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Cryopreservation of Piau‐Breed Wild Boar Sperm: Assessment of Cooling Curves and Centrifugation Regimes 
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下载免费PDF全文 HH Shiomi RO Pinho DMA Lima JB Siqueira MCR Santos EV Costa PS Lopes SEF Guimarães JD Guimarães 《Reproduction in domestic animals》2015,50(4):545-553
This study aimed to assess the effects of different cooling curves and centrifugation regimes used in cryopreservation protocols on the post‐thaw viability of Piau‐breed wild boar (Sus scrofa) sperm using in vitro assessment tests. Two centrifugations (800 g for 10 min and 2400 g for 3 min) and two cooling curves (conventional cooling using nitrogen vapour – freezing 1 and automated cooling using a programmed freezing machine – freezing 2) were tested. Therefore, the treatments were divided into M3 – centrifugation at 2400 g for 3 min and freezing 2; M10 – centrifugation at 800 g for 10 min and freezing 2; R3 – centrifugation at 2400 g for 3 min and freezing 1; and R10 – centrifugation at 800 g for 10 min and freezing 1. No significant differences (p > 0.05) between treatments occurred post‐thawing regarding the total sperm motility means recorded. The mean values of the different treatments were not different from each other regarding the supravital staining (SV), hypo‐osmotic test (HO), sperm–egg binding assay or sperm morphology. This study showed that both the cooling curve and the centrifugation regime affected the quality of post‐thaw sperm, and centrifugation for shorter times and cooling curves using automated cooling are the most suitable for minimizing sperm injury. 相似文献
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Studies were conducled to cstmiate the adsorption parameter k and the bioactivity (in terms of G R50) of di-allate [S-2,3-dichloroallyl N, N-di-isopropyl (thiocar bamate)], iri-allate [S-2,3,3-trichloroallyl N, N -di-isopropyl (thiocar bamate], and [trifiuralin (2,6-dinitro N, N-dlpropyl-4-trifluoromelhylaniline) in a number of Saskatchewan soil. The k values ratiged from 5 for di-allate adsorption m Asquilh loamy sand to 315 for trifluralin adsorption on Melfort loam and were closely related to the soil organic matter content. The relative degree of adsorption was irifluralin > tri-allate >di-allaie. For each herbicide, the G R50 values were positively correlated wich organic matter conienl atid wilh k. It was suggested that these nonionic herbicides may be amenable to a predictive approach for field application rates in different soils. Among herbicides for any one soil, however, there was not the same relationship between G R50andk. since the G R50 was least for trifluralin and there was no significant difference between di-allate and tri-allate. 相似文献
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This paper examines the evolution of integrated pest management (IPM) into the dominant paradigm in crop protection. The driving forces behind the development and adoption of IPM are explored and the conditions under which successful IPM has been practised are outlined. Repeated calls for the adoption of IPM in international agricultural research, extension and resource-poor farming are questioned in respect of claims made by IPM proponents. When examined, it becomes apparent that IPM per se is not a panacea for solving the problems faced by resource-poor farmers. Further investigation into the social, political, economic and ecological parameters associated with the development and implementation of IPM shows that is can work under certain conditions. However, the situation of most resource-poor farmers does not match the necessary criteria for the implemetation of IPM programmes. Viewed thus, it could be argued that IPM is more a vehicle for the continued transfer of technologies developed in response to the pressures exerted by argibusiness rather than a truly farmer first approach to solving the contraints facing the lives of resource-poor farmers in developing countries 相似文献
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