A strategy for control of bovine leukemia virus infection: test and corrective management

Test and corrective management was applied in one dairy herd (130 milking cows) to control bovine leukemia virus infection. It consisted of: raising uninfected calves in order to establish a pool of uninfected replacement heifers, preventing transmission of bovine leukemia virus through transfer of blood from animal to animal and closing the herd. Regular herd testing was combined with selected changes in herd management. These procedures have been followed since January 1979. Prevalence of antibodies (as determined by gel-immunodiffusion) has declined markedly since the program was implemented.     

Effect of floor cooling on performance of lactating sows during summer

Forty Landrace × Large White lactating sows were used to evaluate the effects of cooling of the floor when maintained under high temperature conditions during summer on their productive and reproductive performance. The sows were allocated in a completely randomized design with two treatments with 20 replicates according to parity number and body weight, with each animal being considered an experimental unit. The treatments consisted of cooling of the floor under the sow with water circulation at about 17 °C and no cooling. The resulting temperatures of the floor were 27.6 and 35.8 °C for the cooled and the control treatments, respectively. The sows from both treatments were exposed to average maximum and minimum environmental temperatures of 26.9 and 20.8 °C, respectively. Sows maintained on a cooled floor had a higher feed intake (6.47 vs. 5.61 kg/day; P < 0.01). Despite this higher intake, sows maintained on a cooled floor had higher body weight and body protein losses during the lactation period (P < 0.01) in connection with a higher milk yield and subsequent growth of the litter (2280 vs. 1798 g/day; P < 0.01). There was an effect of treatment on rectal temperature, surface temperatures and respiratory rate (P < 0.01) with lower values in sows submitted to floor cooling. It is concluded that floor cooling under the lactating sow improves its productive and reproductive performance, as well as the performance of its litter.     

The clinical, cerebrospinal fluid, and histopathologic effects of epidural ketorolac in dogs

OBJECTIVE: To evaluate the clinical, cerebrospinal fluid (CSF), and histopathologic effects of epidural ketorolac. STUDY DESIGN: Blinded, randomized, placebo controlled study. ANIMALS: Twenty-two adult mixed breed dogs with 16 treatment and 6 control dogs, weighing 14.4 to 29.8 kg. METHODS: Dogs were anesthetized and epidural catheters were placed at the lumbosacral space. Catheter placement was evaluated fluoroscopically. Ketorolac (0.4 mg/kg) or placebo (5% ethanol) was administered epidurally over a 52-hour period, with 5 injections given at 12-hour intervals. At 1, 2, 4, or 8 hours after the first and last injection of ketorolac, dogs were anesthetized and CSF was obtained. Control dogs had CSF sampled 1 hour after the first and last ethanol injection. Neurologic function and pain responses were evaluated before and during the study. Selected dogs were then killed and necropsies performed. RESULTS: None of the dogs exhibited any clinical or neurologic abnormalities during the study. No statistical difference was noted in pain response or CSF analysis between treatment and control dogs. Gross necropsy revealed gastrointestinal ulceration of varying degrees in all treatment dogs. Histopathologic analysis of the spinal cord and meninges revealed minimal focal leptomeningeal phlebitis in 2 of 8 treatment dogs and minor subdural inflammation in 1 control dog. No changes to the neural structures were noted in any dogs. CONCLUSIONS: Epidural administration of ketorolac did not cause clinical signs, alteration in CSF values, or pathologic changes to the spinal cord when used for short duration. Gastrointestinal ulceration was common when ketorolac was administered epidurally at 0.4 mg/kg every 12 hours for 5 treatments. CLINICAL RELEVANCE: This study documented the neurologic safety of epidural ketorolac in dogs before an efficacy trial can be performed. Gastrointestinal ulceration may limit use to short duration or a single injection.     

Incomplete systemic movement of Xanthomonas campestris pv. musacearum and the occurrence of latent infections in xanthomonas wilt‐infected banana mats

Management of banana xanthomonas wilt (XW) (caused by Xanthomonas campestris pv. musacearum, Xcm) has been impeded by poor adoption of control options that are complex, cumbersome and costly. To improve XW management, this study investigated Xcm survival and latent infections in subsequent generations, survival of latently infected planting materials (suckers), incidence of latent infections in symptomless plants in mats having diseased plants, and XW status across farms and markets in districts previously devastated but currently endemic. On‐station experiments were protected from new infections. Latent bacteria at low levels were detected in up to 20% of the third generation suckers, with a significant (P < 0·05) reduction (43–20%) in subsequent generations. Only 3–6% of latently infected suckers succumbed to XW. Incidence of Xcm in symptomless suckers from farmers' fields (with up to 70% incidence) was low (3%) while it increased (8–25%) with disease severity in mats in controlled experiments. In the surveyed districts, incidence had significantly declined with yields observed to have recovered relative to earlier reports, although latent infections remained high. This study provides evidence that if new infections are prevented, fields with high XW incidence can be rejuvenated. It showed incomplete systemic movement of Xcm in mats coupled to a gradual decline of bacterial load in subsequent generations to levels that cannot initiate disease. These studies explain the current successes in farms practising single diseased plant removal instead of whole mat rouging, and gives hope to farmers lacking access to clean planting material.     

Impact of Air Pollutant Emissions on the Ecosystems in the Vicinity of Industrial Areas of Indian Sub-Tropics

An investigation was conducted near the industrial areas of West Bengal, Indian subtropics to study the effect of emissions through various factories and thermal power plants on the quality of water in lakes, tanks, ponds, even well waters in relation to its use in the welfare of the society (agricultural use, psciculture and other domestic uses). The results showed that intensity of acidity (water pH) as well as concentration of various soluble salts and BOD and COD in the vicinity of an industrial area (i.e. within 100 metres) were very low. A substantially higher acidity and ion concentration were recorded up to 1 km away from industry, where the growth of aquatic plants, organisms and the production of fish (in lakes and tanks) were severely affected. The results further indicated that the acidity of water gradually increases up to pH 5.4 and concentration of sulphates and chlorides (880 and 570 mg 1^?1 respectively) between 1–2 km from the industriy, suggesting that aquatic ecosystems and domestic, agricultural and fish production are less affected with increasing distance from industry.     

Suppression of wheat-seedling diseases caused by Fusarium culmorum and Microdochium nivale using bacterial seed treatment

Snow mould, caused by Microdochium nivale , and seedling blight caused by members of the Fusarium complex, are cereal diseases of great economic importance in many temperate zones. In a glasshouse bioassay designed to enhance disease, about 600 plant-associated bacterial isolates obtained by different methods were screened for suppressive effects in wheat against infection caused by Fusarium culmorum . Although most of the isolates tested had a neutral effect on test plants and disease development, a few were synergistic to the pathogen and about one-fifth showed > 80% disease suppression. During five consecutive growing seasons, 164 bacterial isolates were tested in field experiments against both F. culmorum and M. nivale as causal agents of seedling blight. Tests for effects on yield in experiments with spring and winter wheat, performed in different climatic regions of Sweden, showed that disease-suppressive effects were repeatable. The most efficient isolates, three fluorescent pseudomonads and a species of Pantoea , suppressed disease equal to that of the fungicide guazatine, both with respect to crop stand and yield. Seed treatment with Pantoea sp. (isolate MF 626) increased yield by an average of more than 500 kg ha⁻¹ in six field experiments.     

Effect of induced unilateral synovitis of distal intertarsal and tarsometatarsal joints on sagittal plane kinematics and kinetics of trotting horses

OBJECTIVE: To study the effect of unilateral synovitis in the distal intertarsal and tarsometatarsal joints on locomotion, including the compensating effects within and between limbs. ANIMALS: 4 clinically normal horses. PROCEDURE: Gait analyses including kinematics, force plate, and inverse dynamic analysis were performed at the trot before lameness, after which synovitis was induced by injecting endotoxin into the right distal intertarsal and tarsometatarsal joints. Gait analyses were repeated 24 to 30 hours later during lameness. Differences between the stride variables during the 2 conditions (lame and sound) were identified. RESULTS: Tarsal joint range of motion, peak vertical force, and vertical impulse were decreased during lameness. Mechanical deficits included a decrease in negative work performed by the tarsal extensors during the early stance phase and a decrease in positive work by the tarsal extensors during push off. No compensatory changes in work were performed by other joints within the lame hind limb during the stance phase. Vertical impulse in the diagonal forelimb decreased, but there were no significant changes in forces or impulses in the ipsilateral forelimb or contralateral hind limb. CONCLUSION AND CLINICAL RELEVANCE: Results indicate that horses are able to manage mild, unilateral hind limb lameness by reducing the airborne phase of the stride rather than by increased loading of the compensating limbs.     

Epidemiology of porcine non-specific colitis on Scottish farms

The objective of this study was to investigate epidemiological risk factors for porcine non-specific colitis (NSC). Forty-seven Scottish pig farms, with and without a clinical history of diarrhoea during the growing period (15-40 kg), were selected. The study included farm visits, clinical inspection of pigs, completion of farm management questionnaires, pathological tests into the cause of the diarrhoea and analysis of the non-starch polysaccharide (NSP) content of feeds. The results from 17 farms designated as NSC and 10 control farms suggest dietary associations with NSC. Farms with NSC fed diets with significantly higher levels of NSPs, especially containing the sugars glucose, arabinose and xylose. Few management factors were identified, although the high prevalence of infectious colitis reduced the power of the study.     

Cyclooxygenase ‐2 Expression in Mammary Tumors in Dogs and its Correlation to Histologic and Biologic Behavior

Introduction:  Cyclooxygenase‐2 (Cox‐2) is the inducible form and the rate‐limiting enzyme, for conversion of arachidonic acid to prostaglandins. Cox‐2 overexpression, common in carcinomas, is associated with increased growth rate, resistance to apoptosis, angiogenesis, and overall, both local and distant aggressive behavior. Cox‐2 overexpression has been detected in human and canine mammary tumors (MTs). Histopathology of canine MT is not always predictive of biologic behavior, and anecdotally, only 50% of the malignant MTs are expected to metastasize. We hypothesize that Cox‐2 expression correlates with aggressive behavior.
Methods:  This retrospective study evaluated 48 bitches, presented for excision of MT between 2000 and 2003 at FMVZ de Botucatu‐UNESP, Brasil. Follow‐up varied from 18 months to 24 months and included physical examination and thoracic radiographs. Histopathologic examination was performed in all tumors, as well as in metastatic lesions when detected in the follow‐up period. Immunohistochemistry was used to detect expression of Cox‐2 in paraffin blocks (Rabbit polyclonal anti‐PGHS‐2. Oxford Biomedical). 10 adenomas, 10 carcinomas, 10 benign mixed tumors, 10 malignant mixed tumors and 8 cases of primary carcinomas and their metastatic lesions.
Results:  Expression of Cox‐2 varied among groups. Adenomas (32.1%), mixed benign tumors (38%), carcinomas (60.3%), malignant mixed tumors (65.8%), and metastatic carcinomas (81.25%) and their metastatic lesions (84.35%). Statistically significant differences (p < 0.05) were observed between the benign and malignant counterparts and between carcinomas and metastatic carcinomas.
Conclusions:  Cox‐2 expression correlates with both histologic and biologic behavior in mammary carcinomas, and may serve as a predictor of metastatic potential.     

Effect of dexmedetomidine and xylazine followed by MK-467 on gastrointestinal microperfusion in anaesthetized horses

Objective

To compare the effects of MK-467 during isoflurane anaesthesia combined with xylazine or dexmedetomidine on global and gastrointestinal perfusion parameters.