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排序方式: 共有104条查询结果,搜索用时 187 毫秒
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Donoghue AM Kirby JD Froman DP Lerner SP Crouch AN King LM Donoghue DJ Sonstegard TS 《British poultry science》2003,44(3):498-504
1. Commercial reproduction of turkeys relies on pooling of semen from multiple males for inseminations. Understanding how sperm characteristics influence paternity under commercial breeding conditions is important to improving production efficiency. 2. The objective of this study was to evaluate progeny production of individual toms following commercial practices of pooling semen to determine if sperm mobility influences progeny production in field conditions. 3. A total of 104 toms were evaluated for sperm mobility. A subset of 10 toms were housed together and semen was collected, pooled and used to inseminate hens (n = 28). Hens were inseminated at 30 weeks of age and weekly thereafter. 4. Ejaculates from each tom were evaluated on two separate days for sperm mobility. Semen from each tom was diluted and layered upon 6% (wt/vol) Accudenz solution. The sperm suspension was incubated at 41 degrees C for 5 min and absorbance was measured with a spectrophotometer. 5. Toms were ranked by absorbance and categorised as high or low if mobility score was +/- 1 SD from the flock mean (average). 6. For parentage determination, DNA was extracted from tom, hen and poult blood. Poult parentage (n = 276) was determined at one day of age or at 14 weeks by analysis of marker genotypes that were generated by polymerase chain reaction (PCR) amplification of genomic DNA with selected microsatellite markers. 7. Sperm mobility differed across males with absorbance values ranging from 0.147 to 0.366. 8. Findings demonstrate differences in poult production among individual toms when semen from multiple males was pooled and inseminated. Toms classified as high, average and low produced 55, 41 and 4% of the offspring, respectively. 9. It appears that sperm mobility is a trait that influences sperm competition among toms under field conditions where sperm numbers inseminated from individual toms are not controlled or constant and that toms with low sperm mobility produce few offspring. 相似文献
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Acute cortisol responses of calves to scoop dehorning using local anaesthesia and/or cautery of the wound 总被引:1,自引:0,他引:1
SP SYLVESTER DJ MELLOR KJ STAFFORD RA BRUCE RN WARD 《Australian veterinary journal》1998,76(2):118-122
Objective To measure plasma cortisol responses in calves dehorned using a scoop after administration of local anaesthesia and/or cautery of the wounds.
Design A physiological study with controls.
Procedure There were six treatments: control handling with and without local anaesthesia, dehorning, dehorning after local anaesthesia, dehorning followed by wound cautery, and dehorning after local anaesthesia followed by wound cautery. Blood samples were taken before and after dehorning.
Results Dehorning caused an increase in plasma cortisol concentrations, which decreased a little to plateau values and then declined to pretreatment values 3 to 4 h after dehorning. The peak was smaller after local anaesthesia was administered but when its effects wore off, cortisol concentrations increased and thereafter were similar to those in the dehorned animals. The combination of local anaesthesia and cautery resulted in a plasma cortisol response similar to those in control calves with or without local anaesthesia.
Conclusions If plasma cortisol concentrations reflect the distress being experienced by the calves, then local anaesthesia reduces the acute distress for about 3 h after dehorning but not during the subsequent 3 to 4 h. Combining local anaesthetic and cautery prevented the significant increase in plasma cortisol following dehorning and may eliminate the acute distress caused by scoop dehorning. 相似文献
Design A physiological study with controls.
Procedure There were six treatments: control handling with and without local anaesthesia, dehorning, dehorning after local anaesthesia, dehorning followed by wound cautery, and dehorning after local anaesthesia followed by wound cautery. Blood samples were taken before and after dehorning.
Results Dehorning caused an increase in plasma cortisol concentrations, which decreased a little to plateau values and then declined to pretreatment values 3 to 4 h after dehorning. The peak was smaller after local anaesthesia was administered but when its effects wore off, cortisol concentrations increased and thereafter were similar to those in the dehorned animals. The combination of local anaesthesia and cautery resulted in a plasma cortisol response similar to those in control calves with or without local anaesthesia.
Conclusions If plasma cortisol concentrations reflect the distress being experienced by the calves, then local anaesthesia reduces the acute distress for about 3 h after dehorning but not during the subsequent 3 to 4 h. Combining local anaesthetic and cautery prevented the significant increase in plasma cortisol following dehorning and may eliminate the acute distress caused by scoop dehorning. 相似文献
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RT NORRIS CL McDONALD RB RICHARDS MW HYDER SP GITTINS GJ NORMAN 《Australian veterinary journal》1990,67(7):244-247
In the first of 2 experiments, a simulated voyage was conducted to examine the effects of various treatments on bodyweight change and feeding frequency of inappetant sheep at the end of lot-feeding (non-feeders). The treatments, applied during simulated shipping, were: normal quantities of feed and length of troughs; extra trough length; extra feed. Adult Merino wethers (n = 108) were used in each treatment. A voyage to the Middle East was then conducted to establish whether shipboard mortality could be reduced by separating non-feeders (n = 305) from feeders (n = 5,620) late in the feedlot hase and housing the groups separately aboard ship. A control group of non-feeders (n = 215) mixed with feeders (n = 5,732) was used for comparison. Bars (marker bars), containing a coloured dye, were attached to feed troughs to mark sheep that fed. Most non-feeders (82%) began eating when placed in shipping pens in both studies. However, there was no significant difference in percentage of sheep that fed between non-feeders given extra trough length or extra feed compared with non-feeders given standard management at any stage of simulated shipping. There was no significant difference in mean bodyweights between treatment groups on days 1, 8 and 15 of simulated shipping. Differences in bodyweight on d 22 were probably associated with different levels of gut fill. Death rates were not significantly different in separated and control groups (1.1%, 0.9%, P = 0.6) in the voyage of 14 d to the Middle East.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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Marconni Victor da Costa Lana Noemi Rovaris Gardinali Raquel Aparecida Sales da Cruz Letícya Lerner Lopes Gustavo Sousa Silva João Garcia Caramori Júnior Anderson Castro Soares de Oliveira Marcos de Almeida Souza Edson Moleta Colodel Amauri Alcindo Alfieri Caroline Argenta Pescador 《Tropical animal health and production》2014,46(2):399-404
The objectives of this study were to (1) investigate the occurrence of hepatitis E virus (HEV) in pigs from large-scale and family-scale farms, (2) genetically characterize the strains isolated, and (3) study the pathogenesis of swine HEV infection via immunohistochemistry. A total of 50 pigs from 10 farms in Mato Grosso State, Brazil were divided according to type of production system into either large-scale farms (n?=?5) or family-scale farms (n?=?5). Samples of liver, gallbladder, small and large intestines, bile, and feces from the pigs were analyzed by nested PCR with primers targeting the ORF2 region of HEV and by immunohistochemistry. Of the eight HEV-positive samples from pigs of family-scale farms, phylogenetic analysis revealed that seven of the swine HEV isolates clustered with subtype 3b of genotype 3 and one isolate was categorized with subtype 3 f. The HEV antigen was detected mainly in the small intestine samples from family-scale farms, suggesting an early stage HEV infection. HEV was not detected in the samples of pigs from large-scale farms, reinforcing the need for additional studies to evaluate the risk of transmission of HEV to humans from pigs from family-scale farms in Mato Grosso State. 相似文献
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JI Yun HJ Park MH Park MS Kim JH Choi E Lee SP Gong JM Lim ST Lee 《Reproduction in domestic animals》2014,49(5):705-710
Recently, isolation and in vitro culture of putative spermatogonial stem cells (SSCs) in the domestic cat have been conducted. However, the cellular niche conditions that facilitate the establishment and long‐term maintenance of feline SSCs (FSSCs) have not been described. Therefore, we investigated the type of feeder cells used to stimulate colony formation and growth of FSSCs among the various factors in the FSSC niche. Spermatogonial stem cells isolated from feline testes were cultured on mitotically inactivated testicular stromal cells (TSCs) derived from cats, dogs and mice, and mouse embryonic fibroblasts (MEFs). The formation and growth of colonies derived from SSCs cultured on each type of feeder cell were identified at passage 0, and the morphology, alkaline phosphatase (AP) activity and expression of SSC‐specific genes in surviving colonies were investigated at passage 4. Among these diverse feeder cells, TSCs from cat showed the greatest colony formation, growth and maintenance of FSSCs, and SSC colonies cultured by passage 4 showed a typical dome‐shaped morphology, AP activity and expression of SSC‐specific genes (NANOG, OCT4, SOX2 and CD9). Accordingly, these results demonstrate that feline TSCs could be used as feeder cells to support the establishment and maintenance of SSCs from domestic cats. 相似文献
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Anat Lerner Ezekiel Baudoin Yvan Moenne-Loccoz Edouard Jurkevitch 《Soil biology & biochemistry》2006,38(6):1212-1218
Nucleic acid-based techniques allow the exploration of microbial communities in the environments such as the rhizosphere. Azospirillumbrasilense, a plant growth promoting rhizobacterium (PGPR), causes morphological changes in the plant root system. These changes in root physiology may indirectly affect the microbial diversity of the rhizosphere. In this study, the changes in the rhizobacterial structure following A. brasilense inoculation of maize (Zea mays) plants was examined by PCR-denaturating gradient gel electrophoresis (DGGE) and automated ribosomal intergenic spacer analysis (ARISA), using two universal primers sets for the 16S rRNA gene, and an intergenic 16S-23S rDNA primer set, respectively. Similar results were obtained when using either ARISA or DGGE performed with these different primer sets, and analyzed by different statistical methods: no prominent effect of A. brasilense inoculation was observed on the bacterial communities of plant roots grown in two different soils and in different growth systems. In contrast, plant age caused significant shifts in the bacterial populations. 相似文献
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Evidence for ozone formation in human atherosclerotic arteries 总被引:1,自引:0,他引:1
Wentworth P Nieva J Takeuchi C Galve R Wentworth AD Dilley RB DeLaria GA Saven A Babior BM Janda KD Eschenmoser A Lerner RA 《Science (New York, N.Y.)》2003,302(5647):1053-1056
Here, we report evidence for the production of ozone in human disease. Signature products unique to cholesterol ozonolysis are present within atherosclerotic tissue at the time of carotid endarterectomy, suggesting that ozone production occurred during lesion development. Furthermore, advanced atherosclerotic plaques generate ozone when the leukocytes within the diseased arteries are activated in vitro. The steroids produced by cholesterol ozonolysis cause effects that are thought to be critical to the pathogenesis of atherosclerosis, including cytotoxicity, lipid-loading in macrophages, and deformation of the apolipoprotein B-100 secondary structure. We propose the trivial designation "atheronals" for this previously unrecognized class of steroids. 相似文献