Mapping quantitative trait loci for infectious salmon anaemia resistance in a North American strain of Atlantic salmon     

Forest M. Dussault  Keng Pee Ang  James. A. K. Elliott  Brian D. Glebe  Steven Leadbeater  Anthony J. Manning  Frank Powell  Elizabeth Grace Boulding 《Aquaculture Research》2020,51(1):80-90

Infectious salmon anaemia (ISA) is a highly virulent viral disease of Atlantic salmon that causes massive economic losses to infected aquaculture operations. Our goal was to detect and map quantitative trait loci (QTL) that confer resistance to ISA in an admixed commercial strain of Atlantic salmon that was largely founded from the Saint John River (SJR) in North America. Full‐sibling families were challenged with a virulent strain of ISA virus. Mortality was tracked during two annual trials with individual fish that survived to the end of the trial being classified as ‘resistant’, and those that died were classified as ‘susceptible’. Ten families with intermediate levels of mortality and an average size of 54.2 individuals were chosen for genotyping with a 50K SNP array designed for the SJR strain. Single nucleotide polymorphisms that were segregating within families were first used to make a composite 11K female linkage map that was then used to find the positions of QTL for ISA resistance using a half‐sib model. The dam‐based HS model detected a total of three QTL for ISA resistance including an experiment‐wide significant QTL on Ssa25 that accounted for 8.3% of the phenotypic variance and chromosome‐wide significant QTL on Ssa03 and on Ssa04 that accounted for 6.0% and 6.6% respectively. We conclude that classic linkage mapping within families continues to be an important method of detecting QTL for oligogenic traits in strains founded from multiple populations. Single nucleotide polymorphisms with moderate trait effects are being used to select within families for more ISA‐resistant strains of Atlantic salmon.  相似文献   

The geographic distribution of hydatid infection in cattle in Western Australia Western Australia     

AJ LYMBERY  RCA THOMPSON  CC CONSTANTINE  JG KRUGER 《Australian veterinary journal》1995,72(11):430-432

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Changes in body weight and condition of gestating mares     

L.M. Lawrence MS  PhD  J. DiPietro DVM  MS  K. Ewert DVM  MS  D. Parrett MS  PhD  L. Moser MS  D. Powell MS 《Journal of Equine Veterinary Science》1992,12(6):355-358

Changes in body weight, condition scores, and rump fat thickness were observed in 12 mares during an entire gestation period. Mares had ad libitum access to forage (alfalfa hay or haylage) during the study. Total weight gain during gestation averaged 16% of the mares' initial body weight. The majority of weight gain occurred in the second, rather than third trimester of gestation. Only 30% of the total weight gain occurred in the third trimester of gestation. Estimates of body stores (condition score and rump fat thickness) increased during the second trimester of gestation as well. These observations suggest that the effects of pregnancy on the nutritional requirements of mares may not be confined to the last trimester of gestation.  相似文献   

Clinical and Pathological Findings in Testis, Epididymis, Deferens Duct and Prostate following Vasectomy in a Dog     

CC Pérez-Marín  R López  JM Domínguez  R Zafra 《Reproduction in domestic animals》2006,41(2):169-174

We report the case of a bilateral and multilocular spermatocele and sperm granuloma in a dog that was vasectomized 5 years before. Clinical examination revealed scrotal dermatitis and benign prostatic hyperplasia. Orchiectomy was performed, and gross and histological examination showed testicular degeneration associated with epididymal sperm granuloma. In relation to this case, the literature about long-term effects of vasectomy in dogs has been reviewed. On the basis of these results, a preventive sonogram and physical assessment in prostate and other reproductive structures before vasectomy is recommended.  相似文献   

Oestrus Expression and Ovarian Function in Repeat Breeder Cows, Monitored by Ultrasonography and Progesterone Assay   总被引：1，自引：0，他引：1  

CC Pérez-Marín  F España 《Reproduction in domestic animals》2007,42(5):449-456

Ovarian ultrasonography and plasma progesterone levels were monitored in 37 lactating Holstein cows with a history of repeat breeding; the data obtained were analysed in conjunction with clinical and behavioural signs, to identify the aetiology of the syndrome. Differences were detected between RBCs displaying apparently normal cycles and others with irregular cycles. There were also differences in heat expression; a large number of repeat breeder cows (RBCs, 50%) displayed delayed or silent oestrus. Ovarian disorders were common in RBCs, and included ovarian cysts, mistimed AI, subluteal progesterone levels, luteal dysfunction or ovulation defects. Both ultrasonography and plasma progesterone assays are useful tools for ascertaining the aetiology of the repeat breeder syndrome.  相似文献   

Effect of serum-free co-culture and synchrony of recipients on development of cultured sheep embryos to fetuses   总被引：1，自引：0，他引：1  

C E Rexroad  A M Powell 《Journal of animal science》1991,69(5):2066-2072

The percentage of sheep embryos that continued to develop after collection and immediate transfer on d 2 after estrus was similar when phosphate-buffered saline with 10% fetal calf serum (PBSFCS, 45%), physiological saline (50%), or tissue culture medium 199 supplemented with 10% fetal calf serum (M199FCS, 47%) was used to flush embryos from oviducts. Co-culture of sheep embryos for 3 d with oviductal cells tended (P = .1) to reduce the percentage of embryos that developed to fetuses after transfer compared with those embryos transferred immediately. Tissue culture medium 199 supplemented with .3% BSA (M199BSA) was an adequate substitute for M199FCS for culture of sheep oviductal cells if tissue culture wells were pretreated with fibronectin. Estradiol in concentrations from 10 to 1,000 pg/ml and progesterone at concentrations of 1 or 10 ng/ml in M199BSA failed to stimulate embryo development during 3 d of co-culture beyond that seen in co-culture with M199FCS or M199BSA without added steroid. Transfer of sheep embyros co-cultured for 3 d in M199BSA or M199FCS to recipients synchronized with donors resulted in about 19% of the embryos developing to fetuses, whereas transfer to recipients that were in estrus 24 h after donors resulted in 33% of embryos developing to fetuses. The significant (P less than .05) improvement for delayed recipients may reflect the relatively lesser developmental rate of co-cultured embryos compared with that of embryos in vivo. Embryo development into fetuses was similar after co-culture in M199FCS or M199BSA co-cultures; therefore, serum is not required for the co-culture of sheep embryos.  相似文献   

Expornitic of avian pox in a zoo.     

P K Ensley  M P Anderson  M L Costello  H C Powell  R Cooper 《Journal of the American Veterinary Medical Association》1978,173(9):1111-1114

During a 6-week period at the San Diego Zoo, avian pox occurred in 9 pheasants representing 5 species. Lesions were limited to facial skin and consisted of epithelial cell hyperplasia, secondary inflammatory changes, and intracytoplasmic eosinophilic inclusion bodies which, by electron microscopy, were shown to contain pox virus. The disease was self-limiting in 7 pheasants, but 2 pheasants died. Free-ranging Indian red junglefowl were implicated as the source of the infection.  相似文献   

Effect of short-term feed restriction and calorie source on hormonal and metabolic responses in geldings receiving a small meal     

Powell DM  Lawrence LM  Fitzgerald BP  Danielsen K  Parker A  Siciliano P  Crum A 《Journal of animal science》2000,78(12):3107-3113

The metabolic effects of short-term feed restriction and dietary calorie source were studied in horses receiving high-roughage or high-concentrate diets. Four Thoroughbred geldings were assigned to four treatment groups in a 4 x 4 Latin square experiment. The four treatments were 1) a nutritionally adequate high-roughage ration (70% roughage, 30% concentrate; AHR), 2) a nutritionally adequate high-concentrate ration (40% roughage, 60% concentrate; AHC), 3) 70% of the intake of the AHR diet (RHR), and 4) 70% of the intake of the AHC diet (RHC). Diets AHR and AHC were designed to meet the caloric need of horses undergoing moderately intense work. Blood samples were taken on the first 7 d of each period for analysis of serum T4 and T3 concentrations. On d 9 of each feeding period, each horse was fed 1.0 kg of oats as the morning meal. Jugular blood was sampled before and immediately after, as well as at 30 min after, completion of the meal and subsequently every hour for 7 h. Daily serum T4 and T3 concentrations were not affected by day, feeding level, or diet composition. Meal feeding produced an increase (P < 0.01) in T4 and T3 concentrations when horses were adapted to the AHR and AHC diets but not the RHR or RHC diets. Thyroxine concentrations were lowest (P < 0.05) when horses were adapted to the AHC diet. Glucose (P < 0.05), insulin (P < 0.01), and NEFA (P < 0.01) concentrations were higher in response to the meal when horses received RHR than for the other diets. These results indicate that nutrient restriction alters responses to meal feeding in horses and that this response may also be affected by the dietary roughage:concentrate ratio.  相似文献   

Principles for regulatory testing and interpretation of semi-field and field studies with non-target arthropods     

Candolfi M.  Bigler F.  Campbell P.  Heimbach U.  Schmuck R.  Angeli G.  Bakker F.  Brown K.  Carli G.  Dinter A.  Forti D.  Forster R.  Gathmann A.  Hassan S.  Mead-Briggs M.  Melandri M.  Neumann P.  Pasqualini E.  Powell W.  Reboulet J. -N.  Romijn K.  Sechser B.  Thieme Th.  Ufer A.  Vergnet Ch.  Vogt H. 《Anzeiger für Sch?dlingskunde》2000,73(6):141-147

This paper is a guidance document for side-effect testing with plant protection products on non-target arthropods under semi-field and field conditions. The principles, methods, endpoints and interpretation of non-target arthropod semi-field and field trials which should be conducted for registration of plant protection products in the European Union are presented and discussed. The recommendations presented reflect the opinions of the experts from authority, academia, industry and consulting which participated at the IOBC (International Organisation of Biological Control), BART (Beneficial Arthropod Regulatory Testing) group and EPPO (European Plant Protection Organisation) Joint Initiative workshop held in Versailles (France) on the 25–26 October, 1999.  相似文献   

The effects of kaolin particle film on Plutella xylostella behaviour and development     

Barker JE  Fulton A  Evans KA  Powell G 《Pest management science》2006,62(6):498-504

Studies were conducted to evaluate the effect of a kaolin-based particle film against the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae). The effect of the particle film on development, survival and host plant selection was tested on calabrese seedlings, Brassica oleracea italica Plenck cv. Fiesta F(1), under controlled environmental conditions in the laboratory. Survival to adulthood was significantly reduced and development time increased on kaolin-treated compared with water-treated host plants. The hatch rate of neonate P. xylostella larvae from eggs laid on an artificial substrate was unaffected by the particle film applied after oviposition. Experiments showed that, when given the choice, significantly fewer larvae first made contact with the kaolin-treated compared with the water-treated plant material and that after 24 h there were still significantly fewer larvae present on kaolin-treated leaves. Adult females, however, deposited more eggs on host plants coated with the kaolin particle film. As part of this series of experiments the water control treatment was compared with plant material which had been sprayed with kaolin on the upper surface only and on both leaf surfaces. In general, any observed treatment effect was enhanced with an increase in the particle film coverage. The results warrant the extension of investigations of kaolin-based particle films to field-based P. xylostella management strategies.  相似文献