bluuebunny/crossref_metadata_2025_split huggingface dataset:
230 Microalgae as an Alternative Feed Protein: Opportunities and Challenges
Authors: Lei Xingen 
Published: October 2021

Abstract
A major mission of the animal industry is to help protect global food security with little or no impacts on climate and environment. In fact, the global food security depends on a sustainable protein production and supply. Currently, there is a direct competition between feed and food protein need. As animal feeds use 70–80% of the produced soybean, alternative proteins are required to sustain the industry. This presentation will report research findings from three large consortium projects in exploring the dual application of microalgae as a new generation of feedstock for biofuel production and high-quality feed protein supply. A comprehensive review will be provided on effects of supplemental full- or de-fatted microalgal biomass in diets for broiler chickens, laying hens, pigs, and fish on their production performance, nutrient metabolism and molecular responses, and health values of their products. Discussions will be given on practical concerns over the production cost related to soybean meal, the production volume/scale for a constant supply, and the biosafety and acceptance as a regular ingredient. Future research will be proposed to synchronize the nutritional, health, and sustainability potential of microalgae as a viable feed protein source.
237 Incidence and Implications of Disparate Uterine and Ovarian Development Observed Among Heifers Evaluated During the Peripubertal Period
Authors: Smith Emily G , Thomas Jordan M , Spinka Christine 
Published: October 2021

Abstract
Rapid development in the reproductive tract occurs in the peripubertal period, with variable rates of development of reproductive tissues potentially resulting in perceived disparities in ovarian and uterine development at pre-breeding examination. Data collected from 22,173 heifers evaluated over five consecutive breeding seasons (2014–2018) were analyzed retrospectively to assess relationships between observed disparities in uterine and ovarian development and the timing of conception within the breeding season. Pre-breeding evaluations were conducted 35–45 days prior to breeding. Weight, hip height, and pelvic area were recorded. A single veterinarian conducted all reproductive evaluations via rectal palpation, and heifers were assigned individual scores for ovarian (2=infantile, 3=no significant structures, 4=large follicle and/or corpus luteum) and uterine (2=infantile, 3=mid-sized, distended tract, 4=well-vascularized, distended or coiled tract) development respectively. Heifers received artificial insemination (AI) based on detected estrus following the 14-day MGA-PG protocol. Pregnancy diagnosis was performed via transrectal ultrasonography. Pregnancy rates to AI (P/AI) were greater for scores 4-4 (n = 14,567) in comparison with 3-3 (n=3,941; P &lt; 0.0001) or 2-2 (n = 44; P &lt; 0.0001) and likewise were greater (P &lt; 0.0001) for scores 3-3 in comparison with 2-2. Heifers with disparate scores of 2–3 (n = 38) did not differ (P = 0.53) from those with disparate scores of 3-2 (n = 53) with respect to P/AI, but either disparity was associated with greater (P &lt; 0.01) P/AI relative to scores of 2-2 and reduced P/AI relative to scores of 3-3 (P &lt; 0.01). Scores of 4-3 (1,698) and 3-3 did not differ (P &gt;0.44) in P/AI, but P/AI tended (P = 0.06) to be greater among scores 3–4 (1,832) in comparison with 3-3. Similar (P &gt; 0.33) P/AI was observed among heifers scored 4-4, 4-3, or 3–4. In summary, disparate ovarian and uterine development impacted timing of conception within the breeding season among heifers with lower tract scores. Such disparities were observed among 0.4% of heifers evaluated.
234 Pregnancy and Hormonal Response in Suckled Beef Cows Administered High-concentration Prostaglandin F2α in a 5-day CO-Synch + CIDR Synchronization Program
Authors: Ahmadzadeh Amin , Corpron McKenzie , Hall John B , Ahmadzadeh Amin , Dalton Joe 
Published: October 2021

Abstract
Two injections of prostaglandin F2 (PGF) in a 5-d CO-Synch+CIDR timed-AI protocol (5-d CIDR) is necessary to induce luteolysis and reduce serum progesterone (P4) concentrations by the time of AI in beef cattle. The objectives were to examine the effects of a single high-concentration dose of PGF in a 5-d CIDR protocol on P4 concentration and pregnancy per AI (P/AI) beef cows. Angus-Hereford cows (n = 404) were synchronized (d0) with a 5-d CIDR protocol and assigned to receive either one injection of high-concentration PGF on d5 (HC; total dose: 25 mg; n = 203) or two injections of conventional PGF (2PG; each injection: 25 mg; n = 201), at CIDR removal (d5) and 8 h later. All cows received AI at a fixed time 72 h after PGF treatment (d8). Pregnancy was determined by ultrasound 48–63 days after AI. For P4 and cyclicity determination, blood samples were collected on d -7, 0, and 8. Cyclicity status and proportion of cows with a CL at d0 did not differ between treatments. Proportion of cows detected in estrus was greater (P = 0.01) for 2PG (63.1%) than HC (49.3%). Treatment did not affect P/AI (P = 0.87; 51% vs. 52% for HC and 2PG, respectively). Serum P4 at AI also affected (P &lt; 0.01) P/AI; as P4 concentration increased, P/AI decreased. ROC analysis showed a greater P/ AI when P4 was &lt; 0.43 ng/mL. Fewer (P &lt; 0.01) HC cows had P4 &lt; 0.43 ng/mL at AI than 2PG (84.0 and 97.0%, respectively). Nonetheless, mean P4 concentrations at AI were less than 0.4 ng/mL for HC and 2PG. Although two doses of conventional PGF (total dose: 50 mg) more effectively reduced P4 to &lt; 0.43 ng/mL by the time of AI than one dose of high-concentration PGF (total dose: 25 mg), P/AI was not different between treatments.
236 Factors Influencing Clearance of Pregnancy-associated Glycoproteins in Postpartum Beef Cattle
Authors: Kline Adalaide C , Walker Julie , Andrews Taylor , Zoca Saulo Menegatti , Epperson Kaitlin M , Quail Lacey , Rich Jerica J , Perry George A , Rhoades Jim R 
Published: October 2021

Abstract
Blood pregnancy tests can determine pregnancy status in cattle; however, pregnancy-associated glycoproteins (PAGs) have a long half-life (80 to 100 d). If tested too soon after calving, false positive readings can occur due to elevated concentrations from the previous pregnancy. This study’s objective was to determine factors that impact clearance of PAGs in postpartum beef females. Blood samples were collected from postpartum Angus and Angus-cross females (primiparous n = 46 and multiparous n = 58); once a week for up to 14 weeks after calving (range of first to last sample 1–7 to 98–105 days postpartum; dpp). Serum was tested in duplicate using the IDEXX Alertys Pregnancy Test. Data were analyzed as a repeated measure using the MIXED procedure of SAS (9.4) with parity, calf sex (sex), days postpartum, and all interactions in the model. Data were analyzed using the REG procedure in SAS. There was a significant effect of dpp (P &lt; 0.01) on PAG concentrations; however, PAG concentrations were not influenced by parity (P = 0.24), sex (P = 0.49), parity by dpp (P = 0.12), parity by sex (P = 0.65), sex by dpp (P = 0.37), or parity by sex by dpp (P = 0.99). Concentrations of PAGs rapidly decreased from d 0 to 50 postpartum and then continued to gradually decrease to d 100. Days postpartum accounted for 67.53% of the variation in PAG concentrations. Prior to 50 dpp, PAG concentrations were sufficiently elevated which resulted in false positive readings (S – N ≥ 0.3). In summary, concentrations of PAGs remained elevated after calving, but the clearance of PAGs were not impacted by parity or sex of the calf. Clearance of PAGs were significantly influenced by days postpartum. Additionally, using a blood pregnancy test prior to d 50 postpartum would increase the likelihood of false positive readings due to residual PAG concentrations from the previous pregnancy.
241 Skeletal Muscle Mitochondrial Capacities Are Impacted by Breed and Temperament in Young Angus and Brahman Steers
Authors: Guy Chloey P , Wesolowski Lauren T , Earnhardt Audrey L , Law Dustin , Neuendorff Don A , Long Charles R , Perry George A , Randel Ron D , Welsh Thomas H , White-Springer Sarah H 
Published: October 2021

Abstract
Temperament impacts skeletal muscle mitochondria in Brahman heifers, but this has not been investigated in steers or between cattle breeds. We hypothesized mitochondrial measures would be greater in Angus than Brahman, temperamental than calm steers, and the trapezius (TRAP) than the longissimus thoracis (LT) muscle. Samples from calm (n = 13 per breed), intermediate (n = 12 per breed), and temperamental (n=13 per breed) Angus and Brahman steers (mean±SD 10.0±0.8 mo) were evaluated for mitochondrial enzyme activities via colorimetry. Calm and temperamental LT samples were evaluated for oxidative phosphorylation (P) and electron transfer (E) capacities by high-resolution respirometry. Data were analyzed using linear models with fixed effects of breed, muscle, temperament, and all interactions. Brahman tended to have greater mitochondrial volume density (citrate synthase activity; CS) than Angus (P = 0.08), while intrinsic (relative to CS) mitochondrial function (cytochrome c oxidase activity) was greater in Angus than Brahman (P = 0.001) and greater in TRAP than LT (P = 0.008). Angus exhibited greater integrative (per mg tissue) and intrinsic P with complex I (PCI), P with complexes I+II (PCI+II), maximum noncoupled E, and E with complex II (ECII; P ≤ 0.04) and tended to have greater intrinsic leak (P = 0.1) than Brahman. Contribution of PCI to total E was greater in Angus than Brahman (P = 0.01), while contribution of ECII to total E was greater in Brahman than Angus (P = 0.05). A trend for the interaction of breed and temperament (P = 0.07) indicated calm Angus had the greatest intrinsic ECII (P ≤ 0.03) while intrinsic ECII was similar between temperamental Angus and calm and temperamental Brahman. Integrative PCI+II and ECII, and the contribution of PCI and PCI+II to overall E tended to be greater in temperamental than calm steers (P ≤ 0.09), while intrinsic ECII tended to be greater in calm than temperamental steers (P = 0.07). The impact of these mitochondrial differences on meat quality measures remains to be determined.
244 Fertility Outcomes Associated with Reproductive Tract Cytokines and Microbiota in Postpartum Beef Cows
Authors: Poole Rebecca K , Ault-Seay Taylor B , Payton Rebecca R , Myer Phillip R , Lear Andrea S , Pohler Ky G 
Published: October 2021

Abstract
Local immune activity in the reproductive tract is crucial in the response to uterine diseases, normal reproductive functions, and establishing pregnancy. Few studies have evaluated the influence of the local immune environment of the reproductive tract on fertility outcomes. The objectives were to 1) evaluate reproductive cytokine concentrations in postpartum cows undergoing estrus synchronization followed by timed artificial insemination (TAI) and 2) correlate reproductive bacterial communities with cytokine concentrations. Angus cows (n = 20) were subjected to a 7-Day Co-Synch protocol with pre-synchronization beginning 21 days prior (d -21) to TAI (d 0). Uterine and vaginal flushes were collected on d -21 and -2. Pregnancy was determined by transrectal ultrasound on d 30. Bacterial community profiling and analyses were conducted targeting the V1 to V3 hypervariable regions of the 16S rRNA gene. Cytokine concentrations for interleukin (IL)-1b, IL-6, IL-10, and transforming growth factor beta (TGF-β) were determined by commercial ELISA kits. Concentration data were analyzed using PROC MIXED and correlations using Pearson correlation in SAS. No differences were detected in vaginal samples (P &gt;0.05). No differences in IL-10 or IL-1b concentrations were detected in uterine samples (P &gt;0.05). Uterine TGF-β concentrations were greater in resulting pregnant than non-pregnant cows (44.0 ± 13.4 pg/mL vs 14.7 ± 4.9 pg/mL; P = 0.05). Uterine TGF-β was negatively correlated with the relative abundance of genera Treponema (r = -0.668; P = 0.05) in resulting non-pregnant cows on d -21. Uterine IL-6 concentrations were greater in resulting non-pregnant than pregnant cows (198.7 ± 21.8 pg/mL vs 144.3 ± 16.1 pg/mL; P = 0.05). Uterine IL-6 and the relative abundance of genera Butyrivibrio were positively correlated (r = 0.742; P = 0.02) in resulting non-pregnant cows on d -21. These results suggest possible relationships between uterine bacterial communities and cytokines prior to TAI that may ultimately affect fertility outcomes in beef cattle.
250 Effect of Pre- and Post-ai Nutrition on Ovarian Dynamics, Steroidogenesis, and Expression of Estrus in Beef Heifers
Authors: Epperson Kaitlin M , Rich Jerica J , Zezeski Abigail L , Zoca Saulo Menegatti , Walker Julie , Geary Tom W , Perry George A 
Published: October 2021

Abstract
The objective of this study was to evaluate nutrition before and after artificial insemination (AI) on follicular dynamics, expression of estrus, and steroidogenesis. Seventy-nine beef heifers were randomly assigned to one of two dietary treatments (High;155% and Low;86% of maintenance energy) 30d prior to AI. Estrus was synchronized (PG 6-d CIDR protocol) and heifers received AI (d0) 8 to 12h following onset of estrus. On d0, heifers were randomly reassigned diets generating four Pre-x-Post-AI nutritional treatments; High-High (HH, n = 20), High-Low (HL, n = 20), Low-High (LH, n = 19), and Low-Low (LL, n = 20). Heifers remained on new diet treatments until embryo collection (flush; d7-8). Blood samples were collected daily from d-3 to d0, and on d1, 3, 5, 7 and 8 for plasma concentrations of estradiol (E2) and progesterone (P4). Dominant follicle diameter was evaluated on d-3 and d0, and CL diameter was recorded at flush. Statistical analyses were completed in SAS using the MIXED (body weight, E2, P4), GLIMMIX (expression of estrus), and GLM (ovarian parameters, interval to estrus) procedures. There were Pre-AI (P &lt; 0.0001) and Post-AI by time (P &lt; 0.0001) interactions on body weight; heifers in high and low treatments gained and lost weight, respectively, during both periods. Estradiol concentrations increased (P &lt; 0.0001) from d-3 (2.18±0.15pg/mL) to d0 (6.05±0.04pg/mL). Pre-AI diet increased the proportion of heifers in estrus (80±6.3% vs. 59±7.9%; P = 0.05), and dominant follicle size (11.7±1.42mm vs. 10.68±1.33mm; P = 0.0016) in High vs. Low, respectively. Additionally, High Pre-AI heifers had greater P4 after AI compared to Low Pre-AI heifers (4.85±0.37ng/mL vs. 3.53±0.38ng/mL; P = 0.015). Post-AI treatment did not influence concentrations of P4 (P = 0.88). There was no effect of Pre, Post or Pre-x-Post-AI treatment on initial follicle size, follicle growth rate, E2 concentrations, interval to estrus, or CL size at flush (P &gt; 0.10). In conclusion, nutrient restriction before AI negatively impacted ovarian function, steroidogenesis, and expression of estru.
264 Using in vivo RNA Interference to Investigate Ruminant Placental Function
Authors: Anthony Russell V , Tanner Amelia R , Lynch Cameron S , Kennedy Victoria C , Rozance Paul J , Winger Quinton A 
Published: October 2021

Abstract
Pregnant sheep have been used extensively for investigating pregnancy physiology, providing valuable information about the progression of ruminant pregnancy. The ability to place indwelling catheters, within both maternal and fetal vessels, allows for steady-state investigation of blood flow, nutrient uptakes and utilization, and hormone secretion, under non-stressed and non-anesthetized conditions. As such, our understanding of the in vivo physiology of pregnancy in sheep is unrivalled by any other species. However, until recently, a significant deficit existed in determining the specific function or significance of individual genes expressed by the placenta in livestock. To that end, we developed and have been using in vivo RNA interference (RNAi) within the sheep placenta to examine the function and relative importance of genes involved in conceptus development (PRR15 and LIN28), placental nutrient transport (SLC2A1 and SLC2A3), and placenta derived hormones (CSH). The lentiviral vector LL3.7 is used to generate virus that is stably integrated into the infected cell’s genome, thereby expressing a short-hairpin RNA (shRNA), that when processed within the cell, combines with the RNA Induced Silencing Complex (RISC) resulting in specific mRNA degradation or translational blockage. To accomplish in vivo RNAi, day 9 hatched and fully expanded blastocysts are infected with the lentivirus for 4–5 hours, and then surgically transferred to synchronized recipient uteri. Only the trophectoderm cells are infected by the replication deficient virus, leaving the inner cell mass unaltered, and we typically obtain 70–80% pregnancy rates following transfer of a single blastocyst. Data will be presented from two projects. One is focused on generating a deficiency in placental glucose transporters at mid-gestation, and the other on the impact of CSH RNAi during late gestation, demonstrating the utility of this experimental approach for examining gene function within the placenta of livestock. Supported by NIH-NICHD grants HD093701 and HD094952.
260 Effect of Dam Nutrition on Offspring Reproductive Performance
Authors: Hall John B 
Published: October 2021

Abstract
Domestic ruminants utilize extensive pasture and rangelands as a primary source of nutrition. These forage sources vary greatly in nutritional content and availability due to season, plant species and climatic factors. Therefore, ruminants are exposed to nutrient excesses and deficiencies at varying points during the reproductive cycle. The objectives of this presentation are 1) to review our understanding of the impact of nutritional changes experienced by the dam during gestation on subsequent reproductive performance of female offspring, 2) examine the timing and duration of nutrient restriction on indicators of fertility in domestic ruminants and 3) compare responses under production conditions to mechanisms determined in controlled experiments. Depending on the time and severity of the nutrient deprivation, physiological effects include reduced gonadal weight, reduction in 2° and 3° follicles, alterations in the hypothalamic-pituitary axis, fetal weight and attainment of puberty. Anti-Müllerian hormone (AMH) and antral follicle count (AFC) are indicators of fertility in ruminants. Severe nutrient deprivation of heifers during the first trimester of gestation reduced AMH and AFC in female offspring. In contrast, a more moderate nutritional challenge to mature cows during early gestation did not result in changes in AMH and AFC in female offspring. Heifers from dams that grazed protein deficient range during the third trimester had delayed puberty onset and reduced pregnancy rates compared to heifers from supplemented dams. Recently, we compared indictors of fertility in heifers from dams that grazed range or irrigated pastures during the first two trimesters. Based on preliminary data, cows that grazed range were nutritionally challenged; however, heifers from range dams did not appear to differ in indicators of fertility from heifers from dams grazing irrigated pastures. Continued investigations on impacts of maternal nutrition on reproduction in offspring under production conditions are warranted.
266 Effects of Inflammatory States on Ovarian Biology and Oocyte Competence
Authors: Hernandez Gifford Jennifer A , Ferranti Emily , Forrest Kylee , Gifford Craig A 
Published: October 2021

Abstract
Female fertility is dependent on estradiol concentrations which regulate a multitude of ovarian functions including follicle development and oocyte maturation leading to ovulation of a viable oocyte. Estradiol biosynthesis is regulated by coordinated actions of follicle-stimulating hormone and intra-ovarian control mechanisms including the co-transcription factor beta-catenin. Beta-catenin is a multi-faceted protein recognized for its role in granulosa cell steroid production and is shown to be modulated by lipopolysaccharide (LPS), the endotoxin responsible for stimulation of the immune system in infections caused by Gram-negative bacteria. Beef heifers treated with subacute concentrations of LPS during a synchronized follicular wave demonstrate a decline in serum estradiol concentrations 50 h after CIDR withdrawal, corresponding with dominant follicle maturation and preceding ovulation. The endotoxin exposure also resulted in increased LPS concentration and E2:P4 ratios in follicular fluid suggesting that low dose LPS modulates the intra-follicular hormonal milieu. Additionally, in a granulosa cell line, LPS treatment decreased mRNA expression of aromatase and beta-catenin. These data indicate that LPS alters E2 synthesis by modulating beta-catenin and subsequent steroidogenic enzyme expression. To further explore the contribution of naturally occurring LPS exposure on follicular steroid production and developing oocytes, bovine ovary pairs were collected from local abattoirs. Oocytes were aspirated from small follicles and matured in vitro to evaluate meiotic events related to nuclear maturation and spindle morphology. Small follicles from ovarian pairs were separated by the detectable LPS concentrations into high and low LPS groups. Oocytes matured from low LPS follicles demonstrated an increase in the percent of abnormal maturation events. Data indicate that induced or naturally occurring low doses of LPS can alter circulating and follicular estradiol concentrations impairing oocyte maturation. Perturbation to local ovarian signaling cascades from subclinical inflammatory disease may be an unappreciated factor altering fertility and leading to decreased cow retention.
262 Reproductive Microbiomes as Predicators of Fertility in Beef Cattle
Authors: Poole Rebecca K 
Published: October 2021

Abstract
Over the past decade, a multitude of research has sought to understand the complexity and role of the reproductive microbiome as it pertains to fertility. Previously, the reproductive microbiome was evaluated using culture-dependent methods; however, recent advancements in culture-independent, 16S rRNA gene amplicon community sequencing have vastly expanded our understanding of the reproductive tract microbiome. Early sequencing studies sought to compare the vaginal microbiome of cattle to the vaginal microbiome of healthy women, which predominantly consists of bacteria in the genus Lactobacillus and believed to be an indicator of fertility. In the vagina of beef cattle, however, there are incredibly low abundances of Lactobacillus and a greater diversity of bacterial species present. Beta-diversity, which examine differences in bacterial communities between samples, does not appear to differ in the vagina between unbred, open, or pregnant cattle. In postpartum beef cattle just prior to breeding, there are greater levels of diversity and increased bacterial species richness in the vagina compared to the uterus. Research on bacterial species within the uterus have primarily focused on pathogenic bacteria in postpartum cattle diagnosed with uterine disease. Fewer studies have investigated uterine bacterial species in presumed healthy postpartum beef cattle and the subsequent effects on fertility outcomes (e.g., pregnant vs. open at day 30). When evaluating the uterine microbiome during an industry standard estrus synchronization protocol, bacterial community abundance and diversity reduce over time regardless of resulting fertility outcomes. The greatest difference in uterine bacterial abundance between resulting pregnant and non-pregnant cattle appears to occur just prior to breeding. Numerous mechanisms could be contributing to the fluctuations in the uterine microbiome in beef cattle including circulating hormone concentrations or local immunoregulation. This presentation will focus on recent research investigating potential mechanisms that may alter the reproductive microbiome and ultimately impact fertility.