Effects of Dietary Vitamin A on Juvenile Red Sea Bream Chrysophrys major

A 55-d feeding experiment was conducted to evaluate the effects of dietary vitamin A on growth of juvenile red sea bream Chrysophrys major . Nine semi-purified diets with supplemental retinol palmitate at levels of 0, 300, 600, 1,500, 3,000, 4,500, 6,000, 15,000 and 30,000 retinol eq/kg diet, were fed twice daily to triplicate groups of 10 juveniles per tank with an initial weight of 1.178 ± 0.001 g. Weight gain and specific growth rate increased with the increase of supplemental retinol palmitate in the diet up to a level of 6,000 retinol eq/kg diet, beyond which those indices tended to decrease slightly or to plateau. Significantly lower weight gain and specific growth rate were observed in fish fed with 0 and 300 retinol eq/kg diet. No significant differences were found in survival rates among the different levels of supplementation. The crude protein, lipid, moisture and ash contents in the whole body were not affected by the different vitamin A supplemental levels. Besides the reduced growth, fish fed with low levels of vitamin A supplement showed no other signs of deficiency. No hypervitaminosis A symptoms were observed in fish fed on high levels of supplementation. Fish fed on diets with 0 and 300 retinol eq/kg diet showed a significantly lower content of vitamin A (as a total retinol) in the liver than those in groups fed with higher levels of supplementation. Vitamin A was stored in the liver mainly as retinyl esters. Total retinal content of the eye showed no significant differences among the treatments; however, fish fed with 0 and 300 retinol eq/kg of diet had slightly higher concentrations. According to the results of the mean weight gain, specific growth rate and liver retinol content, the requirement of dietary vitamin A for juvenile red sea bream was estimated to be between 1,500 and 6,000 retinol eq/kg.     

Submicroscopic characterisation of phosphatic and sesquioxidic nodules of some soils of the “Chaco deprimido” (Argentina): Preliminary results

In this paper two examples are presented of the investigation by submicroscopic techniques, of particular problems in the characterisation and analysis of various pedological features in soils of the “Chaco Deprimido”.

The first concerns nodules seen in an alluvial soil. The techniques established their phosphatic composition and identified them as small bone fragments which are undergoing alteration.

The second relates to study of sesquioxidic nodules and cutans in solodised soils and planosols, and shows them to have a dominantly manganiferous composition; this result enables one to make certain interpretations concerning the physicochemical conditions essential for the formation of such pedological features.     

Evaluation of the Local Analgesic Effects of a Commercial Aqueous Extract of Sarracenia purpurea and Ammonium Sulfate in the Equine Abaxial Sesamoid Block Model

Sarracenia purpurea is a carnivorous plant whose aqueous extracts have been proposed to exert analgesic effects by neurolytical action on peripheral nerves. The aim of this study was to determine the local analgesic effects of a commercially available aqueous extract solution of S. purpurea (P-Bloc, St. Joseph, Missouri) and a 1% ammonium sulfate solution, using the horse abaxial sesamoid block model. Twenty horses were randomly assigned to two groups. The first group (n = 10) was used to evaluate the effect of P-Bloc. The horses received a bilateral (medial and lateral) abaxial sesamoid block with 5 mL of P-Bloc in one random forelimb, while in the contralateral forelimb, they received either 5 mL of 2% lidocaine as a positive control (n = 5) or 5 mL of 0.9% NaCl as a negative control (n = 5). The second group (n = 10) was treated as the first but received 5 mL of 1% ammonium sulfate in NaCl (0.9% NaCl) solution instead of P-Bloc. The period of hoof withdrawal reflex latency (HWRL, in seconds) was measured using a custom-made heat projector lamp as a source of a noxious skin heating stimulus applied to the pastern. Lidocaine (2%) prolonged (P ≤ .05) the HWRL period, returning to the negative control basal values after 240 minutes. Neither the treatment with P-Bloc nor 1% ammonium sulfate modified the HWRL period. The lack of effect of these compounds in this model reinforces the results reported elsewhere and suggests a nonlocal anesthetic mechanism of action for the aqueous extract of S. purpurea in the horse.     

Adaptation of ostriches to transport‐induced stress: Physiometabolic response

This study assessed the effects of five different transport periods on physiometabolic responses and gas exchange in ostriches. It included 138 ostriches that were assigned to five experimental groups. G₁ included 78 birds that were set aside as a reference group (RG). Each one of the four remaining experimental groups included 20 ostriches, which were transported in the following manner: G₁ on one occasion for a period of 1 h; G₂ on one occasion for 2 h; and G₃ on one occasion for 3 h; G_4a was made up of the ostriches from G₁ but they were shipped on a second occasion, for 2 h (making a total of 3 h); finally, G_4b was that same group, but after a third transport period, on this occasion during 3 h (for a total of 6 h). Groups G₂ and G₃ presented the most marked blood alterations (P < 0.05), including an increase in pH, hypocapnia (27.8 ± 0.80 mmHg), hypernatremia (171.75 ± 1.84 mmol/L), hypocalcemia (0.95 ± 0.03 mmol/L), and hyperglycemia (224.05 ± 3.94 mg/dL). Also, group G₃ presented the lowest hematocrit values (26.5 ± 0.47 HTC%). Therefore, transporting ostriches with no prior experience for 3 h caused the most pronounced physiometabolic changes.     

A critical assessment of soil amendments (slaked lime/acidic fertilizer) for the phytomanagement of moderately contaminated shooting range soils

Purpose  

The effects of the addition of an acidic fertilizer solution and/or slaked lime (5.5 g Ca(OH)₂ kg⁻¹) on a slightly acidic shooting range soil (pH 6.1, % organic carbon 5.4) with moderate metal (e.g., 620 mg kg⁻¹ Pb) and metalloid (17 mg kg⁻¹ Sb) concentrations on metal and Sb solubility and plant accumulation were investigated.     

A wide diversity of zoonotic intestinal parasites infects urban and rural dogs in Neuquén,Patagonia, Argentina

The presence of parasites was investigated by the examination of 1944 dog faecal samples collected from urban (n = 646) and rural (n = 1298) areas of the province of Neuquén, Patagonia, Argentina. Parasitic agents (PA) were found in 37.86% of samples. A total of 15 different PA were detected, including Toxocara canis (16.35%), Taenia spp./Echinococcus spp. (12.65%), Trichurisvulpis (6.06%), Giardia spp. (1.29%), Toxascaris leonina (0.56%), Ancylostomacaninum (0.41%), Dipylidium caninum (0.31%), Diphyllobothrium spp. (0.10%), among others. Several of these PA are recognized as zoonotic agents. Therefore, the results of this investigation revealed that local population is exposed to a broad spectrum of zoonotic parasites by means of environmental contamination with dog faeces. Prevalence of PA was slightly higher in rural (40.06%) than in urban (33.44%) locations. Distribution of groups of PA (cestodes, nematodes, and protozoa) showed statistical differences between both habitats. Prevalence of cestodes (18.18%) and protozoa (11.86%) was significantly higher in the rural environment than in urban areas and nematodes (29.10%) were more frequent in urban locations. Infection of dogs with Linguatula serrata and Cryptosporidium sp. was demonstrated for the first time in Neuquén. Rural dogs of the study area are under hydatic disease control program, which includes treatment with praziquantel every 6 weeks; thus, the finding of high level of cestode infection in these areas is of great relevance. The epidemiology of zoonotic parasitic infections in urban and rural dogs showed different patterns and, in consequence, different control measurements should be applied in each location.     

Effect of acute sublethal endotoxaemia on in vitro digital vascular reactivity in horses

Endotoxaemia is a syndrome linked to the development of equine laminitis; however, the relationship between them is uncertain. The aim of this experiment was to evaluate the effect of an experimental acute sublethal endotoxaemia model on in vitro equine palmar digital vascular reactivity. Rings of arteries and veins of each forelimb were obtained from 11 clinically healthy horses submitted to two surgical procedures, 3 weeks apart. Before the second surgery, 0.25 microg/kg of lipopolysaccharide from Escherichia coli O55:B5 in saline, was administered i.v. in 30 min. After 3 h, the vessels were harvested and submitted to in vitro vascular reactivity experiments and histopathology. The response to depolarizing Krebs solution (DKS, 40 mm), phenylephrine (PHE), acetylcholine (ACh) and sodium nitroprusside (SNP) were evaluated. All horses showed colic pain and watery diarrhoea, tachycardia, tachypnea, hyperthermia and leucopenia. Concentration-response curve (CRC) to PHE was shifted to the left in arteries rings from endotoxemic horses without any effect on vein rings. The CRC to ACh was shifted to the right with a reduction in the maximal response. The response to SNP and DKS was similar between groups. There was no evidence of histopathological effects. The increased response to PHE in digital arteries together with a reduction of the endothelium-dependent response to ACh in arteries and veins, confirm the existing reports where endotoxaemia was found to modify the digital vascular reactivity during the acute phase. As the digital endothelial function is impaired, there may be an increased potential to develop a digital prothrombotic state with a reduced vasodilatory capacity.     

Comparison of susceptibility of fungal isolates to lufenuron and nikkomycin Z alone or in combination with itraconazole

OBJECTIVE: To evaluate and compare the in vitro antifungal properties of lufenuron and nikkomycin Z against isolates of Coccidioides immitis and Aspergillus fumigatus when used singly and in combination with the azole antifungal agent itraconazole. SAMPLE POPULATION: 3 clinical isolates of A fumigatus and the Silveira strain of C immitis. PROCEDURE: The fungal isolates were tested in vitro for susceptibility to the single and combination of compounds by use of microtiter-format susceptibility methods. Minimum inhibitory concentration end points were determined visually, and the contents of representative wells were examined microscopically for evidence of morphologic effects on fungi. RESULTS: No evidence of inhibition, either by susceptibility testing or direct microscopic examination of treated cells, was obtained with lufenuron under experimental conditions. In contrast, nikkomycin Z, a known inhibitor of fungal chitin synthesis, had potent activity against C immitis when used singly. A synergistic interaction between nikkomycin Z and itraconazole was found against isolates of both species tested. CONCLUSIONS AND CLINICAL RELEVANCE: On the basis of our in vitro data, lufenuron does not appear to possess antifungal properties.