Abstract Pharmacological zinc (2,000-3,000 ppm) is commonly fed to nursery pigs to improve health and growth due to its antimicrobial and anti-inflammatory properties. The objective was to test if pharmacological zinc at time of oral Salmonella vaccination impeded vaccine efficacy. Sixty-four weaned pigs (5.1±0.7 kg BW) were used in a 2 x 2 factorial design. The diets were control (CON) or zinc (3,000 ppm for 1 week, 2,000 ppm for 2 weeks, and no additional zinc for 1 week [ZN]). On d 2 pigs were orally vaccinated for Salmonella with 1 of 2 commercially available vaccines, resulting in 4 treatments (CON1, CON2, ZN1, ZN2; n = 16/treatment). On d 28, n = 8 pigs/treatment were randomly selected and enrolled in a S. Typhimurium challenge study. On d 35 post-weaned, all pigs were inoculated with 108 cfu of a field S. Typhimurium isolate. Pig performance, febrile response, fecal shedding and serology was assessed over a 7-d challenge period. On dpi 7 all pigs were euthanized, and colon contents and ileocecal lymph nodes were collected for culture. The effect of nursery diet, vaccine and their interaction was assessed. Pigs were confirmed Salmonella culture positive at dpi 2 and 6 pigs were culture positive from the ileocecal lymph nodes at dpi 7. Salmonella-specific antibody titers (S/P) increased (P < 0.001) from dpi 0 (0.31) to 7 (2.01), and a time-by-vaccine interaction was reported (P < 0.05). Irrespective of diet and vaccine, core temperatures increased from 39.5°C (dpi 0) to 39.7°C (dpi 2) before decreasing (P = 0.02). Over the challenge period, ADG did not differ (0.67, 0.64, 0.61, 0.62 kg/d, CON1, CON2, ZN1, ZN2, respectively, P = 0.654). Furthermore, ADFI and G:F did not differ by diet or vaccine (P >0.05). In conclusion, pharmacological Zn did not inhibit efficacy of oral Salmonella vaccines.
Toll-like receptors 2 and 4 (TLR2 and TLR4) are well-characterized cell surface receptors that recognize specific pathogen-associated molecular patterns and play an important role in pathogen recognition and activation of the innate immune system. Variable expression of TLR2 and TLR4 has been described in trophoblasts from normal and diseased placentas; yet, there are limited data regarding trophoblast TLR expression in response to specific placental pathogens, and TLR expression in the guinea pig placenta has not been described. The guinea pig is an effective model for Campylobacter-induced abortion of small ruminants, and the authors have shown by immunohistochemistry that C jejuni localizes within syncytiotrophoblasts of the guinea pig subplacenta. The present study was designed to determine if the expression of either TLR2 or TLR4 would be affected in subplacental trophoblasts following infection with C jejuni. Immunohistochemistry for TLR2 and TLR4 was performed on placenta from guinea pigs that aborted following inoculation with C jejuni and from sham-inoculated controls. Quantitative assessment of TLR expression was performed, and mean immunoreactivity for TLR2 was significantly higher in subplacental trophoblasts from animals that aborted compared with uninfected controls (P = .0283), whereas TLR4 expression was not statistically different (P = .5909). These results suggest that abortion in guinea pigs following infection with C jejuni is associated with increased TLR2 expression in subplacental trophoblasts and may reveal a possible role for TLR2 in the pathogenesis of Campylobacter-induced abortion.
Feed efficiency is simply defined as the ratio between growth and feed intake. However, defining the integration of genetic and environmental factors that alter molecular and physiological aspects of growth, appetite, or a combination thereof is quite complex and remains elusive. In livestock such as pigs, limited resources (i.e. nutrients and energy) to allocate towards maintenance, growth, and other life processes, and to what functions these resources are allocated dictates efficiency of feed utilization during both sickness and health. An important aspect of resource reallocation during inflammation or pathogen challenges is the metabolic flexibility of cells and tissues that allows for the immunometabolic prioritization of nutrients and energy for the immune response. It is expected that livestock, such as pigs, will be subjected to moderate and severe inflammatory or pathogen insults at some stage in their production life. However, overzealous or prolonged activation of the immune response will diminish skeletal muscle hypertrophy and whole body growth, and combined with reductions in feed intake, decreased feed efficiency often occurs. Appetite, intestinal function and integrity, skeletal muscle growth, and maintenance energy requirements can be altered in pigs encountering enteric and respiratory viruses including Porcine Reproductive and Respiratory Syndrome virus, Porcine Epidemic Diarrhea virus, and bacteria such as Mycoplasma hyopneumoniae, Lawsonia intracellularis, Salmonella Typhimurium, and Brachyspira hyodysenteriae. However, the severity of impact of these pathogens on performance parameters is dependent on the age of the pig, pathogen virulence, duration of infection, or co-infection with other agents. Further, these pathogen insults are year-round, increase days to reach market weight, and have a significant impact on economic returns for producers. This invited paper will discuss the molecular and physiological impact that inflammation and pathogen challenges have on feed efficiency in growing pigs as it relates to appetite, intestinal function and integrity, metabolism, and tissue accretion.
Additional file 3. Amino acid substitutions in haemolysis-associated genes present only in weakly haemolytic B. hyodysenteriae isolates. Haemolysis-associated genes are identified by locus tag of the reference genome B. hyodysenteriae WA1 and name. Amino acid substitutions are presented using the amino acid single letter code: first letter is amino acid in B. hyodysenteriae WA1, number gives position and last letter is amino acid in weakly haemolytic isolate.
In the past decade, different members of the genus Mamastrovirus have been associated with outbreaks of neurologic disease in humans, cattle, sheep, mink, and, most recently, porcine astrovirus 3 (PoAstV3) in swine. We performed a retrospective analysis of 50 cases of porcine neurologic disease of undetermined cause but with microscopic lesions compatible with a viral encephalomyelitis to better understand the role and pathogenesis of PoAstV3 infection. Nucleic acid was extracted from formalin-fixed paraffin-embedded (FFPE) tissue for reverse transcription quantitative polymerase chain reaction (RT-qPCR) testing for PoAstV3. In addition, 3 cases with confirmed PoAstV3-associated disease were assayed by RT-qPCR to investigate PoAstV3 tissue distribution. PoAstV3 was detected in central nervous system (CNS) tissue via RT-qPCR and in situ hybridization in 13 of 50 (26%) FFPE cases assayed. PoAstV3 was rarely detected in any tissues outside the CNS. Positive cases from the retrospective study included pigs in various production categories beginning in 2010, the earliest year samples were available. Based on these results, PoAstV3 appears to be a recurring putative cause of viral encephalomyelitis in swine that is rarely detected outside of the CNS at the time of clinical neurologic disease, unlike other common viral causes of neurologic disease in swine.
Abstract Pharmacological concentrations of zinc (Zn) are commonly fed in the nursery to benefit early post-weaning performance and reduces scours. Therefore, our objective was to determine the effect of pharmacological Zn on post-weaning pig daily feed intake and performance. Three-hundred weaned pigs (5.7 ± 1.03 kg BW) were selected and allotted to 1 of 3 dietary treatments (n = 10 pens/treatment, 10 pigs/pen). Diets were fed over 2 phases (phase 1: d 0-7, phase 2: d 8-21) and consisted of: 1) Control diet with no growth promoting additives, CON; 2) CON + 3,000 ppm Zn and 200 ppm Cu (phase 1), no pharmacological minerals in phase 2, ZC1; and 3) CON + 3,000 ppm Zn and 200 ppm Cu (phase 1), CON + 2,000 ppm Zn and 200 ppm Cu (phase 2); ZC2). Bodyweights were collected at d 0, 7, and 21. Feed disappearance was recorded daily from d 0-14, and within phase. In phase 1, ZC1 and ZC2 pigs had 29% greater feed consumption compared with the CON pigs (0.09, 0.09, 0.07 kg/d; P < 0.0001). Within 2 d of phase 2 diet change, feed intake of the ZC1 pigs sharply decreased to the same level of the CON pigs, while ZC2 pigs consumed 29% more (P < 0.05). In phase 1, ZC1 and ZC2 pens had increased ADG compared with CON pigs (P < 0.001). In phase 2, ADG was 14% greater in the ZC2 compared with ZC1 and CON pigs (P = 0.023). Overall, ADG was 15% greater in the ZC2 pigs and ADFI was 13 and 24% higher than ZC1 and CON pens, respectively (P < 0.05). In conclusion, early post-weaning feed intake was augmented with pharmacological levels of Zn. These data suggest that pharmacological Zn potentially enhances voluntary feed intake regulation in pigs.
A flock of budgerigars (Melopsittacus undulates) was purchased from a licensed breeder and quarantined at a zoologic facility within the United States in 2016. Following 82 deaths within the flock, the remaining 66 birds were depopulated because of ongoing clinical salmonellosis despite treatment. Gross necropsy was performed on all 66 birds. Histopathologic examination was performed on 10 birds identified with gross lesions and 10 birds without. Pathologic findings were most often observed in the liver, kidney, and spleen. Lesions noted in the livers and spleens were consistent with published reports of salmonellosis in psittacine species. Multisystemic changes associated with septicemia were not noted, most likely because of antibiotic intervention before euthanasia. Of the 20 budgerigars evaluated by histopathology, six had large basophilic intranuclear inclusion bodies within tubular epithelia in a portion of the kidneys. Electronic microscopy, next-generation sequencing, Sanger sequencing, and phylogenetic analyses were used to identify and categorize the identified virus as a novel siadenovirus strain BuAdV-1 USA-IA43444-2016. The strain was 99% similar to budgerigar adenovirus 1 (BuAdV-1), previously reported in Japan, and to a psittacine adenovirus 5 recently identified in a U.S. cockatiel. Salmonella typhimurium carriers were identified via polymerase chain reaction (PCR) and bacterial culture and compared with viral carriers identified via PCR. Inclusion bodies and Salmonella detection were significant in birds with gross lesions versus those without; however, there was no correlation between budgerigars positive with siadenovirus by PCR and concurrent Salmonella infection. Identifying subclinical siadenovirus strain BuAdV-1 USA-IA43444-2016 infection in this flock significantly differs from a previous report of clinical illness in five budgerigars resulting in death caused by BuAdV-1 in Japan. S. typhimurium remains a significant pathogen in budgerigars, and zoonotic concerns prompted depopulation to mitigate the public health risks of this flock.
Senecavirus A (SVA) is the only member of the genus Senecavirus within the family Picornaviridae. This virus was discovered as a serendipitous finding in 2002 (and named Seneca Valley virus 001 [SVV-001]) while cultivating viral vectors in cell culture and has been proposed for use as an oncolytic virus to treat different types of human neoplasia. SVA was found in lesions in pigs affected by porcine idiopathic vesicular disease in Canada and the USA in 2008 and 2012, respectively. In 2014 and 2015, SVA infection was associated with outbreaks of vesicular disease in sows as well as neonatal pig mortality in Brazil and the USA. Phylogenetic analysis of the SVA VP1 indicates the existence of 3 clades of the virus. Clade I contains the historical strain SVV-001, clade II contains USA SVA strains identified between 1988 and 1997, and clade III contains global SVA strains from Brazil, Canada, China, and the USA identified between 2001 and 2015. The aim of this review is to draw the attention of veterinarians and researchers to a recently described infectious clinical-pathologic condition caused by a previously known agent (SVA). Apart from the intrinsic interest in a novel virus infecting pigs and causing economic losses, the major current concern is the similarity of the clinical picture to that of other swine diseases, because one of them-foot and mouth disease-is a World Organization for Animal Health-listed disease. Because the potential association of SVA with disease is rather new, there are still many questions to be resolved.
