Feeding Frequency Affects Growth, Not Fillet Composition, of Juvenile Sunshine Bass Morone chrysops×M. saxatilis Grown in Cages

Abstract.— In an effort to feed sunshine bass Morone chrysops × M. saxatilis efficiently, promote optimal growth, and reduce labor costs associated with feeding, sunshine bass were grown in cages and fed one of four feeding frequencies: once/d, twice/d, once every other day (I X/EOD), and twice every other day (2X/EOD) for 21 wk. Juvenile sunshine bass were fed a commercial floating diet containing 40% protein and 11.5% lipid. One hundred fish were hand-counted and stocked into each of 12 3.5-m³ cages with three replications per treatment. At the conclusion of the study, percentage weight gain of sunshine bass fed twice/d was significantly (P < 0.05) higher (1,850%) compared to fish fed all other feeding frequencies. Specific growth rate (SGR) of fish fed twice/d was significantly higher (2.1%/d) compared to fish fed all other feeding regimes, while fish fed once/d had a higher SGR (2.0%/d) compared to fish fed I X/EOD (1.6%/d) and 2X/EOD (1.8%/d). Percentage survival was not significantly different (P > 0.05) among all treatments and averaged 70.4%r. Feed conversion ratio (FCR) of fish fed twice/d was significantly higher (2.40) compared to fish fed all other feeding regimes. Percentage fillet weight of fish fed twice/d was significantly higher (27.8%) compared to all other treatments. Percentage moisture, protein, lipid, and ash in fillet were not significantly different among all treatments and averaged 75.7%, 19.4%, 3.5%, and 1.2%n, respectively (wet-weight basis). Based upon data from the present study, it appears that producers growing juvenile sunshine bass in cages may want to feed fish twice daily. This feeding regimen allows for higher growth rates, without adverse effects on body or fillet compositions. However, economic analysis needs to be conducted to determine if feeding twice/d is profitable.     

Thrombocytopenia in Cats: A Retrospective Study of 41 Cases

The prevalence of feline thrombocytopenia (<200,000 platelets/L) at North Carolina State University, College of Veterinary Medicine Teaching Hospital, from January 1985 to March 1990, was 1.2% (41/3300). Cats were divided into six categories based on clinical diagnoses: 29% (12/41) had infectious disease, 20% (8/41) had neoplasia, 7% (3/41) had cardiac disease, 2% (1/41) had primary immune-mediated disease, 22% (9/41) had multiple diseases, and 20% (8/41) had disorders of unknown etiology. The mean platelet count for all thrombocytopenic cats was 52,000/μL ± 46,000/μL (1 SD) with a range of 1000–190,000/μL. No significant differences were found between groups with respect to platelet count, packed cell volume, or white blood cell count, though anemia and leukopenia were common among the cats as a whole. Bleeding disorders (hemorrhage or thrombosis) were observed in 29% (12/41) of thrombocytopenic cats and were more likely to be associated with neoplasia, cardiac disease, and platelet counts less than or equal to 30,000/μL. Disseminated intravascular coagulopathy was diagnosed in 12% (5/41) of the cats. Infections and/or neoplasia affecting the bone marrow were the most common diseases associated with thrombocytopenia. Feline leukemia virus and myeloproliferative neoplasia accounted for approximately 44% (18/41) of the specific diagnoses in thrombocytopenic cats. (Journal of Veterinary Internal Medicine 1993; 7:261–265. Copyright © 1993 by the American College of Veterinary Internal Medicine.)     

Production and Environmental Implications of Equine Grazing

Horses' physical and digestive well-being is often enhanced when allowed to graze on pastures. Furthermore, a well-managed pasture can contribute to economic viability. Grazing can however have deleterious effects on the environment if not properly managed. Although equine grazing, defecating, and ground trampling behavior is unique from that of other livestock species, pasture management practices are often based on those derived from cattle grazing. This review summarizes the current knowledge of impacts of equine grazing on pasture quality and environment and identifies gaps where further information is needed to formulate and recommend sustainable grazing methods specific to equine.     

Presettlement and modern disturbance regimes in coast redwood forests: Implications for the conservation of old-growth stands

Coast redwood (Sequoia sempervirens), a western North American conifer of ancient lineage, has a paradoxical combination of late-successional characteristics and strong adaptations to disturbance. Despite its shade tolerance and heavy dominance of the canopy on many sites, redwood saplings are uncommon in upland old-growth stands. Information needed to ensure the conservation of old-growth redwood forests has been limited. In this review paper, we integrate evidence on redwood biology with data on the historic and modern disturbance regimes to help clarify the degree to which key attributes of redwood forests may have been dependent upon periodic disturbance. Available evidence suggests that episodes of fire, flooding, and slope failure prior to European settlement were frequent but predominantly of low to moderate severity and extent, resulting in broadly uneven-aged forests. The majority of fires prior to European settlement were apparently of human origin. Frequency and severity of the major disturbance agents have been radically changed in modern times. Fires have been largely excluded, and flooding has been altered in ways that have often been detrimental to old-growth redwoods on alluvial terraces. However, because of the apparent anthropogenic origin of most presettlement fires, the long-term evolutionary role of fire for coast redwood is ecologically ambiguous. With fire exclusion, redwood possibly could be displaced to some extent on upland sites by increasing abundance of fire-sensitive competitors. Alternatively, redwood may be able to maintain dominance by vegetative sprouting and new seedling establishment on root-wad mounds, fallen logs, and on soil exposed by slope failure. Future research priorities are suggested that will help resolve some of the current ambiguities.     

The influence of perfusate volume on antimicrobial concentration in synovial fluid following intravenous regional limb perfusion in the standing horse

This study investigated the influence of perfusate volume on antimicrobial concentration in synovial fluid following intravenous regional limb perfusion (IVRLP) and assessed the efficacy of low volume IVRLP. The front limbs of 9 horses were randomly assigned to 1 of 3 volume groups: 10 mL (Group 1), 30 mL (Group 2), or 60 mL (Group 3). A tourniquet was applied distal to the carpus and the limbs were perfused with 500 mg genta-micin diluted to the assigned volume via a catheter placed in the lateral palmar digital vein at the level of the proximal sesamoid bones. Synovial fluid samples were collected from the metacarpophalangeal joint at 30 minutes, followed by removal of the tourniquet. Gentamicin concentration in synovial fluid was detected using a fluorescence polarization immunoassay. There were no statistically significant differences among gentamicin concentrations in synovial fluid among perfusate volume groups. Mean gentamicin concentration in Group 1 (125.9 μg/mL) was higher than Group 2 (82.7 μg/mL) and Group 3 (56.1 μg/mL).     

Development of diets for the intensive culture of Pacific lamprey

The Pacific lamprey Entosphenus tridentatus is an ancestral species of critical importance to the ecosystem and indigenous cultures in the Pacific Northwest. Conservation aquaculture has been proposed as a potential technique to restore Pacific lamprey populations. Intensive culture methods and diets for this species have not been developed. A sixteen week feeding trial tested the effects of seven diet treatments on the survival, growth, fatty acid profile and whole body lipid content of Pacific lamprey ammocoetes. Dietary treatments were: active dry yeast, yeast plus fish oil emulsion, micro‐algae, micro‐algae plus fish oil emulsion, yeast with micro‐algae, yeast with micro‐algae plus fish oil emulsion and yeast with larval fish diet. Each diet was offered to five replicate tanks stocked with 20 ammocoetes that were 51 days post hatch. Survival during the trial was not affected by diet. The greatest length and weight increases were in fish fed diets containing yeast. Growth decreased as the amount of algae in the diet was increased. Lipid retention was significantly higher in fish fed yeast with larval fish diet relative to the other treatments. Feed conversion ratio was lowest in fish fed diets containing yeast. Whole body fatty acid profiles tended to reflect the fatty acid profile of the diet. Percentages of 20:5n‐3 and 22:6n‐3 were significantly higher in fish fed diets containing fish oil emulsion. Overall, yeast with larval fish diet provided the best growth performance in larval Pacific lamprey.     

Effect of focused and radial extracorporeal shock wave therapy on equine bone microdamage

OBJECTIVES : To determine whether bone microcracks are altered after application of focused and radial extracorporeal shock wave therapy (ESWT) to the equine distal limb. STUDY DESIGN : An ex vivo experimental model. SAMPLE POPULATION : A contralateral limb specimen was obtained from 11 Thoroughbred racehorses with a unilateral catastrophic injury. Distal limb specimens were also obtained from 5 non-racing horses. METHODS : Three separate skin-covered bone segments were obtained from the mid-diaphysis of the metacarpus (MC3) or metatarsus (MT3). Focused (9,000 shockwaves, 0.15 mJ/mm2, 4 Hz) and radial (9,000 shockwaves, 0.175 mJ/mm2, 4 Hz) ESWT treatments were randomized to the proximal and distal segments and the middle segment was used as a treatment control for pre-existing microcracks. After treatment, bone specimens were bulk-stained with basic fuchsin and microcracks were quantified in transverse calcified bone sections. RESULTS : ESWT had small but significant effects on microcracks. Microcrack density (Cr.Dn) and microcrack surface density (Cr.S.Dn) were increased after focused ESWT, whereas Cr.Le was increased after radial ESWT. In racing Thoroughbreds, Cr.Le increased with increased number of races undertaken. Cr.Dn and Cr.S.Dn were not significantly influenced by the number of races undertaken. CONCLUSION : ESWT has small but significant effects on bone microcracking ex vivo. CLINICAL RELEVANCE : These preliminary data suggest that ESWT has the potential to increase bone microcracking in equine distal limb bone in vivo. Such effects may be more pronounced in Thoroughbreds that are actively being raced, because in vivo microcracking increases with increased number of races undertaken.     

Demonstration of antibodies to Eimeria species in lambs by an enzyme-linked immunosorbent assay

Soluble extracts were prepared from sporulated oocysts, unsporulated oocysts and merozoites of Eimeria crandallis, E faurei and E ovinoidalis. They were assessed for antigenicity and specificity by ELISA using rabbit antisera to sporulated oocysts or merozoites. Antibody levels were examined in sera from colostrum-deprived coccidia-free lambs, conventionally reared lambs and lambs which had received experimental infections. Maternal antibody was demonstrated in colostrum and in serum taken at 24 hours from all conventionally reared animals but not colostrum-deprived animals. Antibody levels in conventional animals dropped over the first five weeks of life and rose again during the next five weeks. Antibody was not detected in coccidia-free animals. Monospecific infections of E faurei or E ovinoidalis demonstrated antibody responses to primary and secondary infections. Some specificity of response was suggested with E faurei infection. The antigen preparations showed considerable cross-reactions between species. These serum antibody responses, although appearing too late for individual diagnosis, may assist diagnosis on a flock basis.     

Heart Rate Variability in Horses Engaged in Equine-Assisted Activities

Although there has been a recent surge in using horses to treat mental and emotional human health issues, the consequences of horse-assisted interventions on the stress response of horses have not been well documented. Assessment of the autonomic nervous system and its regulation of cardiovascular function has been used as an indicator of acute and chronic stress in human beings and horses. Heart rate variability (HRV) is a noninvasive measurement that has been used to assess autonomic nervous system regulation of cardiovascular function. There is evidence to suggest that several factors including the genotype, behavior, environment, temperament, and nutritional status of the horse play a key role in the large inter-individual variations in basal HRV. The present study determined whether 24-hour HRV recordings in horses currently working in equine-assisted therapy (EAT) differ from those previously shown in Thoroughbred horses. Findings from the present study found that in contrast to previous studies in Thoroughbred horses, diurnal and nocturnal low frequency and high frequency powers were not significantly different in horses that are currently engaged in EAT. Future studies are needed to determine the short- and long-term consequences of horses participating in EAT programs. Findings from this study will provide the basis for the development of a physiological/behavioral assessment criteria to determine the consequences of EAT on the well-being of horses as well as to help EAT Centers to improve the beneficial effects of EAT in human beings.