Dicoumarol toxicity in cattle associated with ingestion of silage containing sweet vernal grass (Anthoxanthum odoratum)

A diagnosis of dicoumarol toxicity in a herd of Friesian cattle was made following investigation of the deaths of three mature cows and eleven yearling heifers. Affected stock had been fed wrapped, bailed silage containing approximately 90% sweet vernal grass ( Anthoxanthum odoratum ). Sweet vernal grass contains coumarin, which can be converted to dicoumarol, a vitamin K antagonist, through the action of moulds. Most deaths were preceded by lethargy, severe anaemia and subcutaneous and internal haemorrhage. Dicoumarol toxicosis was suspected based on clinical signs, necropsy findings and prolonged prothrombin and activated partial thromboplastin times. Dicoumarol analysis of blood from affected animals and silage confirmed the diagnosis.     

Appearance and disappearance of swainsonine in serum and milk of lactating ruminants with nursing young following a single dose exposure to swainsonine (locoweed; Oxytropis sericea)

A series of experiments were conducted to investigate the elimination of swainsonine in the milk of lactating ruminants following a single dose oral exposure to swainsonine (locoweed; Oxytropis sericea) and to assess subsequent subclinical effects on the mothers and their nursing young. In a preliminary experiment, lactating ewes were gavaged with locoweed providing 0.8 mg swainsonine/kg BW (n = 4; BW = 75.8 +/- 3.6 kg; lactation = d 45) and lactating cows were offered up to 2.0 mg swainsonine/kg BW free choice (n = 16; BW = 389.6 +/- 20.9 kg; lactation = d 90). Serum and milk were collected at h 0 (before treatment), 3, 6, 12, and 24 for ewes, and h 0 (before treatment), 6, 12, 18, and 24 for cows. Swainsonine was highest (P < 0.05) by h 6 in the serum and milk of ewes. Consumption of at least 0.61 mg swainsonine/kg BW induced consistent (> 0.025 microg/mL) appearance of swainsonine in cow serum and milk. In response to the results obtained in the preliminary experiment, a subsequent experiment utilizing lactating ewes (n = 13; BW = 74.8 +/- 6.4 kg; lactation = d 30) and cows (n = 13; BW = 460.8 +/- 51.9 kg; lactation = d 90) was conducted. Each lactating ruminant was gavaged with a locoweed extract to provide 0 (control), 0.2, or 0.8 mg swainsonine/kg BW and individually penned with her nursing young. Serum and milk from the mothers and serum from the nursing young were collected at h 0 (before treatment), 3, 6, 9, 12, 24 and 48 (an additional sample was obtained at h 72 for ewes and lambs). Serum and milk swainsonine was higher (P < 0.05) in the 0.8 mg treated groups and maximal (P < 0.05) concentrations occurred from h 3 to 6 for ewes and h 6 to 12 h for cows (P < 0.05). Rises in alkaline phosphatase activity indicated subclinical toxicity in the treated ewes (P < 0.05). Following a single dose oral exposure to 0.2 and 0.8 mg swainsonine/kg BW provided by a locoweed extract, swainsonine was detected in the serum and milk of lactating ewes and cows, and rises in serum alkaline phosphatase activity were observed in the ewes. Neither swainsonine nor changes in alkaline phosphatase activity was detected in the serum of the lambs and calves nursing the ewes and cows dosed with swainsonine.     

La situation réelle en matière d'évaluation des pertes de récoltes

Après un bref exposé historique portant sur les 100 dernières annèes, il est fait état des trois éléments intervenant dans l'estimation des pertes de récoltes, à savoir: détection de la présence de l'organisme nuisible, mesure de l'incidence ou de l'intensité de ses attaques et évaluation des réactions de la plante-hôte. Une justification objective des interventions antiparasitaires d'envergure est demandée par les milieux politiques et économiques, tandis que les recherches se poursuivent sur les possibilités d'assurer des gains de production par une lutte efficace; l'accent est mis sur l'importance des prévisions indiquant la nécessité de tels traitements. II importe de bien définir les buts des évaluations envisagées afin de profiter au maximum des économies que permettent de réaliser les méthodes modernes de statistique.     

Soil and agronomic factors associated with cadmium accumulations in kidneys of grazing sheep

SUMMARY Mean concentration of cadmium (Cd) in kidneys of hogget sheep from 67 flocks grazing in the Agricultural Region of Western Australia was tested for association with soil, pastoral, climatic and nutritional factors. Hoggets grazing pastures on acidic soils and soils with a sandy-textured surface had higher Cd concentrations in kidneys than hoggets grazing pastures on more alkaline soils or soils with a clay-textured surface. Application of more than 100 kg of phosphatic fertiliser during the past 3 years to loamy soils was also associated with greater Cd concentration in kidneys of the grazing animals.     

Effectiveness of l‐ascorbyl‐2‐monophosphate Na/Ca as a vitamin C source for yellowtail Seriola quinqueradiata juveniles

A feeding experiment was conducted to examine the efficacy of a vitamin C (L‐ascorbic acid, AsA) derivative, l ‐ascorbyl‐2‐monophosphate Na/Ca (AMP‐Na/Ca) by comparing to l ‐ascorbyl‐2‐monophosphate‐Mg (AMP‐Mg) in terms of growth, AsA content in tissues, and hematology in yellowtail Seriola quinqueradiata juvenile (1.10 ± 0.01 g). Furthermore, a stress resistance test for the species fed AMP‐Na/Ca was also conducted. In experiment 1, 11 test pellet diets with different levels of AMP‐Na/Ca (0, 12, 43, 88, 440 and 881 mg AsA kg^?1diet) and AMP‐Mg (0, 16, 52, 106, 595 and 1164 mg AsA kg^?1 diet) were formulated and fed to the yellowtail three times per day for 50 days. In both the vitamin C sources, the survival rates of the fish fed diets without supplemental AsA were lower than 50% at day 20, and more than 50% mortality occurred in fish that fed the diets containing 12 or 16 mg AsA kg^?1 after day 30. However, no significant differences were detected in survival and growth among fish that fed the diets containing more than 43 mg AsA kg^?1. Liver and brain AsA concentrations generally increased with increasing dietary AsA level in both sources. In experiment 2, test diets were formulated to contain 43, 88, 440 and 881 mg AsA kg^?1 using AMP‐Na/Ca, and after 60 days of feeding, yellowtail juveniles were subjected to low salinity and air exposure stress. The fish that received diets with 440 mg AsA kg^?1 showed significantly higher tolerance to low salinity stress and higher survival rate in air exposure stress than those of other groups. The present study demonstrated that yellowtail juveniles could utilize AMP‐Na/Ca as an AsA source like AMP‐Mg, and that supplementation of 43–52 mg AsA kg^?1 diet was optimum for normal growth. However, this study showed that dietary inclusion of 440 mg AsA kg^?1 would be necessary to improve stress resistance of this species.     

Organogenesis and foetal haemodynamics during the normal gestation of healthy black‐rumped agoutis (Dasyprocta prymnolopha,Wagler, 1831) bred in captivity

The objective of this study was to define the patterns of organogenesis and foetal haemodynamics during the normal gestation of healthy agoutis (Dasyprocta prymnolopha) kept in captivity. Thirty pregnant agoutis that ranged in size from small to medium and weighed between 2.5 and 3 kg underwent B‐mode and Doppler ultrasonography for the biometric evaluation of the foetal organs. The foetal aortic blood flow proved to be predominantly systolic, and the measured flow velocity was 78.89 ± 2.95 cm/s, with a maximum pressure gradient of 2.12 ± 0.27 mmHg. The liver was characterized by its large volume, occupying the entire cranial aspect of the abdominal cavity, and it was associated cranially with the diaphragm and caudally with the stomach. The flow velocity in the portal vein was estimated to equal 12.17 ± 2.37 cm/s, with a resistivity index of 0.82 ± 0.05. The gallbladder was centrally located and protruded cranially towards the diaphragm. The spleen was visualized as an elongated structure with tapered cranial and caudal extremities, and the foetal kidneys were visualized bilaterally in the retroperitoneal region, with the right kidney positioned slightly more cranially than the left. The morphological characterization and hemodynamic analysis of the foetal organs of black‐rumped agoutis via B‐mode and Doppler ultrasonography allow determination of the vascular network and of reference values for the blood flow required for perfusing the anatomical elements essential for maintaining the viability of foetuses at different gestational ages.     

Eye diseases in Siberian husky dogs

A full ophthalmic examination was performed on 40 Siberian husky dogs using direct and indirect ophthalmoscopy, gonloscopy and nasolacrimal cannulation. Eight (20%) of the dogs were found to have distichia, 10 (25%) had excessive medial caruncular hairs, 8 (20%) had absence, displacement, or narrowing of the nasolacrimal puncta, 2 (5%) had bilateral corneal crystalline opacities, and 2 (5%) had unilateral areas of lateral corneal lipidosis. Fifty percent of the dogs had some abnormality of the iridocorneal (drainage) angle. However, in only one of these was the deformity severe enough to require glaucoma prophylaxis. An association between blue iris colour and malformation of the iridocorneal angle was noted.     

Contribution of microorganisms to the biofilm nutritional quality: protein and lipid contents

The nutritional quality of biofilm, a microbial community associated to an organic matrix, was evaluated in artificial substrate (polyethylene screen) in net cages during 30 days in the Patos Lagoon estuary, Southern Brazil. During this period, samples of biofilm were collected each 5 days for analysis of chlorophyll a, microorganisms abundance, dry weight, protein and lipid contents. During the study, chlorophyll a varied from 0.38 to 2.75 μg cm^?2; dry weight between 7.16 and 17.63 mg cm^?2; protein content from 0.43 to 1.76 mg cm^?2 and lipid concentration between 1.21 and 4.23 mg cm^?2. The variation of lipid in the biofilm was closely related to the abundance of free heterotrophic bacteria (34.25–56.54 × 10⁶ cells cm^?2), filamentous cyanobacteria (7.5–15.9 × 10⁶ filaments cm^?2), flagellates (6.92–12.89 × 10⁶ cells cm^?2) and mainly nematodes (29–1,414 organisms cm^?2), while protein content varied similarly to the abundance of unicellular centric diatoms (52.10–179.81 × 10³ cells cm^?2), and nematodes. This information will allow a better management of food supply to raised aquatic organism with the utilization of natural productivity in the culture systems, with considerable decrease in production costs.