Bromine residues in potato and wheat crops grown in soil fumigated with methyl bromide

The bromine content of potato tubers grown in soil fumigated with methyl bromide at 487 and 975 kg/ha (1 lb and 2 lb/100 ft2) averaged 170 and 280 mg/kg of dry weight. Most of the bromine was in the outer layers of the tubers; peeled tubers has less than 100 mg/kg, which remained after boiling. Potato haulm contained 4000 or 6700 mg/kg bromine respectively for the two rates of application. The bromine content of wheat grain grown after potatoes depended on the rate of application of methyl bromide and the time interval between treatment and wheat crop. Wheat grain harvested 31/2 21/2 and 11/2 years after fumigation with methyl bromide at 975 kg/ha had mean bromine contents of 4.5, 15 and 44 mg/kg. but the amounts in grain from plots having the same treatments varied more than two-fold; wheat grain harvested 11/2 years after fumigation at 487 kg/ha contained 23 mg bromine/kg. Wheat yields were unaffected by fumigation.     

ULTRASONOGRAPHIC, GROSS, AND HISTOLOGIC EVALUATION OF A TENDINITIS DISEASE MODEL IN THE HORSE

Collagenase-induced lesions of the superficial digital flexor tendon were monitored using diagnostic ultrasound and subsequently compared with gross and microscopic findings. The postinjury sonograms demonstrated hypoechoic or anechoic areas corresponding to areas of hemorrhage and necrosis. The size of the lesion increased and the echogenicity decreased with increasing units of collagenase injected into the tendon. As postinjury time increased, echogenicity increased, which corresponded to fibrous-tissue invasion and collagen deposition. The extent of tendon injury produced correlated with the amount of collagenase injected into the tendon. Diagnostic ultrasound is useful in evaluating injury and healing in collagenase— induced tendinitis.     

Atraumatic loop electrodes for electroretinography

A simple method is described for producing inexpensive, atraumatic electrodes for electroretinography. Scleral contact is obtained by a loop of ultra-lightweight stainless steel wire placed between the eye and lower lid. Recordings obtained by this method in animals are equal to those recorded with needle electrodes, and the expense and complex construction of contact lens electrodes of varying sizes is avoided. Sample recordings made with loop and needle electrodes from the same ophthalmologically normal dog are presented.     

Effect of Lentil Residues on the Yield and Response of Succeeding Rice to Nitrogen

A field experiment was conducted at the Division of Agronomy, Indian Agricultural Research Institute, New Delhi during 1983-84 and 1984-85 to study the effect of lentil residues on the yield and response of succeeding rice to nitrogen. Lentil residues benefitted the succeeding rice and gave longer and heavier panicles, more grains per panicle, higher 1000-grain weight and higher grain and straw yield of rice as compared to fallow. Rice responded well to applied nitrogen both in the absence and presence of lentil residues. The effect of lentil root residues and root residues plus incorporation of lentil straw was equivalent to 11 and 33 kg N ha⁻¹ when 60 kg N ha⁻¹ was applied to rice; the corresponding values being 54 and 60 kg N ha⁻¹ when 120 kg N ha⁻¹ was applied to rice.     

The effect of humidity in plantain ripening

An examination of the coordination of ripening changes in plantain fruits (Musa AAB, cultivar ‘Apem’) showed that water stress had no effect on the respiratory rate at the climacteric maximum nor on the time between initiation and maximum. Similarly, water stress had little or no effect on the coordination of changes in CO₂ and C₂H₄ evolution, although it slightly increased the magnitude of C₂H₄ production and of the ACC content of the pulp. Stressed and unstressed fruits showed similar synchronised ripening changes after 2 and 3 days from the commencement of the climacteric. However, after 1 day, peel colouration, pulp softening and total soluble solids were less in stressed than in unstressed fruits. The results are discussed in the light of reported work on dessert bananas (Musa AAA cultivars).     

The effect of anti-inflammatory agents on the clinical expression of bovine ephemeral fever

The effect of two anti-inflammatory drugs on the development and persistence of clinical signs in cattle experimentally infected with bovine ephemeral fever (BEF) virus was investigated by their administration, either before or after the commencement of fever. A total of 16 cattle was given phenylbutazone sodium (PBZ). The drug prevented fever and other clinical signs in six cattle when given daily during the incubation period, and at 8-h intervals for 5 days when clinical disease might be expected. When treatment with PBZ was deferred until 2-4 h after the commencement of fever, the rectal temperature returned to normal within 4 h in four of six cattle and the development of other clinical signs was suppressed. Clinical signs of ephemeral fever occurred in four untreated cattle infected at the same time. Viraemia, the development of neutralizing antibodies (at 8-11 days), resistance to subsequent challenge with BEF virus, neutrophilia, lymphopenia and a rise in plasma fibrinogen occurred in all BEF-infected animals whether treated or untreated, despite different clinical appearances. The mean peak of plasma fibrinogen in the untreated cattle was 6.9 g l-1; 3.2 g l-1 when treated 2-4 h after fever developed and 3.8 g l-1 when treated from 18-h post-infection. BEF virus was isolated from leucocytes of each of the cattle, but the frequency of isolation was lower in the treated group. The results indicate that treatment with PBZ blocked the host response which produces the clinical signs and did not have an anti-viral effect. In a similar experiment, a long-acting anti-inflammatory drug, flunixin meglumine, failed to prevent BEF or to modify the clinical signs once they had developed, except for the rectal temperature which returned to normal within 2-4 h of the administration of the drug. The efficacy of this drug was not improved by increasing the dosage to two or three times the recommended level.     

THE INCIDENCE OF DYSTOCIA IN DORSET HORN EWES

The incidence of dystocia was recorded in flocks of Dorset Horn ewes lambing in winter, spring or summer and grazed at 8, 12 or 16 ewes per hectare over a ten-year period. The mean incidence of dystocia was 34% of ewes lambing. Significantly more ewes experience a difficult birth at winter (35%) and spring (39%) than summer (26%) lambings. Neither stocking rates nor pre-lambing ewe bodyweight were related to the incidence of dystocia. The incidence of dystocia was significantly greater in 2-year-old ewes than in any other age group. Foetal size was of major importance in the occurrence of dystocia. Approximately 60% of single and twin born lambs that had birth weights greater than 4.5 kg had a difficult birth whereas in lambs weighing less than 3.2 kg only about 10% were affected. Thirty-six per cent of all perinatal mortality was attributable to dystocia. Approximately 27% of single and 73% of twin presentations in assisted births were abnormal, 31% of all lambs assisted had 1 or both legs retained, 4% had posterior (including breech) presentations and the remaining 8% were of varied forms of malpresentation. Significantly more single male than female lambs experienced a difficult birth and the mean birth weights of single, twin and triplet born lambs that had a difficult birth were greater than the birth weights of singles, twins and triplets born normally.     

The in vitro cytotoxicity of native and modified trichloroacetic acid-extracted antigens from Fusobacterium necrophorum for mouse peritoneal macrophages

A Boivin lipopolysaccharide-protein complex (LPS-P), Westphal LPS (W-LPS), Boivin LPS (B-LPS), and a lipid A-associated protein (LAP) were extracted from Fusobacterium necrophorum bov 5 strain and chemically analyzed for protein, total nitrogen, hydrolyzed hexosamine, and nucleic acid content. Dose and time effects on the in vitro cytotoxicity of these preparations for mouse peritoneal macrophages were determined. Macrophage monolayers were exposed to 2.0 ml of 10, 100, 250, 500, or 1000 μg/ml solutions of the individual preparations for 1, 2, 4, or 6 hr at 37°C, and relative toxicities were determined; B-LPS> LPS-P> LAP, W-LPS. The effects of heat, NaOH, and trypsin and pronase on the native antigens were determined. Heat treatment had no effect on the cytotoxicity of B-LPS, but increased the toxicity of LPS-P and LAP for macrophages. Alkaline treatment decreased the cytotoxicity of B-LPS and increased the toxicity of LPS-P and LAP for macrophages. Enzyme treatment had no effect on LPS-P toxicity. The relationship of lipid A and protein content to toxicity for macrophages is discussed. Lipid A appears to be important in the cytotoxicity of B-LPS, and the protein components of LPS-P and LAP may contribute to their toxic activity. The ability of these bacterial cellular antigens to destroy phagocytic cells may facilitate the establishment of necrotic abscesses in susceptible hosts.     

ANATOMIC ATLAS FOR COMPUTED TOMOGRAPHY IN THE MESATICEPHALIC DOG: HEAD AND NECK

The purpose of this study was to produce a comprehensive anatomic atlas of CT anatomy of the dog for use by veterinary radiologists, clinicians, and surgeons. Whole-body CT images of two mature beagle dogs were made with the dogs supported in sternal recumbency and using a slice thickness of 13 mm. The head was scanned using high-resolution imaging with a slice thickness of 8 mm. At the end of the CT session, each dog was euthanized, and while carefully maintaining the same position, the body was placed in a walk-in freezer until completely frozen. The body was then sectioned at 13-mm (head at 8-mm) intervals, with the cuts matched as closely as possible to the CT slices. The forzen sections were cleaned, photographed, and radiographed using xeroradiography. Each CT image was studied and compared with its corresponding xeroradiograph and anatomic section to assist in the accurate identification of specific structures. Intact, sagittally sectioned, and disarticulated dog skulls were used as reference models. Clinically relevant anatomic structures were identified and labeled in the three corresponding photographs (CT image, xeroradiograph, and anatomic section). In this paper, the CT anatomy of the head and neck of the mesaticephalic dog is presented.     

Efficacy of acaricides against chorioptic mange of goats

Angora goats heavily infested with Chorioptes bovis were dipped one time in either 0.05% amitraz, 0.27% coumaphos, 0.05% fenvalerate, or 0.03% lindane. Control of the mites by the single dips was evaluated for 21 days. Amitraz caused 98% mortality of the mites initially. Both coumaphos and lindane caused greater than 85% mortality at 3 days, but mite numbers increased rapidly thereafter. Only fenvalerate killed all of the mites.