Mycoplasma hyopneumoniae colonization of pigs sired by different boars          下载免费PDF全文

Alvaro Ruiz  Lucina Galina    Carlos Pijoan 《Canadian journal of veterinary research》2002,66(2):79-85

Differences in Mycoplasma hyopneumoniae colonization were evaluated in experimentally inoculated pigs sired by 3 different boars of the same genetic line. Forty-six pigs were used, including a treatment group and positive and negative control groups. The pigs were intratracheally inoculated with an M. hyopneumoniae suspension or with Friis media as a placebo. To evaluate differences in the magnitude of colonization during a 35-day period, nasal and tracheal swabs were collected weekly and tested by nested polymerase chain reaction (N-PCR). Temperature, weight and circulating antibodies were measured for 35 days. At 11 and 35 d postinoculation the pigs were necropsied and macroscopic and microscopic lesions were determined. A section of bronchus was tested by the indirect immunofluorescence test (IFAT), scanning electron microscopy (SEM) and N-PCR. The N-PCR results from the nasal and tracheal swabs showed that the pigs sired by one boar (B3) had a distinctive colonization pattern, different from that of the pigs from the other 2 boars and from the positive controls. SEM studies demonstrated that at 35 d postinoculation a higher proportion of B3 pigs had lower numbers of mycoplasmas attached to the cilia compared with B1 and B2 offspring. No significant differences were observed in temperature and weight gain among groups by ANOVA; however, with use of a 2 × 2 table, temperature differences were observed between pigs sired by boars B1 and B2 at 4 d postinoculation. No pigs seroconverted, showed gross or microscopic lesions, or had positive IFAT results. These results provide evidence of differences in patterns of colonization between pigs sired by different boars, suggesting a possible genetic effect.  相似文献   

动物养殖业所面临的挑战和机会(续)     

Jon Ratcliff 《饲料广角》2001,(17):23-24

内部的挑战和机遇 生产和均一性 挖掘遗传的潜力,也就是繁殖性能或生长的潜力,对于动物养殖业来说是一个连续的挑战。营养通常不是限制的因素。然而,营养学家和养殖者承担这一挑战。为了最大程度地发挥动物的生产性能的潜力,高精确度的分析技术,包括DNA排列顺序,使我们能够充分了解和分析胃肠  相似文献   

Analysis of In vitro Fertilizing Capacity to Evaluate the Freezing Procedures of Boar Semen and to Predict the Subsequent Fertility     

E Sellés  J Gadea  R Romar  C Matás  S Ruiz 《Reproduction in domestic animals》2003,38(1):66-72

A porcine in vitro fertilization (IVF) system and seminal quality parameters of frozen–thawed boar semen were used to assess the effectiveness of two different thawing rates of frozen boar semen, and to address the question of whether differences between fertility of ejaculates could be predicted in a limited field trial. In the first experiment, two thawing procedures were analysed (37°C, 30 s; 50°C, 12 s) and no differences in sperm quality were found. However, when the procedure was 50°C, 12 s the IVF results showed a higher number of sperm per penetrated oocyte and a near 10 points higher rate of pronuclear formation. In the second experiment, the fertility results obtained in the limited field trial show to be efficient enough for application in a commercial use, especially for three of the employed boars (fertility ≥80%). In this limited study, the conventional seminal parameters are not accurate enough to discriminate good and bad boars in relation to fertility. On the contrary, parameters of in vitro penetrability are more precise to predict subsequent fertilities. As conclusion, the IVF fertilization system seems to be a good tool to evaluate the quality of frozen–thawed boar semen previous to its commercial way, to verify the bank semen storage quality and a good way to assay new sperm freezing procedures, as it is the more precise evaluating method in estimating the potential fertilizing ability.  相似文献   

动物养殖业所面临的挑战和机会（续）     

Jon Ratcliff 《饲料广角》2001,(18):24-25

(上接第17期) 霉菌毒素的污染 饲料原料和垫草受到霉菌毒素污染的现象在亚太地区是广泛存在的(Leeson等,1995).亚太的大部分地区属于高温湿热的气候,这给霉菌的生长与繁殖以及产生霉菌毒素提供了有利的条件.由于全球极端的气候条件以及饲料原料的进口,通常没有霉菌毒素问题的国家,如澳大利亚,现在也不得不考虑预防霉菌毒素的问题.人们常常误解:"霉菌毒素是一个季节性的问题".  相似文献   

Paraprotein-induced defective haemostasis in a dog with IgA (kappa-light chain) forming myeloma     

Ruiz De Gopegui R  Espada Y  Vilafranca M  Cuadradas C  Fontcuberta E  Millá F  Roncalés J  Ruzafa A 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》1994,23(3):70-71

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Puberty in beef heifers. III. Induction of fertile estrus.     

E Gonzalez-Padilla  R Ruiz  D LeFever  A Denham  J N Wiltbank 《Journal of animal science》1975,40(6):1110-1118

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Caprine toxoplasmosis in Southern Brazil: a comparative seroepidemiological study between the indirect immunofluorescence assay,the enzyme-linked immunosorbent assay,and the modified agglutination test     

Fortes  Maira Salomão  Lopes-Mori  Fabiana Maria Ruiz  Caldart  Eloiza Teles  Constantino  Caroline  Evers  Fernanda  Pagliari  Sthefany  de Almeida  Jonatas Campos  Barros  Luiz Daniel  Freire  Roberta Lemos  Garcia  João Luis  Headley  Selwyn Arlington  Navarro  Italmar Teodorico 《Tropical animal health and production》2018,50(2):413-419

Tropical Animal Health and Production - This study investigated the prevalence of caprine toxoplasmosis in goat herds from Southern Brazil by the indirect immunofluorescence assay (IFA), and...  相似文献   

Physiological Response of Multiple Contrasting Rice (Oryza sativa L.) Cultivars to Suboptimal Temperatures          下载免费PDF全文

M. M. Rachoski  A. Vidal  O. A. Ruiz  A. B. Menéndez  A. A. Rodríguez 《Journal of Agronomy and Crop Science》2015,201(2):117-127

The physiological response of multiple rice cultivars, eighteen initially and eight cultivars later on, to suboptimal temperatures (ST) conditions was investigated in laboratory and outdoor experimental conditions. Treatment with ST decreased growth in different extents according to the cultivar and affected the PSII performance, determined by chlorophyll fluorescence fast‐transient test, and stomatal conductance, regardless the experimental condition. Two groups of cultivars could be distinguished on the base of their growth and physiological parameters. The group of cultivars presenting higher growths displayed optimal JIP values, and higher instantaneous water use efficiency (WUE_i), due to a lower Gs under ST, unlike cultivars showing lower growth values, which presented worse JIP values and could not adjust their Gs and hence their WUE_i. In this work, we detected at least two cultivars with superior tolerance to ST than the cold tolerant referent Koshihikari. These cultivars could be used as parents or tolerance donors in breeding for new crop varieties. On other hand, positive and significant correlations between data obtained from laboratory and outdoor experiments suggest that laboratory measurements of most of the above mentioned parameters would be useful to predict the response of rice cultivars to ST outdoor.  相似文献   

Effect of Stocking Density on Growth,Survival, and Condition of the Mexican Cichlid Cichlasoma beani     

Edgar A. Aragon‐Flores  Edna F. Valdez‐Hernandez  Leonardo Martinez‐Cardenas  Maria R. Castaeda‐Chavez  Alfonso A. Gonzales‐Diaz  Miriam Soria‐Barreto  Javier M. J. Ruiz‐Velazco  Emilio Pea‐Messina 《Journal of the World Aquaculture Society》2014,45(4):447-453

The Mexican cichlid Cichlasoma beani is currently exploited regionally as food and can be commercialized in the aquarium trade. Natural populations of C. beani may already be negatively affected by anthropogenic alteration of the areas in which it is distributed. The aim of the present study was to examine the effect on growth, survival, and condition of C. beani cultured in three stocking densities: three (D3), six (D6), and nine (D9) fish per each 40 L tank. At the end of a 6‐wk trial the fish cultured in D3 were longer, heavier, and grew faster than the rest of the treatments but their survival was the lowest compared to D6 and D9. The mortalities were caused by a strong aggressive behavior in D3.  相似文献   

Movement patterns of seaward migrating European eel (Anguilla anguilla) at a complex of riverine barriers: implications for conservation          下载免费PDF全文

Adam T. Piper  Jon C. Svendsen  Rosalind M. Wright  Paul S. Kemp 《Ecology of Freshwater Fish》2017,26(1):87-98

River infrastructure such as weirs and hydropower stations commonly present migrating fish with multiple potential passage routes. Knowledge of the cues fish use to navigate such environments is required to protect migrants from hazardous areas and guide them towards safe passage; however, this is currently lacking for many species. Employing high‐resolution positioning telemetry, this study examined movements of downstream migrating adult European eel, Anguilla anguilla, as they encountered a complex of water control structures in one location on the River Stour, southern England. The distribution of eels across five potential routes of passage differed from that predicted based on proportion of discharge alone. Certain routes were consistently avoided, even when the majority of flow passed through them. Passage distribution was partially explained by avoidance in the vicinity of a floating debris boom. Movement paths were nonrandomly distributed across the forebay and eels moved predominantly within a zone 2–4 m from the channel walls. Understanding of avoidance and structure oriented movementation exhibited by eels will help advance effective guidance and downstream passage solutions for adults.  相似文献