Husbandry of animals on land and in water: similarities and differences.

The husbandry of aquatic animals originated in China in approximately 1,100 B.C., thousands of years after the beginning of animal agriculture. The practice did not reach Europe until the Middle Ages. Aquaculture apparently was not very important in Western Europe. The early immigrants from that region did not include fish with the other food animals that they brought with them to the New World. The practice of aquaculture finally came to the United States in the mid-nineteenth century, where it was used for the production of trout for stocking coldwater ponds and streams for sport fishing. Later, cultural practices were extended to warmwater species such as the largemouth black bass and the channel catfish. Thus, aquaculture in the United States was derived from recreational fishing rather than from food production, and from fisheries management rather than from animal science. There are important differences in the hydrosphere and atmosphere as cultural environments. Differences in composition, density, response to physical force, latent heat of fusion, specific heat, transparency, viscosity, and erosiveness of air and water result in different problems for land animal and aquatic animal culturists. Aquaculturists work primarily with "cold-blooded" ("lower") animals, whereas agriculturists work with "warm-blooded" ("higher") animals. In comparison with warm-blooded land animals, cold-blooded aquatic animals are less independent of changes in their environment.(ABSTRACT TRUNCATED AT 250 WORDS)     

Adrenal-associated changes in experimental sporidesmin poisoning of sheep

Sporidesmin-dosed hoggets which developed photosensitisation were shown to have enlarged adrenal glands and premature involution of the thymus. These sheep also developed high concentrations of plasma cortisol after the onset of photosensitisation. Sporidesmin-dosed sheep which did not show photosensitisation showed less or no adrenal associated changes.     

The relative economics of feeding open, aborted, pregnant feedlot heifers

A 90-day finishing trial involving 144 feedlot heifers was conducted to compare the performance parameters and carcass characteristics of open heifers, therapeutically aborted heifers, and pregnant heifers. In the first 28 days of the trial, the aborted heifers had reduced (p < 0.05) feed intake (FI), average daily gain (ADG), and feed efficiency (FE) compared to pregnant and open heifers. Over the entire trial, on a live weight basis, the aborted group had reduced (p < 0.05) final weight, ADG, and FE compared to pregnant and open heifers. However, when the data were adjusted for total uterine weight, the aborted and open heifers had improved (p < 0.05) final weight, ADG, and FE compared to pregnant heifers. The aborted and open group had a higher (p < 0.05) carcass weight, rib eye area, dressing percentage, and cutability estimate compared to the pregnant heifers. The aborted group had lower (p < 0.05) carcass weight than the open heifers. Over the entire 90-day feeding period, there were no statistically significant differences among the groups with respect to feed intake (FI), average fat, grade fat, and carcass grades. Also, there were no significant health problems or mortality in any of the groups.

In the economic analysis, aborted heifers returned $26.41 per head more than pregnant heifers. Open heifers returned $39.94 per head more than aborted heifers, and $66.35 more than pregnant heifers. Thus, aborting feedlot heifers during the second trimester was determined to be a safe and cost effective management decision.

     

Guidelines for euthanasia of domestic animals by firearms

All animals that are to be killed, whether for food, for humane reasons, or because they are homeless, must receive a quick and painless death. In some smaller communities, veterinary or humane society expertise may not be readily available to humanely kill stray and unwanted animals. An alternative that provides for a humane death for the animal is by shooting. The following guidelines are intended to assist persons who must perform this usually distasteful task; they contain recommended techniques that will help to ensure that any animals killed by shooting will die in a humane way.     

Proposed criteria for classification of acute myeloid leukemia in dogs and cats

Blood and bone marrow smears from 49 dogs and cats, believed to have myeloproliferative disorders (MPD), were examined by a panel of 10 clinical pathologists to develop proposals for classification of acute myeloid leukemia (AML) in these species. French-American-British (FAB) group and National Cancer Institute (NCI) workshop definitions and criteria developed for classification of AML in humans were adapted. Major modifications entailed revision of definitions of blast cells as applied to the dog and cat, broadening the scope of leukemia classification, and making provisions for differentiating erythremic myelosis and undifferentiated MPD. A consensus cytomorphologic diagnosis was reached in 39 (79.6%) cases comprising 26 of AML, 10 of myelodysplastic syndrome (MDS), and 3 of acute lymphoblastic leukemia (ALL). Diagnostic concordance for these diseases varied from 60 to 81% (mean 73.3 +/- 7.1%) and interobserver agreement ranged from 51.3 to 84.6% (mean 73.1 +/- 9.3%). Various subtypes of AML identified included Ml, M2, M4, M5a, M5b, and M6. Acute undifferentiated leukemia (AUL) was recognized as a specific entity. M3 was not encountered, but this subclass was retained as a diagnostic possibility. The designations M6Er and MDS-Er were introduced where the suffix "Er" indicated preponderance of erythroid component. Chief hematologic abnormalities included circulating blast cells in 98% of the cases, with 36.7% cases having >30% blast cells, and thrombocytopenia and anemia in approximately 86 to 88% of the cases. Bone marrow examination revealed panmyeloid dysplastic changes, particularly variable numbers of megaloblastoid rubriblasts and rubricytes in all AML subtypes and increased numbers of eosinophils in MDS. Cytochemical patterns of neutrophilic markers were evident in most cases of Ml and M2, while monocytic markers were primarily seen in M5a and M5b cases. It is proposed that well-prepared, Romanowsky-stained blood and bone marrow smears should be examined to determine blast cell types and percentages for cytomorphologic diagnosis of AML. Carefully selected areas of stained films presenting adequate cellular details should be used to count a minimum of 200 cells. In cases with borderline diagnosis, at least 500 cells should be counted. The identity of blast cells should be ascertained using appropriate cytochemical markers of neutrophilic, monocytic, and megakaryocytic differentiation. A blast cell count of > 30% in blood and/or bone marrow indicates AML or AUL, while a count of < 30% blasts in bone marrow suggests MDS, chronic myeloid leukemias, or even a leukemoid reaction. Myeloblasts, monoblasts, and megakaryoblasts comprise the blast cell count. The FAB approach with additional criteria should be used to distinguish AUL and various subtypes of AML (Ml to M7 and M6Er) and to differentiate MDS, MDS-ER, chronic myeloid leukemias, and leukemoid reaction. Bone marrow core biopsy and electron microscopy may be required to confirm the specific diagnosis. Immunophenotyping with lineage specific antibodies is in its infancy in veterinary medicine. Development of this technique is encouraged to establish an undisputed identity of blast cells. Validity of the proposed criteria needs to be substantiated in large prospective and retrospective studies. Similarly, clinical relevance of cytomorphologic, cytochemical, and immunophenotypic characterizations of AML in dogs and cats remains to be determined.