Gonadotrophin-releasing hormone treatment in cattle: a meta-analysis of the effects on conception at the time of insemination   总被引：1，自引：0，他引：1  

WF MORGAN  IJ LEAN 《Australian veterinary journal》1993,70(6):205-209

SUMMARY Data from 40 trials described in 27 published papers were analysed by meta-analysis (pooling of data from numerous trials into a single analysis) to evaluate the effects of injecting gonadotrophin-releasing hormone (GnRH) In cattle at the time of Insemination on the risk of pregnancy. A total of 19 019 cows were involved In these studies. Analyses were stratified by trial and by the effects of dose of GnRH, type of GnRH and Insemination number (first, second or third and greater). Mantel-Haenszel analysis revealed that use of GnRH at Insemination significantly Increased the overall risk of pregnancy by 12.5% In treated cows (P < 0.05). However, Increases In risk of pregnancy were greatest (22.5%) when repeat breeders were treated. Results for use of GnRH or analogue at first service were similar, with Increased risks of pregnancy in treated cows of 5.2 and 8.0%, respectively. The risk of pregnancy tended to be higher (11.1%) when the dose of GnRH was 250 μg and when used at second Insemination (9.9%). The analyses demonstrated that while treatment at Insemination with GnRH and GnRH analogues Increased conception rates In dairy cattle, some variation In study results was attributable to the number of Inseminations after calving at which GnRH Is administered. Further efforts should be made to determine characteristics of populations of cows that have good fertility responses to GnRH and to determine the mode of action of GnRH in Increasing fertility. Meta-analysis proved to be a useful technique for evaluating the apparently conflicting results from trials and in evaluating the effect of factors such as Insemination number, dose and type of GnRH on responses to treatment.  相似文献   

Hepatotoxicosis in cattle associated with consumption of Punica granatum (pomegranate)          下载免费PDF全文

MH Hawes  IJ Gill 《Australian veterinary journal》2018,96(10):408-410

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Serotyping of isolates of Pasteurella multocida from chickens     

LA IRELAND  AR MILNER  IJ SMART 《Australian veterinary journal》1989,66(4):119-120

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A case-control study to identify farm factors affecting fertility of dairy herds: univariate description of factors     

FB WEBSTER  IJ LEAN  D. KENNEDY  K. PHILLIPS 《Australian veterinary journal》1997,75(4):266-273

Objective To identify farm factors which were associated with reproductive performance in dairy herds in New South Wales.
Procedure A survey was administered by face to face interview to examine the responses of producers drawn from 757 herds, which used the New South Wales Agriculture Department Dairy Herd Improvement scheme. A case-control approach was used to select a total of 126 herds from the first (top group - cases) and fourth quartiles (low group - controls) for intercalving interval.
Results We found that the estimated interval from calving to first mating was significantly different between groups (P = 0.03) and that the groups significantly differed in both their target for interval to first mating (P = 0.02) and their perceived optimum time for first mating (P = 0.04). Other factors associated with a longer intercalving interval included, use of embryo transfer programs (P = 0.08), younger managers (P = 0.02), fewer breedings per day (P = 0.01), a greater number of people detecting heats (P = 0.07), but less hours spent detecting heats while handling the cows (P = 0.11), and a failure to vaccinate bulls for campylobacteriosis (P = 0.14).
Conclusions Managers of herds with poorer reproductive performance did not intend to mate cattle as soon after calving as managers with better reproductive performance, were not as active in seeking veterinary advice on reproduction, and were attempting to treat reproductive diseases and disorders themselves.  相似文献   

A comparison of the autecology of Quercus robur L. and Q. pyrenaica Wild.: present habitat in Galicia, NW Spain     

Diaz-Maroto  IJ; Vila-Lameiro  P; Guchu  E; Diaz-Maroto  MC 《Forestry》2007,80(3):223-239

The biotopes occupied by pedunculate oak (Quercus robur L.)and rebollo oak (Quercus pyrenaica Willd.) in Galicia were characterizedusing different parameters, enabling a comparative analysisof its habitats. Thirty-nine plots of pedunculate oak and 40of rebollo oak were inventoried and 25 ecological parameters(physiographic, climatic and edaphic) were measured to describethe biotopes, along with 14 stand parameters to characterizethe structure and the silviculture of these forests; some ofthem were used in previous works about the autecology of bothspecies. Quercus robur was found to occupy a wider range ofecological habitats and their distribution is oceanic; Q. pyrenaicapresents a more Mediterranean phytoclimatic position. The resultsindicated that the distribution of oak forests in Galicia ismore closely related to physiographic and climatic featuresthan to edaphic, because the nature of the substrates that theyoccupy is similar. Analysis of fragility/aggressiveness betweenboth species and chestnut shows that the aggressiveness of bothoaks, mainly pedunculate, was much higher, except at high altitudes,and in areas with a high mean temperature, where rebollo ismore aggressiveness. Comparison of the two Quercus shows formost of the parameters that Q. robur is the more aggressivespecies.  相似文献   

Cattle movement patterns in Australia: an analysis of the NLIS database 2008–2012          下载免费PDF全文

RM Iglesias  IJ East 《Australian veterinary journal》2015,93(11):394-403

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Spatial and temporal evaluation of veterinarians and veterinary employers relative to human and domesticated animal populations in Australia 2002–2012          下载免费PDF全文

GB Smyth  IJ East  RM Wicks 《Australian veterinary journal》2015,93(5):137-144

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Erfassung der Mineralstoffverteilung im wurzelnahen Boden durch Autoradiographie     

N. Claassen  L. Hendriks  A. Jungk 《植物养料与土壤学杂志》1981,144(3):306-316

Determination of the nutrient distribution in the soil-root interface by autoradiography A method is described to determine the nutrient concentration profile in soil in the vicinity of living plant roots. For this purpose plants are grown in flat boxes filled with radioactive labelled soil of 5 mm thickness and then autoradiographs of roots and surrounding soil are taken. The density of the x-ray film is scanned by use of a microdensitometer. The profile of the film density produced by ³³P, which is a β-emitter of relatively low energy, represents the P concentration profile rather accurately. In case of ³²P and ⁸⁶Rb, nuclides of higher β-energy, profiles of the film density deviate markedly from concentration profiles because of cross fire. To account for the cross fire a corrective calculation is applied. The result of the corrective calculation is shown with autoradiographs of maize roots grown in either sand or loess soil labelled with ⁸⁶Rb. Phosphate depletion zones around plant roots growing in soil usually do not exceed the distance of cross fire of ³²P. Therefore, this nuclide is not or at least less appropriate than ³³P.  相似文献   

Phosphatverarmung des wurzelnahen Bodens und Phosphataufnahme von Mais und Raps     

L. Hendriks  N. Claassen  A. Jungk 《植物养料与土壤学杂志》1981,144(5):486-499

Phosphate depletion at the soil — root interface and the phosphate uptake of maize and rape Maize and rape plants were grown in flat containers in a ³3P-labelled sandy soil and the distribution of soil phosphate near roots was determined by using densitometric scans of autoradiographs. The concentration of isotopically exchangeable phosphate at the root surface decreased within a few days by 42 per cent with rape and by 50–65 per cent with maize. Initially the width of the depletion zone is very small. Within six days the depletion zone extended to the final distance from the surface of the root cylinders of about 2 mm for maize and 2.6 mm for rape. The soil within the range of the mean length of root hairs (0.7 mm for maize and 1.3 mm for rape) is almost equally depleted. This indicates that root hairs are very important for P-uptake from soil. This is further supported by higher P-uptake rates per cm root length of rape than of maize. The P-concentration of the soil solution was estimated by means of the phosphate desorption curve. Within the root hair cylinder the P-concentration of the soil solution decreased from 0.8 to 0.03 mg P/l. Changes of the P-depletion profile with time were used to calculate P-uptake rates for roots of different age. The results indicate that for the first 3–5 days P-uptake rates remained near maximum, even though the P-concentration of the soil solution at the root surface had strongly decreased within two days. Phosphate uptake rates per cm root length did not decrease unless the whole root hair cylinder had been depleted.  相似文献   

A Method for Determining Phosphate Diffusion Coefficients by Bulk Diffusion in Soil     

Joachim Kaselowsky  Pratapbhanu B. S. Bhadoria  Norbert Claassen  Albrecht Jungk 《植物养料与土壤学杂志》1990,153(2):89-91

A method is described for the determination of phosphate diffusion coefficients by bulk diffusion in soil using the concentration distance method. Two soil blocks only differing in phosphate concentration are brought into contact. After a diffusion period of two weeks the soil blocks are separated, frozen in liquid nitrogen and sliced into layers about 0.02 cm thick by means of a refrigerated microtome. The soil samples are extracted with 4 N HCl, a procedure which fully recovers the added amount of fertilizer P and thus includes the total amount of P that diffuses from one soil block to the other. A concentration distance profile for P and a calculation of the P diffusion coefficient is presented.  相似文献