bluuebunny/crossref_metadata_2025_split huggingface dataset:
160 The Compensatory Growth of Finishing Pigs Fed Increasing Dietary Lysine Following a Period of Nutrient Restriction
Authors: Hagen Chloe S , Greiner Laura L , Spencer Joel , Krahn Gregory 
Published: April 2022

Abstract
The objective of this experiment was to evaluate the degree of compensatory gain in finishing hogs when fed increasing levels of lysine during the re-alimentation period after being fed a restrictive 97% corn diet for 3 or 6 weeks. One hundred and forty mixed-sex pens (DNA Genetics, Columbus, NE) with a starting body weight of 73.5 ± 2.2 kg were blocked by starting bodyweight and assigned to a 2:3:1 factorial. Twenty replicates of seven treatments were comprised of 2 restriction lengths [3 weeks (3W) vs. 6 weeks (6W)], and 3 lysine inclusion levels at re-alimentation (Lys:ME: 100%, 110%, or 120% of the genetic margin over feed curve), and a control that remained nutrient unrestricted. Pen weight and feed disappearance were recorded at trial day zero and every 3-weeks until market. Whole pens were marketed when the average met 130 kg to evaluate the full re-alimentation period. Data were analyzed by pen (SAS 9.4, Cary, NC) with the fixed effects of restriction length and lysine level nested within restriction length. Control pigs were market weight (130 kg) on d 49 while pigs fed corn diets for 3 weeks or 6 weeks were significantly slower to market (57 and 69 d, respectively; P &lt; 0.01). Overall average daily gain was significantly different between the control, 3W, and 6W groups (Control: 1.17, 3W: 0.99, 6W: 0.82; P &lt; 0.01). Furthermore, overall average daily gain was significantly influenced by the lysine inclusion level during re-alimentation (Control: 1.17, 3W/100%: 0.98, 3W/110%: 0.99, 3W/120%: 1.01, 6W/100%: 0.81, 6W/110%: 0.83, and 6W/120%: 0.84 kg/d; P &lt; 0.03). In conclusion, the use of 97% corn diets significantly reduced average daily gain and increased days to market. However, the use of diets in which the Lys:ME was greater than genetic recommendations after a period of nutrient restriction, resulted in increased compensatory growth.
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

Abstract
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 &lt; 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 &lt; 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

Abstract
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

Abstract
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 &lt; 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

Abstract
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 &lt; 0.08). Implantation rate was not different between treatments (P &gt; 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 &gt; 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 &lt; 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

Abstract
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 &lt; 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

Abstract
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 &lt; 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

Abstract
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

Abstract
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 &lt; 0.01) than ADG of piglets from controls. Additionally, piglet mortality was substantially greater (P &lt; 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

Abstract
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 &lt; 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

Abstract
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.