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41.
42.
Cuthbertson AG Mathers JJ Croft P Nattriss N Blackburn LF Luo W Northing P Murai T Jacobson RJ Walters KF 《Pest management science》2012,68(9):1289-1295
BACKGROUND: Predatory mites (Amblyseius swirskii Athias‐Henriot, Typhlodromips montdorensis Schicha, Neoseiulus cucumeris (Oudemans) and Iphiseius degenerans Berlese) were investigated for their potential to act as control agents for Thrips palmi Karny. Prey consumption rates and compatibility with pesticides were assessed. RESULTS: Second‐instar larvae were the preferred life stage. Typhlodromips montdorensis consumed the most larvae (2.8) and also an average of 1.2 adult T. palmi per 5 day period. Both 24 and 48 h assessments following application of abamectin, spinosad and imazalil demonstrated mortality of predatory mites (across all species), which was significantly higher than with the other treatments (P < 0.001). Spraying with pymetrozine did not provide any increased mortality when compared with the water control. Application of thiacloprid proved detrimental only to I. degenerans. Following indirect exposure of predatory mites to pymetrozine and imazalil, no significant differences in mite mortality were obtained. Indirect exposure to spinosad was identified as the most detrimental treatment (P < 0.001) to all mites. Abamectin also proved detrimental, with only T. montdorensis showing any potential tolerance. CONCLUSION: All predatory mites investigated offer potential for controlling T. palmi. Compatibility with chemicals varied between the mites. The potential of incorporating the mites into eradication strategies for T. palmi is discussed. Copyright © 2012 Society of Chemical Industry 相似文献
43.
BA Freking PH Purdy SF Spiller CS Welsh HD Blackburn 《Journal of animal science》2012,90(8):2515-2523
Selection for 11 generations in swine for ovulation rate (OR) or uterine capacity (UC) resulted in significant changes in component traits of litter size. Our objective was to conserve the unique germplasm for the future and to characterize sperm quality as a correlated response to the selection criterion imposed compared with an unselected control line (CO). Boars representing genetic diversity available in all 3 lines were produced in 2 farrowing seasons. Season 1 was born in September 2005 and was sampled for semen characteristics in October 2006. Season 2 was born in March 2006 and was sampled for semen characteristics in February and March 2007. Each boar (n = 60) was collected twice. The sperm-rich fraction was obtained, and volume and concentration of sperm cells were measured to estimate total sperm production. Each ejaculate was extended 1:3 (vol/vol) with Androhep Plus (Minitube, Verona, WI) and was packed for shipping to the National Animal Germplasm Program laboratory for processing into frozen straws. Semen quality was measured by computer-assisted semen analysis at 3 semen processing points: fresh (FR), 24 h after extender added (E), and postthaw (PT). A mixed model ANOVA was applied to the data. Fixed effects of farrowing season, line, and 2-way interactions were fitted. The random effect of boar (n = 60) within farrowing season and line was used to test line differences. Sperm concentration was not different (P = 0.18) among the lines (0.594 × 10(9), 0.691 × 10(9), and 0.676 × 10(9) cells/mL for CO, OR, and UC lines, respectively). However, significance (P = 0.04) was detected for the volume of the sperm-rich fraction, greatest for OR (86.4 mL), intermediate for UC (75.5 mL), and least for CO (70.2 mL). Line differences were thus detected (P = 0.02) for total sperm production per ejaculate, greatest for OR (54.9 × 10(9)), intermediate for UC (48.7 × 10(9)), and least for CO (40.5 × 10(9)). A larger percentage of progressively motile sperm and greater estimates of sperm velocity only at processing point E (P < 0.01) were detected in favor of CO. Estimates of motility, velocity, and other parameters of sperm movement measured on E processing points were positively correlated with the same estimates obtained PT, but the magnitude was low to moderate (r range -0.03 to 0.23). Thus, selection for component traits of female reproduction had a favorable effect on total sperm production of boars. 相似文献
44.
O H Stalheim S S Stone B O Blackburn J Foley 《American journal of veterinary research》1978,39(11):1734-1737
In horses given whole cultures or cells of Mycoplasma mycoides subsp capri (by subcutaneous and intravenous injections), antibody responses were measured by serologic procedures. During an immunization period of 22 weeks, horses produced an antiserum that was used to identify M mycoides subsp capri by agglutination, complement-fixation, and fluorescent antibody (FA) tests, but not by the growth-inhibition test. Horses that were injected with whole cultures of M mycoides subsp capri responded better than horses that were injected with only cells, ie, antibodies were detectable sooner by agar gel diffusion and FA tests and the serums displayed more bands of precipitation. The FA reagent was stable during lyophilization and storage at 5 C for 60 days. 相似文献
45.
About 140,000 years ago, the breakup of large continental ice sheets initiated the Last Interglacial period. Sea level rose and peaked around 135,000 years ago about 14 meters below present levels. A record of Last Interglacial sea levels between 116,000 years to 136, 000 years ago is preserved at reef VII of the uplifted coral terraces of Huon Peninsula in Papua New Guinea. However, corals from a cave situated about 90 meters below the crest of reef VII are 130, 000 +/- 2000 years old and appear to have grown in conditions that were 6 degreesC cooler than those at present. These observations imply a drop in sea level of 60 to 80 meters. After 130,000 years, sea level began rising again in response to the major insolation maximum at 126,000 to 128,000 years ago. The early (about 140,000 years ago) start of the penultimate deglaciation, well before the peak in insolation, is consistent with the Devils Hole chronology. 相似文献
46.
MT McCulloch AW Tudhope TM Esat GE Mortimer J Chappell B Pillans AR Chivas A Omura 《Science (New York, N.Y.)》1999,283(5399):202-204
Uplifted coral terraces at Huon Peninsula, Papua New Guinea, preserve a record of sea level, sea-surface temperature, and salinity from the penultimate deglaciation. Remnants have been found of a shallow-water reef that formed during a pause, similar to the Younger Dryas, in the penultimate deglaciation at 130,000 +/- 2000 years ago, when sea level was 60 to 80 meters lower than it is today. Porites coral, which grew during this period, has oxygen isotopic values and strontium/calcium ratios that indicate that sea-surface temperatures were much cooler (22 degrees +/- 2 degreesC) than either Last Interglacial or present-day tropical temperatures (29 degrees +/- 1 degreesC). These observations provide further evidence for a major cooling of the equatorial western Pacific followed by an extremely rapid rise in sea level during the latter stages of Termination II. 相似文献
47.
48.
The effect of antibody to caseous lymphadenitis in ewes on the efficacy of vaccination in lambs 总被引:1,自引:0,他引:1
MW Paton AR Mercy† SS Sutherland‡ TM Ellis‡ SR Duda§ 《Australian veterinary journal》1991,68(4):143-146
The effect of maternal antibody to the toxin of Corynebacterium pseudotuberculosis, produced by caseous lymphadenitis (CLA) in ewes or by vaccinating ewes before lambing, on the efficacy of vaccination against CLA in their lambs was examined. Lambs were allocated to treatments according to either the vaccination history of their dam or level of CLA toxin antibody of their dam. They were vaccinated twice using 2 different inoculation regimes and then artificially infected with CLA organisms. The number of lambs with CLA lesions was assessed at slaughter. In one experiment high levels of CLA toxin antibody activity in ewes were associated with decreased efficacy of CLA vaccination in their lambs, when lambs were vaccinated at 2 and 8 weeks or 8 and 14 weeks of age. In a second experiment the efficacy of lamb vaccination at 8 and 12 weeks, but not at 14 and 18 weeks of age, was decreased. In sheep flocks with a high prevalence of CLA, vaccinating lambs against CLA at less than 10 weeks of age may not produce optimum protection against CLA in lambs. There was no difference in infection rate between lambs from vaccinated and unvaccinated ewes. However, vaccination of lambs at 2 and 8 wks was less effective that vaccination at 8 and 14 weeks, probably due to reduced immunocompetence in young lambs. In sheep flocks where significant numbers of lambs receive their primary vaccination at less than 3 weeks of age vaccination programmes to control CLA in lambs may be less effective. 相似文献
49.
A series of simulations were performed to evaluate the effects of mature size (WMA; 60, 70, 80 and 90 kg), slaughter weight (SW; 55, 60 and 65 kg) and three diets fed to feedlot lambs. Rations included a traditional diet (C2L) or placing weaned lambs on alfalfa for either 30 (A30) or 60 (A60) d before placing them on the C2L diet (A30-C2L and A60-C2L). Two lamb pricing schemes were used in the financial analysis of the biological results: sale price based on weight with or without adjustment for carcass fat. Placing lambs on alfalfa pasture increased ownership by 22 d on average compared to C2L. As WMA and SW increased, ownership increased from 3 to 11 d. Across nutritional treatments, fat decreased by 5.8 to 9.0% as WMA increased from 60 and 90 kg. When market lambs were priced on weight, net returns per lamb were greatest for A30-C2L or A60-C2L ($2.34 and $5.21, respectively above C2L) and for greater SW ($4.77 and $7.16 greater for SW 60 and 65 kg than for SW 55). The combination WMA of 90 kg, a SW of 65 kg and nutritional treatment of A60-C2L proved most profitable. However, when sale price was discounted for excessive fat content, the combinations WMA of 60 or 70 with a SW of 65 and A60-C2L were most profitable. The rank correlation between biological efficiency (weight gain/dry matter feed consumption) and net return, when sale price was based on weight, was found to be -.51. This was because lambs slaughtered at lighter weights had high biological efficiencies but low net returns due to a negative price margin. With negative price margins but positive feeding margins, net returns are greatest for heavier, fatter lambs fed longer. 相似文献
50.