Effects of mat feeding on the growth performance, removal, and mortality of pigs after weaning.

Four experiments were conducted to determine the effect of mat feeding strategy on the growth performance, removal, and mortality of pigs after weaning. In exp. 1, 1,392 weanling pigs (initially 7.0 kg; approximately 24 d of age) were randomly allotted to 1 of 2 mat feeding treatments (mat feed vs. no mat feed). Overall, mat fed pigs had a tendency for improved ADG (P = 0.065) and G:F (P = 0.060) compared to pigs not offered mat feed. Mat fed pigs had fewer removals (P = 0.013) compared to pigs not offered mat feed. In exp. 2, 2,912 weanling pigs (initially 5.5 kg; approximately 21 d of age) were randomly allotted to 1 of 2 mat feeding treatments (mat feed vs. no mat feed). Overall, no differences in growth performance were observed. However, mat fed pigs had decreased (P < 0.026) final body weights compared to pigs not offered mat feed. This may be related to removal rates as mat fed pigs had fewer removals (P = 0.026). In exp. 3, 3,264 weanling pigs (initially 5.5 kg; approximately 21 d of age) were randomly allotted to 1 of 4 treatments in a 2 × 2 factorial with main effects of diet form (pellet or crumble) and mat feeding (mat feed vs. no mat feed). No interactions between diet form and mat feeding were observed. No differences were observed in overall growth performance for the main effect of mat feeding. Pigs offered pelleted feed had decreased overall ADFI (feed disappearance from the feeder and feed placed on the mat; P = 0.013) and improved G:F (P < 0.001) compared to pigs offered crumble feed. No differences were observed in removals or mortalities for the main effect of mat feeding or diet form. In exp. 4, 3,227 weanling pigs (initially 5.1 kg; approximately 21 d of age) were randomly allotted to 1 of 3 treatments consisting of mat feeding small (3.2 mm) pellets, mat feeding large (12.7 mm) pellets, or no mat feeding. Overall, no differences were observed in ADG or G:F. Mat fed pigs had increased ADFI (P < 0.001) compared to pigs not offered mat feed. Given the shorter duration of this experiment, the extra feed provided with mat feeding had a greater impact on overall feed usage than exp. 1, 2, and 3. No differences were observed in removals or mortalities. When combining the removal and mortality data for the four experiments, mat fed pigs had fewer removals (P = 0.002) compared to pigs not offered mat feed. In summary, mat feeding may encourage earlier feeding behavior, therefore reducing the removal rate of pigs post-weaning.

Prior to domestication, weaning was a slow process in which young pigs develop new feeding behaviors as they transition from an all milk-based diet to solid feed. However, in modern commercial production, weaning is an abrupt event marked by a multitude of stressors that often interfere with the development of feeding behaviors. This leads to low feed intake and body weight gain immediately post-weaning. For this reason, management strategies, such as mat feeding, have become increasingly important to elicit the natural feeding behavior of pigs at weaning. Mat feeding is accomplished by applying a small amount of feed onto the floor mats of nursery or wean-to-finish pens to introduce weaned pigs to solid feed. Because limited data are available on mat feeding, a series of experiments were conducted to determine the effect of different mat feeding strategies on the growth performance, removal, and mortality of pigs after weaning. Overall, mat feeding had limited effects on the growth performance of pigs; however, mat feeding strategies may encourage the development of feeding behaviors, therefore eliciting early feed intake, and reducing the removal rate of pigs after weaning.

A multiplex real-time PCR assay for the detection and differentiation of the newly emerged porcine circovirus type 3 and continuously evolving type 2 strains in the United States.

A multiplex quantitative real-time polymerase chain reaction (mqPCR) assay was developed and validated for the detection and differentiation of porcine circovirus type 3 (PCV3) and type 2 (PCV2) strains. The assay coverage was 97.9% (184/188) for PCV3 and 99.1% (1889/1907) for PCV2 sequences that were available from the current GenBank database. The PCR amplification efficiencies were 98-99% for plasmids, and 92-96% for diagnostic samples, with correlation coefficients all greater than 0.99. The limit of detection (LOD) determined as plasmid copies per reaction was 17 for PCV3 and 14 for PCV2. The assay specifically detected the targeted viruses without cross reacting to each other or to other common porcine viruses. Among 336 swine clinical samples collected in 2018, 101 (30.1%) were PCV3 positive, 56 (16.7%) were PCV2 positive and 18 (5.4%) were co-positives. Sixty selected PCV3 positives were confirmed by Sanger sequencing, and 53 of the 56 PCV2 positive samples were tested positive by another validated PCR assay.

Fecal Microbiota Transplantation Is Associated With Reduced Morbidity and Mortality in Porcine Circovirus Associated Disease.

Porcine circovirus associated disease (PCVAD) is a term used to describe the multi-factorial disease syndromes caused by porcine circovirus type 2 (PCV-2), which can be reproduced in an experimental setting through the co-infection of pigs with PCV-2 and porcine reproductive and respiratory syndrome virus (PRRSV). The resulting PCVAD-affected pigs represent a subpopulation within the co-infected group. In co-infection studies, the presence of increased microbiome diversity is linked to a reduction in clinical signs. In this study, fecal microbiota transplantation (FMT) was investigated as a means to prevent PCVAD in pigs co-infected with PRRSV and PCV-2d. The sources of the FMT material were high-parity sows with a documented history of high health status and robust litter characteristics. The analysis of the donated FMT material showed the absence of common pathogens along with the presence of diverse microbial phyla and families. One group of pigs (n = 10) was administered the FMT while a control group (n = 10) was administered a sterile mock-transplant. Over the 42-day post-infection period, the FMT group showed fewer PCVAD-affected pigs, as evidenced by a significant reduction in morbidity and mortality in transplanted pigs, along with increased antibody levels. Overall, this study provides evidence that FMT decreases the severity of clinical signs following co-infection with PRRSV and PCV-2 by reducing the prevalence of PCVAD.

Antibody recognition of porcine circovirus type 2 capsid protein epitopes after vaccination, infection, and disease.

Open reading frame 2 (ORF2) of porcine circovirus type 2 (PCV2) codes for the 233-amino-acid capsid protein (CP). Baculovirus-based vaccines that express only ORF2 are protective against clinical disease following experimental challenge or natural infection. The goal of this study was to identify regions in CP preferentially recognized by sera from experimentally infected and vaccinated pigs and to compare these responses to those of pigs diagnosed with porcine circovirus-associated disease (PCVAD), including porcine multisystemic wasting syndrome (PMWS) and porcine dermatitis and nephropathy syndrome (PDNS). The approach was to react porcine sera with CP polypeptide fragments followed by finer mapping studies using overlapping oligopeptides that covered amino acids 141 to 200. The results showed that vaccinated pigs preferentially recognized only the largest polypeptide fragment, CP(43-233). A subset of experimentally infected pigs and pigs with PDNS showed strong reactivity against a CP oligopeptide, 169-STIDYFQPNNKR-180. Alanine scanning identified Y-173, F-174, Q-175, and K-179 as important for antibody recognition. The results from this study support the notion of PCV2 modulation of immunity, including antibody responses that may represent a precursor for disease. The recognition of CP(169-180) and other polypeptides provides opportunities to devise diagnostic tests for monitoring the immunological effectiveness of vaccination.

Predictors of success with methotrexate treatment of tubal ectopic pregnancy at Grady Memorial Hospital.

OBJECTIVE: The purpose of this study was to determine our institutional success rate with single-dose intramuscular methotrexate therapy for the treatment of ectopic pregnancy and to identify predictors of treatment outcome. STUDY DESIGN: This was a retrospective review of consecutive patients who were treated with methotrexate from January 2000 until April 2002. Successful treatment was defined as the resolution of the ectopic pregnancy without surgical intervention. RESULTS: Our overall success rate was 85% (69/81 patients). The median pretreatment serum beta-human chorionic gonadotropin level was lower in those women in whom treatment was successful compared with those women with treatment failure (793 vs 3804 mIU/mL, P <.002). The presence of a yolk sac that was visualized on vaginal ultrasonography was the only significant predictor of treatment failure (adjusted odds ratio, 19.3; P <.002). CONCLUSION: Our institutional success rate (85%) with methotrexate for treatment of tubal ectopic pregnancy is comparable with other published results. However, a finding unique to this study was that visualization of a yolk sac was a risk factor for failure.