Influence of spray dried porcine plasma in starter diets associated with a conventional vaccination program on wean to finish performance

Biosecurity and Mitigation Strategies to Control Swine Viruses in Feed Ingredients and Complete Feeds

No system nor standardized analytical procedures at commercial laboratories exist to facilitate and accurately measure potential viable virus contamination in feed ingredients and complete feeds globally. As a result, there is high uncertainty of the extent of swine virus contamination in global feed supply chains. Many knowledge gaps need to be addressed to improve our ability to prevent virus contamination and transmission in swine feed. This review summarizes the current state of knowledge involving: (1) the need for biosecurity protocols to identify production, processing, storage, and transportation conditions that may cause virus contamination of feed ingredients and complete feed; (2) challenges of measuring virus inactivation; (3) virus survival in feed ingredients during transportation and storage; (4) minimum infectious doses; (5) differences between using a food safety objective versus a performance objective as potential approaches for risk assessment in swine feed; (6) swine virus inactivation from thermal and irradiation processes, and chemical mitigants in feed ingredients and complete feed; (7) efficacy of virus decontamination strategies in feed mills; (8) benefits of functional ingredients, nutrients, and commercial feed additives in pig diets during a viral health challenge; and (9) considerations for improved risk assessment models of virus contamination in feed supply chains.

Feeding Spray-Dried Porcine Plasma to Pigs Improves the Protection Afforded by the African Swine Fever Virus (ASFV) BA71∆CD2 Vaccine Prototype against Experimental Challenge with the Pandemic ASFV-Study 2

This study aimed to evaluate the effects of feeding spray-dried porcine plasma (SDPP) on the protection afforded by the BA71∆CD2 African swine fever virus (ASFV) vaccine prototype. Two groups of pigs acclimated to diets without or with 8% SDPP were intranasally inoculated with 10⁵ plaque-forming units (PFU) of live attenuated ASFV strain BA71∆CD2 and, three weeks later, left in direct contact with pigs infected with the pandemic Georgia 2007/01 ASFV strain. During the post-exposure (pe) period, 2/6 from the conventional diet group showed a transient peak rectal temperature >40.5 °C before day 20 pe, and some tissue samples collected at 20 d pe from 5/6 were PCR+ for ASFV, albeit showing Ct values much higher than Trojan pigs. Interestingly, the SDPP group did not show fever, neither PCR+ in blood nor rectal swab at any time pe, and none of the postmortem collected tissue samples were PCR+ for ASFV. Differential serum cytokine profiles among groups at vaccination, and a higher number of ASFV-specific IFNϒ-secreting T cells in pigs fed with SDPP soon after the Georgia 2007/01 encounter, confirmed the relevance of Th1-like responses in ASF protection. We believe that our result shows that nutritional interventions might contribute to improving future ASF vaccination strategies.

A dietary spray-dried plasma feeding programme improves growth performance and reduces faecal bacterial shedding of nursery pigs challenged with enterotoxigenic Escherichia coli K88

This study aimed to assess the effects of different spray-dried plasma (SDP) feeding programmes to pigs on performance, intestinal histomorphology and faecal bacterial shedding after an Escherichia coli K88 challenge. A total of 96 piglets (5.77 ± 0.01 kg) were weaned at 21 days of age (Day 0) and challenged with 3 ml of 1 × 10¹⁰  CFU of E. coli K88 in total 3.0 × 10¹⁰  CFU/animal on Days 0, 2 and 4. Pigs were fed nursery diets containing 0.0%, 3.0%, 6.0% or 9.0% SDP from weaning to 35 days of age; 0.0%, 1.5%, 3.0% or 4.5% SDP from 36 to 49 days; and the same control diet (without SDP), for the last 10 days of the experiment (50-59 days of age). Performance was measured from 35 to 59 days of age and faecal bacterial shedding and intestinal histomorphometry were evaluated at Days 28 and 49 of age respectively. From 21 to 35 days of age, there was a linear effect for body weight (BW) and average daily gain (ADG), a trend of linear effect for average daily feed intake (ADFI) and a quadratic effect for feed:gain ratio (FG). From 21 to 49 days, the 9.0:4.5% and 6.0:3.0% SDP feeding programmes improved BW, ADG and FG when compared to the other treatments. At 59 days of age, BW and ADG were increased by the two highest SDP feeding programmes. The 9.0:4.5% SDP feeding programme increased ADFI from 21 to 59 days of age, with 6.0:3.0% being intermediate and the other two treatments being lowest. The CFU counts of E. coli/g of faeces decreased linearly with increasing addition of SDP. These results indicate that an extended inclusion of increased SDP levels in post-weaning diets can improve growth potential and decrease bacterial shedding induced by E. coli K88.

Estimated quantity of swine virus genomes based on quantitative PCR analysis in spray-dried porcine plasma samples collected from multiple manufacturing plants

This survey was conducted to estimate the incidence and level of potential viral contamination in commercially collected porcine plasma. Samples of spray dried porcine plasma (SDPP) were collected over a 12- month period from eight spray drying facilities in Spain, England, Northern Ireland, Brazil, Canada, and the United States. In this survey, viral load for several porcine pathogens including SVA, TGEV, PRRSV (EU and US strains), PEDV, PCV-2, SIV, SDCoV and PPV were determined by qPCR. Regression of Ct on TCID₅₀ of serial diluted stock solution of each virus allowed the estimate of potential viral level in SDPP and unprocessed liquid plasma (using typical solids content of commercially collected porcine plasma). In this survey SVA, TGEV or SDCoV were not detected in any of the SDPP samples. Brazil SDPP samples were free of PRRSV and PEDV. Samples of SDPP from North America primarily contained the PRRSV-US strain while the European samples contained the PRRSV-EU strain (except for one sample from each region containing a relatively low estimated level of the alternative PRRSV strain). Estimated viral level tended to be in the range from <1.0 log₁₀ TCID₅₀ to <2.5 log₁₀ TCID₅₀. Estimated level of SIV was the exception with a very low incidence rate but higher estimated viral load <3.9 log₁₀ TCID₅₀. In summary, the incidence of potential viral contamination in commercially collected porcine plasma was variable and estimated virus level in samples containing viral DNA/RNA was relatively low compared with that occurring at the peak viremia during an infection for all viruses or when considering the minimal infectious dose for each of them.

Genomic Analysis of IgG Antibody Response to Common Pathogens in Commercial Sows in Health-Challenged Herds

Losses due to infectious diseases are one of the main factors affecting productivity in the swine industry, motivating the investigation of disease resilience-related traits for genetic selection. However, these traits are not expected to be expressed in the nucleus herds, where selection is performed. One alternative is to use information from the commercial level to identify and select nucleus animals genetically superior for coping with pathogen challenges. In this study, we analyzed the genetic basis of antibody (Ab) response to common infectious pathogens in health-challenged commercial swine herds as potential indicator traits for disease resilience, including Ab response to influenza A virus of swine (IAV), Mycoplasma hyopneumoniae (MH), porcine circovirus (PCV2), and Actinobacillus pleuropneumoniae (APP; different serotypes). Ab response was measured in blood at entry into gilt rearing, post-acclimation (∼40 days after entering the commercial herd), and parities 1 and 2. Heritability estimates for Ab response to IAV, MH, and PCV2 ranged from 0 to 0.76. Ab response to APP ranged from 0 to 0.40. The genetic correlation (r _G ) of Ab response to IAV with MH, PCV2, PRRSV, and APP_mean (average Ab responses for all serotypes of APP) were positive (>0.29) at entry. APP_mean was negatively correlated with PCV2 and MH at entry and parity 2 but positively correlated with MH at post-acclimation and parity 1. Genomic regions associated with Ab response to different APP serotypes were identified on 13 chromosomes. The region on chromosome 14 (2 Mb) was associated with several serotypes of APP, explaining up to 4.3% of the genetic variance of Ab to APP7 at entry. In general, genomic prediction accuracies for Ab response were low to moderate, except average Ab response to all infectious pathogens evaluated. These results suggest that genetic selection of Ab response in commercial sows is possible, but with variable success depending on the trait and the time-point of collection. Future work is needed to determine genetic correlations of Ab response with disease resilience, reproductive performance, and other production traits.

Immune responses induced by a combined vaccination with a recombinant chimera of Mycoplasma hyopneumoniae antigens and capsid virus-like particles of porcine circovirus type 2

BACKGROUND

Mycoplasma hyopneumoniae (Mhp) and porcine circovirus type 2 (PCV2) are two important pathogens causing Mycoplasma pneumonia of swine (MPS) and porcine circovirus diseases and porcine circovirus-associated diseases (PCVDs/PCVADs), respectively, and resulted in considerable economic loss to the swine industry worldwide. Currently, vaccination is one of the main measures to control these two diseases; however, there are few combination vaccines that can prevent these two diseases. To determine the effect of combination immunization, we developed capsid-derived (Cap) virus-like particles (VLPs) of PCV2 and a new recombinant chimera composed of the P97R1, P46, and P42 antigens of Mhp. Then we investigated the immune responses induced by the immunization with this combination vaccine in mice and piglets.

RESULTS

The high level antibodies against three protein antigens (P97R1, P46, and P42 of Mhp) were produced after immunization, up to or higher than 1:400,000; the antibody levels in Pro group continuously increased throughout the 42 days for all the antigens tested. The lymphocyte proliferative response in PCV2 group was stronger than that in PBS, VP, Mhp CV in mice. The antibody levels for Cap remained stable and reached the peak at 35 DAI. The IFN-γ and IL-4 in sera were significantly enhanced in the Pro group than that in the negative control-VP group on Day 14 and 28 post-the first immunization in piglets.

CONCLUSIONS

Above all, the combination immunization could induce humoral and cellular immune responses against all four antigens in mice and piglets. Therefore, our approach is a simple and effective vaccination strategy to protect pigs against MPS and PCVD/PCVAD.

The effect of a feed additive supplemented with porcine plasma protein on growth performance and selected biochemical indices of nursing piglets

The aim of this study was to evaluate the health state, performance, and selected serum biochemical indices in nursing piglets after supplementation of a feed additive containing porcine plasma protein in comparison to the control group fed a standard pre-starter feed mixture. The study was carried out in the conditions of industrial farming. Four sows of the Large White swine breed with their litters were included in the study. Piglets were homogenously distributed into control (22) and experimental (24) groups according to weight and sex. Piglets in both groups suckled their mothers' milk. In addition, piglets in the experimental group were also fed a feed supplemented by porcine plasma protein (5%), starting on the third day post partum, whereas piglets in the control group were offered a standard pre-starter feed mixture. We recorded average daily weight gains calculated per the 27-day trial, and body weight at weaning. Clinical findings, mortality, and selected biochemical indices of protein (total immunoglobulins, total protein, albumin, creatinine, urea), and energy (glucose, total cholesterol, total lipids) metabolism were assessed as well. Results of the study showed a significant difference (P < 0.01) in average daily weight gains in the experimental group compared to the control group (0.245 kg and 0.177 kg, respectively). Addition of plasma protein in the experimental group also resulted in a significantly higher serum concentration of total immunoglobulins, total protein and creatinine, and a significantly lower concentration of urea and albumin in this group compared to the control group at weaning.

Impact of formaldehyde addition to spray-dried plasma on functional parameters and animal performance1

Experimental objectives of this study were to determine effects of formaldehyde treatment on the chemical composition of spray-dried plasma (SDP) and to test the hypothesis that growth performance of pigs fed formaldehyde-treated diets containing SDP or diets containing formaldehyde-treated SDP is not reduced compared with pigs fed untreated control diets. Sal CURB ASF liquid antimicrobial and CURB RM Extra liquid mold inhibitor (Kemin Industries, Des Moines, IA) were applied on SDP at 0.1% or 0.3% to determine effects of the products on chemical and functional properties of SDP. Regardless of product, there were no changes in SDP for analyzed protein, ash, pH, or moisture concentration, but IgG concentration in SDP was decreased 8% and 24%, respectively, for 0.1% and 0.3% inclusion of Sal CURB or CURB RM. Two feeding studies using weaned pigs were conducted to determine effects of formaldehyde applied at 0.3% to SDP (experiment 1) or 0.3% to a complete diet containing 5% SDP (experiment 2). Experiment 1 pigs (n = 265) were weaned at 20 ± 2 d of age and allotted to five treatment groups. Experiment 2 pigs (n = 135) were weaned in two groups at 20 ± 2 d of age and allotted to three treatments groups. In experiment 1, the untreated control diet contained soy protein concentrate (SPC) and test diets contained 2.5% or 5.0% SDP without or with formaldehyde treatment. In experiment 2, formaldehyde was applied to a diet containing 5% SDP and an untreated SPC control diet and an untreated diet containing 5% SDP were also included in the experiment. In experiment 1, linear increases (P < 0.05) in average daily gain (ADG), average daily feed intake (ADFI), and gain-to-feed ratio (G:F) were observed as SDP was included in the diets and the relative bioavailability of formaldehyde-treated SDP was 62% (P = 0.018) if calculations were based on ADG and 15% (P = 0.031) if calculations were based on ADFI. In experiment 2, pigs fed the SDP diet untreated or treated with formaldehyde had increased (P < 0.05) final body weight, ADG, ADFI, and G:F compared with pigs fed the control diet. However, formaldehyde treatment of the plasma-containing diet did not affect pig growth performance compared with pigs fed the untreated SDP diet. In conclusion, formaldehyde treatment applied directly on SDP affects analyzed concentrations of IgG and reduces growth rate of pigs. Treating a complete diet containing 5% SDP with formaldehyde did not affect pig growth performance, and pigs fed diets containing SDP had improved growth performance than those fed the control diet without SDP.

Effects of specialty proteins as alternatives to bovine or porcine spray-dried plasma in non-medicated diets fed to weaned pigs housed in an unsanitary environment

Two experiments were done to compare growth performance of pigs weaned at 21 ± 2 d of age that were housed in unsanitary pens and fed non-medicated diets containing alternative proteins versus spray-dried porcine (SDPP; Exp. 1) or bovine (SDBP; Exp. 2) plasma. Experiment 1 used 360 pigs fed 1 of 6 experimental diets from d 0 to 15, followed by a common diet fed to all pigs from d 15 to 28 post-weaning with 11 pens of 5 or 6 pigs/pen allotted per treatment. Experimental diets were based on 8.04% soy protein concentrate (SPC) as the control protein or a similar diet with either 2.50 or 5.00% SDPP or 0.17, 0.33, or 1.00% activated porcine plasma (APP) replacing SPC on an equal Lys basis. Experiment 2 used 300 pigs that were fed 1 of 6 experimental diets from d 0 to 14 post-weaning with 10 pens of 4 to 6 pigs/pen allotted per diet. Experiment 2 diets were based on 8.04% SPC as the control protein source or similar diets with the following specialty proteins replacing SPC on an equal Lys basis: 0.40% APP; 10.66% enzymatically hydrolyzed soy and yeast protein (EHSY); a combination (CB) of 6.36% EHSY, 0.40% APP, and 2.50% fish meal; 0.44% spray-dried whole egg from hyper-immunized hens (IEGG); or 5.00% SDBP. Results of Exp. 1 indicated pigs fed SDPP diets had greater (P < 0.05) ADG and ADFI at d 7 and 15 compared with pigs fed SPC or APP diets. Gain:feed at d 7 was higher (P < 0.05) for pigs fed diets with SDPP compared with other diets. Average BW at d 7 was greater (P < 0.05) for pigs fed diets with SDPP compared to other diets and pigs fed the 5.00% SDPP diet had greater BW at d 15 compared to diets without SDPP. At d 28 BW was greater (P < 0.05) for pigs fed the 2.50% SDPP diet compared with pigs fed diets with SPC, 0.33% APP, or 1.00% APP. Performance of pigs fed the SPC diet did not differ from APP diets at any period of the study. In Exp. 2, pigs fed the SDBP diet had greater (P < 0.05) BW, ADG, and ADFI at d 7 and 14 compared with pigs fed the other diets. Gain:feed did not differ significantly among diets. Average daily gain and ADFI of pigs did not differ among diets that did not contain SDBP. In conclusion, during the initial 2 wk post-weaning, pigs housed in unsanitary pens and fed non-medicated diets with APP in Exp. 1, or APP, EHSY, CB, or IEGG in Exp. 2 had equivalent performance to pigs fed SPC; however, performance of pigs fed diets with the alternatives was not equivalent to diets containing SDPP in Exp. 1 or SDBP in Exp. 2.

Ultraviolet irradiation of spray-dried porcine plasma does not affect the growth performance of nursery pigs when compared with nonirradiated bovine plasma

Ultraviolet light irradiation of spray-dried porcine plasma (SDPP) decreases the risk of disease transmission, but it may decrease the activity of bioactive components in SDPP. Therefore, the objectives of this study were to determine growth performance, morbidity, and mortality responses of nursery pigs fed UV-irradiated SDPP (UV-SDPP) compared with nonirradiated spray-dried bovine plasma (SDBP). Pigs (n = 480; 6.09 ± 2.4 kg initial BW) were blocked by initial BW, and blocks were assigned to pens. the sex ratio was equalized within blocks and pens. Pens were randomly assigned to 1 of 5 dietary treatments (8 pigs/pen and 12 replicates/treatment) in a 3-phase feeding program (phase 1 = d 0 to 13, phase 2 = d 14 to 27, and phase 3 = d 28 to 55). Dietary treatments included a control diet without UV-SDPP or SDBP and diets containing 3% UV-SDPP, 3% SDBP, 6% UV-SDPP, or 6% SDBP during phase 1. Diets were formulated to meet or exceed nutrient requirements and contained the same concentrations of standardized ileal digestible Lys and Lys:ME ratio within phases. Pigs were provided ad libitum access to diets throughout the 55-d experiment. Dietary inclusion rates during phase 2 were reduced to 1.5% UV-SDPP, 1.5% SDBP, 3% UV-SDPP, and 3% SDBP, and all pigs were fed a common diet without UV-SDPP or SDBP during phase 3. Growth performance data were analyzed as a 2 × 2 factorial arrangement of treatments with a control within a completely randomized block design to evaluate the main effects of plasma processing (UV irradiated vs. nonirradiated) and dietary inclusion level, and block, room, and pen were random effects. In phase 1, there were no differences in G:F among treatments, but pigs fed 6% UV-SDPP and 6% SDBP had greater (P < 0.01) ADG (0.11 vs. 0.08 kg/d) and ADFI (0.17 vs. 0.15 kg/d) than pigs fed the control, 3% SDBP, and 3% UV-SDPP diets. After phase 1 (d13), feeding UV-SDPP or SDBP increased (P = 0.02) the BW of pigs. In phases 2 and 3 and the overall feeding period (d 0 to 55), there were no differences in ADG, ADFI, and G:F among dietary treatments. There was a linear decrease (P < 0.01) in mortality of nursery pigs as dietary inclusion rate of SDBP and UV-SDPP increased. In conclusion, feeding SDBP or UV-SDPP diets improved ADG and ADFI during the first 2 wk after weaning due to improved feed consumption, and UV irradiation appeared to have no detrimental effects on the feeding value of SDPP.