body measures were obtained and ovarian follicles were assessed in mid-lactation and post-weaning. Lactation data were analyzed for the effects of TRT, and fertility data after weaning were assessed for TRT x PG600. There were no interactions of TRT x PG600. During lactation, 22.2% of HN sows lost ≥4 pigs and were removed from analysis. The HN sows lost more (P < 0.05) body weight (-6.2 kg), backfat (-1.0 mm), body condition score (-0.4), and nursing piglets (-0.4) than LN sows. However, HN sows weaned more pigs (14.0) than LN sows (11.0). There was no effect of TRT on wean to estrus interval (4.2 d), but was 0.5 d shorter for PG600 (P = 0.004). There were no effects of TRT or PG600 on estrus within 6 d after weaning (85.6%), but PG600 induced smaller (P = 0.002) follicles at estrus (6.7 mm) than Control (7.3 mm). In the subsequent parity, there were no effects of TRT or PG600 on farrowing rate (93.9%) and total born (13.2). Overall, HN sows lost more piglets and body condition, although they weaned more pigs, but had no effects on reproductive performance.
177 Early Weaning Impairs Reproductive Development and Fertility of the Male
Authors: Clifton Lauryn , Petty Amber , Burns Morgan , Desaulniers Amy T
Published: April 2022

Reproductive failure remains a major limitation to the efficiency of livestock production. Early weaning has been linked with reduced male fertility; however, the biological mechanisms mediating this effect are largely undefined. The objective of this study was to develop a murine model to examine the effects of early weaning on testis development and function. Neonatal CD-1 mice were reared with their dams and littermates; pups were randomly assigned to either conventional (21 d; n = 12) or early (18 d; n = 12) weaning. At maturity, males were paired with a primiparous, non-littermate female. Copulatory plugs were detected daily, and females were euthanized at d 14 of gestation to assess reproductive traits; males were also euthanized to evaluate reproductive development. Gravid uterine weight tended to be reduced (P = 0.09) in females bred to early-weaned males, which was likely due to differences in litter size because early-weaned males tended to sire fewer viable fetuses (P < 0.08). Implantation rate was not different between treatments (P > 0.10), but the number of fetal reabsorptions tended to be greater in litters produced from early-weaned males (P = 0.10). Early embryonic survival was unaffected by treatment (P > 0.10), but late embryonic survival tended to be reduced (P = 0.08) in litters sired by early-weaned compared with conventionally-weaned controls. Furthermore, average conceptus weight was greater in litters sired by early-weaned males, which may be a reflection of their smaller litter sizes. These data suggest that early-weaned males produce sperm that yield defects in embryonic development not conception. Notably, testis and seminal vesicle weights were reduced (P < 0.01) in males weaned early versus conventionally-weaned controls, even when adjusting for body weight. Smaller testes and seminal vesicles suggest impaired sperm production capacity and testosterone biosynthesis, respectively. Together, these results indicate that early weaning impairs the development and function of the murine testis leading to reduced male fertility.
173 Identification of Biological Markers to Detect Early Estrus in Pre-Pubertal Gilts
Authors: Dierking Shannon L , Morton Jodi , Pinilla Juan Carlos , Gonda Michael , Clapper Jeffrey A , Levesque Crystal L
Published: April 2022

A proven predictor of reproductive success in swine breeding herds is age at puberty. Early puberty is associated with improved long-term reproductive performance. The objective of this study was to identify biomarkers of reproductive success at key periods in gilt reproductive development. Pre-pubertal gilts (n = 13) in 2 cohorts were followed from 70 d of age until first estrus or 213-215 d of age. Vaginal epithelia were collected using a swabbing technique at 5 key timepoints during reproductive development (70/77, 100/110, 130, 160 d of age, and first estrus or end of trial). Of the 13 gilts, 3 exhibited estrus early (d169 to 171), 2 were average (d 194 to 195), 2 were late (d 203 to 213), 3 were deemed anestrus and 2 had a silent estrus (one prior to d160 and 1 after d200). Total RNA were isolated and relative gene expression measured for RPLP0 (reference gene), TLR-4, TLR-5, IGF-1, ER-alpha and TAC-3 by quantitative real-time RT-PCR. Target genes were those involved with cellular protein function within the reproductive tract (IGF-1) and that prevent infection while allowing fertilization and implantation to occur (toll-like receptors 4 and 5). Gene ER-alpha is essential in the maturation of the female phenotype. Gene TAC-3 is critical for gonadal function. Comparison of relative expression of each gene of interest at different time points relative to 70 d was performed using the PCR package in RStudio (version 1.2.5025). Expression of IGF-1 and TAC-3 were up-regulated 9-fold and 7-fold, respectively, at the start of boar exposure (d 160; P < 0.05). Expression of ER-alpha tended to be upregulated 3-fold at 100 d of age (P = 0.08). Expression of TLR-4 and TLR-5 was not detected for most samples until standing estrus. These transcripts may be putative biomarkers for early estrus detection.
184 Correlating Microbial Community Membership of Cervical Fluid, Vagina and Feces in Post-Partum Sows
Authors: Koester Lucas R , Kiefer Zoe E , Studer Jamie M , Johnson Erika M , Baumgard Lance H , Ross Jason W , Greiner Laura L , Keating Aileen F , Farkas Attila , Pantoja Lucina Galina , Vonnahme Kimberly A , Schmitz-Esser Stephan
Published: April 2022

Postpartum metritis, or the inflammation of the uterus after parturition, is often a direct result of bacterial infection and considered to contribute to agalactia / dysgalactia in multiple species. Diagnosing metritis has included evaluation of vaginal and cervical fluid (CF) discharge for signs of infection (i.e., purulent discharge, strong odor, and discoloration). Metritis in sows results in economic losses for the swine industry due to increased numbers of sows requiring repeat inseminations to establish pregnancy, longer weaning to estrus intervals, association with increased abortions, and is also linked to agalactia. This study aimed to compare the microbial communities of the CF, the vaginal cavity, and feces from sows shortly after parturition, to identify similarities and differences in relative microorganism abundance between these body sites. Fecal and vaginal swabs were collected from 82 sows within 24-36 hours post-parturition. Additionally, CF was collected from each sow and classified based on color and consistency. Extraction of DNA was performed from all 246 samples and used for 16S rRNA gene Illumina MiSeq sequencing. Sequence analysis was conducted using MOTHUR (V1.43.0). No changes in CF microbial community composition or structure were determined related to CF color but differences (P < 0.05) were detected relative to CF consistency. Taxa were compared across body sites to identify correlated phylotypes using CoNet (V1.1.1). The abundances of several phylotypes harboring metritis-relevant pathogens were correlated with common commensal microorganisms across body sites (including Fusobacterium, Streptococcus, Escherichia, and Staphylococcus) suggesting interactions between these body sites exist. This work provides initial insights into postpartum sow CF microbial communities, and the interconnectedness with the vaginal and fecal microbiota. This project was supported by Zoetis (TI-07021).
185 The Validation of the Existence of the Entero-Mammary Pathway and the Assessment of the Differences of the Pathway Between Gilts and Sows
Authors: Greiner Laura L , Humphrey Dalton C , Holland Shayla , Anderson Chiron J , Schmitz-Esser Stephan
Published: April 2022

Forty sows (PIC Camborough 1050) from a single farm were randomly selected at 112 d of gestation to evaluate if gut bacteria transverse the blood system of the sow to deposit gut microbiota into colostrum for piglet gut inoculation via the entero-mammary pathway. Fourteen first-parity gilts and twenty third-parity sows were used for the study. At the time of farrowing, colostrum, fecal samples and blood samples were collected to evaluate the presence of bacteria in each sample. Colostrum and blood samples were processed via centrifugation to separate the immune cell fraction. Total deoxyribonucleic acid (DNA) was extracted from fecal, colostrum and white blood cell fractions. 16S ribosomal ribonucleic acid (rRNA) gene amplicon sequencing was conducted at the Iowa State University DNA Facility (Ames, IA) to further characterize the bacterial and archaeal taxa present within each sample. Data were analyzed using Mothur and using R v4.0.3 (R Core Team, 2020). The experimental unit was the female. Tables were generated to demonstrate the relative abundances of bacteria and archaea present in each type of sample and also identify organisms differentially abundant between sample types. Firmicutes was the most abundant phylum in colostrum and fecal samples and Tenericutes had the greatest abundance in blood comparative to other phyla. Further evaluation of the classification of bacteria present demonstrated that a few genera of bacteria are present in all 3 samples. Clostridum_sensu_stricto 1 was present in high relative abundance in colostrum and in moderate abundance in the feces while also being present within the blood. Other genera present in all 3 sample types includes Ruminococcus and Mycoplasma. In conclusion, the data suggests that there are bacteria present in all 3 locations of the sow at the time of farrowing and that gilts have different microbial populations than sows.
183 Circulating Biomarkers and Leukocyte Profiles in Agalactic Sows
Authors: Studer Jamie M , Kiefer Zoe E , Koester Lucas R , Johnson Erika M , Baumgard Lance H , Schmitz-Esser Stephan , Greiner Laura L , Keating Aileen F , Farkas Attila , Pantoja Lucina Galina , Vonnahme Kimberly A , Ross Jason W
Published: April 2022

Agalactia is characterized by reduced milk production after farrowing, resulting in economic losses due to increased piglet mortality. Although a variety of management factors have been associated with the etiology of agalactia, a specific causative mechanism has not been identified. Since clinical signs of agalactia develop in the days following farrowing, the objective of the current study was to determine if periparturient immune cell profiles and circulating biomarkers are predictive of future agalactia. Blood samples and litter weights were collected from sows (n = 374) within 24-36 hours after farrowing (timepoint 1) and sows were subsequently monitored for symptoms of agalactia and gaunt piglets. When a sow was designated as agalactic (n = 36) blood samples and litter weights were collected again (timepoint 2) and also from a parity matched healthy control sow (n = 46) of the same day of lactation. Agalactia diagnosis occurred on average 9.25 ± 2.67 d after farrowing. Average daily gain (ADG) of piglets from agalactic sows was 55% less (P < 0.01) than ADG of piglets from controls. Additionally, piglet mortality was substantially greater (P < 0.01) in litters from agalactic sows compared with controls. Circulating immune cells and metabolites were determined. Cholesterol, blood urea nitrogen, and globulin were increased 22.3, 17.8, and 34.1%, respectively, in agalactic compared with control sows at timepoint 2 (P ≤ 0.01). Aspartate aminotransferase tended to increase in agalactic sows compared with control at timepoint 1 (P = 0.08). No differences in immune cell profiles were observed between agalactic and control sows at either timepoint (P ≥ 0.14). Collectively, these data suggest metabolic changes are occurring in sows experiencing agalactia compared with healthy herd mates, but that very few of the metrics analyzed at timepoint 1 predicted future agalactia. This project was supported by Zoetis; TI-07023.
186 Vitamin and Mineral Supplementation During Gestation does not Influence Milk Yield or Composition During Early Lactation in Grazing or Parlor-Milked Beef Heifers
Authors: Baumgaertner Friederike , Hurlbert Jennifer L , Bochantin Kerri A , Menezes Ana Clara Baiao B , Sedivec Kevin K , Kirsch James D , Underdahl Sarah R , Dahlen Carl R
Published: April 2022

Two experiments were conducted to evaluate effects of vitamin and mineral supplementation during gestation on milk yield and composition at a single point in time, or via daily milk production during early lactation in beef heifers. Forty-one Angus-based heifers received either a basal ration (CON) or the basal diet plus vitamin mineral supplementation (VTM, 113 g•heifer-1•d-1) from breeding until parturition. For experiment 1, 29 heifers (12 CON and 17 VTM) were managed as one pasture group after parturition. Using a portable milking machine, heifers were milked at d 56 postpartum between 7 and 10.5 hours after calf removal. For experiment 2, 12 heifers (6 CON and 6 VTM) were acclimated to a free stall barn and milked twice daily for 78 d following parturition. Milk yield was recorded at each milking and samples were collected at d 32, 58, and 78 for component analysis. Data were analyzed using the GLM procedure of SAS. For grazing heifers, milk yield and components (P ≤ 0.91) did not differ between treatments, with mean yield of 9.95 ± 0.34 kg/d, 4.09 ± 0.11% fat and 2.82 ± 0.04% protein. Twice daily milking data (8.19 ± 0.08 kg/d mean yield with 3.43 ± 0.14 % fat and 3.17 ± 0.03 % protein) revealed that after d 7 milk yield remained similar for the rest of the evaluation period (P ≥ 0.12); however, protein was greater (P = 0.02) at d 58 (3.26 ± 0.05%) compared with d 32 (3.10 ± 0.05%) and urea was reduced (P < 0.0001) at d 78 compared with either d 32 or 58 (11.24 ± 0.55 vs. 18.84 ± 0.55 and 19.10 ± 0.55 mg/dL, respectively). Overall, the successful management of these beef heifers in a dairy facility lays the platform for future work that will establish energy requirements during early lactation for primiparous beef cows.
191 Improving Climatic Resilience in Pigs Through Physiological Genomics
Authors: Brito Luiz F F , Johnson Jay S S
Published: April 2022

Breeding programs have improved productive and reproductive efficiency in worldwide swine populations. However, greater performance is often accompanied by reduced climatic resilience due to greater metabolic heat production. Genomic selection is an effective tool for alleviating the negative effects of heat stress, but it requires traits that effectively capture the physiological, behavioral, and morphological mechanisms regulating the heat stress response. In this presentation we will first describe the genetic background of heat tolerance based on routinely recorded phenotypes (growth, carcass composition, and reproduction) and climatic variables obtained from public-weather-station databases. There are clear genotype-by-environment interactions across environmental conditions and the definition of the critical periods for quantifying the environmental gradient directly impacts the accuracy of genomic prediction of breeding values for heat tolerance. Secondly, we will describe the genetic background of various behavioral, physiological, and morphological indicators of heat stress in maternal line pigs, including automatically recorded vaginal temperature, skin temperature measured in different body locations and times of the day, respiration rate, panting score, body condition score, hair cortisol, hair density, and ear area. These traits are heritable and can be successfully included in genomic breeding programs. Furthermore, we will discuss the transgenerational effects of heat stress in maternal-line pigs, including an epigenomic analyses of in-utero heat stress that identified over 200 genomic regions that are differentially methylated. In summary, we will: 1) provide a comprehensive description of the environmental-gradient variables and critical periods fitted in genomic evaluations of heat tolerance; 2) describe the genetic background of various indicators of heat tolerance, including heritability, genetic correlations, candidate genes, differentially-methylated regions, and metabolic pathways associated with the significant genomic regions; 3) present the accuracies of genomic predictions for each indicator trait; and, 5) make recommendations for the implementation of genomic selection for improved heat tolerance in pigs. This research was supported by the Agriculture and Food Research Initiative (AFRI) Competitive Grants number 2020-67015-31575 and 2021-67015-34458 from the USDA National Institute of Food and Agriculture.
199 Characterizing Digestion Traits of Corn Bran Products from Corn Wet Milling
Authors: Xiong Jiehua , Suntara Chanon , Sjostrand Rebecca , Spore Tyler , Youngers Maggie , Stock Rick , Erickson Galen E , MacDonald Jim C
Published: April 2022

Evaluation of new bran products are necessary for continual improvement of wet milling feeds used by the cattle industry. The objective of this study was to evaluate 3 novel corn bran products from Cargill Corn Milling on rumen fermentation and nutrient digestion in beef cattle. Eight ruminally fistulated beef steers were utilized in a 4×4 replicated Latin Square design with 4 dietary treatments and 4 periods (21 d in length for each period with 14 d of adaptation and 7 d of collection). Four treatment diets were bran products (Bran A/B/C) included at 70% of diet dry matter (DM) with 25% steam flaked corn (SFC), and an internal control (SFC control) diet consisted of 70% SFC and 25% Sweet Bran, with 5% wheat straw in all 4 diets. The SFC control exhibited the greatest DM, organic matter (OM) and starch digestibility (P ≤ 0.06), and the least neutral detergent fiber (NDF) digestibility (P < 0.01). When 3 bran products each included at 70%, there was no difference in DM or OM intake and digestibility. Starch and NDF digestibility were greatest (P < 0.01) for bran A fed steers, least for bran C with bran B intermediate. Bran products had minimal effect on energy digestibility, ruminal pH, rumination activity and jugular vein blood parameters. Total ruminal VFAs concentration was greatest (P = 0.04) for SFC control, with no difference among bran A, B and C fed steers. Acetate: Propionate ratio was least (P < 0.01) for SFC control fed steers, greatest for bran A with bran B and C being intermediate. Digestion trait differences existed among different corn bran products, of which feeding bran A resulted in better digestion of starch and NDF, and greater starch content of bran B and C resulted in greater ruminal propionate production.
207 Polyclonal Antibodies Inhibit Growth of Key Cellulolytic Rumen Bacterial Species
Authors: Tondini Sara M , Mackie Roderick I , McCann Joshua C
Published: April 2022

The objective was to develop efficacious polyclonal antibodies to inhibit growth of targeted cellulolytic rumen bacterial species. Many rumen microorganisms have overlapping functions, so inhibiting the activity of targeted bacterial species may help elucidate their dynamic contributions to rumen fermentation. Egg-derived, polyclonal antibodies were developed against whole-cell cultures of Ruminococcus albus 7 (anti-RA7), Ruminococcus albus 8 (anti-RA8), and Fibrobacter succinogenes S85 (anti-FS85). Antibodies were added to a cellobiose-containing growth medium of pure cultures of the 3 targeted species. Antibody efficacy was determined via an inoculation time (0 and 4 h) and dose response. Antibody doses included: 0 (CON), 0.013 (LO), 1.3 (MD), 13 (HI) mg antibody per 10 mL of medium. Each targeted species inoculated at 0 h with HI of their respective antibody had decreased (P < 0.01) final optical density and total volatile fatty acid (VFA) concentration after a 52-h growth period when compared with CON or LO. Live/dead stains of R. albus 7 and F. succinogenes S85 dosed at 0 h with HI of their respective antibody indicated a decrease (≥ 96%; P < 0.05) of live bacterial cells during mid-log phase compared with CON or LO. Addition of HI of anti-FS85 at 0 h in F. succinogenes S85 cultures reduced (P < 0.01) total substrate disappearance over 52 h by at least 48% when compared with CON or LO. Cross-reactivity was assessed by adding HI at 0 h to non-targeted bacterial species. Addition of anti-RA8 or anti-RA7 to F. succinogenes S85 cultures did not affect (P ≥ 0.45) total VFA accumulation after 52 h incubation. Overall, polyclonal antibodies were more efficacious at inhibiting growth of targeted cellulolytic bacteria than non-targeted bacteria. Specific polyclonal antibodies can be used to further characterize functional contributions of bacterial species to rumen fermentation.
209 Effects of Biochar in Finishing Beef Cattle Diets on Greenhouse Gas Emissions
Authors: Heil Holly A , Troyer Braden , McPhillips Levi J , Sperber Jessica L , Watson Andrea K , Erickson Galen E
Published: April 2022

Two experiments were conducted to evaluate impacts of biochar on methane (CH4) and carbon dioxide (CO2) emissions, performance, and carcass characteristics of finishing beef cattle. Experiment 1 (initial BW = 329 kg ± 19 kg) utilized biochar sourced from pistachio shells (VGrid Energy Systems) in a 70% corn, 20% distillers grains, and 5% corn residue diet. Experiment 2 (initial BW = 386 kg ± 19 kg) utilized biochar sourced from ponderosa pine wood waste (Vital Ag) in a 40% corn, 40% Sweet Bran, and 15% corn silage diet. Both experiments evaluated 2 treatments: control (CON) diet containing no biochar and biochar (BIO) replacing 1% of dietary corn. Pen was the experimental unit with 8 steers per pen and 8 replications. Four replications rotated through a two-chamber emissions barn in 5-d cycles to measure CH4 and CO2 emissions. Cattle performance data were analyzed using the MIXED procedure of SAS with treatment and body weight block as fixed effects and emissions data analyzed as repeated measure. There were no statistical differences in experiment 1 for CH4, g/d (P = 0.75) and g/kg of dry matter intake (DMI; P = 0.99) or CO2 as g/d (P = 0.94) and g/kg DMI (P = 0.88). No impact on cattle performance or carcass characteristics were observed (final BW, DMI, average daily gain, gain to feed, hot carcass weight, longissimus muscle area, USDA quality grade, 12th rib fat; P ≥ 0.21). In experiment 2, there were no statistical differences between treatments for CH4, g/d (P = 0.78) and g/kg DMI (P = 0.84) or CO2, g/d (P = 0.50) and g/kg DMI (P = 0.52). Supplementing biochar at 1% of diet DM did not impact CH4 and CO2 emissions from finishing beef cattle. Cattle performance and carcass characteristics were not impacted by biochar in experiment 1.
211 Greenhouse Gas Emissions from Two Beef Systems from Birth to Slaughter in Eastern Nebraska
Authors: McPhillips Levi J , Carlson Zachary , MacDonald Jim C , Suyker Andy , Awada Tala , Watson Andrea K , Okalebo Jane , Xiong Yijie , Dangal Shree , Heil Holly A , Stowell Rick , Erickson Galen E
Published: April 2022

Greenhouse gas emissions from a conventional (CONV) pasture-based cattle production system with cows wintered on corn residue and summer grazing of brome pasture was compared with partial-confinement system (ALT) with cows and calves in a drylot during the summer and grazed cover crops and corn residue over the fall and winter. Four groups of 20 cows were in each system. Eddy covariance methods were used to measure emissions from grazed areas (corn residue and pasture) and pen chambers were used to measure emissions from feedlot pens (cows and calves). Cattle from the CONV system produced more CH4 and CO2 but produced more beef per cow exposed (321 and 303 kg HCW for CONV and ALT, respectively). Measured CH4 and modeled N2O emissions totaled 7.5 ± 0.3 and 7.4 ± 0.3 kg CO2e kg-1 HCW for CONV and ALT production, respectively. There was a measured uptake of 233 g C m-2 and 98 g C m-2 from brome pasture and cover crop, respectively. Accounting for CH4 and N2O emissions using global warming potential (GWP) of 23 and 298 resulted in a net sink of 0.7 ± 0.2 kg CO2e kg-1 HCW for CONV and source of 16.7 ± 1.5 kg CO2e kg-1 HCW for ALT. The same calculation using global warming potential (GWP) of 4 and 234 resulted in a net sink of 10.9 ± 1.0 kg CO2e kg-1 HCW for CONV and source of 7.1 ± 1.5 kg CO2e kg-1 HCW for ALT. Carbon sequestration from perennial grasslands in the CONV was enough to offset all emissions and biogenic CO2 and the annual forage grazed in the ALT system offset 33 to 72% of systems emissions depending on GWP metric used.
226 Evaluation of a Low-Moisture, Molasses-Based Block Containing Organic Trace Minerals and a Saccharomyces Cerevisiae Fermentation Culture in Newly Weaned Beef Steer Calves
Authors: Hamilton Thomas G , Rusche Warren C , Walker Julie , Wright Cody , Smith Zachary K
Published: April 2022

The objective of this study was to evaluate growth performance responses and hepatic trace mineral status of newly weaned steer calves offered a molasses-based “stress” tub. Steers [n = 46; body weight (BW) = 240; SEM = 1.0 kg) were used in a randomized complete block design experiment. On d -1 all steers were stratified by initial BW and allotted to pens (n = 4 to 5 steers per pen; 5 pens/treatment).Treatments were: 1) No “stress” tub (Con) or 2) Ad libitum access to a “stress” tub (Stress Tub; Purina Animal Nutrition, St. Louis, MO) for the first 21-d (Tub). Steers were allotted to their study pens within 36-h of weaning and the “stress” tub was introduced approximately 24-h post arrival. Tub disappearance was monitored daily. Liver biopsies (n = 2 steers/pen) were collected on d 7, 21, and 42 for determination of Co, Cu, Mn, and Zn. From d 1 to 21 and d 1 to 42 steers from in the Tub treatment consumed greater (P ≤ 0.01) amounts of Co, Cu, Mn, and Zn. A treatment × day interaction for hepatic concentrations of Co (P = 0.09), Cu (P = 0.01), and Zn (P = 0.01) were noted. On d 7, steers from Tub had greater (P≤0.01) hepatic Co, Cu, and Zn . On d 21, steers from Tub had greater (P ≤ 0.01) hepatic Co and Cu. On d 42 steers from Tub had greater (P = 0.01) hepatic concentrations of Cu. During the initial 21-d of the experiment gain efficiency was enhanced (P = 0.03) by 25.0% in steers from Tub compared with Con. Cumulative ADG, DMI, dietary NE utilization, and G:F did not differ (P ≥ 0.14). It is concluded that stress tubs do not influence overall growth performance or NE value of the diet during a 42-d period. Stress tub consumption increased hepatic mineral stores during the initial 21-d and enhanced Cu status of calves throughout the 42-d receiving period.
223 Proteomic Analysis Reveals Differential Tissue Responses to Road Transportation in Beef Steers
Authors: Deters Erin L , Hansen Stephanie L
Published: April 2022

Thirty-six Angus-cross steers (324 ± 36 kg) were used to assess the effects of long-duration road transport on protein profiles of liver and skeletal muscle. Steers were randomly assigned to treatments (initiated on d 0): control (CON) = no transit with ad libitum access to feed, deprivation (DEPR) = no transit with no feed or water for 18 h, or transit (TRANS) = road transport with no feed or water for 18 h (1,790 km). Liver and muscle (longissimus dorsi) samples were collected from all steers immediately after treatment termination. Following extraction for total metabolite analysis, tissue protein fractions were submitted to the Protein Facility at Iowa State University for protein identification via liquid chromatography-mass spectrometry and quantification via chemical labeling with isobaric mass tags. Data were analyzed with MetaboAnalystR package v.3.0. Proteins were considered differentially abundant if the t-test P-value was ≤ 0.1 and the absolute value of change between treatments (fold change) was ≥ 1.2. In the liver, several proteins involved in energy metabolism were less abundant for DEPR or TRANS compared with CON. Nicotinate-nucleotide pyrophosphorylase, an enzyme involved in NAD biosynthesis, was less abundant in TRANS compared with CON or DEPR. Several proteins involved in inflammation and innate immunity were more abundant in TRANS compared with CON. In the muscle, alpha-2-HS-glycoprotein, a regulator of inflammation and insulin resistance, was more abundant in TRANS compared with CON or DEPR. Several proteins involved in antioxidant defense (Mn-superoxide dismutase and glutathione transferase) were less abundant in TRANS compared with DEPR. These data suggest some, but not all, physiological changes associated with long-duration transport can be attributed to feed deprivation. The physical exertion required during transport appears to affect oxidative stress in the muscle, which could impact local and systemic inflammation and nutrient metabolism.
227 Diet and Management Strategies to Mitigate Decreased Feed Intake Associated with Terminal Implant Administration in Finishing Beef Steers
Authors: Kelly Alexandria M , Smith Zachary K , Wright Cody , Gonda Michael
Published: April 2022

Terminal implant administration in beef steers often leads to decreased feed intake, leading to less growth. Our objective was to identify diet and management changes that can mitigate this decreased intake. Single-sourced Angus x Simmental steers [n = 27, initial BW = 385.1kg (SD 30.8)] were enrolled in a completely randomized trial to assess the effects of animal movement and dietary net energy for gain (NEg) reduction on feed intake. Steers were implanted with Synovex Choice (100 mg trenbolone acetate and 14 mg estradiol benzoate; Zoetis, Parsippany, NJ) and re-implanted 88 d later with Synovex Plus (200 mg trenbolone acetate and 28 mg estradiol benzoate). Steers had been consuming the finishing diet for approximately 88 d at the time of re-implanting. Steers were allocated into 1 of 3 treatment groups: 1) remained on a 1.43 Mcal/kg NEg diet and moved a shorter distance between the pen and working facility (0.43km), 2) remained on a 1.43 Mcal/kg NEg diet and moved a longer distance (1.05km) to simulate movement in a larger feedlot and 3) fed a 1.32 Mcal/kg NEg diet and moved 1.05km between the pen and working facility. Individual feed and water intake was collected with Insentec feeders and waterers. Individual rumination data was collected with SenseHub Beef (AllFlex Livestock Intelligence). There was no significant difference in feed intake among treatments (P = 0.26) for 14 d after re-implant. There was significant difference in rumination among treatments (P = 0.03), with treatment 1 having the greatest minutes of rumination overall. Treatment 1 had significantly greater minutes of rumination than Treatment 3 (P = 0.04) and tended to have greater minutes of rumination than Treatment 2 (P = 0.08). Decreasing NEg of the diet did not mitigate feed intake depression but travelling a greater distance did negatively impact rumination for 14 d after re-implanting.
233 Feeding and Managing Dairy Cattle Genetics for Beef
Authors: Carvalho Pedro H V , Felix Tara L , Jaborek Jerad
Published: April 2022

The contribution of dairy steers to the U.S. fed beef supply has increased over the last 2 decades. In part, due to declining beef cow numbers and increased use of sexed dairy semen to produce genetically superior replacement heifers from the best dairy cows in the herd. Raising dairy cattle for beef production offers unique opportunities and challenges when compared with feeding native beef cattle. Dairy steers offer predictable and uniform feedlot performance (ADG, DMI, G:F) as a group, and improved quality grades compared with their native beef counterparts. However, dairy steers yield less red meat compared with native beef cattle due to a greater ratio of bone to muscle, internal fat, organ size, and gastrointestinal tract weight. Dairy steers present carcass size problems in the beef packing industry, with Holstein carcasses being too long and Jersey carcasses being light weight. Beef × dairy crossbreeding strategies are being implemented on some dairy farms to increase the income generated from bull calves and to improve the feed efficiency and yield of beef produced from the U.S. dairy herd. This new model of beef production from the dairy herd is not without its challenges. Early beef × dairy crossbreeding efforts have demonstrated variable results. Successful adoption of beef × dairy crossbreeding in the cattle industry will depend on the proper selection of beef sires that excel in calving ease, growth, muscling, and marbling traits to complement the challenges realized with dairy genetics involved in beef production.
247 Effects of Feeding Frequency During Lactation on Sow and Litter Performance
Authors: Silva Junior Sudario Roberto , Manu Hayford , Swartz Drew , Baidoo Samuel
Published: April 2022

The objective of this study was to determine the effects of feeding frequency on sow and litter performance during lactation. At d 109 of gestation, a total of 300 sows (Landrace × Yorkshire; BW 245± 3.2 kg; parity 2.54 ± 0.21); were blocked by parity and randomly assigned to 1 of 2 treatments. The treatments were: sows fed twice daily at 0730 and 1530 h (T1) or 3 times daily at 0730, 1130, and 1530 h (T2). Sows were fed a corn-soybean meal- containing 3.4 Mcal of ME/kg and 1.03% SID Lys. Sow BW and BF measurements were recorded at d 109 and at weaning. Litters were cross-fostered within treatments within 24-h after farrowing, and litter weights were collected at 12-h post-farrow, and again at weaning. Normality of the data set was checked using proc univariate procedure of SAS and analyzed using GLIMMIX procedure. Statistical significance was set at P ≤ 0.05, and a trend as 0.05 < P ≤ 0.10. An individual sow and a litter were the experimental unit. Comparisons were performed with Student’s t-test at 5% of significance. No evidence (P > 0.10) for treatment differences were observed in sow BW, BF, total born, mummified fetuses, stillbirth rate, and litter or piglet weight gain during lactation. Sows fed twice daily had a greater (9.8 % vs. 11.2 %) (P < 0.05) pre-weaning mortality during lactation period than sows fed 3 times daily. In conclusion, feeding sows 3 times daily exhibited the potential to reduce the pre-weaning mortality rate by 1.4% during lactation.
248 Relationships Between Sow and Litter Parameters and Sow Rectal Temperature at the End of Farrowing
Authors: Vande Pol Katherine D , Shull Caleb M , Ellis Michael
Published: April 2022

There is evidence that sow rectal temperature during farrowing may be associated with farrowing duration and difficulty, and stillbirth rates. However, factors affecting sow temperature during parturition have not been well quantified. The objective of this study was to evaluate relationships between sow and litter parameters and sow rectal temperature at the end of farrowing. Data (1005 sows/litters) were from 5 studies conducted on the same commercial farrowing facility with the same management. Independent variables included sow parity, use of farrowing induction, number of piglets born alive, litter weight, farrowing duration (on a sub-sample of 289 litters), and room temperature at the start of farrowing. Sow temperature at the end of farrowing averaged 38.5 ± 0.53°C. Data were analyzed using PROC REG of SAS. Models accounted for the linear, quadratic, and cubic effects of continuous independent variables, and/or the categorical effect of farrowing induction. Sow rectal temperature at the start of farrowing had a positive relationship with sow temperature at the end of farrowing and the greatest R2 value (0.33; Table 1). Individually, sow parity, farrowing duration, and induction were related (P ≤ 0.05) to sow rectal temperature at the end of farrowing. However, these factors explained a small proportion of the variation (R2 ≤ 0.05) in sow temperature. For the multivariate model, only room temperature and sow rectal temperature at the start of farrowing were related (P ≤ 0.05) to temperature at the end of farrowing, explaining 34% of the variation. In conclusion, these results suggest that sow temperature at the start of farrowing had the greatest influence on temperature at the end and that other factors (sow parity, farrowing duration, farrowing induction, and room temperature) were relatively unimportant.
250 Associations Between Sow and Litter Parameters and Piglet Birth Weight and the Within-Litter Coefficient of Variation of Piglet Birth Weight
Authors: Vande Pol Katherine D , Shull Caleb M , Ellis Michael
Published: April 2022

The objective was to evaluate associations between sow, litter, and piglet parameters and both piglet birth weight (BW), and within-litter coefficient of variation of piglet birth weight (CV). Data (1,005 sows/litters, 12,857 piglets) were from 5 studies conducted on the same commercial farrowing facility using the same management. Independent variables included sow parity, use of farrowing induction, number of piglets born alive, litter weight, BW (for analysis of CV), and piglet sex (for analysis of BW) and birth order (for analysis of BW; on a sub-sample of 289 litters/3,643 piglets). Data were analyzed using PROC REG of SAS. Models accounted for linear, quadratic, and cubic effects of each independent variable. The BW and CV averaged 1.49 ± 0.271 kg and 19.5 ± 6.69%, respectively. All independent variables were related (P ≤ 0.05) to BW (Table 1), with litter size having the strongest relationship (R2 = 0.11), and all other variables having weak relationships (R2 ≤ 0.01). All independent variables were related (P ≤ 0.05) to CV, with the exception of farrowing induction. Litter size explained the greatest amount of variation (R2 = 0.17), followed by litter weight and average piglet birth weight (R2 = 0.10 and 0.07, respectively). Other variables each explained a relatively small proportion (R2 ≤ 0.05) of variation in CV. Multivariate models including all significant (P ≤ 0.05) variables explained 13 and 22% of the variation in BW and CV, respectively. In conclusion, the primary variable associated with both BW and CV was litter size. Increases in litter size were associated with reductions in BW and increases in CV. Other variables showed weak relationships. However, even when all of these variables were accounted for, there was a large proportion of variation in both BW and CV that was not explained.
255 Impact of Water Flow Rate on Finishing Pig Performance Under Commercial Conditions
Authors: Miller Hannah E , Perez-Palencia Jorge Y , Samuel Ryan S , Levesque Crystal L , Thaler Robert C
Published: April 2022

A survey of South Dakota pork producers in 2019 reported that 68% had water flow rates above the recommended rate of 500-1,000 mL/min. The objective of this study was to determine the impact of water flow rate on finishing pig performance during from June to September in a commercial barn. A total of 1,227 mixed sex pigs (61 ± 4.38 kg) at 8-weeks post-wean were utilized in an 84-d trial with 26 pigs/pen and 2 cup waterers/pen. Pens were assigned to 1 of 3 water flow rates (high, medium, low) based on the 3-hole diameter of the water nipples (2.0, 1.0, 0.80 mm; n = 16 pens/setting). Individual pen water flow rate, water disappearance, BW, and feed disappearance were recorded every 2 weeks. Carcass data was collected at the conclusion of the trial. Water flow rates averaged 1,565±96, 1,115±265, and 605±203 mL/min for high, medium, and low flow rates, respectively. Ambient temperature ranged from 4 to 37 °C. There was no difference in growth performance based on means separation test. Due to variability of water flow rate within a setting, data was further analyzed using regression with flow rate as the independent variable. There was a positive quadratic relationship (P < 0.05) for daily water disappearance (adjR2 =0.87) and daily gain (adjR2 =0.11) with water flow rate and a tendency for positive linear relationship between final BW (P = 0.07, adj. R2 = 0.06) and flow rate. Feed conversion had a negative cubic relationship with water flow rate (P < 0.05, adj. R2 = 0.20) and no relationship between hot carcass weight or average daily feed intake and water flow rate. The low R2 values associated with pig performance and high association with water disappearance suggest that excess water flow rate has a low impact on finishing pig performance but contributes to water wastage and its associated costs.
254 Impact of Preweaning Factors on Nursery Throughput
Authors: Knauer Mark , Armstrong Terry , Barnes Brandon , Jones Austin , Mobley Bo , O'Dell Tyler , Tyre Lee , Wynn Matthew
Published: April 2022

The objective was to evaluate factors associated with nursery throughput. Data consisted of 3,260 piglets from 320 litters at the NCDA Tidewater Research Station. At weaning, piglets were housed nine per pen (0.23m2 per pig) in onsite nursery facilities for 35 d. Using linear models, farrowing batch (BATCH), gender, litter size (LS), average piglet birth weight (BWT), birth weight CV (BWT_CV), piglet weaning weight (WWT), weaning weight CV (WWT_CV) and weaning age (WEANAGE) were associated with nursery average daily gain (NurADG), nursery exit weight (NurEXITWT), nursery survival (SURVIVAL) and full-value nursery pigs (FULLVALUE, pigs >13.6kg at nursery exit). Litter was the experimental unit. Average WEANAGE, WWT, SURVIVAL and FULLVALUE were 28.1 (±4.7 d), 7.8kg, 98.7% and 94.3%, respectively. Correlations between NurADG with gender, LS, BWT, BWT_CV, WWT, WWT_CV and WEANAGE were zero, -0.04, 0.24, 0.09, 0.81, 0.10 and 0.73, respectively. Factors related (P < .01) to NurADG included BATCH, BWT, WWT and WEANAGE (R2 = 0.80). Within these factors, WWT and WEANAGE explained 70% of the variation in NurADG. A 1kg increase in BWT and WWT increased (P < 0.01) NurADG by 60.3 and 19.4g per pig per d, respectively. A 1 d older WEANAGE increased (P < 0.01) NurADG by 9.36g per pig per d. Increased NurEXITWT was associated (P < 0.05) with BATCH and greater BWT, WWT and WEANAGE (R2=0.88). Within these, WWT and WEANAGE explained 83% of the variation in NurEXITWT. A 1kg increase in BWT and WWT increased (P < 0.01) NurEXITWT by 2.09 and 1.68kg per pig, respectively. A 1 d older WEANAGE increased (P < 0.01) NurEXITWT by 323g per pig. Increased BWT was associated (P < 0.01) with greater SURVIVAL, explaining 4% of the variation. Improved FULLVALUE was associated with (P < 0.05) BATCH and generally greater BWT, WWT and WEANAGE (R2 = 0.44). Of the factors studied, WWT had the greatest impact on the percentage of FULLVALUE at nursery exit (R2 = 0.36).