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41.
SC Finch JS Munday BL Sutherland JB Vlaming LR Fletcher 《New Zealand veterinary journal》2013,61(6):322-326
Abstract
AIMS
To determine if equine fescue oedema (EFO) induced by grazing Mediterranean-type tall fescue (Lolium arundinaceum) infected with selected endophytes (Epichloë coenophiala) could be prevented by treatment with the corticosteroid, methylprednisolone, and anti-histamine, cetirizine, and to determine concentrations of lolines, specifically N-acetyl norloline (NANL), in grasses grazed by horses that did and did not develop EFO. 相似文献42.
Effect of Repeated Stress Treatments During the Follicular Phase and Early Pregnancy on Reproductive Performance of Gilts 总被引:2,自引:0,他引:2
NM Soede JB Roelofs RJE Verheijen WPG Schouten W Hazeleger B Kemp 《Reproduction in domestic animals》2007,42(2):135-142
In pig husbandry, stress is being considered an important cause of impaired reproductive performance. Therefore, an experiment was performed to quantify effects of repeated stressors during the follicular phase and/or during early pregnancy on reproductive performance of gilts. Eighty-one cyclic gilts were assigned to one of four treatments, namely, stress treatment during the follicular phase (n = 20), stress treatment during early pregnancy (n = 20), stress treatment during both phases (n = 21) and no stress treatment (n = 20). All gilts were housed individually, but gilts in the stress treatments had no opportunity for visual or physical contact with other gilts. Further, animals in a stress-treatment were grouped for half an hour at the start of the treatment and during the treatment period nose-sling and an unpredictable feeding scheme were applied regularly. The extent of stress was monitored using heart rate measurements, behavioural observations and saliva cortisol levels during nose-sling fixation. Of the 81 gilts, 93% showed oestrus and were inseminated. Of these, 93% were pregnant at day 35, having 17.9 +/- 0.3 ovulations and 15.6 +/- 0.3 foetuses. These parameters were not affected by treatment. The stress treatment during the follicular phase tended to shorten cycle length (stress: 20.8 +/- 0.20; control: 21.2 +/- 0.17 days, p = 0.07) and weight of foetuses at day 35 (stress: 4.47 +/- 0.08 g; no stress: 4.69 +/- 0.08 g, p = 0.06); stress during early pregnancy did not affect any of the reproduction parameters. Percentage stereotypic behaviour, heart rate and saliva cortisol levels varied greatly between animals and between days, but did not differ between the treatments. No relationships were found between any of the reproductive parameters and any of the stress parameters (heart rate, cortisol, stereotypic behaviour). These results indicate that the repeatedly applied acute stressors did not generate a chronic stress-response and that these stressors during the follicular phase and/or during early pregnancy did not affect reproductive processes. It is not clear how these findings relate to suggested effects of stress(ors) on reproductive performance in pig husbandry. 相似文献
43.
44.
JB MOLLOY PM BOWLES DP KNOWLES TF McELWAIN RE BOCK TG KINGSTON GW BLIGHT RJ DALGLIESH 《Australian veterinary journal》1999,77(4):245-249
OBJECTIVE: To compare a recently developed recombinant MSP-5 competitive inhibition ELISA with a card agglutination test for detection of antibodies to Anaplasma marginale and Anaplasma centrale in Australian cattle. MATERIALS AND METHODS: The ELISA was compared with the card agglutination test using 208 sera from cattle in Anaplasma-free herds, 86 sera from cattle experimentally infected with A marginale or A centrale and 757 sera from cattle in areas endemic for A marginale. RESULTS: The specificity of the ELISA, based on testing 208 sera from cattle in Anaplasma-free areas, was 99.5%, and the sensitivities for detection of antibodies to A marginale and A centrale in sera from the experimentally infected cattle were 98.0% and 100%, respectively. For the same sets of sera, the specificity of the card agglutination test was 98.6% and the sensitivities for detection of antibodies to A marginale and A centrale were 98.0% and 100%, respectively. For the 757 sera collected from cattle in areas endemic for A marginale, the agreement between the ELISA and the card agglutination test depended on the positive threshold selected for the ELISA. The maximum achievable agreement was 91.5% (kappa = 0.73; 95% confidence interval 0.66, 0.79). CONCLUSION: We conclude that the competitive inhibition ELISA is a useful alternative to the card agglutination test for detection of A marginale or A centrale infection in cattle. The assay should be particularly useful for epidemiological applications such as prevalence studies and control programs. 相似文献
45.
JB Losos TR Jackman A Larson K Queiroz L Rodriguez-Schettino 《Science (New York, N.Y.)》1998,279(5359):2115-2118
The vagaries of history lead to the prediction that repeated instances of evolutionary diversification will lead to disparate outcomes even if starting conditions are similar. We tested this proposition by examining the evolutionary radiation of Anolis lizards on the four islands of the Greater Antilles. Morphometric analyses indicate that the same set of habitat specialists, termed ecomorphs, occurs on all four islands. Although these similar assemblages could result from a single evolutionary origin of each ecomorph, followed by dispersal or vicariance, phylogenetic analysis indicates that the ecomorphs originated independently on each island. Thus, adaptive radiation in similar environments can overcome historical contingencies to produce strikingly similar evolutionary outcomes. 相似文献
46.
JB McClain DE Betts DA Canelas ET Samulski JM DeSimone JD Londono HD Cochran GD Wignall D Chillura-Martino R Triolo 《Science (New York, N.Y.)》1996,274(5295):2049-2052
Interfacially active block copolymer amphiphiles have been synthesized and their self-assembly into micelles in supercritical carbon dioxide (CO2) has been demonstrated with small-angle neutron scattering (SANS). These materials establish the design criteria for molecularly engineered surfactants that can stabilize and disperse otherwise insoluble matter into a CO2 continuous phase. Polystyrene-b-poly(1,1-dihydroperfluorooctyl acrylate) copolymers self-assembled into polydisperse core-shell-type micelles as a result of the disparate solubility characteristics of the different block segments in CO2. These nonionic surfactants for CO2 were shown by SANS to be capable of emulsifying up to 20 percent by weight of a CO2-insoluble hydrocarbon into CO2. This result demonstrates the efficacy of surfactant-modified CO2 in reducing the large volumes of organic and halogenated solvent waste streams released into our environment by solvent-intensive manufacturing and process industries. 相似文献
47.
MC Playford I Evans JB Lloyd P Lawton AR Rabiee IJ Lean 《Australian veterinary journal》2012,90(11):415-422
48.
Diane L. Larson JB. Bright Pauline Drobney Jennifer L. Larson Nicholas Palaia Paul A. Rabie Sara Vacek Douglas Wells 《Biological conservation》2011,144(12):3127-3139
Tallgrass prairie restoration has been practiced for more than 75 years, yet few studies have systematically tested restoration methods over large geographic regions with the intent of refining methodology. In this study, we used three planting methods (dormant-season broadcast, growing-season broadcast and growing-season drill) fully crossed with three levels of seed species richness (10, 20, and 34 spp). We replicated the study on nine former agricultural fields located from east-central Iowa (Neal Smith National Wildlife Refuge) to northwestern Minnesota (Litchfield, Fergus Falls and Morris Wetland Management Districts), USA, within the northern tallgrass prairie biome. Objectives were to evaluate the relative influences of planting method, seed mix richness, and their interactions, on (1) planted cover (both total and by guild) and richness, (2) exotic species cover, and (3) non-planted native species cover. Optimal techniques varied between the two study areas: the dormant broadcast method produced greater cover of planted species at the Minnesota sites and the growing-season drill method produced greater cover of planted species at Iowa sites. The dormant broadcast method strongly favored establishment of perennial forbs while the growing-season drill favored warm-season grasses. Although increasing richness of the seed mix produced greater planted species richness, this did not result in greater resistance to exotic invasion. We conclude that, if planting during the growing season, drilling seed is preferable to broadcasting, but if the choice is between broadcasting seed in the dormant or growing season, the dormant season is preferred. 相似文献
49.
E de P Lopes JB Siqueira RO Pinho JD Guimarães AN Rocha GR de Carvalho CAA Torres 《Reproduction in domestic animals》2011,46(2):261-267
The objective of this study is to evaluate the reproductive efficiency in donors and recipient Mangalarga Marchador mares in commercial programmes of embryo transfer (ET) and the effects of some reproductive characteristics and ET methodology on conception rates in the recipient mares. A total of 1140 flushing procedures were performed and 830 embryos (72.8%) were recovered. There were no differences between the rates of embryonic recovery in the different breeding seasons (p > 0.05) and 92.8% of the recovered embryos were 8–9 days old. There was no difference in the embryonic recovery regarding the collection order from the first to the ninth embryo collection along the breeding season, as well as among mares inseminated during the foal heat or subsequent cycles (p > 0.05). Pregnancy rates observed in the total period of all reproductive seasons at 15, 30, 45 and 60 days of pregnancy were 73.4, 69.9, 66.7 and 64.5%, respectively. Differences in pregnancy rate and early embryonic loss rates were not observed between embryos transferred immediately after collection (66.8% and 13.5%) and embryos transported at room temperature for periods of <1 h (62.9% and 14.4%; p > 0.05). Pregnancy rates were higher when the interval between ovulations of donor and recipient mares remained between ?3 and ?2 days (p < 0.05), and the lowest rates were observed for intervals of ?6 days (p < 0.05) with intermediary values for intervals of ?1, 0 and +1 (p > 0.05). Embryonic loss rates, however, did not differ between intervals of ovulation’s synchronism between donor and recipient mares (p > 0.05). This flexibilization in the ovulatory synchronism between donor and recipient mares optimizes the use of recipient mares, thus reducing costs and facilitating management of horse breeding farms. 相似文献
50.
R Kasimanickam M Asay S Schroeder V Kasimanickam JM Gay JP Kastelic JB Hall WD Whittier 《Reproduction in domestic animals》2014,49(6):1063-1067
Profitability of a beef operation is determined by the proportion of cows attaining pregnancy early in the breeding season and those that are pregnant at the end of breeding season. Many factors, including temperament, contribute to those reproductive parameters. The objective of this study was to evaluate effects of temperament on reproductive performance of beef cows. In Experiment 1, Angus and Angus‐cross beef cows (n = 1546) from eight locations were assigned a body condition score (BCS; 1 = emaciated; 9 = obese) and chute exit and gait score (1 = slow exit, walk; calm temperament; 2 = jump, trot or run; excitable temperament). Cows were grouped with bulls (1 : 25 to 1 : 30; with satisfactory breeding potential and free of venereal disease) for an 85‐day breeding season. Pregnancy status and stage of gestation were determined (transrectal palpation) 35 days after the end of the breeding season. Controlling for BCS (p < 0.01) and handling facility (p < 0.0001) and handling facility by temperament score interaction (p < 0.001), breeding season pregnancy rate was lower in excited versus calm cows [88.6% (798/901) vs 94.1% (607/645); p < 0.001]. Cows with an excitable temperament took 24 more days to become pregnant compared to calm cows (median days to pregnancy, 35 vs 59 days; p < 0.0001). In Experiment 2, Angus and Angus‐cross beef cows (n = 1407) from 8 locations were assigned scores for body condition and chute exit and gait (as described in Experiment 1) and assigned to bulls (breeding sound and free of venereal disease; 1 : 25 to 1 : 30) for 85 days. Pregnancy status was determined by transrectal palpation at 2 and 6 months after the onset of the breeding season. Controlling for BCS (p < 0.05), pregnancy loss was higher in excited versus calm cows [5.5% (36/651) vs 3.2% (20/623), p < 0.0001]. In conclusion, beef cows with an excitable temperament had significantly lower reproductive performance than calmer cows. The modified two‐point chute exit–gait scoring method was repeatable and identified cattle with an excitable temperament. 相似文献