Impacts of Bolbophorus damnificus (Digenea: Bolbophoridae) on Production Characteristics of Channel Catfish,Ictalurus punctatus,Raised in Experimental Ponds     

David J. Wise  Menghe H. Li  Matt J. Griffin  Edwin H. Robinson  Lester H. Khoo  Terrence E. Greenway  Todd S. Byars  Josh R. Walker  Charles C. Mischke 《Journal of the World Aquaculture Society》2013,44(4):557-564

Bolbophorus damnificus was recognized as a threat to channel catfish, Ictalurus punctatus, production in Louisiana and Mississippi in 1997 and 1999, respectively. Severe to moderate outbreaks (≥34% prevalence) are correlated to heavy losses, but impact of mild outbreaks with low prevalence (<33%) was unknown. Laboratory and field studies were conducted to evaluate sublethal acute (early stage) and chronic (late stage) trematode infection impacts on catfish production. Fish raised in ponds seeded with ram's horn snails from ponds harboring active B. damnificus outbreaks resulted in infection prevalence ranging from 1.6 to 20.4%. Compared to fish raised in ponds not seeded with infected snails (0% prevalence), fish biomass, number harvested, and total feed fed were significantly lower. These data agree with previous studies where mild infections reduced feed consumption, fish production, and economic returns. Infected fish were collected from ponds and used in a laboratory growth study. Once removed from the infection source, weight gain, growth rate, feed consumption, and feed efficiency were equal to or greater than trematode‐free fish. This suggests that although early B. damnificus infection (premetacercarial development) can severely impact production, infection has little impact on performance once metacercarial cysts are fully developed, and the infection source is removed.  相似文献   

Immunization against 5α-androstenone in boarsL'immunisation contre la 5-androsténone chez le verratImmunisierung gegen 5α-Androstenon in Ebern     

E.D Williamson  R.L.S Patterson  E.R Buxton  K.G Mitchell  I.G Partridge  N Walker 《Livestock Production Science》1985,12(3):251-264

The effects of specific immunization against 5α-androstenone have been examined in large, genetically homologous groups of boars reared either to bacon weight (90–95 kg live weight) or to heavy manufacturing weight (115–120 kg live weight). At the lighter weight, immunization significantly (P < 0.05) reduced the concentration of androstenone in the adipose tissue from a mean value of 1.77 (S.E. 0.2) μg g^?1 fat in untreated boars (n=39) to 1.10 (S.E. 0.18) μg g^?1 for animals (n=19) treated with 5α-androstene-3-BSA. In contrast, boars (n=20) treated with 5α-androstenone-11-BSA as immunogen accumulated androstenone to a level of 1.99 μg g^?1 fat (S.E. 0.38). At the heavier weight, immunization reduced the accumulation of androstenone in adipose tissue from a mean value of 1.81 μg g^?1 fat (S.E. 0.22) in untreated boars (n=76) to 1.17 μg g^?1 (S.E. 0.19) for animals (n=22) treated with androstene-3-BSA as immunogen. In contrast, boars (n=21) treated with androstenone-11-BSA as immunogen accumulated androstenone to a mean level of 1.74 μg g^?1 fat (S.E. 0.46). No detrimental side-effects were observed in the immunized animals and the advantages of male-type performance and carcass composition were fully preserved.  相似文献   

Effect of level of intake and supplemental barley on marker estimates of fecal output using an intraruminal continuous-release chromic oxide bolus     

P G Hatfield  J W Walker  H A Glimp  D C Adams 《Journal of animal science》1991,69(4):1788-1794

Sixty wethers (average BW = 45 kg) fitted with fecal collection bags were used in four experiments to evaluate the ability of a intraruminal continuous-release chromic oxide bolus to predict fecal DM output. In Exp. 1, 18 wethers housed in metabolism crates were fed barley at either 0, 100, or 200g/d and allowed ad libitum consumption of alfalfa pellets. In Exp. 2, 18 wethers were housed in metabolism crates and fed alfalfa pellets at either 70, 85, or 125% of pre-study ad libitum consumption. In Exp. 3, 12 wethers grazed a sagebrush-bunchgrass range and were individually fed barley at 0 or 200 g/d. In Exp. 4, 12 wethers grazed either an ungrazed (383 kg/ha herbaceous biomass) or a heavily grazed (175 kg/ha herbaceous biomass) sagebrush-bunchgrass range. Experiments 1 and 2 were balanced 3 x 3 Latin squares, and Exp. 3 and 4 were crossover designs. Chromium content was determined in rectal grab samples. Treatment effects were compared using marker-estimated fecal output divided by total fecal collection, multiplied by 100, as the dependent variable. Accuracy of the estimate was verified by comparing marker-estimated fecal output with total fecal collection using a paired t-test. In Exp. 1 and 2, treatments were different (P less than .05). No differences (P greater than .50) were detected in Exp. 3 and 4. In Exp. 1, 2, and 3 accuracy was different (P less than .02) among wethers within study and treatment. Only in Study 4 were minor or no differences (P greater than .09) in accuracy found.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

Strangles in horse studs: incidence, risk factors and effect of vaccination     

JK FAIRLEY 《Australian veterinary journal》1991,68(8):282-283

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Changes in productivity and profitability of wool-growing farms that follow recommendations from agricultural and veterinary studies     

GR LEAN  AL VIZARD  JK WEBB WARE 《Australian veterinary journal》1997,75(10):726-731

Objective To estimate the changes in productivity and profitability in a group of wool-growing farms as they adopted major recommendations from agricultural and veterinary studies.
Farms Four wool-growing farms in south western Victoria were selected from the clients of the Mackinnon Project, a farm consultancy service run from the University of Melbourne. Each farm had closely followed recommended procedures, kept comprehensive financial and physical records and had been clients for at least 5 years. The comparison group was the South Western Victoria Monitor Farm Project (SWVMFP), about 45 farms in the same region as the study farms that were monitored annually by Agriculture Victoria.
Procedure For a 7-year period, the financial and physical performance of both groups of farms was estimated. Stocking rate, wool production, gross farm income, farm operating costs, net farm income and return on assets were compared.
Results Mean gross farm income of the four study farms steadily rose from 86% of the average SWVMFP farm before the adoption of recommendations to an average of 155%. During the same period, net farm income rose from 70% to 207% of the average of the SWVMFP. Return on asset of the four farms rose irregularly from 26% to 145% of the average of the SWVMFP. Farm operating costs on the four farms were higher than for the SWVMFP group, but the ratio of costs remained relatively constant.
Conclusion The adoption of proven research results was associated with large increases in net farm income. An increase in gross income, rather than a reduction in costs was the main reason for this. Research results offer a way to increase the financial viability of wool-growing farmers, many of whom are currently unable to maintain their lifestyle, resources and infrastructure.  相似文献   

Identification of trichomonadid protozoa from the bovine preputial cavity by polymerase chain reaction and restriction fragment length polymorphism typing.     

Dawn C Hayes  Rebecca R Anderson  Richard L Walker 《Journal of veterinary diagnostic investigation》2003,15(4):390-394

Accurate identification of the bovine pathogen Tritrichomonas foetus is sometimes complicated by the presence of other trichomonadid protozoa in clinical samples. A highly specific and reproducible approach for differentiating 3 common types of bovine trichomonadid protozoa found in the bovine preputial cavity, T. foetus, Pentatrichomonas hominis, and a Tetratrichomonas species, was developed using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis. Universal trichomonadid protozoa primers, TFR1 and TFR2, were used to amplify the 5.85 rRNA gene and internal transcribed spacer regions (ITSRs), and the products were digested with the restriction enzyme HpyCH4IV. Restriction fragment length polymorphism analysis was performed on 55 trichomonad isolates from bovine preputial washing and scraping samples. The RFLP results correlated 100% with 5.85 rRNA gene and ITSR sequence resultsand PCR results with primers specific for T. foetus. The results of this study demonstrate that PCR and RFLP analysis can be used in lieu of DNA sequencing to identify the specific trichomonadid protozoa isolated from the bovine preputial cavity.  相似文献   

Heart failure caused by gossypol poisoning in two dogs     

C S Patton  A M Legendre  R E Gompf  M A Walker 《Journal of the American Veterinary Medical Association》1985,187(6):625-627

Two hound-type dogs from the same kennel were admitted in terminal stages of congestive heart failure. An investigation revealed the owner had been feeding the dogs cottonseed meal daily with their kibbled meal. Gossypol toxicosis from feeding this meal caused marked abnormalities in myocardial contractility. Although in severe congestive heart failure, one dog had only minimal dilatation of its heart, as revealed by thoracic radiography. Disseminated intravascular coagulopathy also was diagnosed in this dog. Gossypol is a cumulative toxin; the amount of free gossypol fed was approximately 5.4 to 5.7 mg/kg/day for an unknown duration.  相似文献   

Effects of intraoperative irradiation on gastric and urinary bladder incisions in the dog     

J A Craig  R Sigler  M Walker 《American journal of veterinary research》1985,46(8):1647-1652

Fourteen adult dogs of mixed breeding were given intraoperative irradiation (25 Gy) after surgical incisions were made into the greater curvature of the stomach and the ventral surface of the urinary bladder. Sequential biopsy samples were obtained 10 days to 180 days after surgical operation. All irradiated stomachs developed gastritis and persistent ulceration of the irradiated field. Microscopic changes induced by irradiation of both the bladder and stomach progressed from severe submucosal edema to severe submucosal fibrosis. A parallel progression of fibrinoid degeneration of the small blood vessels was seen in both organs. Severe gastric ulceration persisted up to 180 days after irradiation, although a degree of mucous neck cell and gastric gland regeneration did occur. Pathologic changes were less severe in the bladder than in the stomach. The bladder had greater resiliency and capability for healing and, in contrast to the stomach, showed a capability to reepithelialize the radiation-induced ulcers. Conclusions of this study are as follows: (a) the canine urinary bladder tolerated intraoperative radiation therapy after tissue resection better than did the canine stomach, (b) the combination of surgical operation and irradiation resulted in a more prolonged and complicated healing pattern than did either procedure alone, and (c) the introduction of a surgical procedure upon irradiated tissue within an undetermined time span relative to irradiation resulted in a similar pattern of disturbed healing.  相似文献   

Sublingual administration of buprenorphine for long-term analgesia in the horse     

Walker AF 《The Veterinary record》2007,160(23):808-809

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Ontario courts award compensation for emotional distress associated with the loss of a pet          下载免费PDF全文

Walker AF 《The Canadian veterinary journal. La revue veterinaire canadienne》2007,48(9):967-969

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