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排序方式: 共有510条查询结果,搜索用时 46 毫秒
91.
92.
Varga S Diez C Fernández L Alvarez J Katchicualula A Hidalgo CO Tamargo C Carbajo M 《Acta veterinaria Hungarica》2011,59(1):129-139
The optimum culture system for in vitro matured and fertilised oocytes still remains to be clarified. Culture media (CM) for mammalian embryos are routinely prepared fresh for use and preserved under refrigeration during one or two weeks. The purposes of this work were (1) to compare the efficiency of a synthetic oviduct fluid (SOF) with two different bovine serum albumin (BSA) concentrations (3 and 8 g/L) for the in vitro production of bovine blastocysts, (2) to test the effect of timing on adding fetal calf serum (FCS) to the SOF, and (3) to evaluate the effects on bovine embryo development of freezing and lyophilisation as procedures for preserving the SOF. Supplementation of SOF with 3 g/L BSA increased Day-7 blastocyst expansion rates (18.3 ± 1.6 vs. 14.4 ± 0.7; P < 0.05), although no differences in hatching rates were found. Addition of FCS to SOFaa (SOF with amino acids) medium supplemented with sodium citrate (SOFaaci) at 48 and at 72 h post-insemination (PI) allowed obtaining higher Day-6 embryo development rates than when FCS was added at 18 or 96 h PI (Day-6 morulae + blastocyst rate: 30.0 ± 1.1, 40.8 ± 1.1, 43.9 ± 2.3 and 39.3 ± 0.5 for FCS addition at 18, 48, 72 and 96 h, respectively). Hatching rates were significantly improved when serum was added at 72 h PI. Finally, both refrigeration and lyophilisation appeared as useful cryopreservation procedures for SOFaaci, although a significant loss of its ability to support embryo development, compared to the control fresh culture medium, was observed. 相似文献
93.
Patricia Miretzky Monica Rodriguez Avendaño Carolina Muñoz Alejandro Carrillo-Chavez 《Journal of Soils and Sediments》2011,11(4):619-627
Purpose
Tessier's sequential extraction method is usually used to study metal parting among different phases in soils. The main objective of this study was to determine the redistribution of trace metals which were added simultaneously to a sandy loam soil by use of the fractional distribution and reduced partition indexes and the risk of assessment code (RAC). 相似文献94.
95.
Ivan Carvalho Filho Daniele Botelho Diniz Marques Carolina Filardi de Campos José Domingos Guimarães Simone Eliza Facioni Guimarães Paulo Sávio Lopes Fabyano Fonseca e Silva Renata Veroneze 《Reproduction in domestic animals》2020,55(1):38-43
Nellore is the main cattle breed used in Brazil, being the largest commercial herd in the world. Beyond the importance of male reproductive efficiency for farm profit, the use of reproductive techniques, mainly artificial insemination, turns the evaluation of male reproductive traits even more important. Estimation of genetic parameters increases the knowledge on traits variances and allows envisaging the possibility of the inclusion of new traits as selection criterion. Genetic parameters for fifteen traits that can be classified as testicular biometry or physical and morphological semen traits were estimated for a Nellore bull population ranging from 18 to 36 months. Single-trait and bi-trait animal models were used for (co)variance components estimation. The contemporary group was considered as fixed effect and age at measurement as covariable. Scrotal circumference presented heritability of 0.47 ± 0.12. This value is similar to the heritabilities found for all testicular biometry traits (0.34–0.48). Sperm progressive motility, which has a direct effect on bull fertility, presented low heritability (0.07 ± 0.08). Major and total sperm defects presented moderate to high heritabilities (0.49 ± 0.18 and 0.39 ± 0.15, respectively), indicating that great genetic gain can be obtained through selection against sperm defects. High and positive genetic correlations were observed among testicular biometry traits, which also presented favourable genetic correlations with physical and morphological traits of the semen with magnitude ranging from high to low. Scrotal circumference presented moderate to high and favourable genetic correlations with sperm progressive motility, sperm turbulence, major sperm defects and total sperm defects. Thus, the selection for scrotal circumference results in favourable correlated genetic response for semen quality. The results show that the use of scrotal circumference as reference trait for bull fertility is appropriate, since it presents high heritability and favourable genetic correlation with semen quality. 相似文献
96.
Maria Florencia Gallelli Carolina Bianchi Enzo Zampini Virginia Trasorras Mariana Gambarotta Marcelo Miragaya 《Reproduction in domestic animals》2020,55(1):74-80
The aim of this study was to characterize corpus luteum vascularization and its association with plasma progesterone concentration in early stages of pregnancy, when maternal recognition of pregnancy is expected to occur. In all animals, both plasma progesterone concentration and corpus luteum vascularization increased from Day 6 to Day 8 post-mating and afterwards in non-pregnant llamas they started to decrease to reach basal levels around Days 12 to 14 post-mating, while in pregnant animals, both variables remained elevated until the end of the study. A lineal positive relationship between corpus luteum vascularization and plasma progesterone concentration was observed in pregnant (r2 = .46, p < .0001) and non-pregnant llamas (r2 = .66, p < .0001). Pregnant animals showed higher plasma progesterone concentration and corpus luteum vascularization than the non-pregnant ones from Day 12 post-mating until the end of the study (p ˂ .05 and p ˂ .01, respectively). These results suggest that maternal recognition of pregnancy should occur before Day 12 post-mating in order to expand luteal lifespan, maintaining corpus luteum vascularization and progesterone production. Also, the assessment of CL vascularization area could be a useful and non-invasive method for early pregnancy diagnosis due to its association with plasma progesterone concentration. 相似文献
97.
Costa Olmar Antônio Denardin Ferreira Otoniel Geter Lauz Henrique Douglas Sampaio Vaz Ricardo Zambarda Fluck Ana Carolina Paris Wagner Kröning Alexsandro Bahr Griffith Luis Alberto Alonzo Matos Oscar Ivan Tuz 《Tropical animal health and production》2020,52(2):547-554
Tropical Animal Health and Production - The aim was to monitor the growth, the dry mass accumulation curve, and the structural photosynthetic components of forage peanut pasture, in different... 相似文献
98.
Juliana Lis Mendes de Brito Thales Simioni Amaral Ludmilla Moura de Souza Aguiar Carolina Madeira Lucci 《Anatomia, histologia, embryologia》2020,49(2):307-314
The aim of this study was to analyse the reproductive aspects of male bats of three common species of the Phyllostomidae family: Artibeus lituratus, Platyrrhinus lineatus and Sturnira lilium, during dry and rainy months in a specific area of the Cerrado biome. Body weight was significantly higher during the dry months for S. lilium. The gonadosomatic index (GSI) and testicular weight were not significantly different between dry and rainy periods. The tubular parameters were significantly bigger in A. lituratus than in the other two species during both periods. No difference in the tubular/interstitial ratio was observed in any of the species during both periods. In both periods, all sperm cells and germ cell developmental stages were visible on seminiferous tubules whereas sperm cells were observed in epididymides of all sampled animals. The percentage of morphologically normal sperm was low (35%–60%), with no difference between periods. Spermatozoa from A. lituratus presented a leaf-shaped head, while the head was round-shaped in the other two species. In conclusion, our data suggest that males from the three studied species did not present reproductive latency during the most critical weather periods (dry and rainy months) in the metropolitan region of Brasilia, Brazil. 相似文献
99.
Isadora A. Silva Larissa C. Vieira Vanda Regina M. Mancini Ana Carolina L. Faillace Marcelo Ismar S. Santana 《Anatomia, histologia, embryologia》2020,49(2):184-195
Cockatiels are popular pets. Still, despite medical and surgical relevance, the radiographic anatomy of the cockatiel (Nymphicus hollandicus) skeleton, like that of different wild and exotic bird species, has seldom been described. This study set out to describe the radiographic anatomy of the cockatiel skeleton. Twelve adult male and nine adult female specimens were radiographed using a digital X-ray system and different views. The radiographic anatomy of these birds was similar to that of other Psittacidae. However, some particularities inherent to the target species were detected, such as the presence of four flexion zones in the skull (craniofacial, nasal, jugal arch and palatine), complete bony orbit comprising a suborbital arch, 34–38 vertebrae (10 or 11 cervical, 8 or 9 thoracic, 9 or 10 lumbosacral, 5 or 6 caudal vertebrae and a pygostyle comprising 2 fused vertebrae), eight or nine pairs of ribs and a notarium made up of fused T2–T6 vertebrae. Poor radiopacity of the notarium, ribs and respective uncinate processes, and synsacral vertebrae made demarcation of these structures difficult. The appendicular skeleton of the cockatiel was very similar to that of other Psittacidae, and there were no gender-related differences. 相似文献