Evaluation of citrus fiber as a natural alternative to sodium tripolyphosphate in marinated boneless broiler chicken breast and inside beef skirt (transversus abdominis)

OBJECTIVE

This research was conducted to evaluate the effects of citrus fiber (CF) as a natural alternative to sodium tripolyphosphate (STPP) in marinated broiler boneless chicken breast and inside beef skirt on overall retention rate, shear force, and consumer sensory attributes.

METHODS

Five different marinade formulations were targeted to include 0.9% salt, either 0.25% or 0.50% STPP or CF and water on a finished product basis. Water and salt only were considered the negative control (CON). Chicken breasts (n = 14) and inside beef skirt (n = 14) were randomly assigned to a treatment, raw weights recorded and then placed in a vacuum tumbler. Marinated weights were recorded, individually packed, and randomly assigned to either retail display for 10-day retention rate, shear force analysis, cook loss, or consumer sensory panel.

RESULTS

Pickup percentage, and overall retention was similar among treatments for chicken breast and inside beef skirt. Citrus fiber treatments resulted in higher cooking loss compared to the CON in chicken breast; though, CF050 resulted in similar cooking loss compared to STPP025 in inside beef skirt. No differences were found in sensory attributes for chicken breast, however, WBSF data showed CF025 was tougher than CF050, STPP050, and CON. Inside beef skirt with CF050 were least liked overall by the consumer panel.

CONCLUSION

Citrus fiber included in marinades at a lower percentage rate can produce similar texture characteristics, and sensory properties compared with those marinated with STPP.

PSI-1 An Evaluation of Functionality of Cryopreserved Sperm Cells Treated with Heifer-Plus™

The commercial beef cattle industry produces calves for replacement or slaughter. Female replacements are important to advance herd genetics, therefore, a tool to influence sex ratios may enhance reproductive efficiency. A commercial semen sexing kit, Heifer-Plus™, used in conjunction with artificial insemination, may alter the sex ratio of offspring by increasing motility of the X chromosome-bearing sperm. The aim of this research was to assess the methodology of Heifer-Plus™ through evaluation of motion patterns and kinematic parameters in conventional semen straws. Four bulls representing Angus, Wagyu, and Holstein breeds were utilized. Six straws of cryopreserved semen from each bull were thawed in a water bath (37.5°C for 35 sec). Three straws from each bull were pooled and treated with Heifer-Plus™ and 3 straws were pooled as the no-treatment control. Post treatment, all samples were aliquoted in microcentrifuge tubes and Computer Assisted Semen Analysis (CASA) measurements of motility and kinematic factors were assessed. Semen samples were held at 37.5°C for incubation for three 15-min periods (15-mins, 30-mins, and 45-mins) measuring thermoresistance and longevity of spermatozoa. After incubation, 80 µL of each semen sample were observed on CASA. Data were analyzed using ANOVA method in GraphPad Prism and P-values ≤ 0.05 were considered significant. No effect of treatment on motility parameters or rapid velocity were measured, however there was a decrease in total motility (P=0.0045), progressive motility (P=0.0115) and rapid velocity (P =0.0099) across time intervals. Heifer-Plus™ treated cells had higher incidence of static velocity compared to control (P = .0038). Semen samples were clustered into subpopulation threshold-based on sperm average path velocity (VAP) and linearity (LIN) at each time point. Spermatozoa treated with Heifer-Plus™ consistently exhibited a high velocity and variable linearity therefore were categorized consistently into two categories at each time point.

16 Beyond the Breeding Soundness Exam: The Evaluation of the Motility and Viability of Sperm Cells as Well as a Quantification and Evaluation of Mirna 26a-5p and Mirna 574, as Parameters of Bull Infertility

Sperm cryopreservation is an important tool for assisted reproductive techniques, nonetheless there are major factors associated with reduced longevity and poor survivability of cryopreserved sperm in the female reproductive tract. Several studies have focused on molecular markers associated with apoptosis, mitochondrial integrity and oxidative stress in cryopreserved sperm. Research indicates miRNA 26a-5p and miRNA-574 exhibit anti-inflammatory attributes in some cells, by downregulating the effects on specific genes associated with inflammation and apoptosis. The aim of this study was to evaluate the quality of bovine semen, including a variety of breeds, post-thaw viability through kinetic screening using Computer Assisted Semen Evaluation (CASA). Cryopreserved semen samples from 5 bulls were thawed in a water bath (37.5°C for 35 s), then aliquoted in eppendorf tubes and initial CASA (Version 14 CEROS) measurements of total motility, progressive motility, and kinematic factors were assessed. Semen samples were placed in a heat block at 37.5 C for incubation for three 30-minute periods (30-minutes, 60-minutes, and 90-minutes) to measure thermoresistance and longevity to extrinsic factors influencing oxidative stress. After incubation periods 80 µL of each semen sample was screened on CASA. Data were analyzed using a Student-T in GraphPad Prism. Data are presented as LSMEANS and P-values ≤ 0.05 were considered significant and tendencies were considered at a P > 0.05. Semen samples were clustered into subpopulation threshold-based on sperm velocity and linearity at each time point. Levels of miRNA-574 and miRNA-26a-5p were quantified using qPCR. No significant differences of miRNA-574 or miRNA-26a-5p were detected in semen at post-thaw. Incubation of semen for 30-minutes resulted in total motility decrease (P = 0.02) and progressive motility tended to decline (P = 0.06). None of the semen was viable past the first 30-minute period. These data suggest that there are limited differences in thermoresistance in sperm in a rapid stress test. However, further research needs to be conducted to evaluate the cells on aspects of viability and overall function.

26 The Effect of Cannabidiol on Follicular Growth and Ovulation in Cattle

The role of the endocannabinoids in regulating female reproductive processes such as follicular development has become an area of heightened interest with the prevalence of Cannabidiol (CBD) increasing as a natural mediator to physiological issues as well as the addition of hemp meal as a feedstuff for livestock. Initial studies indicate that cannabis use including Δ 9- tetrahydrocannabinol (THC) has negative implications on folliculogenesis and multiple aspects of pregnancy. However, there is limited knowledge on the effect of CBD on follicular growth and ovulation. The objective of this study was to identify the presence of the endocannabinoid system (ECS) in bovine ovarian theca and granulosa cells and its effect on follicular dynamics leading to ovulation. Theca and granulosa cells from medium (< 4 mm) and large ( >4 mm) follicles from abattoir bovine ovaries (n=61) were collected. Upon completion of pooling theca and granulosa cells, protein was isolated for detection of cannabinoid receptors, type 1 (CB1) and type 2 (CB2) through western blot. Receptors CB1 and CB2 are G- protein coupled receptors with an effect on the adenylyl cyclase pathway, which is key to many reproductive functions in the ovary. A strong visual representation of CB1 receptor detection was found in large granulosa cells and theca cells. Using Stain-Free total protein measurement as the loading control, the densitometric ratio in medium granulosa cells and large granulosa cells had a greater abundance of CB2 (P < 0.05) compared to theca cells. This data suggests a detectable effect by cannabinoids on granulosa and theca cells. Future studies are needed to investigate the role the ECS has in folliculogenesis and key steroidal production for successful ovulation. The subsequent knowledge is a key first step in understanding the effect CBD has on fertility and pregnancy in livestock.

31 The Effect of Increasing Inclusion of Hempseed Meal on Fiber Digestibility and Performance in Meat Rabbits

Legalization of hemp production in the United States shows potential for utilizing hempseed meal (HSM) as an effective byproduct feedstuff. Our objective was to determine total-tract fiber digestibility of rations containing increasing percentages of HSM in meat rabbits. Thirty-two Californian rabbits, assigned randomly to one of four treatments, were used in a generalized complete block design experiment with two 35-d feeding periods. Treatments replaced soybean meal and alfalfa such that 0%, 25%, 50%, and 75% CP was replaced by HSM. Diets were isonitrogenous and contained 28% steam-flaked corn. Weights were collected every 7 d, and total feed, orts, and fecal samples were collected in the final 7 d of feeding for digestibility determination. Rabbits were harvested after feeding periods, and stomach (S) and cecum (C) content sampling was conducted. Feed, orts, and fecal samples were assayed for DM and fiber fractions for digestibility determination. There was no effect of dietary treatment on DMD (52.5%; P = 0.05), NDFD (-29.5%; P = 0.54), or ADFD (-57.7%; P = 0.56). There was also no effect of dietary treatment on S NDF (11.9 g; P = 0.62), S ADF (8.4 g, P = 0.80), S ADL (2.6 g; P = 0.88), C NDF (8.0 g; P = 0.23), C ADF (5.5 g; P = 0.26), or C ADL content (3.2 g; P = 0.33). S and C digesta data were calculated as a ratio (S:C) to evaluate fiber disappearance in GI tract. However, there was no effect of treatment on S:C NDF (1.6:1; P = 0.43), S:C ADF (1.6:1; P = 0.42), or S:C ADL (1.4:1; P = 0.34). Despite lack of differences, ADG was greatest (P < 0.05) from 25% HSM (35.1 g ± 1.16), least from 75% HSM (20.7 g ± 1.20), and intermediate from 0% (30.5 g ± 1.20) and 50% HSM (33.2 g ± 1.16). Data interpreted to mean that HSM may be a viable feedstuff in rabbit diets up to 50% without detrimental effects.

PSX-A-7 Late-Breaking: Correlation of mitochondrial membrane potential and rough motility scores in cryopreserved bovine spermatozoa

Spermatozoon motility is an important factor in successful artificial reproductive technologies. Successful reproduction requires properly developed spermatozoa with adequate forward, progressive motility that allows for transport through the female reproductive tract. Motility is driven by production of ATP; however, cryopreservation is known to have damaging effects on spermatozoa. Mitochondria utilize oxidative phosphorylation to synthesize ATP through an electrochemical proton motive force that is composed primarily of mitochondrial membrane potential (Δψm). The mitochondrial membrane potential can be measured using a fluorescent, carbocyanine JC-1 dye (5,5’,6,6’-tetrachloro-1,1’,3,3’-tetraethylbenzimi-dazolylcarbocyanine iodide). The objective of this study was to examine correlations between the mitochondrial membrane potential and motility score. Cryopreserved semen samples from three bulls were donated to Tarleton State University for research purposes. Samples were thawed, placed under a phase contrast microscope, and analyzed by three individuals with varying levels of training for rough motility. These samples were then prepared with JC-1 dye according to manufacturer’s instructions. Two microliters of dye were added to a stock preparation of each sample. Samples were examined on a FACS Calibur flow cytometer at University of Texas Southwestern Core in Dallas, TX. Flow cytometry analysis was performed using FlowJo V10.7. Statistical analysis was performed using SAS v9.4. The Pearson correlation coefficient showed a strong, positive correlation (r = 0.90) between the mitochondrial membrane potential and motility (P = 0.28), thus indicating as the mitochondrial membrane potential increases, so does the rough motility score. These data represent a subset of a population that demonstrates the need of further research on the ability for spermatozoa to produce ATP and the correlation in forward, progressive motility. This research can provide a foundation in which future researchers may develop an assay that allows for testing of mitochondrial membrane potential by producers to select bulls with greater breeding potential.

Inhibition of the C-X-C Motif Chemokine 12 (CXCL12) and Its Receptor CXCR4 Reduces Utero-Placental Expression of the VEGF System and Increases Utero-Placental Autophagy

The placenta, a unique organ that only develops during pregnancy, is essential for nutrient, oxygen, and waste exchange between offspring and mother. Yet, despite its importance, the placenta remains one of the least understood organs and knowledge of early placental formation is particularly limited. Abnormalities in placental development result in placental dysfunction or insufficiency whereby normal placental physiology is impaired. Placental dysfunction is a frequent source of pregnancy loss in livestock, inflicting serious economic impact to producers. Though the underlying causes of placental dysfunction are not well-characterized, initiation of disease is thought to occur during establishment of functional fetal and placental circulation. A comprehensive understanding of the mechanisms controlling placental growth and vascularization is necessary to improve reproductive success in livestock. We propose chemokine C-X-C motif ligand 12 (CXCL12) signaling through its receptor CXCR4 functions as a chief coordinator of vascularization through direct actions on fetal trophoblast and maternal endometrial and immune cells. To investigate CXCL12–CXCR4 signaling on uteroplacental vascular remodeling at the fetal–maternal interface, we utilized a CXCR4 antagonist (AMD3100). On day 12 post-breeding in sheep, osmotic pumps were surgically installed and delivered either AMD3100 or saline into the uterine lumen ipsilateral to the corpus luteum for 14 days. On day 35 of ovine pregnancy, fetal/placental and endometrial tissues were collected, snap-frozen in liquid nitrogen, and uterine horn cross sections were preserved for immunofluorescent analysis. Suppressing CXCL12–CXCR4 at the fetal–maternal interface during initial placental vascularization resulted in diminished abundance of select angiogenic factors in fetal and maternal placenta on day 35. Compared to control, less vascular endothelial growth factor (VEGF) and VEFG receptor 2 (KDR) were observed in endometrium when CXCL12–CXCR4 was diminished. Less VEGF was also evident in fetal placenta (cotyledons) in ewes receiving AMD3100 infusion compared to control. Suppressing CXCL12–CXCR4 at the fetal–maternal interface also resulted in greater autophagy induction in fetal and maternal placenta compared to control, suggestive of CXCL12–CXCR4 impacting cell survival. CXCL12–CXCR4 signaling may govern placental homeostasis by serving as a critical upstream mediator of vascularization and cell viability, thereby ensuring appropriate placental development.

CXCR4 signaling at the fetal-maternal interface may drive inflammation and syncytia formation during ovine pregnancy†

Early pregnancy features complex signaling between fetal trophoblast cells and maternal endometrium directing major peri-implantation events including localized inflammation and remodeling to establish proper placental development. Proinflammatory mediators are important for conceptus attachment, but a more precise understanding of molecular pathways regulating this process is needed to understand how the endometrium becomes receptive to implantation. Both chemokine ligand 12 (CXCL12) and its receptor CXCR4 are expressed by fetal and maternal tissues. We identified this pair as a critical driver of placental angiogenesis, but their additional importance to inflammation and trophoblast cell survival, proliferation, and invasion imply a role in syncytia formation at the fetal-maternal microenvironment. We hypothesized that CXCL12 encourages both endometrial inflammation and conceptus attachment during implantation. We employed separate ovine studies to (1) characterize endometrial inflammation during early gestation in the ewe, and (2) establish functional implications of CXCL12 at the fetal-maternal interface through targeted intrauterine infusion of the CXCR4 inhibitor AMD3100. Endometrial tissues were evaluated for inflammatory mediators, intracellular signaling events, endometrial modifications, and trophoblast syncytialization using western blotting and immunohistochemistry. Endometrial tissue from ewes receiving CXCR4 inhibitor demonstrated dysregulated inflammation and reduced AKT and NFKB, paired with elevated autophagic activity compared to control. Immunohistochemical observation revealed an impairment in endometrial surface remodeling and diminished trophoblast syncytialization following localized CXCR4 inhibition. These data suggest CXCL12-CXCR4 regulates endometrial inflammation and remodeling for embryonic implantation, and provide insight regarding mechanisms that, when dysregulated, lead to pregnancy pathologies such as intrauterine growth restriction and preeclampsia.

CXCR4 signaling at the ovine fetal-maternal interface regulates vascularization, CD34+ cell presence, and autophagy in the endometrium†

Placenta development is characterized by extensive angiogenesis and vascularization but if these processes are compromised placental dysfunction occurs, which is the underlying cause of pregnancy complications such as preeclampsia and intrauterine growth restriction. Dysregulation of placental angiogenesis has emerged as one of the main pathophysiological features in the development of placental insufficiency and its clinical consequences. The signaling axis initiated by chemokine ligand 12 (CXCL12) and its receptor CXCR4 stimulates angiogenesis in other tissues, and may be central to placental vascularization. We hypothesized that CXCL12-CXCR4 signaling governs the pro-angiogenic placental microenvironment by coordinating production of central angiogenic factors and receptors and regulates endometrial cell survival essential for placental function and subsequent fetal longevity. The CXCR4 antagonist, AMD3100, was used to elucidate the role of CXCL12-CXCR4 signaling regarding uteroplacental vascular remodeling at the fetal-maternal interface. On day 12 postbreeding, osmotic pumps were surgically installed and delivered either AMD3100 or PBS into the uterine lumen ipsilateral to the corpus luteum. On day 20, endometrial tissues were collected, snap-frozen in liquid nitrogen, and uterine horn cross sections preserved for immunofluorescent analysis. In endometrium from ewes receiving AMD3100 infusion, the abundance of select angiogenic factors was diminished, while presence of CD34+ cells increased compared to control ewes. Ewes receiving AMD3100 infusion also exhibited less activation of Akt/mTOR signaling, and elevated LC3B-II, a marker of cellular autophagy in endometrium. This study suggests that CXCL12-CXCR4 signaling governs placental homeostasis by serving as a critical upstream mediator of vascularization and cell viability, thereby ensuring appropriate placental development.