Meat Science Commons^™

Fat Deposition, Β- Carotene, And Vitamin A Metabolism In Bulls, Steers, And Heifers, Tesla Trammell

Masters Theses & Specialist Projects

Research highlights the impact of Vitamin A on cattle growth and meat quality. Supplementing Vitamin A early in life has been linked to enhanced IMF content and growth rates in calves, especially when administered at birth or during early developmental stages. This is attributed to the role of the ZFP423 gene in adipocyte formation, with studies noting its involvement in the development of IMF during the finishing phase.

This study aims to add to the present research by evaluate the effect of calves’ sexual class on blood β-carotene and Vitamin A before weaning. The second study evaluated the β- carotene …

Using High-Pressure Processing To Improve The Quality Of Dark-Cutting Beef, Ashley A. Hahn

Department of Animal Science: Dissertations, Theses, and Student Research

Previous studies have shown high-pressure processing (HPP) can be utilized to improve lean color of dark-cutting beef color by increasing the lightness and redness of steaks. However, the optimal parameters of length of time product is held under pressure and at which pressure must be applied have yet to be fully defined. Furthermore, the impact of HPP on color labile muscles in dark-cutting beef are currently unknown. Therefore, two studies were designed and specific efforts were focused on first defining optimal parameters for color stable muscles, followed by determining the effect of HPP on dark-cutting color labile muscles.

In the …

Porcine Peritoneal Macrophages Are Susceptible To Porcine Reproductive And Respiratory Syndrome Virus Infection, Kassandra Durazo-Martinez, Jayeshbhai Chaudhari, Sushmita Kumari, Hiep Vu

Department of Animal Science: Faculty Publications

Previous studies have suggested that porcine peritoneal macrophages (PPMs) are resistant to PRRSV infection, whereas porcine alveolar macrophages (PAMs) are highly susceptible. This contrast is intriguing, as both cell types belong to the same monocyte/macrophage family. The current study aimed to investigate the host factors contributing to the differing susceptibility of PPMs and PAMs to PRRSV infection. We found that PPMs exhibit a higher frequency of CD14+ cells compared to PAMs, suggesting a more immature macrophage phenotype in PPMs. Importantly, PPMs expressed both CD163 and CD169, the key receptors for PRRSV entry, although the frequency and intensity of CD163 and …

Managing The Beef Breeder Herd In Southern Western Australia, Department Of Primary Industries And Regional Development, Western Australia

Animal production and livestock factsheets

Kilograms of beef produced per hectare is a significant driver of profit for a beef business. Cow longevity (length of productive life) plays an important role in achieving a profitable business. A balanced approach to genetic selection and nutritional management are essential factors underpinning the efficiency of the breeding herd.

Protracted Maternal Malnutrition Induces Aberrant Changes In Maternal Uterine Artery Hemodynamics And The Metabolic Profiles Of The Dam And Neonate, Jennifer F. Thorson, Ligia D. Prezotto

Department of Animal Science: Faculty Publications

Malnutritional stress during gestation is a well-established driver of metabolic disfunction in offspring. Extended exposure to malnutrition requires metabolic plasticity as the animal shifts toward a catabolic state. In this paper we demonstrate the influence of malnutrition throughout gestation on uterine artery hemodynamics and the metabolism of the dam and neonate. We hypothesized that gestational malnutrition reduces blood flow of the maternal uterine artery and regulates the metabolic profile of the dam and offspring. Further, the combination of these factors consequently influences the concentration of metabolites in the cerebrospinal fluid of the neonate at birth. To test our hypotheses, pregnant …

Cattle Performance Grazing Canola And Cereal Crops, Department Of Primary Industries And Regional Development, Western Australia

Animal production and livestock factsheets

The Department of Primary Industries and Regional Development conducted research to investigate and demonstrate the performance of cattle grazing canola and cereal compared to animals left on pasture and investigate the value of spelling the pasture during the time the cattle are grazing crops.

Cattle grazing cereal crops had a higher liveweight gain compared to the cattle that remained on the pasture. However to see a significant benefit from grazing dual purpose crops, the grazing period may need to be longer than 4 weeks particularly when grazing canola.

The highest growth rates for cattle grazing the cereal crops were achieved …

Confined Paddock Feeding And Feedlotting Of Sheep, Department Of Primary Industries And Regional Development, Western Australia

Animal production and livestock factsheets

Confinement feeding (also referred to as lot feeding or feedlotting) is an intensive feeding system in a confined area where all, or the majority of, feed and water is supplied to the contained animals. The department recommends using confinement feeding as part of a whole farm livestock, pasture and erosion management program.

We recommend having a confinement feeding system as an integral part of a whole farm livestock, pasture and erosion management program. Guides and resources that provide more detailed information are listed at the bottom of this fact sheet.

Adding Gastrointestinal Parasite Resistance To The Breeding Objective In Hair Sheep: Initial Step, Robert M. Forbes, Thomas W. Murphy, Joan M. Burke, David R. Notter, Matthew L. Spangler, Michael D. Macneil, Ronald M. Lewis

Department of Animal Science: Faculty Publications

The U.S. Maternal Hair Index was designed by the National Sheep Improvement Program (NSIP) to increase total weight of lamb weaned per ewe lambing (TW). Producers are interested in adding gastrointestinal nematode (GIN) resistance to this breeding objective since parasitism causes substantial economic losses. The NSIP provides producers with estimated breeding values (EBV) for postweaning fecal egg count (PFEC), an indicator of GIN resistance. Our objective was to gauge the effects of including PFEC as another selection criterion and goal trait. Selection index theory was used to construct 11 indexes. …

Analyses Of Whole-Genome Sequences From 185 North American Thoroughbred Horses, Spanning 5 Generations, Ernie Bailey, Carrie J. Finno, Jonah N. Cullen, Ted Kalbfleisch, Jessica Lynn Petersen

Department of Animal Science: Faculty Publications

Whole genome sequences (WGS) of 185 North American Thoroughbred horses were compared to quantify the number and frequency of variants, diversity of mitotypes, and autosomal runs of homozygosity (ROH). Of the samples, 82 horses were born between 1965 and 1986 (Group 1); the remaining 103, selected to maximize pedigree diversity, were born between 2000 and 2020 (Group 2). Over 14.3 million autosomal variants were identified with 4.5–5.0 million found per horse. Mitochondrial sequences associated the North American Thoroughbreds with 9 of 17 clades previously identified among diverse breeds. Individual coefficients of inbreeding, estimated from ROH, averaged 0.266 (Group 1) and …

Breeding Ewes Are Worth Feeding, Department Of Primary Industries And Regional Development, Western Australia

Animal production and livestock factsheets

Despite potentially elevated grain prices, strong prices for meat and wool mean that Western Australian sheep farmers can confidently supplementary feed their underweight ewes in summer/autumn.

Analysis in 2019, based on then-current prices, showed it was a profitable investment to feed all ewes to maintain condition during pregnancy, and to feed low condition score single bearing ewes and low and medium condition score twin bearing ewes to gain condition.

In 2019, John Young from Farming Systems Analysis Service completed an analysis on the value of a ewe in the WA farming system. His report had some important messages for the …

Technical Note: Assessing Gps Sensor Accuracy Using Real-Time Kinematic Device For Livestock Tracking, Biquan Zhao, Rebecca Mcdermott, Galen E. Erickson, Yijie Xiong

Department of Animal Science: Faculty Publications

The technical aspects of global positioning system (GPS) sensors have been improved substantially over the years, making them valuable and popular tools for livestock tracking. Using GPS sensors allows producers and researchers to locate grazing livestock, monitor their behavior and distribution, and gather referencing information about the health status of the animals and pastures. However, interpreting the behavior of grazing livestock, such as cattle, from GPS data can be difficult due to positioning inaccuracies. Without knowing the positioning accuracy range of GPS sensors, achieving high-level confidence in determining grazing densities and identifying abnormal livestock movement patterns is challenging. …

Knockdown Of Gonadotropin-Releasing Hormone Ii Receptor Impairs Ovulation Rate, Corpus Luteum Development, And Progesterone Production In Gilts, Amy T. Desaulniers, Rebecca Cederberg, Clay A. Lents, Brett White

Department of Animal Science: Faculty Publications

Reproduction is classically controlled by gonadotropin-releasing hormone (GnRH-I) and its receptor (GnRHR-I) within the brain. In pigs, a second form (GnRH-II) and its specific receptor (GnRHR-II) are also produced, with greater abundance in peripheral vs. central reproductive tissues. The binding of GnRH-II to GnRHR-II has been implicated in the autocrine/paracrine regulation of gonadal steroidogenesis rather than gonadotropin secretion. Blood samples were collected from transgenic gilts, with the ubiquitous knockdown of GnRHR-II (GnRHR-II KD; n = 8) and littermate controls (n = 7) at the onset of estrus (follicular) and 10 days later (luteal); serum concentrations of 16 steroid hormones …

Impact Of Partial Oil Removal On Energy Content Of Distillers Grains Plus Solubles For Finishing Cattle, Jordan E. Burhoop, J. L. Sperber, Curt J. Bittner, F. Henry Hilscher, J. C. Macdonald, Galen E. Erickson

Department of Animal Science: Faculty Publications

Two experiments evaluated the impact of the reduction in the percentage of corn oil remaining in distillers grains plus solubles (DGS) after the ethanol plant de-oiling process or by adding corn oil back to DGS following de-oiling on finishing cattle performance and nutrient digestion. Experiment 1 utilized 320 yearling steers (initial BW = 413 kg; SD = 25 kg) fed in 32 pens (10 steers/pen) and assigned to one of four treatments (n = 8 pens/treatment). The four treatments consisted of a blended DRC:HMC corn control diet (CON), de-oiled modified distillers grains plus solubles included at 40% of diet DM …

Balancing The Scales: Evaluating Variables Of Greatest Impact To Profit Margins When Finishing Cattle, Ryan Bake

All Graduate Reports and Creative Projects, Fall 2023 to Present

This study examines the risk associated with finishing cattle in a feedlot, specifically in the context of historically high cattle prices and quality grade grid marketing systems that have not adjusted to these elevated prices. The analysis also looks at performance factors that drive profitability differences in pens of cattle in a commercial feedlot, and how market factors also impact profitability. Regression analysis determines the significance of performance variables such as days on feed, average daily gain, feed conversion rates, and carcass characteristics on pen profitability. The impact of cattle breeding and pre-feedlot management of the cattle are also considered …

Assessment Of Genetic Diversity And Population Structure Of U.S. Polypay Sheep From Breed Origins To Future Genomic Selection, Carrie S. Wilson, Jessica Lynn Petersen, Luiz F. Brito, Brad A. Freking, Sara M. Nilson, J. Bret Taylor, Thomas W. Murphy, Ronald M. Lewis

Department of Animal Science: Faculty Publications

Knowledge of past and present genetic diversity within a breed is critical for the design and optimization of breeding programs as well as the development of strategies for the conservation of genetic resources. The Polypay sheep breed was developed at the U.S. Sheep Experiment Station (USSES) in 1968 with the goal of improving productivity in Western U.S. range flocks. It has since flourished in the more intensively managed production systems throughout the U.S. The genetic diversity of the breed has yet to be documented. Therefore, the primary objective of this study was to perform a comprehensive evaluation of the genetic …

Evaluation Of The Capacity And Effective Angle Of Thalamic Damage For 2 Commercially Available Captive Bolt Tool Types On Cadaver Heads From Sows >200 Kg Body Weight, Karly N. Anderson, Ruth Woiwode, Ashlynn A. Kirk, Jennifer Berger, Arquimides A. Reyes, Perle E. Zhitnitskiy, Kurt D. Vogel

Department of Animal Science: Faculty Publications

This study evaluated the ability of 2 penetrating captive bolt (PCB) types (PISTOL, INLINE) to reach and disrupt the thalamus when applied in 2 placements (FRONTAL, BEHIND EAR) to chilled cadaver heads (N = 60) from sows >200 kg. Heads were randomly distributed across 6 treatments (n = 10): FRONTAL-INLINE, FRONTAL-PISTOL, FRONTAL-NO SHOT, BEHIND EAR-INLINE, BEHIND EAR-PISTOL, and BEHIND EAR-NO SHOT. The FRONTAL shot was placed 3.5 cm superior to the optic orbits at the midline; the BEHIND EAR shot was placed directly caudal to the pinna of the ear on the same plane as the eyes and targeting the …

Development Of A Durable And Low-Dose Universal Vaccine Against Swine Influenza A Virus, Erika Petro-Turnquist

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Swine Influenza A Virus (IAV-S) imposes a significant burden on the pork industry and poses a great threat to public health due to its zoonotic potential. Susceptibility to human, avian, and swine influenza make pigs the ultimate mixing vessels for reassorted influenza A virus strains. Current vaccination strategies induce short-lived and strain-specific responses against IAV-S. Further, the substantial genetic diversity of IAV-S necessitates consistent revaccination and updating of commercial vaccines. Computational platforms have recently emerged as a promising strategy to develop new-age vaccines against infectious diseases in livestock animals. Here, we describe a computationally derived set of vaccine immunogens, called …

Study On Performance Behavior Of Fayoumi And Rhode Island Red Poultry Breeds, Rameez Raja Kaleri Rrk, Hubdar Ali Kaleri, Ghulam Mustafa Solangi, Zainab Lanjar, Raza Ali Mangi, Imran Ahmed, Sajid Mahmood Sajid, Deepesh Kumar Bhuptani, Zoya Parveen Soormro, Habibullah Janyaro, Abdul Wahid Solangi, Zahid A., Dilbar Hussain Jamali

Journal of Bioresource Management

The present study was conducted to compare the performance and behavior of Fayoumi and Rhode Island Red poultry breeds. A total of forty-two birds at 26 weeks of age, with thirty-six females and six males from each breed, were distributed into 6 groups with one male and six females each. All the experimental groups were reared in separate partitions with provisions of nests, feeders, and drinkers under proper management conditions. The results of the current study revealed that Rhode Island Red chickens showed significantly higher (P < 0.05) body weight, egg weight, daily egg production, eggshell thickness, and other quality parameters compared to Fayoumi chickens. It was also noted that Rhode Island Red chickens consumed less feed and gained heavier bodies with higher egg production than Fayoumi chickens. There was a non-significant difference in feed intake between both breeds. Rhode Island Red chickens produced eggs with better shell quality and higher breaking strength compared to Fayoumi chickens. In conclusion, the Rhode Island Red chicken breed is better in terms of body weight, egg performance, and feed efficiency compared to Fayoumi chickens.

Daily Eicosapentaenoic Acid Infusion In Iugr Fetal Lambs Reduced Systemic Inflammation, Increased Muscle Adrβ2 Content, And Improved Myoblast Function And Muscle Growth, Haley Beer, Taylor A. Lacey, Rachel L. Gibbs, Micah S. Most, Zena M. Hicks, Pablo C. Grijalva, Eileen S. Marks-Nelson, Ty B. Schmidt, Jessica Lynn Petersen, Dustin T. Yates

Department of Animal Science: Faculty Publications

Intrauterine growth-restricted (IUGR) fetuses exhibit systemic inflammation that contributes to programmed deficits in myoblast function and muscle growth. Thus, we sought to determine if targeting fetal inflammation improves muscle growth outcomes. Heat stress-induced IUGR fetal lambs were infused with eicosapentaenoic acid (IUGR+EPA; n = 9) or saline (IUGR; n = 8) for 5 days during late gestation and compared to saline-infused controls (n = 11). Circulating eicosapentaenoic acid was 42% less (p < 0.05) for IUGR fetuses but was recovered in IUGR+EPA fetuses. The infusion did not improve placental function or fetal O2 but resolved the 67% greater (p < 0.05) circulating TNFα observed in IUGR fetuses. This improved myoblast function and muscle growth, as the 23% reduction (p < 0.05) in the ex vivo differentiation of IUGR myoblasts was resolved in IUGR+EPA myoblasts. Semitendinosus, longissimus dorsi, and flexor digitorum superficialis muscles were 24–39% lighter (p < 0.05) for IUGR but not for IUGR+EPA fetuses. Elevated (p < 0.05) IL6R and reduced (p < 0.05) β2 adrenoceptor content in IUGR muscle indicated enhanced inflammatory sensitivity and diminished β2 adrenergic sensitivity. Although IL6R remained elevated, β2 adrenoceptor deficits were resolved in IUGR+EPA muscle, demonstrating a unique underlying mechanism for muscle dysregulation. These findings show that fetal inflammation contributes to IUGR muscle growth deficits and thus may be an effective target for intervention.

Puberty Classifications In Beef Heifers Are Moderately To Highly Heritable And Associated With Candidate Genes Related To Cyclicity And Timing Of Puberty, Melanie K. Hess, Anteneh Mersha, Sadie S. Ference, Sarah R. Nafziger, Jessica A. Keane, Anna M. Fuller, Scott G. Kurz, Courtney M. Sutton, Matthew L. Spangler, Jessica Lynn Petersen, Andrea S. Cupp

Department of Animal Science: Faculty Publications

Introduction: Pubertal attainment is critical to reproductive longevity in heifers. Previously, four heifer pubertal classifications were identified according to attainment of blood plasma progesterone concentrations > 1 ng/ml: 1) Early; 2) Typical; 3) Start-Stop; and 4) Non-Cycling. Early and Typical heifers initiated and maintained cyclicity, Start-Stop started and then stopped cyclicity and Non- Cycling never initiated cyclicity. Start-Stop heifers segregated into Start-Stop- Discontinuous (SSD) or Start-Stop-Start (SSS), with SSD having similar phenotypes to Non-Cycling and SSS to Typical heifers. We hypothesized that these pubertal classifications are heritable, and loci associated with pubertal classifications could be identified by genome wide association …

Malnutrition Alters Protein Expression Of Kndy Neuropeptides In The Arcuate Nucleus Of Mature Ewes, Jennifer F. Thorson, Ligia D. Prezotto

Department of Animal Science: Faculty Publications

The neuropeptides kisspeptin, neurokinin B, and dynorphin A are imperative for the pulsatile secretion of gonadotropin-releasing hormone and luteinizing hormone to ultimately regulate reproductive cyclicity. A population of neurons co-expressing these neuropeptides, KNDy neurons, within the arcuate nucleus of the hypothalamus (ARC) are positioned to integrate energy status from afferent neuronal and glial cells. We hypothesized that KNDyexpressing neurons in the ARC of mature ewes are influenced by energy balance. To test this hypothesis, ovary-intact, mature ewes were fed to lose, maintain, or gain body weight and hypothalamic tissue harvested during the luteal phase of the estrous cycle. Fluorescent, multiplex …

Unraveling The Role Of Lipid Droplets And Perilipin 2 In Bovine Luteal Cells, Michele R. Plewes, Heather A. Talbott, Micah B. Schott, Jennifer R. Wood, Andrea S. Cupp, John S. Davis

Department of Animal Science: Faculty Publications

Steroidogenic tissues contain cytosolic lipid droplets that are important for steroidogenesis. Perilipin 2 (PLIN2), a structural coat protein located on the surface of lipid droplets in mammalian cells, plays a crucial role in regulating lipid droplet formation and contributing to various cellular processes such as lipid storage and energy homeostasis. Herein, we examine the role that PLIN2 plays in regulating progesterone synthesis in the bovine corpus luteum. Utilizing gene array databases and Western blotting, we have delineated the expression pattern of PLIN2 throughout the follicular to luteal transition. Our findings reveal the presence of PLIN2 in both ovarian follicular and …

On-Farm Hog Processing Demonstration For Teenage Exhibitors: Blending Academic, Laboratory, And Farm-Based Learning, Katherine A. Wells, Chris L. Bruynis, Lyda G. Garcia

Journal of Extension

COVID-19 challenges induced a U.S. meatpacking industry bottleneck. [University] Extension identified the need and responded by creating a three-step hands-on training for teenage junior fair exhibitors. [University] Extension Meat Scientist and graduate students assisted in demonstrating an on-farm hog harvest and processing event in collaboration with a local Extension office for 4-H and FFA teenagers. To add a practical perspective, a local hog-producing and harvesting family was asked to assist with the event. An online post-survey reflected 90-100% gains in five educational areas and 100% said they would a similar event in the future and recommend it to a friend.

Consumer-Focused Meat Science Extension Program Increase Consumer Confidence And Knowledge Of Meat Selection And Preparation, Stacy Zuelly, Yufei Guo, Melinda Dennis, Emily Ford, Melissa Davis

Journal of Extension

Science-based, meat science education is often limited outside of universities, creating possibilities to develop Extension activities to educate and impower consumers in principles of meat science. The Indiana BBQ Bootcamp was developed to provide consumers information on meat selection, proper cooking techniques, food safety, and meat seasoning (spice rubs and marinades) through demonstrations and product sampling. Attendees were surveyed before and after the program to report their confidence in their ability to perform basic meat science techniques. Responses to all survey questions showed significant increase in the attendees’ confidence demonstrating improvement in their meat science knowledge.

Live Cattle Assessment, Department Of Primary Industries And Regional Development, Western Australia

Animal production and livestock factsheets

Cattle producers regularly make visual assessments of their cattle. Frame, structure, muscularity, fatness and condition score can all be assessed by visual appraisal. Some traits cannot be assessed visually (for example fertility or marbling). To evaluate the genetic merit of an animal, estimated breeding values (EBVs) can be used.

Alternative Energy And Protein Feed Sources For Sheep And Cattle, Department Of Primary Industries And Regional Development, Western Australia

Animal production and livestock factsheets

During dry times and drought there are a wide range of alternative feedstuffs producers may consider using to maintain stock. Some of these feeds can have health risks associated with them and should not be used as the sole food source as they often lack sufficient energy and protein.

An Autosomal Recessive Variant In Pygm Causes Myophosphorylase Deficiency In Red Angus Composite Cattle, Mackenzie Batt, Leila G. Venzor, Keri Gardner, Rachel R. Reith, Kelsey A. Roberts, Nicolas J. Herrera, Anna M. Fuller, Gary Sullivan, J. Travis Mulliniks, Matthew L. Spangler, Stephanie J. Valberg, David J. Steffen, Jessica Lynn Petersen

Department of Animal Science: Faculty Publications

Background Between 2020 and 2022, eight calves in a Nebraska herd (composite Simmental, Red Angus, Gelbvieh) displayed exercise intolerance during forced activity. In some cases, the calves collapsed and did not recover. Available sire pedigrees contained a paternal ancestor within 2–4 generations in all affected calves. Pedigrees of the calves’ dams were unavailable, however, the cows were ranch-raised and retained from prior breeding seasons, where bulls used for breeding occasionally had a common ancestor. Therefore, it was hypothesized that a de novo autosomal recessive variant was causative of exercise intolerance in these calves.

Results A genome-wide association analysis utilizing SNP …

Genetic Diversity Of United States Rambouillet, Katahdin And Dorper Sheep, Gabrielle M. Becker, Jacob W. Thorne, Joan M. Burke, Ronald M. Lewis, David R. Notter, James L. M. Morgan, Christopher S. Schauer, Whit C. Stewart, R. R. Redden, Brenda M. Murdoch

Department of Animal Science: Faculty Publications

Background Managing genetic diversity is critically important for maintaining species fitness. Excessive homozygosity caused by the loss of genetic diversity can have detrimental effects on the reproduction and production performance of a breed. Analysis of genetic diversity can facilitate the identification of signatures of selection which may contribute to the specific characteristics regarding the health, production and physical appearance of a breed or population. In this study, breeds with well-characterized traits such as fine wool production (Rambouillet, N = 745), parasite resistance (Katahdin, N = 581) and environmental hardiness (Dorper, N = 265) were evaluated for inbreeding, effective population size …

Genetic Impact Of External Targhee Sires At The U.S. Sheep Experiment Station: A Case Study Of Introgression, Carrie S. Wilson, J. Bret Taylor, Ronald M. Lewis, David R. Notter

Department of Animal Science: Faculty Publications

Sheep breeders requested that the U.S. Sheep Experiment Station (USSES) to participate in national genetic evaluation through the National Sheep Improvement Program (NSIP). The reasons included the need for (1) a comparison of the productivity of industry and United States Department of Agriculture (USDA) lines, (2) transparency of USDA flocks, (3) genetic ties for NSIP by sampling of industry flocks, and (4) development of premium genetic lines for public release. In response, USSES began to incorporate external sires from NSIP participating flocks into the USSES Targhee flock. Our objective, based on a pedigree analysis, was to test if introgression of …

Recent Progress On Gene-Deleted Liveattenuated African Swine Fever Virus Vaccines, Hiep L.X. Vu, David Scott Mcvey

Department of Animal Science: Faculty Publications

African Swine Fever (ASF) is a highly lethal viral disease in swine, with mortality rates approaching 100%. The disease has spread to many swine-producing countries, leading to significant economic losses and adversely impacting global food security. Extensive efforts have been directed toward developing effective ASF vaccines. Among the vaccinology approaches tested to date, liveattenuated virus (LAV) vaccines produced by rational deleting virulence genes from virulent African Swine Fever Virus (ASFV) strains have demonstrated promising safety and efficacy in experimental and field conditions. Many gene-deleted LAV vaccine candidates have been generated in recent years. The virulence genes targeted for deletion from …