Porcine epidemic diarrhea virus reduces feed efficiency in nursery pigs

Abstract

Porcine epidemic diarrhea virus (PEDV) infects enterocytes and in nursery pigs, results in diarrhea, anorexia, and reduced performance. Therefore, the objective of this study was to determine how PEDV infection influenced growth performance and repartitioning of amino acids and energy in nursery pigs. A total of 32 barrows and gilts, approximately 1 wk post-wean (BW = 8.46 ± 0.50 kg), and naïve for PEDV were obtained, weighed, and allotted based on sex and BW to one of two treatments: 1) Control, PEDV naïve and 2) PEDV-inoculated (PEDV) with eight pens of two pigs each per treatment. On day post-inoculation (dpi) 0, PEDV pigs were inoculated via intragastric gavage with PEDV isolate (USA/Iowa/18984/2013). Pig and feeder weights were recorded at dpi -7, 0, 5, and 20 in order to calculate ADG, ADFI, and G:F. Eight pigs per treatment were euthanized on dpi 5 and 20, and tissues and blood were collected. At dpi 5, all PEDV pigs were PCR positive for PEDV in feces. Overall, PEDV pigs tended (P < 0.10) to increase ADFI, which resulted in reduced (P < 0.05) feed efficiency. At dpi 5, PEDV pigs had reduced (P < 0.05) villus height and increased (P < 0.05) stem cell proliferation in the jejunum compared with Control pigs. Pigs inoculated with PEDV had increased (P < 0.05) serum haptoglobin and increased insulin-to-glucose ratios compared with Control pigs at dpi 5. Markers of muscle proteolysis were not different (P > 0.05) between treatments within dpi; however, at dpi 5, 20S proteasome activity was increased (P < 0.05) in longissimus dorsi of PEDV pigs compared with Control pigs. Liver and jejunum gluconeogenic enzyme activities were not different (P > 0.05) between treatments within dpi. Overall, PEDV-inoculated pigs did recover the absorptive capacity that was reduced during PEDV infection by increasing proliferation of intestinal stem cells. However, the energy and nutrients needed to recover the epithelium may be originating from available luminal nutrients instead of muscle proteolysis and gluconeogenesis. This study provides insight into the effects of an enteric coronavirus on postabsorptive metabolism in nursery pigs.

Display of Porcine Epidemic Diarrhea Virus Spike Protein on Baculovirus to Improve Immunogenicity and Protective Efficacy

“…Recently, several studies using full-length ectodomain trimeric S protein [ 40 ] or different truncated S proteins derived from different G2b PEDVs were combined with commercial adjuvants as subunit vaccine regimens. Despite that these subunit vaccines were able to induce robust systemic IgG and neutralizing antibody against PEDVs, they fail to completely prevent clinical symptoms and fecal viral shedding [ 47 , 48 , 49 ]. In the present study, piglets vaccinated with S-Bac can be elicited higher neutralizing antibody titers and good protective efficacy over the S1-Bac vaccinated pigs, despite both of them promoting robust levels of systemic PEDV S-specific IgG in pigs and mice.…”

Metabolic adaptation of pigs to a Mycoplasma hyopneumoniae and Lawsonia intracellularis dual challenge1

“…Briefly, PEPCK activity was determined by a modified method as described previously (Wimmer, 1988;Jin et al, 2004;Curry et al, 2018) via measuring the 2-step transformation of oxaloacetate to phosphoenolpyruvate and then to ATP. Luminometric production of ATP was measured via reaction with 90-μL luciferase reagent following the ATP Determination Kit (ThermoFisher Scientific, Waltham, MA).…”

“…Fructose-1,6-bisphosphatase activity was determined as previously described (Curry et al, 2018) using protocol EC 3.1.3.11 (Sigma-Aldrich, St. Louis, MO). All samples were blank corrected, and activity was expressed as μmol NADPH produced per minute per mg hepatic protein.…”

“…All samples were blank corrected, and activity was expressed as μmol NADPH produced per minute per mg hepatic protein. Activity of G6P was quantified by measuring the release of phosphate from glucose-6-phosphate as described previously (Curry et al, 2018). Activity was expressed as mM Pi released per minute per mg protein.…”

Amino acid requirements of health challenged pigs

“…Further, this also extends to potential increases in BEL of AA due to increased intestinal mucin production and cell sloughing due to disease Wilberts et al, 2014b). In pigs, this notion of nutrient (i.e., AA) repartitioning is supported by research from our group, and others, where feed efficiency and tissue accretion rates are significantly reduced due to infection with systemic and enteric pathogen challenges Curry et al, 2018;. However, it is unclear to what degree, if any, SID of AA requirements and BEL change during these disease states in growing pigs.…”