Growth performance,vitamin E status,and proximate and fatty acid composition of channel catfish, <Emphasis Type="Italic">Ictalurus punctatus</Emphasis>, fed diets containing various levels of fish oil and vitamin E

A study was conducted to determine the effect of increasing dietary levels of fish oil on vitamin E requirement and their effect on growth performance, liver vitamin E status, and tissue proximate and fatty acid compositions of channel catfish. Basal purified diets (42% protein and 3,800 kcal DE/kg) supplemented with 6, 10, and 14% menhaden fish oil were each supplemented with 50, 100, and 200 mg vitamin E/kg (3 × 3 factorial experiment). Each diet was fed to juvenile channel catfish in three random aquaria to apparent satiation twice daily for 12 weeks. Weight gain, feed intake, and feed efficiency ratio were not affected by dietary levels of fish oil, vitamin E, or their interaction. Survival rate at the end of week 12 was significantly lower for fish fed diets containing 14% fish oil, regardless of vitamin E content. Whole-body moisture significantly decreased and lipid increased when dietary lipid levels were increased to 10 or 14%. Dietary vitamin E levels had no effect on body proximate composition. Lipid content of liver was not influenced by dietary levels of fish oil and vitamin E or their interaction. Hepatosomatic index significantly decreased with increasing lipid levels but was not affected by dietary levels of vitamin E. Liver vitamin E increased with increasing dietary vitamin E but decreased with increasing fish oil levels. Fatty acid composition of whole body and liver reflected that of dietary lipid but was not influenced by dietary levels of vitamin E. Whole-body saturates increased, whereas MUFA decreased with increasing dietary levels of fish oil. Liver saturates were not affected by fish oil levels, but MUFA and n-6 decreased and increased, respectively, with increasing fish oil levels. Total n-3 and n-3 HUFA in both tissues increased with increasing fish oil levels in diets, but liver stored much higher levels of these fatty acids.     

Acquired myasthenia gravis associated with oral sarcoma in a dog

Acquired myasthenia gravis is a common neuromuscular disorder resulting from autoantibody directed against the post-synaptic acetylcholine nicotinic receptors in skeletal muscle. Myasthenia gravis has been reported previously as a paraneoplastic syndrome. This case report presents myasthenia gravis secondary to an oral sarcoma in a juvenile Mastiffdog.     

Pheochromocytoma in a white rhinoceros (Ceratotherium simum)

A 46-yr-old male white rhinoceros (Ceratotherium simum) died during anesthesia following agonal excitation. On postmortem, a well-demarcated 2.5-cm tan mass was identified in the right adrenal gland. Histopathology confirmed the presence of a pheochromocytoma, and elevated levels of epinephrine in serum collected shortly prior to the animal's death, as compared with sera from healthy controls, demonstrated the functional nature of the tumor. Although rare, pheochromocytoma should be considered as a differential diagnosis in cases of suspected hypertension and acute death in rhinos.     

Draft genome sequence of the sexually transmitted pathogen Trichomonas vaginalis

We describe the genome sequence of the protist Trichomonas vaginalis, a sexually transmitted human pathogen. Repeats and transposable elements comprise about two-thirds of the approximately 160-megabase genome, reflecting a recent massive expansion of genetic material. This expansion, in conjunction with the shaping of metabolic pathways that likely transpired through lateral gene transfer from bacteria, and amplification of specific gene families implicated in pathogenesis and phagocytosis of host proteins may exemplify adaptations of the parasite during its transition to a urogenital environment. The genome sequence predicts previously unknown functions for the hydrogenosome, which support a common evolutionary origin of this unusual organelle with mitochondria.     

Development of an ELISA to measure the humoral immune response of hybrid striped bass Morone chrysops×M. saxatilis to Streptococcus iniae

A previously developed monoclonal antibody (mAb) specific for the heavy chain of hybrid striped bass (HSB) Morone chrysops×M. saxatilis immunoglobulin was used in an assay to detect the humoral response to antigens of Streptococcus iniae. In order to validate this assay, an anti‐S. iniae antibody was produced in HSB by immunization with formalin‐killed cells of S. iniae mixed with Freund's complete adjuvant (FCA). After boosting with cells mixed with Freund's incomplete adjuvant (FIA), fish were challenged with live S. iniae by i.p. injection. This resulted in mortalities of 100%, 13% and 7% for non‐immunized, immunized and non‐challenged fish respectively. Live S. iniae were recovered only from moribund non‐immunized challenged fish, indicating that the immunization conferred protection against S. iniae. Sera were taken at 28 and 42 days post challenge and anti‐S. iniae antibody was measured by both agglutination and indirect ELISA. Titres of anti‐S. iniae antibody increased only in the immunized group as measured by agglutination and ELISA. Serum complement measured in the final bleeding was significantly higher in the immunized group. Western blotting using immune HSB serum indicated that the predominant antigen in this case was the high molecular weight polysaccharide of S. iniae.     

Immune Response and Resistance to Stress and Edwardsiella ictaluri Challenge in Channel Catfish, Ictalurus punctatus, Fed Diets Containing Commercial Whole-Cell Yeast or Yeast Subcomponents

Dietary supplementation of yeast or yeast subcomponents (YYS) as commercial preparations of β‐glucan (MacroGard^®; Biotec‐Mackzymal, Tromsø, Norway; and Betagard A^®; Aqua‐In‐Tech, Inc., Seattle, WA, USA), mannan oligosaccharide (Bio‐Mos? Aqua Grade; Alltech, Nicholasville, KY, USA), or whole‐cell Saccharomyces cerevisiae (Levucell SB20^®; Lallemand Animal Nutrition, Milwaukee, WI, USA) at the manufacturer’s recommended levels was evaluated on the physiological performance of juvenile channel catfish, Ictalurus punctatus. Fish were fed YYS diets for 4 wk, followed by 2 wk of control diet. Fish were sampled at the end of each feeding period (4 and 6 wk) to measure hematological and immune parameters and growth and to determine the effects of dietary β‐glucan on resistance to Edwardsiella ictaluri infection and to low‐water stress (6 wk). Supplementation of YYS in diets did not affect growth performance, hematology, or immune function. Survival from E. ictaluri infection was from 5 to 17.5% higher in fish fed YYS diets than in the control group, but the increases were not significant. Some improvement in stress resistance was observed in YYS‐fed catfish after exposure to low‐water stress. Stress reduction in fish fed diets supplemented with yeast subcomponents has been reported previously, but thus far, no explanation has been proposed for this effect. The present study and the previously published research suggest that dietary YYS supplementation does not appear to improve resistance of channel catfish to E. ictaluri.