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排序方式: 共有239条查询结果,搜索用时 15 毫秒
201.
B Leboeuf JA Delgadillo E Manfredi A Piacère V Clément P. Martin M Pellicer P Boué R de Cremoux 《Reproduction in domestic animals》2008,43(S2):379-385
Reproductive seasonality observed in all breeds of goats originating from temperate latitudes and in some breeds from subtropical latitudes can now be controlled by artificial changes in photoperiod. Short days stimulate sexual activity, while long days inhibit it. This knowledge has allowed the development of photoperiodic treatments to control sexual activity in goats, for both the buck and doe. In the French intensive milk production system, goat AI plays an important role to control reproduction and, in conjunction with progeny testing, to improve milk production. Most dairy goats are inseminated out of the breeding season with deep frozen semen, after induction of oestrus and ovulation by hormonal treatments. This protocol provides a kidding rate of approximately 65%. New breeding strategies have been developed, based on the buck effect associated with AI, to reduce the use of hormones. With the development of insemination with frozen semen, a classical selection programme was set up, including planned mating, progeny testing and the diffusion of proved sires by inseminations in herds. Functional traits have become important for efficient breeding schemes in the dairy goat industries. Based on knowledge gained over the past decade, the emphasis in selective breeding has been placed on functional traits related to udder morphology and health. New windows have been opened based on new molecular tools, allowing the detection and mapping of genes of economic importance. 相似文献
202.
203.
L Cattaneo ML Signorini J Bertoli JA Bartolomé NC Gareis PU Díaz GA Bó HH Ortega 《Reproduction in domestic animals》2014,49(6):1028-1033
To describe the epidemiology of cystic ovarian disease (COD), to find possible risk factors associated with the incidence of cysts and to analyse the impact of COD on the reproductive performance of dairy cows, databases from 22 dairy herds from the main dairy region in Argentina were retrospectively evaluated throughout a 3‐year period (2009–2011). A total of 248 COD cases over 9156 parturitions were recorded, resulting in a cumulative incidence rate of 2.7%. Cystic ovarian disease incidence density was lower during the first 100 days post‐partum (DPP) than during later stages of lactation. Seasonality had a significant influence on the disease presentation with higher incidence rates during winter and spring. Cows with a previous diagnosis of clinical mastitis showed 2.72 times more chances of developing ovarian cysts. Cystic cows had longer calving to first service and calving to conception intervals and lower conception rate than controls. 相似文献
204.
A Casao M Mata‐Campuzano L Ordás JA Cebrián‐Pérez T Muiño‐Blanco F Martínez‐Pastor 《Reproduction in domestic animals》2015,50(4):688-691
The presence of apoptotic features in spermatozoa has been related to lower quality and functional impairment. Members of the poly‐ADP‐ribose polymerases (PARP) familyare involved in both DNA repair and apoptosis, playing important roles in spermatogenesis. Poly‐ADP‐ribose polymerase can be cleaved by caspases, and the presence of its cleavage product (cPARP) in spermatozoa has been related to chromatin remodelling during spermatogenesis and to the activation of apoptotic pathways. There are no reports on immunodetection of cPARP in ram spermatozoa; thus, we have tested a commercially available antibody for this purpose. cPARP was microscopically detected in the acrosomal ridge of some spermatozoa (indirect immunofluorescence). A preliminary study was carried out by flow cytometry (direct immunofluorescence, FITC). Ram semen was extended in TALP and incubated for 4 h with apoptosis inducers staurosporine (10 μm ) or betulinic acid (200 μm ). Both inducers and incubation caused a significant increase in cPARP spermatozoa (0 h, control: 21.4±3.3%, inducers: 44.3±1.4%; 4 h, control: 44.3±2.4%, inducers: 53.3±1.4%). In a second experiment, we compared the sperm fractions after density gradient separation (pellet and interface). The pellet yielded a slightly lower proportion of cPARP spermatozoa (28.5±1.2% vs 36.2±2.0% in the interface; p < 0.001), and a 12‐h incubation increased cPARP similarly in both fractions (p < 0.001). cPARP seems to be an early marker of apoptosis in ram semen, although its presence in untreated samples was weakly related to worse quality (pellet/interface). We suggest to study the relationship of PARP and cPARP levels with between‐male differences on sperm fertility. 相似文献
205.
A 13-year-old Morgan gelding was examined for right forelimb lameness and tenosynovitis of the right common carpal sheath of the digital flexor tendons. The horse had moderate right forelimb lameness at the trot and marked effusion of the right common carpal sheath of the digital flexor tendons. Ultrasonographic examination revealed a soft tissue mass within the proximal pouch of the affected tendon sheath, located adjacent to the distal physis of the radius. Cytology and culture of the fluid revealed a sterile, eosinophilic tenosynovitis. Tenoscopic exploration confirmed the presence of a capsulated soft tissue mass. Thecotomy was required to fully debride the mass, which histology revealed to be a mast cell tumour. At 22 months postoperatively, the horse developed mild right forelimb lameness and eosinophilic tenosynovitis because of recurrence of the mastocytoma. Mastocytosis is a possible differential diagnosis in any horse exhibiting lameness associated with tenosynovitis. Surgical excision combined with rest and postoperative intrasynovial and systemic corticosteroids may be palliative. 相似文献
206.
由猪传统日粮所用饲料原料带来的成本和供应问题促使人们寻找更新的饲料原料,并以求最大程度地利用所选原料中的养分。 相似文献
207.
JC Monteiro JSA Gonçalves JA Rodrigues CF Lúcio LCG Silva MEOA Assumpção CI Vannucchi 《Reproduction in domestic animals》2009,44(S2):359-362
Poor sperm viability post-thaw has resulted in constant research into methods of cryopreservation of canine semen. One factor that may be involved in poor viability is sperm oxidative stress caused by excessive formation of reactive oxygen species. The present study was performed in order to evaluate the effect of different concentrations of ascorbic acid (AA) and glutathione (Glu) added to an extender for the freeze-thawing of dog sperm. Semen from five mature dogs was collected and frozen in two studies. Prior to and after freezing, sperm motility, morphology and membrane status were examined. In addition, sperm motility was examined up to 120 min after thawing to evaluate thermo-resistance. In study I, semen was collected twice from each dog. On both occasions, semen was divided into three aliquots: control, Glu 1 m m and Glu 5 m m . In study II, semen was collected twice and divided into three aliquots; control, AA 50 μ m and AA 250 μ m . Initial sperm motility was significantly higher in sperm diluted with AA 50 μ m ; sperm longevity, however, measured by a thermal-resistance test (TRT), was higher for Glu treatments. Higher concentration of Glu produced significant improvement in TRT and membrane status, whereas higher concentration of AA had a negative impact in sperm longevity. Antioxidant supplementation to semen freezing extenders improved semen quality post-thaw. Moreover, Glu had the most beneficial effect when supplemented at 5 m m . 相似文献
208.
Mining the ESROM: A study of breeding value classification in Manchego sheep by means of attribute selection and construction 总被引:1,自引:0,他引:1
M. Julia Flores Jos A. Gmez Juan L. Mateo 《Computers and Electronics in Agriculture》2008,60(2):167-177
Manchego sheep breeding represents an important factor in the economy in the region of Castilla-La Mancha, Spain. For this reason, the selection scheme for Manchego sheep (ESROM) was created to improve milk production in ewes belonging to the Manchego breed. This scheme relies on the use of several tools that depend on ewes’ genetic merit, which is calculated by using a sophisticated linear regression model. This paper presents a study about how the use of data mining techniques can help to approximate the genetic qualities of a ewe, before the official 6 months assessment is carried out, and by using less input. This study focuses on two well-known data mining tasks: pre-processing and classification. In the pre-processing stage, state-of-the-art algorithms and new proposals are used to identify relevant subsets of features by means of selection and construction. By using these subsets of highly predictive variables, different classifiers are trained, which in turn, are used to assess the genetic quality merit of any given ewe. As a result, original and constructed relevant variables have been identified for the target problem, this being a valuable result in itself. Furthermore, from simulated tests, reliable classification rates have been obtained when using the identified classifiers to approach ESROM tasks. 相似文献
209.
J. KOHOUT I. JAŠKOVÁ I. PAPOUŠEK A. ŠEDIVÁ V. ŠLECHTA 《Fisheries Management and Ecology》2012,19(3):252-263
Abstract Stocking has had a considerable effect on wild brown trout, Salmo trutta L., populations throughout Europe. To elucidate this impact and to outline further management strategies, the genetic structure of 25 wild populations and five hatchery stocks from Czech Republic and Slovakia were analysed using mitochondrial (control region) and nuclear DNA (microsatellites, LDH‐C1*) markers. Stocking practices have caused massive hybridisation between the Atlantic and Danube brown trout strains in the central Danube basin and have lead to a loss of among‐population divergence in Slovakia and the eastern part of Czech Republic. Comparison with studies from neighbouring countries revealed substantial differences in haplotype, allele frequencies and genetic diversity across Central Europe. Differences in stocking management and origin of breeding stocks appear to be crucial factors for the spatial variability of the genetic structure of brown trout. 相似文献
210.