The value of sea urchin,Lytechinus variegatus,egesta consumed by shrimp,Litopenaeus vannamei

Sea urchins produce high‐energy, membrane‐bound fecal pellets that contain residual nutrients and large quantities of microbiota. These egesta are readily consumed by the shrimp, Litopenaeus vannamei. Egesta of the sea urchin, Lytechinus variegatus, were evaluated as a feed supplement or total replacement for a commercial shrimp diet. Shrimp were stocked at 0.49 g ± 0.06 g initial body weight and housed individually in 2.8‐L tanks in a commercial recirculating zebrafish system. Shrimp were assigned to one of six diets: commercial shrimp feed, reference sea urchin feed, collected dried sea urchin egesta, collected wet sea urchin egesta, half ration of shrimp feed and half collected wet sea urchin egesta, and egesta naturally produced by two sea urchins in polyculture. Equivalent dry matter amounts of each diet were proffered to shrimp in each treatment twice daily, except for those that had complete access to natural egesta excreted by sea urchins in polyculture. Sea urchins were proffered a reference sea urchin feed at 2% body weight daily. After 27 days, shrimp proffered collected dried or wet egesta did not differ significantly in percent weight gain and showed the lowest weight gain. The percent weight gain of shrimp fed the commercial shrimp diet did not differ significantly from that of the shrimp fed half commercial shrimp diet and half egesta. The highest weight gain was recorded for those shrimp that consumed the untouched egesta produced by sea urchins in polyculture. These data suggest that consumed egesta have noteworthy nutritional value and therefore would be beneficial to the culture of extractive species in an integrated multitrophic aquaculture system.     

No effect of turkey herpesvirus infections on the outcome of avian pneumovirus infections in turkeys.

To determine whether turkey herpesvirus (HVT) impairs the aspecific and specific defense against an avian pneumovirus (APV) infection, specific-pathogen-free turkeys were inoculated at 7 days of age with HVT and 1, 5, or 7 wk later with APV. Clinical signs, APV replication, and development of antibodies against APV were evaluated. No differences were found between the birds that received both HVT and APV and those that received only APV.     

Culture of bovine bone marrow progenitor cells in vitro.

In vitro methylcellulose cultures of bovine bone marrow progenitor cells were developed. An existing technique described for bovine species was compared to a method for human tissue and further adapted during subsequent experiments. Bovine bone marrow samples were collected at the slaughterhouse, and mononuclear cells were separated by gradient centrifugation (1.077 g/ml specific density and 400 g). The use of 3% bovine leucocyte-conditioned medium, produced by stimulation of blood lymphocytes with 4 microg/ml concanavalin A and harvested on day 4 of culture, gave better results than the use of supernatant of the human bladder carcinoma 5637, which is widely used in human bone marrow cultures. However, bovine leucocyte-conditioned medium was not added to erythroid cultures because inhibitory effects were observed. Erythroid colonies were stimulated with erythropoietin, and hemin was added to enable microscopic identification. Reduced oxygen tension was necessary to induce growth of erythroid colonies. This was not necessary for myeloid cultures. In conclusion, the results of this study show that the growth of myeloid and erythroid colonies in methylcellulose-based medium requires different culture conditions, which are different from the culture conditions for human cells.     

A Tremor Syndrome With a Central Axonopathy in Scottish Terriers

A central axonopathy in 2 male and 1 female Scottish Terrier puppies from 3 different but related litters is reported. Clinical signs consisting of severe whole-body tremors and ataxia were first detected at the age of 10 to 12 weeks. They worsened with activity and excitement and diminished during rest or sleep. Two dogs also had paraparesis. In 1 dog the neurological deficits progressed over several months. Neuropathological examination revealed widespread axonal changes, vacuolation, and gliosis in the white matter of the central nervous system.     

Influence of 17-α-Methyltestosterone on Red Tilapia Under Two Thermal Regimes

Fingerling red tilapia ( Oreochromis mossambicus ± O. niloticus ) were orally administered 17-α-methyltestosterone (MT) under a warmwater (27.0 ± 0.5 C) and coolwater (21.5 ± 0.5 C) thermal regime. In the warmwater experiment, fish received either 0, 1, 5, 10, 30, 60, or 100 mg MT/kg feed for 75 days. In the coolwater experiment, fish received 0, 10, or 60 mg MT/kg feed for 75 days followed by a 34 day withdrawal period. After 75 days, fish receiving 60 mg MT/kg feed (best treatment) in the warmwater and coolwater experiments exhibited significantly higher growth rates than controls by 35.3 and 45.8%, respectively. Likewise, feed conversion among groups receiving 60 mg MT/kg feed in the warmwater and coolwater experiments were significantly better than the controls (1.14 versus 1.30 and 1.44 versus 1.77, respectively). During the withdrawal period, no significant differences in growth rates or feed conversion were observed between the control and treatment groups. MT treatment significantly affected the body composition (whole body and empty carcass) of the red tilapia in both experiments, elevating percent moisture and protein values, but depressing percent fat values. Results demonstrated that incorporation of MT into fingerling diets offers potential for extending the period when tilapias actively feed and grow in temperate climates.     

Particle Size Distribution in Two Lipid Emulsions Used for the Enrichment of Artemia nauplii as a Function of Their Preparation Method and Storage Time

The present study examined the distribution of particle sizes in two experimental standardized lipid emulsions (distributed by ICES, International Council for the Exploration of the Sea) as a function of the preparation method (hand shaking or ultrasonic blending) and as a function of storage time. A 24-h enrichment trial compared the incorporated HUFA levels in the nauplii of Artemia franciscana .
The emulsion droplets in the 50% HUFA emulsion (ICES 50, ethyl ester based) were much smaller than in the 30% HUFA emulsion (ICES 30, triacylglycerol-based) in which 90% of the droplets had a diameter below 12.3 μm as compared to 1.3 pn in ICES 50. The blending method highly affected particle sizes. High-shear blending instead of the classical hand shaking of the emulsion of both ICES 30 and 50 reduced the mean particle size from 5.06 to 1.07 μm and from 0.38 to 0.11 μm, respectively. The particle size distributions remained stable during the 1-wk storage, suggesting the absence of agglomeration or bacterial development. The fatty acid composition of 24-h enriched Artemia reflected differences in the HUFA profile of the emulsions, but was independent of observed differences in the size of the particles.     

MAGNETIC RESONANCE IMAGING OF CEREBRAL CORTICAL NECROSIS (POLIOENCEPHALOMALACIA) IN A DOG

A 3-year-old neutered female mixed breed dog was examined because of severe, generalized seizure activity, tetraparesis, and encephalopathic signs. Cerebrospinal fluid (CSF) evaluation was unremarkable except for a mild increase in protein. Serum and CSF titers for infectious diseases were negative. Magnetic resonance (MR) imaging examination of the brain was performed and lesions were found within the cerebral gray matter of the temporal and parietal lobes. The lesions had increased signal intensity on T1, T2, and proton density-weighted images. There was mild inhomogeneous enhancement following intravenous contrast medium administration. Neurologic status improved and the seizures were well controlled, but the dog never regained normal mentation and euthanasia was performed 10 weeks after initial evaluation. At necropsy, severe cerebral cortical necrosis was found in the regions corresponding to the lesions seen on MR imaging examination. Large numbers of fat-containing macrophages (gitter cells) were found within these areas, and are thought to be responsible for the characteristic hyperintensity seen on the MR images.     

Blastocyst Evaluation by Means of Differential Staining: a Practical Approach

Techniques for in vitro production of embryos have been developed world-wide in different species, with promising results in human and ruminants. Thousands of human IVF-babies have been born during the last 20 years and thousands of in vitro -produced calves have been born since the late 1980s. With current methods for bovine in vitro fertilization, about 30–40% of in vitro -fertilized bovine oocytes develop further to the blastocyst stage and can be used for transfer. A proper evaluation of blastocyst quality remains however, an important challenge for every researcher involved in embryology and for every clinician who wants to select the best embryos for transfer. This review attempts to summarize the different methods available for estimation of blastocyst quality with a special emphasis upon differential staining.