Effect of defoliation on flower initiation in white clover in summer

Flowering behaviour of plants of six cultivars of Trifolium repens (Kent Wild White, Grasslands Huia, S100, Blanca, Olwen and Milkanova) growing in field plots at the Grassland Research Institute, Hurley, was recorded in mid-July. Half of each plot had been defoliated in early May, the other half in mid-June. In all cultivars defoliated in May, inflorescence initiation had stopped even though the natural photoperiod at that time was well above the critical daylength for initiation Defoliation in mid-June had led to a renewal of inflorescence initiation in all cultivars.
The results confirm that the stimulatory effect of defoliation on inflorescence initiation in plants that have stopped initiation in long days, which has previously been observed in Grasslands Huia in controlled environments, also occurs in the field and in other cultivars.     

Osteofascial Compartment Syndrome in the Dog

Experimentally induced osteofascial compartment syndrome (OFCS) has been reported in the craniolateral compartment of the canine crus. In this study, anatomic dissections and contrast radiographs were used to describe three additional osteofascial compartments in canine limbs. Experimental OFCS was produced in four different compartments, and caused muscle and nerve pathology in each. When compartment pressures were evaluated in traumatized animals, moderate elevations in compartment pressures were found. A compartment syndrome that developed in one dog was surgically decompressed, returning elevated pressures to a safe level.     

Effects of Halothane, Enflurane, and Isoflurane on Supraventricular and Ventricular Rate in Dogs With Complete Atrioventricular Block

Complete atrioventricular (AV) block was produced in 32 chloralose-anesthetized autonomically intact dogs to determine the effects of halothane, enflurane, and isoflurane on supraventricular and ventricular rate. Halothane (n = 17), enflurane (n = 6), and isoflurane (n = 9) were administered in three separate experiments in sequential minimum alveolar concentration (MAC) multiples of 0.5, 1.0, 1.5, 2.0, 1.5, and 1.0. Supraventricular rate, ventricular rate, and mean arterial blood pressure (MAP) were measured and recorded at baseline and after a 20-minute equilibration period of each inhalation anesthetic at each MAC multiple. Increasing concentrations of enflurane and isoflurane significantly decreased supraventricular rate ( P < .05). Ventricular rate was not significantly changed by sequential MAC multiples of halothane, enflurane, and isoflurane. Increasing concentrations of halothane, enflurane, and isoflurane significantly decreased MAP with enflurane producing the most significant decrease ( P < .05). Ventricular arrhythmias occurred in 5 of 17 dogs anesthetized with halothane and 1 of 9 dogs anesthetized with isoflurane. Inhalation anesthesia can significantly decrease supraventricular rate and MAP, does not alter ventricular rate, and can produce ventricular arrhythmias in dogs with complete AV block.     

Modelling water flow through undisturbed soil cores using a transfer function model derived from 3HOH and Cl transport

Large undisturbed soil cores (20 cm diam. × 25–30 cm long) were irrigated at rates of 0.5–4 cm h^?1 with 0.005 M CaCl₂ solution labelled with ³HOH. The cores were used at varying initial water contents and flow in all cases was unsaturated. Breakthrough curves for Cl and ³HOH were markedly asymmetric and unlike those reported for columns of packed aggregates. The data could be satisfactorily described using a density distribution function of the logarithm of cumulative drainage D. The mean and standard deviation of In D were estimated by a curve-fitting procedure from Cl and ³HOH effluent concentrations in each core. The mean pore water velocity and fraction of the soil water that participated in solute transport (the mobile volume) were also calculated. The apparent velocity of Cl movement was always greater than that of ³HOH which suggested that the mobile volume involved in convective and diffusive transport of Cl was less than that for ³HOH. We suggest that Cl and ³HOH diffused at different rates out of flowing water films in a relatively few large conducting channels into essentially immobile water within the surrounding soil matrix. The difference in mobile volume for Cl and ³HOH was used to calculate the perimeter of voids in any horizontal cross-section of the soil through which water flowed, assuming a planar interface between the mobile and immobile water.     

Standardization of an experimental disease model of Streptococcus zooepidemicus in the equine

A reproducible experimental disease model in horses using Streptococcus zooepidemicus was developed. An intravenous challenge dose of 1 X 10(10) colony-forming units (CFU), followed 24 h later with another challenge of 1 X 10(8) CFU of Strep. zooepidemicus produced the desired disease model. The disease was characterized by depression, pyrexia, anorexia, abnormal lung sounds, inflammation of joints, moderate to severe lameness, gradual loss of condition and emaciation. The effects of the disease on hematology, serum chemical profile and different protein fractions were studied. The disease state had no effect on serum glucose, sodium, potassium, chloride, urea nitrogen, creatinine, uric acid, calcium, phosphorus and enzymes SGOT or SGPT. However, the alkaline phosphatase showed a gradual decline. The serum iron levels dropped markedly and remained low to the last day of observations (post-infection day, PID 13). On serum protein electrophoresis, the albumin showed a gradual decrease; whereas, alpha II, beta and gamma globulin levels rose suggesting an immune response. The elevation of rectal temperatures and white blood cell counts related well with clinical observations. The serum iron levels proved very helpful in predicting the severity of clinical signs and often dropped before the onset of clinical signs and pyrexia.     

Effect of Preoperative Erythromycin or Dexamethasone/Vitamin C on Postoperative Abomasal Emptying Rate in Dairy Cows Undergoing Surgical Correction of Abomasal Volvulus

Objective— To determine the effects of preoperative erythromycin or combined dexamethasone/vitamin C treatment on postoperative abomasal emptying rate in cows undergoing surgical correction of abomasal volvulus (AV).
Study Design— Prospective, controlled, clinical study using a convenience sample.
Animals— Lactating Holstein–Friesian cows (n=45) with AV were alternately assigned to 3 groups (n=15): group C: untreated (control); group E: erythromycin (10 mg/kg intramuscularly [IM]); group D: dexamethasone (0.02 mg/kg intravenously [IV]) and vitamin C (10 mg/kg IV).
Methods— Drugs were administered 1 hour before surgical correction of AV. d -xylose solution (50%, 0.5 g/kg body weight) was injected into the abomasal lumen during surgery. Jugular venous blood samples for determination of serum d -xylose concentration were periodically obtained. Time to maximal serum d -xylose concentration (T_max-model) was pharmacokinetically determined.
Results— Abomasal emptying rate was significantly ( P <0.05) faster in group E (T_max-model=182±69 min; mean±SD) than in group C cows (T_max-model=237±64 min). Abomasal emptying rate was similar in group D (T_max-model=196±47 min) and group C. Both treatments improved postoperative milk yield within 1 day after surgery.
Conclusion— Preoperative injection of erythromycin (10 mg/kg IM) is an effective method for ameliorating postoperative abomasal hypomotility in cows with AV.
Clinical Relevance— Parenteral erythromycin can be recommended for preoperative treatment of cows with AV.