Effectiveness of different corn dried distillers grains with solubles feeding strategies and increasing the time intervals between the second Improvest dose and slaughter of immunologically castrated pigs on belly and pork fat quality.

Effects of dried distillers grains with solubles (DDGS) feeding strategies (a corn-soybean meal (CS) fed continously; CS+40% DDGS fed continously; CS+40, 30, 20, or 10% DDGS in 4 phases, respectively; or CS+40% DDGS in phases 1 to 3 and CS in phase 4 before slaughter) on belly and pork fat quality of immunologically castrated (n=192) pigs were evaluated. All pigs received the first Improvest dose at 11week of age, and the second dose at 9, 7, or 5week before slaughter at 24week of age. Increasing the time interval of the second Improvest dose before slaughter reduced IV in all fat depots and increased belly thickness. Gradually decreasing dietary DDGS and DDGS withdrawal feeding strategies reduced IV in all fat depots. Calculated IV were greater using the Meadus et al. (2010) equation compared with using the AOCS (1998) equation because it includes more long-chain unsaturated fatty acids.

Growth performance of immunologically castrated pigs slaughtered at 5, 7, or 9 weeks after the second Improvest dose and fed diets containing corn dried distillers grains with solubles.

Growth performance of immunologically castrated (IC) pigs (863 total) was determined at increasing time intervals between the second Improvest (gonadotropin releasing factor analog-diphtheria toxoid conjugate; Zoetis Inc., Florham Park, NJ) dose and slaughter (TD) and with 4 different dried distillers grains with solubles (DDGS) feeding strategies (FS) in a 4 × 3 factorial arrangement of treatments. The feeding period was divided into 4 separate diet phases. Dietary treatments included 1) corn-soybean meal control diets (PCon), 2) a gradual decrease of dietary DDGS inclusion rate from 40%, 30%, 20%, and 10% in phases 1 to 4 (GD), respectively, 3) feeding 40% DDGS diets in phases 1 to 3 and removal of DDGS from the phase 4 diet (WD), and 4) feeding 40% DDGS diets in all 4 phases (NCon). Pigs received the second Improvest dose at 9 (TD9), 7 (TD7), or 5 (TD5) wk before slaughter. In each group, all pigs were slaughtered on the same day. There were no 3-way interactions among FS, TD, and week of feeding period for any measure of growth performance. Pigs fed PCon and WD had greater ( < 0.05) overall ADFI than pigs fed NCon, especially when slaughtered 9 wk after the second Improvest dose (2.45 and 2.44 vs. 2.31 ± 0.08 kg/d, respectively). This response was partly due to withdrawing DDGS from the diet at 19 wk of age (WD), which led to a tendency ( < 0.10) for increased ADFI from the wk 19 to 21 interval to the wk 21 to 24 interval (3.26 vs. 3.51 ± 0.09 kg/d, respectively). During the same time period, ADFI was unchanged ( > 0.05) in pigs fed PCon, GD, and NCon. Overall G:F was improved ( < 0.05) in TD5 pigs compared with TD9 pigs and tended ( < 0.10) to be improved compared with TD7 pigs. Final BW was similar among pigs fed GD, WD, and PCon (123.1, 122.3, and 125.3 kg, respectively), but pigs fed PCon and GD had greater ( < 0.05) BW than pigs fed NCon (120.0 kg). Throughout the growing-finishing period, BW was similar among TD treatments. The GD FS was more effective than the WD FS in maintaining overall G:F (0.424 and 0.414 ± 0.005, respectively) and ADG (0.94 and 0.93 ± 0.03 kg/d, respectively), which were similar ( > 0.05) to those of pigs fed PCon (0.427 ± 0.005 and 0.96 ± 0.03 kg/d, respectively). Growth performance of pigs fed GD more closely reflected that of pigs fed PCon than that of pigs fed WD. Delaying the second dose of Improvest from 9 to 5 wk before slaughter resulted in improved growth performance.

Effect of time interval between the second Improvest® dose and slaughter and corn dried distillers grains with solubles feeding strategies on carcass composition, primal cutout, and pork quality of immunologically castrated pigs.

Effects of dried distillers grains with solubles (DDGS) feeding strategies on carcass composition, primal cutout, and lean quality of immunologically castrated (IC; n=863) pigs were evaluated, and consisted of: 1) corn-soybean meal (CS) diet (PCon); 2) CS+40% DDGS (NCon); 3) CS+40, 30, 20, or 10% DDGS fed in phases 1 to 4, respectively (SD); or 4) CS+40% DDGS fed in phase 1 to 3 and CS in phase 4 (WD). All pigs received the first dose of Improvest® at 11weeks. of age, and the second dose was administered at either 9, 7, or 5weeks. before slaughter at 24weeks. of age. The SD and WD improved carcass dressing percentage and resulted in intermediate primal cut yields and pork loin quality compared with pigs fed PCon and NCon. Increasing the time interval between second dose of Improvest® and slaughter increased adipose tissue accretion but did not affect lean quality of pork.

Effect of immunological castration management strategy on lipid oxidation and sensory characteristics of bacon stored under simulated food service conditions.

The objectives of this study were to determine the effect of 1) immunological castration (Improvest, a gonadotropin releasing factor analog-diphtheria toxoid conjugate) management strategy (age at slaughter and time of slaughter after second dose) and 2) sex on lipid oxidation and sensory characteristics of bacon stored under simulated food service conditions. For Objective 1, immunological castration management strategies included 24-wk-old immunologically castrated (IC) barrows 4, 6, 8, or 10 wk after the second Improvest dose (ASD); 26-wk-old IC barrows 6 wk ASD; and 28-wk-old IC barrows 8 wk ASD ( = 63). Objective 2 ( = 97) included IC barrows, physically castrated (PC) barrows, and gilts slaughtered at 24, 26, and 28 wks of age. Bellies from 2 slaughter dates were manufactured into bacon under commercial conditions. Bacon slices were laid out on parchment paper, packaged in oxygen-permeable poly-vinyl-lined boxes, and frozen (-33°C) for 1, 4, 8, or 12 wk to simulate food service conditions. At the end of each storage period, bacon was evaluated for lipid oxidation, moisture and lipid content, and sensory characteristics. Data from both objectives were analyzed using the MIXED procedure in SAS with belly as the experimental unit. For both objectives, as storage time increased, lipid oxidation of bacon increased ( < 0.01), regardless of management strategy or sex. Also, there was no sex or management strategy × week of frozen storage interaction for any traits evaluated ( ≥ 0.25). For Objective 1, lipid content of bacon from IC barrows increased as time of slaughter ASD increased ( < 0.05), regardless of age at slaughter. Additionally, there were no differences in sensory attributes of bacon across management strategies. For the evaluation of sex effects in Objective 2, lipid oxidation was greater ( < 0.05) in IC barrows compared with PC barrows but was not different than gilts ( > 0.05). After 12 wk of frozen storage, lipid oxidation values for IC barrows, PC barrows, and gilts were still below 0.5 mg malondialdehyde/kg of meat, the threshold at which trained panelists may deem a food to be rancid. In conclusion, bacon shelf life characteristics were not altered by the immunological castration management strategy and bacon from IC barrows was similar to bacon from gilts. Therefore, bacon from IC barrows would result in shelf life and sensory quality similar to PC barrows and gilts.

Effects of time after a second dose of immunization against GnRF (Improvest) independent of age at slaughter on commercial bacon slicing characteristics of immunologically castrated barrows.

The objective was to determine the effects of time after a second dose of anti-GnRF immunization on fresh belly characteristics and slicing yields of immunologically castrated (IC) barrows, physically castrated (PC) barrows and gilts slaughtered at 24 weeks of age. The second dose was staggered so that IC barrows were slaughtered at 4, 6, 8, or 10 weeks after the second dose. Fresh belly characteristics (N=141) were collected at slaughter and bacon was manufactured commercially. The main effects in the model were treatment and the random effects of block and block within replication. Thickness, flop distance, and lipid content increased (L; P<0.04) and iodine value tended to decrease (L; P=0.08) with time after the second dose in IC barrows. Slicing yields increased with time after the second dose (L; P<0.01), but were similar (P=0.11) among sexes. Increasing time of slaughter after second anti-GnRF dose improves fresh belly and bacon slicing characteristics in IC barrows.

Improving pig health through genomics: a view from the industry.

Health is one of the most important contributors to animal welfare, productivity and profitability in pig production today. For the past 30 years, pig breeders have focused on genetic improvement of lean growth, feed efficiency, meat quality and reproduction. However, in recent years, selection objectives have been broadened to include livability, robustness and disease resistance. A DNA marker for selection of resistance to F18+ E. coli has been available for several years. This marker decreases mortality and improves growth on farms experiencing post-weaning scours and/or oedema disease. However, for most diseases affecting intensive production systems such as porcine reproductive and respiratory syndrome (PRRS), porcine circovirus type 2-associated diseases (PCVAD), Haemophilus parasuis, and swine influenza virus, resistance is a complex and polygenic trait. Selection for improved resistance to these diseases will be incremental and require use of multiple markers in complex breeding schemes. Novel technologies such as pig gene microarrays, single nucleotide polymorphism (SNP) panels and advanced bioinformatics are being used to identify new health candidate genes for these economically important diseases. Lagging behind, however, is availability of large DNAdatasets from pedigreed populations with accurately measured health phenotypes that are needed to identify associations between SNPs and health traits. Increased focus on datasets with health traits will be the key to finding useable discoveries with new genomics technologies. Currently, the industry uses dozens of SNP markers to increase the accuracy of selection for complex breeding objectives, including disease resistance. As the pig genome is sequenced and barriers to genotyping thousand of markers are eliminated, genomic selection for health traits will receive increasing attention from commercial breeders.

Dynamic differential regulation of innate immune transcripts during the infection of alveolar macrophages by the porcine reproductive and respiratory syndrome virus.

Porcine reproductive and respiratory syndrome virus (PRRSV), an arterivirus, is the etiologic agent of an infectious disease of that name, characterized by respiratory disorders, abortion in pregnant sows and high mortality in piglets, resulting in significant economic losses in the pig industry worldwide. In order to identify whether genetic differences in PRRSV response may exist in pigs, alveolar macrophages were used to assess the progression of the type-I interferon (IFN) transcript response in porcine alveolar macrophages infected by PRRSV. Our results suggest that a dynamic differential regulation of the type-I IFN and chemokine transcripts may operate during the first hours of infection with and entry of the virus in alveolar macrophages, and provide a compelling mechanism for the establishment of PRRSV replication in susceptible cells.

Associations between polymorphisms in the porcine haptoglobin gene and baseline levels of serum haptoglobin.

Haptoglobin (Hp) is an acute phase protein that is a marker in blood for clinical and subclinical disease in the pig. The aim of this study was to identify single nucleotide polymorphisms (SNPs) in the Hp gene and analyse their influence on baseline serum levels. DNA samples and serum were collected from 345 boars. Of 13 SNPs identified, 5 were genotyped using PCR-RFLP and Pyrosequencing. Serum Hp levels were measured using a biochemical assay. A general linear model was fitted with line and genotype as fixed effects. In addition, linkage disequilibrium (LD) was estimated between the 5 SNPs using r-square and D prime. Serum Hp concentrations in the population showed a skewed distribution with a mean of 0.34 g/L (range 0-2.65 g/L). Three SNPs were found to be associated with baseline Hp levels (p-value = 0.0093, 0.0051 and 0.0094). These 3 SNPs were also found to be in high LD with each other. This is the first study to find associations between polymorphisms in the porcine Hp gene and baseline Hp serum levels. The results have implications for breeding for resistance to infection.

Relationship between immune cell phenotypes and pig growth in a commercial farm.

The objective of this study was to evaluate the relationship between the level and function of circulating immune cells with average daily gain, live and carcass measurements, feed intake, and feed conversion. Production performance was monitored throughout the pig's lifetime. Pigs were moved in weekly batches through the nursery and growing/finishing rooms at specific target weights. Animals were individually weighed at birth and at weaning, and then every two weeks while they were "on test" until they were "off test" and sent to the slaughterhouse. At six to seven weeks of age, the pigs were bled in the nursery. The percentage of immune cell subsets and lymphocyte proliferation was estimated using swine monoclonal antibodies and flow cytometric analysis. The predictive effect of the immune cell subset markers and lymphocyte proliferation on production traits was statistically analyzed. The results indicated that the proportion of several peripheral cell subsets, including CD16+, CD2+/CD16+, and CD8+ lymphocytes, appear to predict growth during the entire productive life of the pig. Larger percentages of lymphocytes expressing CD16+ CD2+/CD16+, and CD8+receptors in blood resulted in a reduction in average daily gain. In addition, high percentages of SLA-DQ+ cells were associated with better carcass weight and feed conversion. The CD16+, CD2+/CD16+, CD8+, and SLA-DQ+/- cell subsets appear to be important biomarkers involved with the inherent ability of the pig to efficiently grow and produce better carcass weight in representative commercial environments.

Acute feed intake and acute-phase protein responses following a lipopolysaccharide challenge in pigs from two dam lines.

This study was conducted to evaluate the response of two dam lines of pigs to acute increases of LPS. Acute-phase proteins were also measured to determine their potential use as biological indicators of the immune response. Thirty-six pigs (initial body weight = 21.3 +/- 0.48 kg) were allotted by dam line (Lines 1 and 2) and sex (castrates and gilts) to one of three LPS dose treatments and penned individually. Treatments were a single i.m. injection of 0 (LPS-0), 25 (LPS-25) or 50 microg LPS/kg body weight (BW) (LPS-50). Acute changes in feed intake were related to a pre-injection baseline intake. Feeders were weighed daily to establish baseline feed intake (average daily feed intake -48 to 0 h prior to injection). The acute feed intake response (AFIR) was computed as the average daily feed intake 0-48 h after injection divided by baseline intake. Serum was harvested at time 0 and 48 h after injection. LPS-0 pigs grew faster and consumed more feed than the LPS-25 or LPS-50 pigs (0.79 kg/d versus 0.51 and 0.50 kg/d; 1.15 kg/d versus 0.96 and 0.89 kg/d, respectively; P<0.001). The AFIR of Line 1 castrates and Line 2 gilts was similar for LPS-25 and LPS-50 treatments, while Line 1 gilts and Line 2 castrates had decreased AFIR with increased LPS dose (sex x line x LPS, P<0.05). Three of 18 castrates died but no gilts died following the LPS challenge (P<0.10). Castrates had higher haptoglobin (Hpt) concentrations than gilts on d 0 (18.1 units of absorption/mg of protein versus 13.1 units of absorption/mg of protein; P<0.03). Line 1 pigs had higher C-reactive protein (CRP) concentrations than Line 2 pigs (P<0.05) on d 0. LPS treatment did not change serum concentrations of CRP, Hpt or ceruloplasmin (Cp). However, the change in serum amyloid A (SAA) concentration decreased quadratically (from 0 to 48 h) with increasing LPS dose (P<0.02). This change in SAA was negatively correlated with the AFIR (r= -0.80; P<0.001). In general, castrates appear to be more sensitive to endotoxin challenges than gilts. Serum amyloid A, but not the other acute-phase proteins evaluated, was a good biological indicator of immune system activation following an acute lipopolysaccharide challenge when compared to the acute change in feed intake.

Ehrlichia equi infection of horses from Minnesota and Wisconsin: detection of seroconversion and acute disease investigation.

Equine granulocytic ehrlichiosis (EGE) is caused by infection with Ehrlichia equi. EGE has been reported primarily in northern California, where E equi is transmitted by the tick Ixodes pacificus. Reports of EGE and the emergence of human granulocytic ehrlichia in Minnesota prompted a seroprevalence study of E equi in horses of Minnesota and Wisconsin. Tick (Ixodes scapularis) endemic areas of Minnesota and Wisconsin were compared to nonendemic regions of Minnesota. Indirect fluorescent antibody was used to detect the presence of serum antibodies to E equi. Serum samples from healthy horses, 375 samples from I scapularis endemic counties, and 366 samples from nonendemic counties were screened at a 1:40 dilution. Results demonstrated a seroprevalence of 17.6% in endemic areas versus 3.8% in nonendemic areas. Ehrlichial DNA from 2 samples was successfully amplified by polymerase chain reaction and 919 base pairs were sequenced. The DNA sequence of 1 Minnesota/Wisconsin strain differed from the GenBank strain (M73223) of E equi at positions 84 and 886 and from the MRK strain of E equi at position 84, and was identical to the human granulocytic ehrlichiosis (HGE) agent. The 2nd Minnesota/Wisconsin strain was identical to the 1st with the exception of a substitution of "A" at position 453 that is not present in E phagocytophila, E equi, or HGE agent strain sequences. Based on the results of this study, we concluded that E equi is present and causes infection in horses in Minnesota and Wisconsin. The occurrence of infection is higher in tick endemic regions.

Use of repetitive sequence-based polymerase chain reaction for molecular epidemiologic analysis of Streptococcus equi subspecies equi.

OBJECTIVE: To determine whether repetitive sequence-based polymerase chain reaction (rep-PCR) could be used to differentiate Streptococcus equi isolates, to examine S equi isolates from throughout the world, and to determine whether a horse had > 1 subtype of S equi during an outbreak of disease. SAMPLE POPULATION: An initial group of 32 S equi isolates, 63 S equi isolates from various geographic areas, and 17 S equi isolates obtained during outbreaks of disease. PROCEDURE: An aliquot of S equi genomic DNA was amplified, using enterobacterial repetitive intergenic consensus primers. Gel electrophoresis was performed on 1.5% agarose gels, and a computed-assisted program was used to compare rep-PCR results. RESULTS: Use of these primers to analyze 100 ng of S equi genomic DNA resulted in patterns of 6 to 14 bands. The 32 initial isolates were separated into 7 rep-PCR subtypes. There were 30 rep-PCR subtypes found among 29 S equi isolates obtained from Minnesota, Michigan, Canada, and Australia and 34 S equi isolates obtained from Kentucky and other sources. Furthermore, the same clone was identified in several horses during an outbreak of disease. Infected horses on the same farm all had a single clone of S equi. CONCLUSION AND CLINICAL RELEVANCE: Analysis of these results suggests that rep-PCR is useful for delineating S equi into rep-PCR subtypes. Results revealed that isolates with the same geographic source or similar date of collection did not always have the same rep-PCR subtype. A single clone of S equi usually predominated during an outbreak of disease.

Antibacterial properties of a silver chloride-coated nylon wound dressing.

OBJECTIVE: A silver chloride-coated nylon wound dressing (Ag-WD) was evaluated in vitro for antimicrobial activity against five common equine wound pathogens. STUDY DESIGN: Bacterial susceptibility study. SAMPLE POPULATION: Equine wound pathogens: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Streptococcus equi subspecies zooepidemicus, and Staphylococcus aureus. METHODS: An inoculum of each pathogen was incubated directly with Ag-WD and quantitated after 24 to 48 hours of incubation. To determine if bactericidal activity of Ag-WD was contact dependent, an inoculum of E. coli and Staphylococcus aureus was incubated separately from Ag-WD by a filter and quantitated after 18 hours of incubation. Inductively coupled plasma emission spectrometry (ICP) determined the silver concentration of Mueller-Hinton broth containing Ag-WD after 24 hours of incubation. To establish if the rate of bacterial killing by Ag-WD differed from a constant silver concentration, pathogens were exposed to a silver concentration of 6.45 microg/mL and quantitated after 18 hours. RESULTS: Direct exposure to Ag-WD significantly reduced bacterial numbers after 15 minutes for K. pneumoniae, 30 minutes for E. coli, 1 hour for P. aeruginosa, and 2 hours for S. equi subspecies zooepidemicus and Staphylococcus aureus. Indirect exposure to Ag-WD resulted in > or =99.9% and > or =90% kill of the inoculum doses of E. coli at 2 hours and Staphylococcus aureus at 18 hours, respectively. Incubation of the pathogens at the constant silver concentration resulted in bacterial killing rates similar to those obtained by incubation with Ag-WD. CONCLUSIONS: In vitro, equine pathogens are effectively killed when exposed to Ag-WD, and the rate of bacterial killing by Ag-WD is similar to a constant silver concentration of 6.45 microg/mL. CLINICAL RELEVANCE: The in vitro antimicrobial properties of this silver-coated nylon wound dressing are promising for future prevention of equine wound infections.

Invasion and intracellular development of the human granulocytic ehrlichiosis agent in tick cell culture.

Human granulocytotropic ehrlichias are tick-borne bacterial pathogens that cause an acute, life-threatening illness, human granulocytic ehrlichiosis (HGE). Ehrlichias within neutrophil granulocytes that invade tick bite sites are likely ingested by the vector, to be transmitted to another mammalian host during the tick's next blood meal. Thus, the cycle of replication and development in the vector is prerequisite to mammalian infection, and yet these events have not been described. We report tick cell culture isolation of two strains of the HGE agent directly from an infected horse and a dog and have also established a human isolate from HL60 culture in tick cells, proving that the blood stages of the HGE agent are infectious for tick cells, as are those replicating in the human cell line HL60. This required changes to the culture system, including a new tick cell line. In tick cell layers, the HGE agent induced foci of infection that caused necrotic plaques and eventual destruction of the culture. Using the human isolate and electron microscopy, we monitored adhesion, internalization, and replication in vector tick cells. Both electron-lucent and -dense forms adhered to and entered cells by a mechanism reminiscent of phagocytosis. Ehrlichial cell division was initiated soon after, resulting in endosomes filled with numerous ehrlichias. During early development, pale ehrlichias with a tight cell wall dominated, but by day 2, individual bacteria condensed into dark forms with a rippled membrane. These may become compacted into clumps where individual organisms are barely discernible. Whether these are part of an ehrlichia life cycle or are degenerating is unknown.

Ethanol ingestion reduces antipneumococcal activity of rat pulmonary surfactant.

Because chronic ethanol ingestion decreases pulmonary clearance of Streptococcus pneumoniae in rats, and extracellular antipneumococcal factors in rat surfactant are important in the early clearance of pneumococci from the rat alveolus, the effects of ethanol ingestion on surfactant bactericidal activity were investigated. Normal surfactant from chow-fed rats showed potent anti-pneumococcal activity, even against bacteria growing in nutrient-rich media under favorable conditions. In contrast, surfactant from ethanol-fed rats and from calorie-restricted control-fed rats had significantly reduced antipneumococcal activity compared with surfactant from chow-fed rats. The reductions in surfactant bactericidal activity produced by ethanol ingestion or caloric restriction did not appear to be mediated through changes in either the total amount or the distribution of fatty acids, the antipneumococcal factors in normal surfactant. Rather, ethanol ingestion, and to a lesser extent caloric restriction, produced a surfactant inhibitor of free fatty acids that was partially characterized as a hydrophobic protein.

Cirrhosis impairs serum bacteriostasis for Escherichia coli.

To study the effects of cirrhosis on serum inhibition of Escherichia coli, cirrhosis with ascites was induced in male Sprague-Dawley rats by intragastric administration of carbon tetrachloride. Heat-inactivated (56 degrees C for 30 minutes) serum from cirrhotic rats (CRS) or that from control rats (NRS) was inoculated with 1 x 10(5) colony-forming units per milliliter (CFU/ml) of E. coli, and growth was measured after 24 hours. The mean growth of E. coli in CRS was significantly higher than growth in NRS: 3.5 +/- 5.4 x 10(8) CFU/ml versus 1.2 +/- 2.0 x 10(6) CFU/ml, respectively (p < 0.01). Fifty-four percent of CRS samples (22/41) completely lacked bacteriostatic activity. These CRS samples were categorized as growth-supporting (G+CRS) because their growth exceeded the mean + 2 SD of NRS (5.2 x 10(6) CFU/ml). Serum bacteriostasis could be restored to G+CRS by adding purified rat apotransferrin (1 mg/ml), suggesting the presence of excess iron in G+CRS. However, serum iron concentration (SI) and total iron binding capacity (TIBC) were virtually the same in G+CRS (SI = 120 +/- 22 micrograms/dl; TIBC = 351 +/- 45 micrograms/dl) as in growth-inhibitory CRS (SI = 131 +/- 16 micrograms/dl; TIBC = 347 +/- 46 micrograms/dl) but were significantly less than NRS (SI = 208 +/- 29 micrograms/dl; TIBC = 533 +/- 57 micrograms/dl), p < 0.01. The percent transferrin saturation was similar in all groups: 34% +/- 6%; 38% +/- 5% and 39% +/- 9%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of cirrhosis on the production and efficacy of pneumococcal capsular antibody in a rat model.

We sought to study the immunogenicity of Type 3 pneumococcal capsular polysaccharide (PCP) antigen and the protective efficacy of Type 3 PCP antibodies in a rat model of cirrhosis. Cirrhosis with ascites was induced in male Sprague-Dawley rats by weekly gavage with CCl4. Cirrhotic and age-matched control rats were vaccinated with 25 micrograms of Type 3 PCP. Serum antibodies against Type 3 PCP were determined before vaccination and on postvaccination Days 5, 7, 10, 14, 21, 28, and 42 by radioimmunoassay. Maximum concentrations occurred at 7 days in cirrhotic rats and 10 to 14 days in control rats. Geometric mean Type 3 PCP antibody levels (ng AbN/ml) were higher in cirrhotic versus control rats before vaccination (75.9 versus 33.8; p = 0.011) and on post-vaccination Day 5 (626 versus 158; p = 0.008) and Day 7 (1,755 versus 493; p = 0.002). Postvaccination antibody from immunized control and cirrhotic animals provided passive immunity to Type 3 Streptococcus pneumoniae infection in mouse protection studies. Sham-immunized and PCP-immunized control and cirrhotic rats were challenged with 10(7) cfu Type 3 S. pneumoniae. Immunization was associated with a greater reduction in postchallenge mortality in control rats (91% reduced to 36%; p = 0.02) compared with cirrhotic rats (100% reduced to 83%; p = 1.0). Thus, the increased serum concentrations of functional, type-specific anticapsular antibody in vaccinated cirrhotic rats does not reverse their impaired resistance to Type 3 pneumococcal pneumonia.