Modulation of porcine biotransformation enzymes by anthelmintic therapy with fenbendazole and flubendazole

Fenbendazole (FEN) and flubendazole (FLU) are benzimidazole anthelmintics often used in pig management for the control of nematodoses. The in vivo study presented here was designed to test the influence of FLU and FEN on cytochrome P4501A and other cytochrome P450 (CYP) isoforms, UDP-glucuronosyl transferase and several carbonyl reducing enzymes. The results indicated that FEN (in a single therapeutic dose as well as in repeated therapeutic doses) caused significant induction of pig CYP1A, while FLU did not show an inductive effect towards this isoform. Some of the other hepatic and intestinal biotransformation enzymes that were assayed were moderately influenced by FEN or FLU. Strong CYP1A induction following FEN therapy in pigs may negatively affect the efficacy and pharmacokinetics of FEN itself or other simultaneously or consecutively administered drugs. From the perspective of biotransformation enzyme modulation, FLU would appear to be a more convenient anthelmintic therapy of pigs than FEN.     

Safety of a modified-live combination vaccine against respiratory and reproductive diseases in pregnant cows

A combination vaccine (Bovi-Shield FP4 + L5, Pfizer Animal Health) containing modified-live virus (MLV) components against bovine herpesvirus-1 (BHV-1), bovine viral diarrhea virus BVDV), parainfluenza virus-3 (PI3), bovine respiratory syncytial virus (BRSV), and inactivated cultures of Leptospira canicola, grippotyphosa, hardjo, icterohaemorrhagiae, and pomona was evaluated for safety in pregnant beef and dairy animals. Heifers vaccinated prebreeding with the minimum immunizing dose (lowest antigen level initiating immunizing effects) of the vaccine's MLV BHV-1 or BVDV components and during pregnancy (approximately 200 days of gestation) with vaccine containing 10x doses of the same BHV-1 and BVDV components delivered live, healthy calves that were determined to be serologically negative (titer less than 1:2) for neutralizing antibodies to BHV-1 and BVDV prior to nursing. Additionally, in three field safety studies, previously vaccinated cows and heifers that received a field dose (vaccine containing antigen levels required for commercial sale of the MLV combination vaccine during either the first, second, or third trimester of pregnancy had abortion rates similar to those of pregnant cows and heifers vaccinated during the same stage of pregnancy with sterile water diluent.     

Optimization of conditions for in vitro production of radical oxygen species and expression of tissue factor by canine mononuclear cells and granulocytes for use in high-throughput assays

The purpose of this study was to optimize conditions for high throughput measurement of radical oxygen species (ROS) production and expression of tissue factor, also termed procoagulant activity, by canine leukocytes. Granulocytes and mononuclear cells were separated by density gradient centrifugation from peripheral blood collected on several occasions from three healthy large breed dogs. To determine optimal conditions for ROS production, granulocytes were incubated for 1 or 3h in PBG (PBS containing 0.5% BSA and 5mM glucose) or RPMI containing 10% fetal bovine serum (FBS); lipopolysaccharide (LPS), zymosan, peptidoglycan (PGN) and phorbol myristate acetate (PMA) were used as stimuli. ROS was assessed by conversion of the nonfluorescent dye dihydrorhodamine 123 to fluorescent rhodamine 123 by radical species released into the media. To identify optimal conditions for expression of tissue factor, mononuclear cells were incubated for 5h in RPMI containing different concentrations of heat-inactivated FBS (HI-FBS), and LPS, zymosan, PGN or PMA as stimuli. Expression of tissue factor was determined using a one-stage recalcification assay performed in an automated nephelometric coagulation analyzer. Neither LPS nor zymosan increased ROS production by granulocytes incubated in PBG media. In contrast, granulocytes incubated in RPMI had dose-dependent increases in ROS production in response to zymosan and PGN. ROS production was significantly increased by incubation with concentrations of LPS of 0.01microg/ml or greater, and by zymosan concentrations of 0.1microg/ml or greater. ROS production in response to incubation with PMA was significantly increased starting at 10(-7)M, and was significantly greater for cells incubated in RPMI than cells incubated in PBG. LPS-, zymosan- and PGN-stimulated procoagulant activity increased in a dose-dependent manner, whereas PMA-stimulated procoagulant activity peaked at 10(-7)M. Increasing concentrations of HI-FBS significantly increased LPS-, zymosan- and PGN-induced procoagulant activity of mononuclear cells. Results obtained in this study indicate production of ROS by canine granulocytes is optimal when these cells are incubated for 3h in RPMI with LPS (0.1microg/ml), zymosan (10 microg/ml), PGN (10 microg/ml), and PMA (10(-7)M). Furthermore, canine mononuclear cells express procoagulant activity in response to LPS, zymosan, PGN, and PMA, and responses to LPS, zymosan and PGN are enhanced by the addition of HI-FBS. These findings suggest that HI-FBS retains important serum proteins that facilitate interactions between each of these bacterial or yeast derived products and the mononuclear cells. Consequently, future studies regarding the regulation of procoagulant activity by canine mononuclear cells should be performed in the presence of HI-FBS. Both assays utilized in this study allow high throughput of samples, and therefore are appropriate choices for rapid screening of conditions and/or therapeutic interventions affecting the canine inflammatory system.     

Improved milk production through PG–PL system by provision of in‐house shelter management in lactating Murrah buffaloes during winter season

Comprehensive information on the role of β‐casein and plasminogen–plasmin (PG–PL) system in milk secretion of Murrah buffaloes during winter season is lacking, although effects of cold stress can be ameliorated to an extent by altering microclimate at farm level. Hence, this study was aimed to determine the changes in productivity along with PG–PL system of milk, plasma hormones and metabolites of buffaloes during winter (December–January) season under two different management systems. Average minimum temperature and wind chill index during this season were 7.02 and 12.74 °C respectively. Buffaloes were divided in two groups of six animals each: control and treatment, where treatment group animals were placed in‐house with floor bedding of paddy straw and the control group animals in loose housing system without straw bedding. Physiological responses were recorded, and milk and blood samples were collected at weekly intervals for six‐week experimental period. Under in‐house management system, buffaloes experienced better comfort by alleviating environmental stress as their physiological responses such as respiration rate and pulse rate were significantly reduced (p < 0.01) as compared to the control, which subsequently resulted higher milk yield by 9.92% (p < 0.05). Analysis of milk samples revealed higher concentration of plasminogen (10.6 vs. 8.05 μg/ml; p < 0.01) and β‐casein (p < 0.05), and lower plasmin level (0.299 vs. 0.321 μg/ml; p < 0.05) in buffaloes under treatment group. It was also found that plasma cortisol, glucose and non‐esterified fatty acids levels were higher (p < 0.01) in control group as compared to the treatment animals by 13.6%, 8.14% and 12.6% respectively. However, milk composition, growth hormone, epinephrine and norepinephrine level in plasma were similar in both the groups. Hence, it may be concluded that provision of in‐house shelter management with floor bedding of paddy straw during winter was effective to minimize environmental stress and improved milk production through manipulation of PG–PL system in buffaloes.     

Analysis of the reactivity of anti-bovine CD8 monoclonal antibodies with cloned T cell lines and mouse L-cells transfected with bovine CD8

Mouse L-cells transfected with bovine CD8 and two Theileria parva-infected cloned T cell lines expressing bovine CD8 were used to screen the panel of ten monoclonal antibodies (mAbs) submitted to the workshop. Eight of the ten mAbs reacted with the transfectant and both the cloned T cell lines. However, two mAbs CC58 and BAT82A did not recognise the transfectant and only reacted with one of the T cell lines. Further biochemical studies indicated that the eight mAbs react with both homo- and heterodimeric forms of bovine CD8 whilst the two mAbs CC58 and BAT82A react with only heterodimeric forms. These data suggest that bovine DC8 is encoded by two genes as is the case in mouse and man.     

Analysis of a site x year experiment with timothy polycross progeny

Summary Results from a cooperative breeding programme with timothy for the northern areas of Scandinavia are presented. The main aim of the programme was to identify genotypes for synthetic populations that are high yielding, adapted over the whole area and stable over years. A polycross comprising 12 genotypes from each of five sites within the region was formed. The subsequent 60 half-sib families and four reference varieties were then compared under sward conditions at the same sites. The trials lasted for three years and results for total dry matter yields are presented.Significant differences in yield between lines were found. There were also significant two and three factor interactions between lines, sites and years. A new two-step procedure is presented to select the genotypes to make up a synthetic variety. Firstly, a superiority measure (Q-value) is used to select a group of genotypes that are high yielding and stable over sites and years. Secondly, the GxE part of the Q-value is split into two terms. One measures adaptation to predictable environmental conditions. The other one measures stability to unpredictable changes in the environment. A plot of these two measures provides a tool for discarding unstable or poorly adapted genotypes. The statistical properties of the selection parameters are discussed.     

Evaluating processing temperature and feeding value of extruded-expelled soybean meal on nursery and finishing pig growth performance

We conducted two experiments comparing the use of extruded-expelled soybean meal (EESoy) to solvent-extracted soybean meal (SBM) in swine diets. In Exp. 1, the objective was to determine the optimal processing temperature of EESoy for nursery pig growth performance. Pigs (n = 330, 13.2 +/- 2.3 kg of BW) were fed a control diet containing SBM with added fat or one of five diets containing EESoy extruded at 143.3, 148.9, 154.4, 160.0, or 165.6 degrees C. All diets were formulated on an equal apparent digestible lysine:ME ratio. From d 0 to 20, no differences were observed (P > 0.32) in ADG or ADFI (average of 544 and 924 g/d, respectively). However, gain:feed ratio (G/F) improved (quadratic, P < 0.01, range of 0.56 to 0.60) with increasing processing temperature, with the greatest improvement at 148.9 degrees C. In Exp. 2, the objective was to determine the feeding value of EESoy relative to SBM with or without added fat for growing-finishing pigs in a commercial production facility. A total of 1,200 gilts (initially 24.5 +/- 5.1 kg of BW) was used, with 25 pigs per pen and eight replications per treatment. Dietary treatments were arranged in a 2 x 3 factorial, with two sources of soybean meal (SBM or EESoy) and three levels of added fat. Pigs were phase-fed four diets over the experimental period and added fat (choice white grease) levels were 0, 3.4, and 7% initially, with the added fat levels decreasing in the next three dietary phases. Energy levels were based such that the higher energy in EESoy (with or without added fat) was calculated to be equal to that provided by SBM with added fat. From 24.5 to 61.2 kg, pigs fed EESoy had greater (P < 0.07) G/F than those fed SBM. Increasing added fat in either EESoy- or SBM-based diets increased G/F (linear, P < 0.0003). From 61.2 to 122.5 kg, ADG and G/F were unaffected in pigs fed EESoy and/or increasing added fat (P > 0.10). For the overall growing-finishing period, ADG was unaffected (P > 0.61) by increasing energy density of the diet; however, ADFI decreased (P < 0.05) and G/F increased (P < 0.02, range of 0.37 to 0.40) as energy density increased with either EESoy or added fat. Carcass leanness was not affected by dietary treatment. These results indicate that EESoy should be extruded at 148.9 to 154.4 degrees C, and that increasing dietary energy density by using EESoy and/or added fat improves feed efficiency in finishing pigs reared in a commercial environment.     

The possible role of methionine in the detoxification of faba bean (Vicia faba L.) tannins in chick diets

1. A metabolism trial was designed to investigate the role of methionine as a specific detoxifying agent of the condensed tannins present in faba beans (Vicia faba L.).

2. A 5 x 5 factorial approach was employed where 5 concentrations of dietary methionine were obtained (ranging from 3.9 to 12.15 g/kg diet dry matter) by the addition of DL‐methionine, and 5 concentrations of condensed tannins (ranging from 0.5 to 19.7 g/kg diet dry matter) by altering the ratio of tannin‐free and tannin‐containing faba bean hulls added to a basal diet.

3. The intake of condensed tannins had a significant, depressive effect on apparent available nitrogen (P< 0.001) and nitrogen corrected apparent metabolisable energy (AME_n ) (P< 0.001). There was no interaction between methionine and tannin (P>0.05). Thus the depressive effect of tannin was independent of methionine levels in the diet.

4. Methionine does not act as a specific detoxifier of faba bean condensed tannins.     

Syringomyelia in cavalier King Charles spaniels: the relationship between syrinx dimensions and pain

OBJECTIVES: This study was designed to test the hypothesis that pain associated with syringomyelia in dogs is dependent upon size and involvement of the dorsal part of the spinal cord. METHODS: Masked observers determined syrinx dimensions and precise location within the spinal cord on magnetic resonance images of 55 cavalier King Charles spaniels with syringomyelia. After removal of masking, syrinx size and location were compared between the cohorts of dogs that exhibited pain with those that did not. RESULTS: Maximum syrinx width was the strongest predictor of pain, scratching behaviour and scoliosis in dogs with syringomyelia. Both pain and syrinx size were positively correlated with syrinxes located in the dorsal half of the spinal cord. CLINICAL SIGNIFICANCE: Large syrinxes associated with damage to the dorsal part of the spinal cord are associated with persistent pain suggesting that the pain behaviour expressed by this group of patients is likely to be "neuropathic pain," resulting from disordered neural processing in the damaged dorsal horn. As such it is likely that conventional analgesic medication may be ineffective.