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81.
Crossbred cows (n = 1073) from five locations had oestrous cycles synchronized with 100 μg of GnRH IM and insertion of controlled internal drug release device (CIDR) on Day 0 followed by 25 mg of PGF IM and CIDR removal on Day 7. Kamar® patches were placed on all cows at CIDR removal. Cows were observed three times daily for oestrus after PGF administration. In the Ovsynch‐CIDR group, cows detected in oestrus (n = 193) within 48 h after PGF were inseminated using the AM–PM rule. Among these cows, 80 received and 113 did not receive a second GnRH at 48 h after PGF. Cows (n = 345) not detected in oestrus received a second GnRH at 48 h after PGF on Day 9, and fixed‐time AI 16 h after the GnRH on Day 10. In the CO‐Synch‐CIDR group, cows detected in oestrus (n = 224) within 48 h after PGF were inseminated using the AM–PM rule. Among these cows, 79 received and 145 did not receive a second GnRH at 64 h after PGF. Cows (n = 311) not detected in oestrus received a second GnRH on Day 10 at the time of AI, 64 h after PGF. The AI pregnancy rates were not different between the Ovsynch‐CIDR and CO‐Synch‐CIDR groups (p = 0.48). There were no differences in the AI pregnancy rates for cows inseminated at a fixed time (p = 0.26) or at detected oestrus (p = 0.79) between the treatment groups. Among cows inseminated in oestrus, there were no differences in the AI pregnancy rates between cows that received or did not receive the second GnRH (p = 0.47). In conclusion, acceptable AI pregnancy rates can be achieved with or without inclusion of oestrus detection in the Ovsynch‐CIDR and CO‐Synch‐CIDR protocols. Among cows detected in oestrus, cows that received a second GnRH yielded similar pregnancy rates when compared with cows that did not receive the second GnRH.  相似文献   
82.
The use of selective breeding is still relatively limited in aquaculture species. Information on such activities is sparse, hindering an overall evaluation of their success. Here, we report on the results of an online survey of the major aquaculture breeding companies operating in Europe. Six main reared fish species were targeted. A total of 31 respondents contributed to the survey, representing 75 % of European breeding organizations. Family-based breeding schemes were predominant, but individual selection was more frequently applied in marine species. Artificial fertilization is the preferred means of reproduction; however, mass spawning is often used as a fallback method. The most frequently selected trait is growth performance, but the number of selected traits has been increasing over the years through the addition of traits such as disease resistance or product quality. The use of molecular tools is now common in all programs, mainly for pedigree traceability. An increasing number of programs use either genomic or marker-assisted selection. Results related to the seed production market confirmed that for Atlantic salmon there are a few dominant players at the European level, with 30–50 % market share. Only part of the European fish aquaculture industry today fully exploits selective breeding to the best advantage. A larger impact assessment still needs to be made by the remainder, particularly on the market share of fish seed (eggs, larvae or juveniles) and its consequences for hatchery stability.  相似文献   
83.
The aim of this study was to determine the optimal maturation culture period of ovum pick up (OPU)‐derived cumulus oocytes complexes (COCs) in relation to their developmental capacity. Embryo production, embryo cryotolerance, post‐transfer embryonic survival and calf characteristics such as gestation length, birthweight and sex ratio were investigated. This retrospective study covers the analyses of ovum pick up –in vitro production and calving results from a commercial programme that took place between March 1994 and September 2004. Donors were both heifers (of which approximately 90% pregnant) and cows (of which approximately 10% pregnant). Embryo production analyses were based on 7800 OPU sessions conducted from January 1995 until January 1999. Analyses of calving rate were based on 13 468 embryo transfers performed during January 1995 until May 2002. Analyses on calf characteristics were based on 2162 calves born between March 1994 and September 2004. The in vitro maturation culture period ranged from 16 to 28 h. The mean production rate of transferable embryos was 16.5% (1.2 embryos per OPU session). Length of maturation culture period did not affect the production of transferable embryos. Mean calving rate was 40.9% and 38.7% for fresh and frozen/thawed embryos, respectively. Calving rate was not affected by the maturation culture period. Mean birthweight, gestation length and proportion of male calves were 46 kg, 281.9 days and 52.8%, respectively. Maturation culture period did not affect these variables. In conclusion, this study shows that the in vitro maturation culture period within the range of 16–28 h does not affect in vitro embryo production, embryo cryotolerance, post‐transfer embryonic survival and calf characteristics, suggesting that all COC batches collected by OPU on the same day, can be fertilized in one IVF session without a significant loss in the production from oocyte to calf.  相似文献   
84.
Summary Stereological procedures were used to estimate the amount of amyloid deposition in the pancreatic islets of 83 cats from random sources in south-eastern Queensland. Most had only minor deposits of less than 20% of islet volume (median 9%), but deposits equal to more than 50% of the islet volume were found in 10% of the cats. Amyloid deposition in pancreatic islets was correlated with the age of the cat. Although similar observations have been made previously in cats from the USA, the frequency of amyloid deposition was higher in this population of cats from south-eastern Queensland.  相似文献   
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The present work studied different spermatozoa parameters and the ability of frozen rabbit spermatozoa to fertilize, in vitro, in vivo‐matured oocytes, as a test to predict their in vivo fertility and prolificacy. Semen from rabbit bucks was frozen using two freezing protocols [in a freezer at ?30°C or in liquid nitrogen vapour (LNV)]. For the in vivo trial, females were inseminated with frozen‐thawed spermatozoa. Oocytes used for in vitro testing were recovered 14 h after ovulation induction from donors and co‐incubated with 2 × 106 frozen‐thawed spermatozoa during 4 h at 37°C in Tyrode's medium under an atmosphere of 5% CO2 in air with maximal humidity. After co‐incubation period, presumptive zygotes were cultured in TCM199 supplemented with 20% foetal bovine serum (FBS), under the same conditions described above. Although no statistical differences were observed between freezing protocols in seminal parameters [motility rate: 40 and 35%, VCL: 35 and 46 μm/s, amplitude of lateral head displacement (ALH): 1.7 and 2.4 μm, for semen frozen at ?30°C and in LNV, respectively], significant differences were noted in the fertilizing ability in vivo and in vitro. Semen frozen at ?30°C showed the highest fertilizing ability in vitro (26.7% vs 6.2 and 8.7% for semen frozen at ?30°C, in LNV and fresh semen, respectively) and the lowest fertility rate in vivo (21.7% vs 64.2% and 70.6% for semen frozen at ?30°C, in LNV and fresh semen, respectively). Sperm frozen at ?30°C seemed to be more capacitated.  相似文献   
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89.
Herpes simplex virus-1 (HSV-1) encephalitis (HSE) is the most common form of sporadic viral encephalitis in western countries. Its pathogenesis remains unclear, as it affects otherwise healthy patients and only a small minority of HSV-1-infected individuals. Here, we elucidate a genetic etiology for HSE in two children with autosomal recessive deficiency in the intracellular protein UNC-93B, resulting in impaired cellular interferon-alpha/beta and -lambda antiviral responses. HSE can result from a single-gene immunodeficiency that does not compromise immunity to most pathogens, unlike most known primary immunodeficiencies. Other severe infectious diseases may also reflect monogenic disorders of immunity.  相似文献   
90.
Exposure to microbes during early childhood is associated with protection from immune-mediated diseases such as inflammatory bowel disease (IBD) and asthma. Here, we show that in germ-free (GF) mice, invariant natural killer T (iNKT) cells accumulate in the colonic lamina propria and lung, resulting in increased morbidity in models of IBD and allergic asthma as compared with that of specific pathogen-free mice. This was associated with increased intestinal and pulmonary expression of the chemokine ligand CXCL16, which was associated with increased mucosal iNKT cells. Colonization of neonatal-but not adult-GF mice with a conventional microbiota protected the animals from mucosal iNKT accumulation and related pathology. These results indicate that age-sensitive contact with commensal microbes is critical for establishing mucosal iNKT cell tolerance to later environmental exposures.  相似文献   
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