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Alvarado IR Villegas P El-Attrache J Jensen E Rosales G Perozo F Purvis LB 《Avian diseases》2007,51(1):27-32
An avian adenovirus (AAV) was isolated from liver samples of two 2-wk-old broiler-breeder flocks obtained from grandparents vaccinated at 10 and 17 wks of age with an autogenous inactivated vaccine containing the European AAV 8 (8565 strain) and 11 (1047 strain) serotypes (AAV8/11 vaccine). Affected broiler-breeders exhibited clinical signs and macroscopic and microscopic lesions associated with inclusion body hepatitis (IBH). The isolated adenovirus, identified as Stanford, was molecularly characterized as European serotype 9. The pathogenicity of the Stanford strain was confirmed after inoculation of specific-pathogen-free (SPF) chickens at 1-7 days of age, causing 100% and 20% mortality, respectively. The level of protection against IBH was evaluated in two broiler-breeder progenies from AAV 8/11-vaccinated grandparent flocks and a commercial broiler flock by challenge at 1 or 7 days of age with the AAV 8 and 11 serotypes and/or the Stanford strain. The broiler-breeder progenies and the commercial broiler flock exhibited protection against IBH after challenge. No significant differences in mean body weights were observed at 3 wk of age in any of the evaluated groups. We conclude that broiler-breeder progenies from 30- to 50-wk-old grandparents vaccinated with the AAV 8/11 vaccine were adequately protected against challenge with the AAV 8 and 11 serotypes and the Stanford strain. 相似文献
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Performance of light vs heavy steers grazing Plains Old World bluestem at three stocking rates 总被引：1，自引：0，他引：1
Ackerman CJ Purvis HT Horn GW Paisley SI Reuter RR Bodine TN 《Journal of animal science》2001,79(2):493-499
Live weight gains of light and heavy calves grazing Plains Old World bluestem at three stocking rates were evaluated during the summers of 1997 and 1998. Initial weights of mixed-breed light-weight steers (LHT) were 141 SD = 17 kg (n = 214) in 1997 and 160 SD = 23 kg (n = 193) in 1998. Initial weights of mixed-breed heavy steers (HWT) were 265 SD = 17 kg (n = 115) in 1997 and 248 SD = 13 kg (n = 126) in 1998. Initial stocking rates for both sizes of steers were as follows: light, 392 kg of live weight/ha; moderate, 504 kg of live weight/ha (increased to 616 kg live weight/ha in 1998); and heavy, 840 kg of live weight/ ha. Averaged gain and gain/hectare are reported as stocking rate by steer type within year. Heavy steers had greater ADG than LHT steers during both years. Forage intake, expressed as a percentage of BW, was greater (P = 0.05) for LHT (3.1%) than for HWT (2.8%) calves. Grazing time (min/d; 1998 only) was greater (P = 0.05) for LHT (665) than for HWT (624) steers. Forage CP and in vivo digestible organic matter (DOM) were slightly greater (P < 0.05) in pastures grazed by HWT vs LHT cattle. Gain/hectare was greater (P < 0.05) for LHT than for HWT calves at all three stocking rates during both years. A linear decline in ADG was observed (P < 0.07) as stocking rates increased for HWT steers in 1997 and LHT steers in 1998. However, ADG did not decline with increasing stocking rate for LHT calves during 1997 or HWT calves during 1998. Forage intake was not different among stocking rates in either 1997 or 1998. Grazing time was greatest (P < 0.05) for steers in the moderate and heavy stocking rates. Forage in vivo DOM decreased (P < 0.05) as stocking rate increased. Both LHT and HWT steers had lower (P < 0.05) ADG at all three stocking rates during 1998 compared with 1997. Despite lower ADG, LHT steers had greater gain/hectare than HWT steers during both 1997 and 1998. 相似文献
4.
Personal and family backgrounds of first-year veterinary science students at The University of Queensland 总被引：1，自引：0，他引：1
TJ HEATH 《Australian veterinary journal》1997,75(12):902-905
Objective To provide information on changes in the social and educational backgrounds of veterinary students over a 10 year period in an effort to determine the extent to which they are representative of the community.
Methods Questionnaires were completed by first-year veterinary students at The University of Queensland in 1985 and 1986 (152 students), and 1995 and 1996 (154), and the data were analysed using the SAS System for Windows.
Results The gender ratio of first-year veterinary students was 50:50 (male:female) in 1985 and 1986 but 10 years later it had changed to 38:62. In 1985 and 1986 77% had come directly from school, with 43% of the total coming from government schools, 17% from Catholic schools and 34% from other private (Independent) schools. A decade later the percentage coming directly from school had decreased to 40%, that from Independent schools increased to 45% and that from cities increased from 53% to 64%. The educational backgrounds of parents varied widely though a high percentage had university degrees; mothers had received less formal education than fathers, and the educational attainments of both parents were higher at the beginning than at the end of the study. More than half (57% initially; 67% 10 years later) the fathers were in professional or managerial occupations, and a similar number (50% initially; 48% 10 years later) of mothers were teachers, nurses or clerks. The number of males from country areas decreased from 26 to 16 over this period.
Conclusion These veterinary students differed from the community generally in that progressively more were female, more were from Independent schools, their parents had more formal education and more of their parents were in professional, managerial or clerical occupations. 相似文献
Methods Questionnaires were completed by first-year veterinary students at The University of Queensland in 1985 and 1986 (152 students), and 1995 and 1996 (154), and the data were analysed using the SAS System for Windows.
Results The gender ratio of first-year veterinary students was 50:50 (male:female) in 1985 and 1986 but 10 years later it had changed to 38:62. In 1985 and 1986 77% had come directly from school, with 43% of the total coming from government schools, 17% from Catholic schools and 34% from other private (Independent) schools. A decade later the percentage coming directly from school had decreased to 40%, that from Independent schools increased to 45% and that from cities increased from 53% to 64%. The educational backgrounds of parents varied widely though a high percentage had university degrees; mothers had received less formal education than fathers, and the educational attainments of both parents were higher at the beginning than at the end of the study. More than half (57% initially; 67% 10 years later) the fathers were in professional or managerial occupations, and a similar number (50% initially; 48% 10 years later) of mothers were teachers, nurses or clerks. The number of males from country areas decreased from 26 to 16 over this period.
Conclusion These veterinary students differed from the community generally in that progressively more were female, more were from Independent schools, their parents had more formal education and more of their parents were in professional, managerial or clerical occupations. 相似文献
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The hierarchical nature of phylogenies means that random extinction of species affects a smaller fraction of higher taxa, and so the total amount of evolutionary history lost may be comparatively slight. However, current extinction risk is not phylogenetically random. We show the potentially severe implications of the clumped nature of threat for the loss of biodiversity. An additional 120 avian and mammalian genera are at risk compared with the number predicted under random extinction. We estimate that the prospective extra loss of mammalian evolutionary history alone would be equivalent to losing a monotypic phylum. 相似文献
8.
Phylogenies provide new ways to measure biodiversity, to assess conservation priorities, and to quantify the evolutionary history in any set of species. Methodological problems and a lack of knowledge about most species have so far hampered their use. In the future, as techniques improve and more data become accessible, we will have an expanded set of conservation options, including ways to prioritize outcomes from evolutionary and ecological processes. 相似文献
9.
Albert C. Purvis 《Scientia Horticulturae》1984,23(3):261-267
Differences in chilling injury susceptibility of grapefruit from exterior and interior tree canopy positions were used to investigate the hypothesis that water loss is related to chilling injury symptom development during low-temperature storage. The sun-exposed surface of grapefruit from exterior canopy positions was more susceptible to chilling injury and had lower diffusive resistance than the shaded surface of the same fruit. Reducing the rate of fruit transpiration during the first week of storage by a pre-cooling treatment prior to low-temperature storage delayed, but did not eliminate, the development of chilling injury. 相似文献
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