- ItemOpen AccessChallenges for Porcine Reproductive and Respiratory Syndrome (PRRS) Vaccine Design: Reviewing Virus Glycoprotein Interactions with CD163 and Targets of Virus Neutralization(MDPI, 2019-01-17) Stoian, Ana; Rowland, Raymond R. R.One of the main participants associated with the onset and maintenance of the porcine respiratory disease complex (PRDC) syndrome is porcine reproductive and respiratory syndrome virus (PRRSV), an RNA virus that has plagued the swine industry for 30 years. The development of effective PRRS vaccines, which deviate from live virus designs, would be an important step towards the control of PRRS. Potential vaccine antigens are found in the five surface proteins of the virus, which form covalent and multiple noncovalent interactions and possess hypervariable epitopes. Consequences of this complex surface structure include antigenic variability and escape from immunity, thus presenting challenges in the development of new vaccines capable of generating broadly sterilizing immunity. One potential vaccine target is the induction of antibody that disrupts the interaction between the macrophage CD163 receptor and the GP2, GP3, and GP4 heterotrimer that protrudes from the surface of the virion. Studies to understand this interaction by mapping mutations that appear following the escape of virus from neutralizing antibody identify the ectodomain regions of GP5 and M as important immune sites. As a target for antibody, GP5 possesses a conserved epitope flanked by N-glycosylation sites and hypervariable regions, a pattern of conserved epitopes shared by other viruses. Resolving this apparent conundrum is needed to advance PRRS vaccine development.
- ItemOpen AccessThe use of cells from ANPEP knockout pigs to evaluate the role of aminopeptidase N (APN) as a receptor for porcine deltacoronavirus (PDCoV)(Elsevier, 2019-12-24) Stoian, Ana; Rowland, Raymond R. R.; Petrovan, Vlad; Sheahan, Maureen; Samuel, Melissa S.; Whitworth, Kristin M.; Wells, Kevin D.; Zhang, Jianqiang; Beaton, Benjamin; Cigan, Mark; Prather, Randall S.The coronaviruses, porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV), and porcine deltacoronavirus (PDCoV) represent important sources of neonatal diarrhea on pig farms. The requirement for aminopeptidase N (APN) as a receptor for TGEV, but not for PEDV, is well established. In this study, the biological relevance of APN as a receptor for PDCoV was tested by using CRISPR/Cas9 to knockout the APN gene, ANPEP, in pigs. Porcine alveolar macrophages (PAMs) from ANPEP knockout (KO) pigs showed resistance to PDCoV infection. However, lung fibroblast-like cells, derived from the ANPEP KO PAM cultures, supported PDCoV infection to high levels. The results suggest that APN is a receptor for PDCoV in PAMs but is not necessary for infection of lung-derived fibroblast cells. The infection of the ANPEP KO pigs with PDCoV further confirmed that APN is dispensable as a receptor for PDCoV.
- ItemOpen AccessProtein turnover in pigs: A review of interacting factors(Wiley, 2023-11-17) Sarri Espinosa, Laura; Balcells Terés, Joaquim; Seradj, Ahmad Reza; de la Fuente Oliver, GabrielProtein turnover defines the balance between two continuous and complex processes of protein metabolism, synthesis and degradation, which determine their deposition in tissues. Although the liver and intestine have been studied extensively for their important roles in protein digestion, absorption and metabolism, the study of protein metabolism has focused mainly on skeletal muscle tissue to understand the basis for its growth. Due to the high adaptability of skeletal muscle, its protein turnover is greatly affected by different internal and external factors, contributing to carcass lean‐yield and animal growth. Amino acid (AA) labelling and tracking using isotope tracer methodology, together with the study of myofiber type profiling, signal transduction pathways and gene expression, has allowed the analysis of these mechanisms from different perspectives. Positive stimuli such as increased nutrient availability in the diet (e.g., AA), physical activity, the presence of certain hormones (e.g., testosterone) or a more oxidative myofiber profile in certain muscles or pig genotypes promote increased upregulation of translation and transcription‐related genes, activation of mTORC1 signalling mechanisms and increased abundance of satellite cells, allowing for more efficient protein synthesis. However, fasting, animal aging, inactivity and stress, inflammation or sepsis produce the opposite effect. Deepening the understanding of modifying factors and their possible interaction may contribute to the design of optimal strategies to better control tissue growth and nutrient use (i.e., protein and AA), and thus advance the precision feeding strategy.
- ItemOpen AccessCircularity and livestock diversity: Pathways to sustainability in intensive pig farming regions(Elsevier, 2024-01-01) Álvarez Rodríguez, Javier; Ryschawy, Julie; Grillot, Myriam; Martin, GuillaumeCONTEXT: Intensive pig farming is challenged by high environmental impacts and dependence on outsourced inputs. Circular feeding strategies to improve nutrient cycling and livestock diversity have emerged as pathways to improve the sustainability. OBJECTIVE: This study explored the potential of increasing feed circularity and introducing sheep to improve the sustainability of a typical pig fattening region in the semiarid zone of Spain. METHODS: Three alternative circular scenarios were designed to relocate pig feed production while reintroducing sheep production. These scenarios were then compared to a business-as-usual (BAU) scenario. The feeding strategies scenarios differed in crude protein (CP) and in-feed amino acid (AA) supplementation for pigs (CircHigh, high CP with low AA; CircLow, low CP with high AA; CircNoAA, low CP without AA) and included grazing sheep to use crop residues, alfalfa and temporary vetch-oat pastures on fallow land. Yearly feed requirements for pigs were planned, and were met with cereal grains, oilseeds, legumes, rice bran and chopped alfalfa hay. Sheep carrying capacity was estimated from available forage sources. Indicators in five sustainability dimensions were considered: economic performance, landscape mosaic, livestock diversity, nitrogen (N) cycling, and feed-food competition. RESULTS AND CONCLUSIONS: Outsourced (BAU) pig feeding without sheep had low scores for indicators in all five dimensions. The feeding strategy for pigs strongly influenced the land area required to produce feed as well.
- ItemOpen AccessAnnual short-burst mass anthelmintic administration reduces tuberculosis severity but not prevalence in a wildlife reservoir(Frontiers Media SA, 2023) Lello, Joanne; Gassó, Diana; Gonçalves, Pilar; Risco, David; García, Waldo L.; Segalés, Joaquim; Garrido-Amaro, Cristina; Mentaberre García, Gregorio; Torres-Blas, Irene; Velarde, Roser; López-Olvera, Jorge R.; Fernández-Llario, PedroIntroduction: Tuberculosis (TB), caused by the Mycobacterium tuberculosis complex (MTC), is an important disease in both human and animal systems. Helminths are commonly found in coinfection with MTC and TB is often exacerbated in such coinfections. Long-term anthelmintic administration, to control helminths, can improve a host’s ability to control MTC infection. Mass drug administration programmes, in which anthelmintics are given only once or twice a year, leaving periods where helminth reinfection can occur, are common in both human and domestic animal populations. To date, the effect of such intermittent control programmes on MTC infection and severity has not been explored. Methods: Here we investigate the consequences of a ten-day, annual, mass ivermectin administration on TB prevalence and severity in free-ranging juvenile and yearling ([removed]