Tetrodotoxin- and resiniferatoxin-induced changes in paracervical ganglion ChAT- and nNOS-IR neurons supplying the urinary bladder in female pigs

The aim of the present study was to establish the effect of intravesical administration of resiniferatoxin (RTX) and tetrodotoxin (TTX) on the chemical coding of paracervical ganglion (PCG) neurons supplying the urinary bladder in the pig. In order to identify the PCG neurons innervating the bladder, retrograde tracer Fast Blue was injected into the bladder wall prior to intravesical RTX or TTX administration. Consequent application of immunocytochemical methods revealed that in the control group 76.82% of Fast Blue positive PCG neurons contain nitric oxide synthetase (nNOS), and 66.92% contain acetylcholine transferase (ChAT). Intravesical infusion of RTX resulted in a reduction of the nNOS-IR neurons to 57.74% and ChAT-IR to 57.05%. Alternative administration of TTX induced an increase of nNOS-IR neurons up to 79.29% and a reduction of the ChAT-IR population down to 3.73% of the Fast Blue positive PCG cells. Our data show that both neurotoxins affect the chemical coding of PCG cells supplying the porcine urinary bladder, but the effects of their action are different. Moreover, these results shed light on the possible involvement of NO-ergic and cholinergic neurons in the mechanisms of therapeutic action exerted by RTX and TTX in curing the overactive bladder disorder.     

Blastomycotic osteomyelitis associated with severe lameness in a horse

A 12-year-old Quarter horse gelding was presented for evaluation of severe right forelimb lameness, 2 draining tracts over the lateral aspect of the right proximal antebrachium, and weight loss. A presumptive diagnosis of blastomycotic osteomyelitis was established based on radiographs and cytology of the exudate. This diagnosis was confirmed at necropsy.     

The Incidence of Aeromonas Species in the Feces of Nondiarrheic Horses

Aeromonas species have been isolated from the feces of diarrheic adult horses and foals. However, Aeromonas species have also been isolated from the feces of approximately 5% of clinically normal adult horses outside the United States. The objectives of this study were to determine whether Aeromonas species can be shed in the feces of nondiarrheic adult horses and identify any effects of season of year, transportation, and hospitalization on possible fecal shedding of Aeromonas species. Feces were cultured for Aeromonas and Salmonella species from 138 nondiarrheic adult horses examined in the hospital and by field services for complaints other than gastrointestinal disease. Fecal Aeromonas and Salmonella species were isolated from 6.5% and 2.2% of nondiarrheic horses, respectively. All Aeromonas isolates were identified as A caviae. There were no apparent effects on time of year, hospitalization, or transport on isolation of Aeromonas species from feces. Isolation of Aeromonas species from diarrheic horses in the absence of other possible enteric pathogens indicates intestinal disease as a result of Aeromonas infection, but Aeromonas species can also occur as copathogens with Salmonella infections.     

Effects of dietary yeast extract on turkey stress response and heterophil oxidative burst activity

1. Effective nutritional approaches to counteract the negative effects of stress may provide food animal producers with useful alternatives to antibiotics. In this study, turkeys were fed on a standard diet, or the same diet supplemented with yeast extract (YE), to determine if YE would improve disease resistance in a stress model.

2. At 16 weeks of age, half of the birds were exposed to a bacterial challenge using a coarse spray of the pen environment. A subset of control and challenged birds was also treated with dexamethasone (Dex) prior to challenge (Dex/challenge). At 18 weeks, another subset was subjected to a 12?h transport stress protocol (Challenge/transport). All birds were bled and necropsied the morning after transport. The numbers and proportions of blood cells and the heterophil oxidative burst activity (OBA) were determined. Serum corticosterone (Cort) levels of male birds were measured using a commercial ELISA kit. Body weight and gain were increased by YE during week 1.

3. YE decreased mortality and bacterial isolation following Dex/challenge only in females. Cort levels in male turkeys were decreased by YE and Dex treatment. OBA was higher in males and in birds given YE and was reduced by challenge and transport.

4. These results suggest there may be gender differences in the turkey stress response and that dietary YE has potential for modulating the impact of stress on innate immunity of turkeys.     

Grass Yields Under Clipping and Watering Explain Varied Efficacy of Management Intensive Grazing on Rangelands

Management intensive grazing (MIG) may not maximize plant productivity on rangelands because of morphophysiological traits of grassland vegetation. We examined defoliation and moisture effects on the biomass yield of rhizomatous and caespitose grass pairs that were either phylogenetically similar or of similar agroclimatic adaptation, including two agronomic grasses. From relatively low to high moisture regime adaptation, species pairs included western wheatgrass (Pascopyrum smithii [Rydb.] A. Love) and needle-and-thread (Hesperostipa comata [Trin. & Rupr.] Barkw.), northern wheatgrass (Elymus lanceolatus [Scribn. & J.G. Sm.]) and western porcupine grass (H. curtiseta [Hitchc.] Barkw.), plains and foothills rough fescue (Festuca hallii [Vasey] and F. campestris Rydb.), and smooth and meadow brome (Bromus inermis Leyss. and B. riparius Rehm). Response variables were shoot yield, root-shoot ratio, and water-use efficiency. We hypothesized that caespitose grasses, regardless of their origin or adaptation to agroclimate regime, would respond more determinately in biomass accumulation. Defoliation effects on shoot biomass were more pronounced under high moisture. Low intensity ? high frequency defoliation yielded similarly to deferred controls in all grasses, and the same was true for high-intensity ? low-frequency (HILF) defoliation in 1 rhizomatous grass. Three of the 4 rhizomatous grasses and 1 caespitose grass yielded greater under HILF defoliation compared with high-intensity ? high-frequency defoliation. Caespitose grasses allocated more biomass to roots under low moisture conditions. Water-use efficiency decreased under high moisture conditions and more intense and/or frequent defoliation and peaked in agronomic grasses. Overall, our results suggested that growth patterns corresponded more with phylogenetic similarity as opposed to growth form. A conceptual model from these results showed that across all species, only the introduced bromes generated greater biomass under HILF defoliation, and this may explain why past research consistently concludes that MIG does not enhance plant productivity on rangelands.