Evaluation of Three Feeds for Hatchery Rearing Channel Catfish Fry     

Edwin H.  Robinson  JamesA.  Steeby  J. Robert  Brent 《Journal of the World Aquaculture Society》1989,20(4):256-260

Two 7 day feeding trials were conducted with channel catfish swim-up fry to evaluate growth, feed conversion ratio, and body composition of fish fed one of the following feeds: salmon starter, catfish starter, or trout starter. Fish fed the salmon or trout starter feeds gained 50–75% more weight, converted feed more efficiently, and had higher body fat stores than fish fed the catfish starter feed. This may be related to the higher protein and energy content of these two feeds. It may be advantageous to feed salmonid starter feeds to hatchery reared catfish fry; however, it is not known whether or not the improved performance observed in the hatchery continues once the fish are stocked into nursery and grow out ponds.  相似文献   

Detection and genetic diversity of porcine rotavirus A,B and C in eastern Australian piggeries     

B Genz  J Gerszon  Y Pollock  B Gleeson  R Shankar  MJ Sellars  RJ Moser 《Australian veterinary journal》2023,101(4):153-163

Rotaviruses (RV) have a high prevalence in piggeries worldwide and are one of the major pathogens causing severe diarrhoea in young pigs. RV species A, B, and C have been linked to piglet diarrhoea in Australian pig herds, but their genetic diversity has not been studied in detail. Based on sequencing of the structural viral protein 7 (VP7) RVA G genotypes G3, G4 and G5, and RVC types G1, G3, G5, and G6 have been identified in Australian piggeries in previous studies. Although occurrence of RVB was reported in Australia in 1988, no further genetic analysis has been conducted. To improve health management decisions in Australian pig herds, more information on RV prevalence and genetic diversity is needed. Here, 243 enteric samples collected from 20 pig farms within Eastern Australia were analysed for the presence of RV in different age groups using a novel PCR-based multiplex assay (Pork MultiPath™ enteric panel). RVA, RVB, and RVC were detected in 10, 14, and 14 farms, respectively. Further sequencing of VP7 in selected RV-positive samples revealed G genotypes G2, G5, G9 (RVA), G6, G8, G14, G16, G20 (RVB), and G1, G3, G5, G6 (RVC) present. RVA was only detected in young (<10 weeks old) pigs whereas RVB and RVC were also detected in older animals (>11 weeks old). Interestingly, RVB and RVC G-type occurrence differed between age groups. In conclusion, this study provides new insights on the prevalence and diversity of different RV species in pig herds of Eastern Australia whilst demonstrating the ability of the Pork MultiPath™ technology to accurately differentiate between these RV species.  相似文献   

Effect of Arthroscopic Lavage on Systemic and Synovial Fluid Serum Amyloid A in Healthy Horses          下载免费PDF全文

Andres F. Sanchez‐Teran  José L. Bracamonte  Steven Hendrick  Hilary J. Burguess  Tanya Duke‐Novakovski  Monica Schott  Brent Hoff  Luis M. Rubio‐Martínez 《Veterinary surgery : VS》2016,45(2):223-230

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Spontaneous femoral capital physeal fractures in adult cats: 26 cases (1996-2001)     

McNicholas WT  Wilkens BE  Blevins WE  Snyder PW  McCabe GP  Applewhite AA  Laverty PH  Breur GJ 《Journal of the American Veterinary Medical Association》2002,221(12):1731-1736

OBJECTIVE: To determine clinical, radiographic, and histologic abnormalities in adult cats > 1 year old with spontaneous (ie, nontraumatic) femoral capital physeal fractures. DESIGN: Retrospective study. ANIMALS: 26 cats. PROCEDURE: Medical records of cats > 1 year old with femoral capital physeal fractures and no history of trauma were examined. RESULTS: Mean +/- SD age of the cats was 22.5 +/- 6.5 months. Twenty-five cats were neutered males. Mean weight of the cats was significantly greater than mean weight of a group of age- and sex-matched control cats. Of 16 cats for which age at the time of neutering was known, 14 had been neutered before 6 months of age. Nine cats had bilateral fractures. Severity of femoral neck osteolysis and sclerosis increased with increased duration of clinical signs. The contralateral femoral capital physis, distal femoral physes, and proximal tibial physes were radiographically open in 13 of 18,19 of 24, and 24 of 24 cats, respectively. Histologically, the epiphysis contained normal articular cartilage and bone, but attached growth plate cartilage lacked the normal columnar arrangement of chondrocytes. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that adult cats with spontaneous femoral capital physeal fractures were most likely to be heavier, neutered males with delayed physeal closure.  相似文献   

Live Transport of Striped Bass and Rainbow Trout Using a Hidrostal Pump     

Louis A.  Helfrich Raymond  Bark Charles R.  Liston D. L. Weigmann  Brent  Mefford 《Journal of the World Aquaculture Society》2004,35(2):268-273

Immediate and delayed (96 h) mortality, descaling, and injury rates of striped bass Morone sax-atilis and rainbow trout Oncorhynchus mykiss that were inserted into the entrance (suction side) of a Hidrostal pump were compared to those of control fish that were inserted at the exit (pressure side). Comparisons were made in 158-paired trials of striped bass and 86 trials with rainbow trout. The Hidrostal pump had no significant effect on immediate or delayed (96 h) mortality. Immediate mortality for striped bass and rainbow trout averaged 0.1 and 0%, respectively, and delayed mortality averaged 2.9 and 0.1%, respectively. Mean scale loss after passage for striped bass and rainbow trout was low (0.2 and 1.0%, respectively). Frequency of injury to the head, eyes, skin, and tins of pumped striped bass averaged 1.9, 2.8, 1.9, and 18.7%, respectively, and those of rainbow trout averaged 2.3, 0, 2.4, and 3.1%. No significant relationships were detected between fish mortality and pump speed, injected fish density, and debris load. Results suggest that large Hidrostal pumps have the capacity to transport live striped bass and rainbow trout at high density (1-6 fish/L) with little mortality and body injury.  相似文献   

Analyses of assumptions and errors in the calculation of stomatal conductance from sap flux measurements     

Ewers BE  Oren R 《Tree physiology》2000,20(9):579-589

We analyzed assumptions and measurement errors in estimating canopy transpiration (E(L)) from sap flux (J(S)) measured with Granier-type sensors, and in calculating canopy stomatal conductance (G(S)) from E(L) and vapor pressure deficit (D). The study was performed in 12-year-old Pinus taeda L. stands with a wide range in leaf area index (L) and growth rate. No systematic differences in J(S) were found between the north and south sides of trees. However, J(S) in xylem between 20 and 40 mm from the cambium was 50 and 39% of J(S) in the outer 20-mm band of xylem in slow- and fast-growing trees, respectively. Sap flux measured in stems did not lag J(S) measured in branches, and time and frequency domain analyses of time series indicated that variability in J(S) in stems and branches is mostly explained by variation in D. Therefore, J(S) was used to estimate transpiration, after accounting for radial patterns. There was no difference between D and leaf-to-air vapor pressure gradient, and D did not have a vertical profile in stands of either low or high L suggesting a strong canopy-atmosphere coupling. Therefore, D estimated at one point in the canopy can be used to calculate G(S) in such stands. Given the uncertainties in J(S), relative humidity, and temperature measurements, to keep errors in G(S) estimates to less than 10%, estimates of G(S) should be limited to conditions in which D >/= 0.6 kPa.  相似文献   

Contribution of the natural biota associated with substrates to the nutritional requirements of the post-larval shrimp, Penaeus esculentus (Haswell), inhigh-density rearing systems     

Michele A Burford  Melony J Sellars  Stuart J Arnold  Sandy J Keys  Peter J Crocos  & Nigel P Preston 《Aquaculture Research》2004,35(5):508-515

The contribution of epiphytes associated with physical substrates to the nutritional requirements of post‐larval shrimp, Penaeus esculentus Haswell, was determined in high‐density rearing systems (3000, 6000 and 11 000 m^?3). Stable isotope signatures of epiphytes on polyethylene mesh substrate, AquaMats? and tank walls were compared with shrimp signatures. Two methods were used: the determination of carbon and nitrogen natural abundance ratios; and ¹⁵N‐nitrogen enrichment ratios after the addition of ¹⁵N‐ammonium to tanks. Using the natural abundance technique and a simple mixing model, epiphytes were found to contribute substantially to the carbon requirements of post‐larval shrimp (39–53%). This was despite the addition of formulated feed at satiation levels. There was no indication of a reduced contribution of carbon from epiphytes to shrimp nutrition at higher shrimp densities. The lack of a difference in the ¹⁵N/¹⁴N ratios of the two food sources meant that mixing models could not be used to calculate the contribution of nitrogen from epiphytes vs. artificial feed to shrimp nutrition. Using the ¹⁵N‐nitrogenenrichment method, the amount of nitrogen contributed by epiphytes to shrimp nutrition over 24 h could be determined. This method showed that nitrogen from epiphytes was assimilated by shrimp. ¹⁵N‐enrichment methods provided a more accurate alternative to natural abundance techniques, particularly when the stable isotope signals ofthe food sources are similar. This experiment hasshown the benefits in providing substrates for P.esculentus in high‐density rearing systems to provide an additional food source for shrimp.  相似文献   

Optimal chemical triploid induction in geoduck clams, Panopea abrupta, by 6-dimethylaminopurine     

Brent Vadopalas  Jonathan P. Davis   《Aquaculture (Amsterdam, Netherlands)》2004,230(1-4):29-40

The development of geoduck culture techniques coupled with increased market demand during the past decade led to cultured intertidal geoduck beds, over which concerns have arisen regarding the potential genetic risk posed by the reproductive contribution of hatchery outplants to wild stocks. Although an ongoing study to determine the genetic stock structure of Puget Sound geoducks has yet to yield definitive results, sterile triploids would enable geoduck culture to proceed irrespective of any genetic differences found, and may increase rate of growth. At 15 °C and salinity of 30‰, we evaluated the suitability of cytochalasin B (CB) and 6-dimethylaminopurine (6-DMAP) for triploid induction in geoducks. Parallel tests of induction agent, start time, duration, and concentration were conducted on the same gamete pool. We found optimal triploid induction (92%) and suitable survivorship (30%) resulted from a 600 μM 6-DMAP treatment. This work enables the future examination of the efficacy of triploid induction for conferring sterility and increasing growth rate in this commercially valuable species.  相似文献   

Efficacy of an equal blend of canola oil and poultry fat as an alternate dietary lipid source for Atlantic salmon (Salmo salar L.) in seawater. II: effects on haematology and immunocompetence   总被引：1，自引：0，他引：1  

Shannon K Balfry  Janice Oakes  Mahmoud Rowshandeli  Greg Deacon  Brent J Skura  & David A Higgs 《Aquaculture Research》2006,37(2):192-199

This research examined the haematological and immunological responses of quadruplicate groups of juvenile (～400 g initial weight) Atlantic salmon (Salmo salar L.) that had each been fed daily to satiation for 12 weeks one of three high‐energy extruded diets of identical composition except for the supplemental dietary lipid (234.7 g kg^?1) source. The three experimental diets varied in the composition of supplement lipid; diet 1 contained 100% anchovy oil (AO), while diets 2 and 3 replaced 29.8% and 59.7% of the AO (respectively) with a 1:1 blend of canola oil (CO) and poultry fat (PF). Immediately following the feeding trial, a random sample of fish from each diet was sampled for determination of baseline levels of various haematological and immunological parameters. Thereafter, duplicate diet groups were vaccinated (against Listonella anguillarum) and reared on their respective experimental diets for an additional 4 weeks. At that time, the remaining fish were sampled similarly, and the different parameters were measured again. Comparisons between the different diet treatment groups were made before and after vaccination. There were no significant diet treatment effects at either sample time, for haematocrit, differential leucocyte counts, erythrocyte counts, serum hemolytic activity or head kidney leucocyte respiratory burst activity. The fish fed diet 1 however, did show significantly higher post‐vaccination levels of peripheral blood leucocyte respiratory burst activity and higher serum antibody titres against L. anguillarum. The results suggest that the relatively low n‐6/n‐3 fatty acid ratios in the muscle and presumably other tissues of fish fed diet 1, may have resulted in a reduced production of immunocompromising eicosanoids than were produced in fish ingesting the other two diets that were based in part on the different amounts of the CO and PF blend. Long‐term studies are required to confirm this possibility.  相似文献   

Triploid induction in Penaeus japonicus (Bate) with 6-dimethylaminopurine     

Belinda J Norris  Frank E Coman  Melony J Sellars  & Nigel P Preston 《Aquaculture Research》2005,36(2):202-206

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