Systemic necrotizing vasculitis in nine young beagles.

A systemic necrotizing vasculitis of unknown etiopathogenesis may be termed juvenile polyarteritis syndrome (JPS). The syndrome has been recognized primarily in young Beagles used for toxicologic studies. We studied 9 young Beagles with JPS. Affected dogs had fever (40 to 41.5 C), anorexia, and signs of pain in the cervical area. They had a characteristic hunched stance, and were unwilling to move. Laboratory abnormalities in all dogs included nonregenerative anemia, hypoalbuminemia, and leukocytosis characterized by a mature neutrophilia. Analysis of CSF revealed a moderate to severe neutrophilic pleocytosis and a mildly high protein concentration in most dogs. Signs of disease resolved rapidly with high doses (2.2 mg/kg of body weight, PO) of prednisone. If untreated, clinical signs and laboratory abnormalities had a remitting and relapsing course in most dogs. Findings at necropsy included necrotizing arteritis with fibrinoid necrosis, periarteritis, thrombosis, and intimal proliferation that most frequently affected small- to medium-sized vessels in the cervical spinal cord, mediastinum, and heart. An immune-mediated pathogenesis for this disease is suspected.     

Beekeeping management practices in southwestern Quebec

The growing number of honey bee colonies and beekeepers in Canada has led to a great diversity of beekeeping practices. All beekeeping operations, however, need to implement consistent management measures for the control of diseases. The objective of this study was to document the actual disease management practices of beekeeping productions in southwestern Quebec, Canada. A survey was conducted to describe management practices used by 15 beekeepers who own 1824 colonies in that area. Data were obtained by telephone interviews. When infectious diseases were suspected, beekeepers generally avoided using potentially toxic acaricides and chemical treatments associated with antimicrobial resistance and instead used preventive, physical or management methods, although laboratory diagnosis was rarely used. This study highlights the wide variety of operation sizes, activities, and disease management strategies among beekeepers in southwestern Quebec. It identifies the need to encourage the use of services available to them and to propose a standardized preventive medical approach for field veterinarians to avoid the spread of infectious diseases.     

Digestible lysine requirement of starter and grower pigs

Three experiments were conducted to determine the digestible lysine requirement of starter (6 kg BW initially) and of grower (21 kg BW initially) pigs. Experiment 1 used 294 starter pigs and lasted 28 d; Exp. 2 used 182 grower pigs and lasted 35 d. Protein and total lysine contents of the basal corn-peanut meal diets were 20 and .8% for Exp. 1 and 16 and .54% for Exp. 2. Basal diets were fortified with five incremental additions of lysine.HCl to provide lysine contents ranging from .8 to 1.3% in Exp. 1, and .54 to .94% in Exp. 2. Diets contained crystalline tryptophan, threonine and isoleucine (Exp. 1 only) to provide dietary concentrations equal to 18, 70 and 60% of the highest lysine level fed. Average daily gain and gain/feed of both starter and grower pigs increased (P less than .05) linearly and quadratically as dietary lysine level increased. For starter pigs, ADG and gain/feed were optimized at 1.1 to 1.2% total lysine. For grower pigs, ADG and gain/feed were optimized at .86% total lysine. In Exp. 3, barrows fitted with an ileal T-cannula were used in a 4 X 4 Latin square design. Basal diets and diets with added lysine were evaluated. Apparent lysine digestibility of the basal starter and grower diets and lysine.HCl were 79.9, 74.1 and 96.7%, respectively. Based on these values and the total lysine contents found to optimize performance, the digestible lysine requirements of starter and grower pigs are 1.03 and .71%, respectively.     

Gastric ulceration and suspected vitamin A toxicosis in grower pigs fed fish silage.

In 3 feeding trials, gastric ulceration was diagnosed in 2 of 12 lame and recumbent grower pigs fed a diet of 50% fish silage produced from the offal of farmed Atlantic salmon. Premature femoral physeal closure and elevated serum retinyl palmitate levels, features of vitamin A toxicosis, were also observed.     

Antigenic characterization of an H3N2 swine influenza virus isolated from pigs with proliferative and necrotizing pneumonia in Quebec.

A new strain of swine influenza A virus, designated A/Swine/Saint-Hyacinthe/150/90 has been isolated from pigs with severe proliferative and necrotizing pneumonia in Quebec. The antigenic characterization of the hemagglutinin was performed by hemagglutination inhibition test, immunoblot and indirect immunoprecipitation using polyclonal antisera. Only the last test was able to detect an antigenic relationship between the hemagglutinin of this isolate and an H3 subtype influenza virus. The immunoprecipitation test was a useful alternative for determining the hemagglutinin of influenza A virus subtypes. The neuraminidase inhibition test demonstrated a reactivity between the A/Swine/Saint-Hyacinthe/150/90 and antiserum against a N2 subtype influenza virus. Our results indicate that this new strain isolated for the first time in the porcine population of Canada is related to A/Sw/Hong Kong/76 H3N2 swine influenza virus.     

Glycemic index of starch affects nitrogen retention in grower pigs

Three studies were performed to examine the effect of starch and protein digestion rates on N retention in grower pigs. In Exp. 1, the glycemic index (GI) of corn, a malting barley, and a slow-rumen-degradable barley (SRD-barley) were measured using 6 barrows (BW = 18.0 ± 0.5 kg). The GI of malting barley was greater (P < 0.05) than that of SRD-barley (71.1 vs. 49.4), and the GI of both barley cultivars was less (P < 0.05) than that of corn (104.8). In Exp. 2, the standardized ileal digestibility of AA and DE content of the 3 ingredients were determined using 5 ileal-cannulated barrows (BW = 20.7 ± 2.3). The apparent total-tract energy digestibility values of corn (86.1%) and malting barley (85.7%) were greater (P < 0.05) than that of SRD-barley (82.3%). The standardized ileal digestibility of Lys was 94.0, 92.6, and 92.4% for corn, malting barley, and SRD-barley, respectively, and did not differ among grains. In Exp. 3, 6 diets were formulated to equal DE (3.40 Mcal/kg), standardized ileal digestibility of Lys (8.6 g/kg), starch (424.9 g/kg), and digestible CP (180.0 g/kg) using the values obtained in Exp. 2. Three GI [high (corn), medium (malting barley), and low (SRD-barley)] and 2 rates of protein digestion [rapid (soy protein hydrolysate) and slow (soy protein isolate)] were tested in a 3 × 2 factorial arrangement with 36 barrows (BW = 32.2 ± 2.5 kg). Pigs were fed 3.0 times the maintenance energy requirement daily in 2 meals for 2 wk and were housed in metabolic crates to collect feces and urine separately. At the end of the study, intestinal contents were collected from 4 equal-length segments of the small intestine. The percentage of unabsorbed CP in segment 1 relative to dietary CP was greater (P < 0.05) for the soy protein isolate diet than for the soy protein hydrolysate diet (170.3 vs. 116.5%). The percentages of unabsorbed starch in segments 1 and 2 were greater (P < 0.05) for the SRD-barley diet than for the malting barley or corn diet. Nitrogen intake and fecal N excretion were greater (P < 0.05) for pigs fed the malting barley and SRD-barley diets than for pigs fed the corn diet. Urinary N excretion was greater (P < 0.05) for pigs fed the SRD-barley diet than for pigs fed the corn or malting barley diet. Pigs fed slowly digestible starch (SRD-barley; 46.6%) had less (P < 0.05) net N retention than pigs fed corn or malting barley (54.7 and 54.1%, respectively). In conclusion, slowly digestible starch sources such as SRD-barley may not be suitable to support maximum protein deposition in restricted-fed grower pigs.     

Hematologic and biochemical reference intervals for Norwegian crossbreed grower pigs

Background: Hematologic and biochemical reference intervals depend on many factors, including environment and age. Reference intervals for Norwegian grower pigs are lacking, and previously published reference intervals for similar pigs from other countries are now outdated due to significant changes in management and breeding on the pig farms. Objectives: The aim of this study was to determine updated reference intervals for hematologic and biochemical analytes in healthy crossbred grower pigs, and to compare the results among 3 different farms. Methods: Blood samples were collected from 104 clinically healthy pigs of the most common Norwegian crossbreed (Landrace Yorkshire sow × Landrace Duroc boar). The pigs were 12–16 weeks old, weighed 30–50 kg, of both sexes, and lived on 3 farms in eastern Norway. Automated hematologic and biochemical analysis were performed using ADVIA 2120 and ADVIA 1650 analyzers. Results: Five samples were excluded because of hemolysis (1) or outliers (4). Reference intervals were calculated using parametric or nonparametric methods, depending on data distribution. Mean, median, minimum, and maximum values were tabulated. Conclusions: The reference intervals calculated in this study will be useful for the diagnosis and monitoring of disease in this widespread crossbreed pig. Compared with previously published reference values, reference intervals for total WBC count, creatine kinase and alanine aminotransferase activities, and albumin, bilirubin, and urea concentrations in this study differed notably.     

Xylanase supplementation improves energy digestibility of wheat by-products in grower pigs

Value-added processing of cereals produces high-value fractions for food and bio-processing application and by-products that are used in animal nutrition to reduce feed costs. Wheat by-products contain arabinoxylans that might limit nutrient digestibility. Effects of xylanase supplementation (0 or 4375 U/kg feed) on energy digestibility were studied in a wheat control and by-product diets (30% millrun, middlings, shorts, screenings, and bran) in a 2 × 6 factorial arrangement. The wheat control diet was formulated to contain 3.34 Mcal digestible energy (DE)/kg and 2.8 g apparent digestible lysine/Mcal DE, and included 0.4% chromic oxide as a marker for digestibility. Twelve ileal-cannulated pigs (32.5 ± 2.5 kg) were each fed seven of 12 diets. Faeces and then digesta were each collected for 2 d, and diet digestibility values are reported. Wheat had higher ileal and total-tract energy digestibility than by-products (P < 0.01). Xylanase improved energy digestibilities for by-products (P < 0.001) but not for wheat. Among by-products, ileal energy digestibility was lowest for middlings (62%), then bran < screenings < millrun, and highest for shorts (66%). Xylanase improved (P < 0.05) ileal energy digestibility of millrun by 19% to 76%. Total-tract energy digestibility of millrun improved from 72 to 79% (similar to wheat) with xylanase (P < 0.05). In summary, xylanase improved energy digestibility in the selected wheat by-product diets, indicating that arabinoxylans in wheat by-products limit nutrient digestibility.     

Lysine restriction during grower phase on growth performance,blood metabolites,carcass traits and pork quality in grower finisher pigs

Abstract

The effects of lysine restriction during grower phase and realimentation during finisher phase on growth performance, nutrient digestibility, blood metabolites, carcass traits and pork quality were studied. Sixty-four pigs (two castrated males and two females per pen) weighing 34.34±5.22 kg were assigned to four dietary treatments. During grower (35–55 kg), pigs were fed isoenergetic lysine-restricted diets. The different lysine content of diets were 0.950 (NRC recommendation), 0.760, 0.665 and 0.570%, corresponding to lysine restriction of 20, 30 and 40%. Then all pigs were fed with common finisher 1 (55–85 kg) and 2 (85–115 kg) diets. Lysine restriction during the grower phase resulted in poor performance and lower concentration of blood metabolites but improved the nutrient digestibility and efficiency of lysine utilization. Compensatory growth response in terms of improved weight gain and feed efficiency was observed in pigs previously fed lysine-restricted diets during finisher 1, but the concentration of blood urea nitrogen and total protein were lower. No differences in growth performance, digestibility of nutrients and blood metabolites were noted during finisher 2. Lysine restriction of grower diets decreased the dressing percentage (quadratic, P=0.024), and protein content of longissimus muscle (linear P=0.034, and quadratic P=0.009). Thus, it could be concluded that pigs subjected to lysine restriction during grower phase exhibited compensatory growth responses in weight gain and improved efficiency of feed and lysine utilization for weight gain and lean accretion during finisher phase.     

Serological characterization of Actinobacillus pleuropneumoniae strains isolated from pigs in Quebec.

A total of 3306 isolates of A. pleuropneumoniae originating from lung tissues of pigs that died of acute pleuropneumonia and 140 isolates recovered from tonsils or nasal cavities of apparently healthy pigs from chronically infected herds were serotyped. Various serotyping methods, such as slide agglutination, tube agglutination, ring precipitation, coagglutination, immunodiffusion, indirect hemagglutination and counterimmunoelectrophoresis either alone or in combination were used. The techniques used for serotyping continued to evolve during the last 10 years depending on the problem encountered in serotyping. Antisera prepared in rabbits against formalinized whole cell suspensions of reference strains of A. pleuropneumoniae of serotypes 1 to 12 were employed for serotyping. Serotype 1 was predominant ranging from 55 to 87% from year to year during the last 10 years with an average prevalence of 68%. Serotype 5 was second in prevalence ranging from 9 to 30% with a mean of 23%. Both subtypes of serotype 5 (5a and 5b) were present in Quebec. Serotypes 3, 6, 7, 8, 10 and 12 were isolated in small numbers together accounting for about 9%. Serotypes 4, 9 and 11 were not present. Cross-reactions were observed among isolates of serotypes 3, 6 and 8, and 1, 9 and 11 and were easily differentiated from each other by quantitation of type and group specific antigens by coagglutination and immunodiffusion tests. Serotypes 1, 5 and 7 were isolated most frequently from tonsils of pigs from chronically infected herds. Prevalence of different serotypes in different countries has also been reviewed.     

Actinobacillus suis infection in pigs in southwestern Ontario

Actinobacillus suis was isolated from tissues of 39 pigs, 2 porcine lungs, and 1 uterine swab submitted for diagnostic evaluation from 24 farms in southwestern Ontario between 1985 and 1988. These isolates represented a gradually increasing incidence of herd outbreaks caused by A. suis in southwestern Ontario. The outbreaks were typified by sudden death in suckling or recently weaned pigs; 87% of the affected pigs examined at the laboratory were between two and 28 days old. Petechial to ecchymotic hemorrhages in the thoracic and abdominal organs accompanied by serofibrinous exudates in both cavities were the most common gross lesions. The lesions were characterized histologically by bacterial thromboembolism and necrosis randomly scattered in thoracic and abdominal organs. Occasionally, bacterial thromboemboli were surrounded by centrifugally radiating, eosinophilic, club-like colonies. Diffuse necrohemorrhagic myocarditis that was more severe in the atria, and diffuse subacute meningoencephalitis, were less frequent but distinctive lesions. Multiple litters were affected in most herd outbreaks, and mortality often approached 50% in affected litters. Although the A. suis organism was susceptible to nearly every antibiotic against which it was tested, the suddenness of herd outbreaks precluded attempts at treatment.     

Growth performance and carcass traits of pigs subjected to marginal dietary restrictions during the grower phase.

Sixty-four individually housed pigs were used to investigate the effect of amino acid content of finisher diets on growth performance of pigs subjected to marginal dietary amino acid restrictions (80% of the 1988 NRC lysine recommendation) during the grower phase. In each of the two trials, low- and high-amino-acid grower diets (.421 and .765 g lysine/MJ DE, respectively) and four finisher diets (.421, .516, .612, and .707 g lysine/MJ DE) were randomly assigned within sex to 16 gilts and 16 castrated males weighing 23.0 +/- 2.0 kg in a 2 x 4 factorial arrangement of treatments. The average weight of pigs after a completion of diet change was 50.4 +/- 2.1 kg. All pigs were slaughtered at an average weight of 105.2 +/- 4.1 kg. Ultrasound backfat thickness was measured at the time of diet change and before slaughter. Pigs were allowed ad libitum access to feed and water. During the grower phase, pigs fed the high-amino-acid diet grew faster (P < .001) and more efficiently (P < .001) and had less ultrasound backfat (P < .001) than those fed the low-amino-acid diet. The grower diet had no effect on weight gain during the finisher phase. Consequently, pigs fed the high-amino-acid grower diet had better overall weight gain (P < .01) than those fed the low-amino-acid diet. The rate of lean accretion was, however, similar between the two groups of pigs. Furthermore, pigs fed the low-amino-acid grower diet seemed to have better carcass quality, as indicated by less ultrasound backfat (P < .01) and larger carcass longissimus muscle area (P < .05). Average and 10th rib carcass backfat decreased linearly (P < or = .05) and lean accretion rate improved linearly (P < .05) as the amino acid content of finisher diets increased, but there was no grower x finisher diet interaction in these and other response criteria. Although no evidence of compensatory weight gain was observed, it is possible that compensatory lean tissue growth may have occurred in pigs subjected to early amino acid restrictions at the expense of fatty tissue growth.     

Antigenic variant of swine influenza virus causing proliferative and necrotizing pneumonia in pigs.

A new antigenic variant of swine influenza virus was isolated from the lungs of pigs experiencing respiratory problems in 7 different swine herds in Quebec. Pigs of different ages were affected, and the main clinical signs were fever, dyspnea, and abdominal respiration. Coughing was not a constant finding of the syndrome. At necropsy, macroscopic lesions included the overall appearance of pale animals, general lymphadenopathy, hepatic congestion, and consolidation of the lungs. Histopathologic findings were mainly proliferative pneumonia with a significant macrophage invasion, necrotic inflammatory cells in the alveoli and the airways, a marked proliferation of type II pneumocytes, and thickening of the alveolar septae. Fluorescent antibody examination of lungs of sick piglets did not demonstrate porcine parvovirus, transmissible gastroenteritis virus, or encephalomyocarditis virus. However, evidence of the presence of an influenza type A infection was demonstrated by indirect immunofluorescence (IIF) staining using monoclonal antibody directed to nucleocapsid protein (NP) of human type A influenza virus. The virus was isolated either by intra-allantoic inoculation of specific-pathogen-free embryonating hens' eggs or propagation in canine kidney (MDCK) cells in the presence of trypsin. By hemagglutination inhibition tests, no cross-reactivity was demonstrated with human influenza H1N1, H2N2, and H3N2 strains, and infected MDCK cells did not react by IIF with monoclonal antibodies to NP protein of type B influenza virus. The hemagglutination activity of plaque-purified isolates was only partly inhibited by hyperimmune serum produced to subtypes A/Wisconsin/76/H1N1 and A/New Jersey/76/H1N1 of swine influenza virus. Gnotobiotic piglets that were infected intranasally with egg-adapted isolates of this new antigenic variant of swine influenza virus developed the very same type of lesions observed in field cases.