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排序方式: 共有178条查询结果,搜索用时 31 毫秒
51.
JC O''KELLY 《Australian veterinary journal》1991,68(8):261-263
Factors influencing the serum concentrations of gamma-globulin (gamma-G) during the neonatal period were studied in Shorthorn x Hereford (SH), Africander x SH and Brahman x SH calves born to cows grazing in a tropical environment. There were no significant effects of age of dam, sex or breed of calf on the gamma-G concentrations of calves from birth to 48 hours of age. Concentrations of gamma-G fell within two ranges: group A, 10 to 20 g/l and group B, 35 to 70 g/l. The number of calves in each group was not significantly different between breeds and overall 30% of calves were in group A. Body weight gain from birth to 10-day-old was greater (P less than 0.01) in calves in group B than in group A. Plasma cholesterol concentrations in 10-day-old calves were higher in group B than in group A calves supporting the interpretation that group B calves had higher milk intakes. Identification of calves receiving adequate amounts of colostrum has fundamental significance for the efficient production of cattle in the tropics. 相似文献
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S Caceres G Silvan L Martinez‐Fernandez MJ Illera P Millan B Monsalve L Peña JC Illera 《Reproduction in domestic animals》2014,49(4):611-617
Isoflavones are the most common phytoestrogens found in human diets. However, it is still not clear whether isoflavones have effects on the reproductive and the endocrine systems under normal dietary intake and overdose. The aim of this study was to determine how the most important isoflavones, genistein and daidzein, affect androgen and glucorticoid levels on male prepuberal rats. A hundred and seventy‐five 30‐day‐old male Wistar rats were dosed orally by stomach tube every day for 35 days, with saline solution, low and high doses of genistein, daidzein and a mixture of both. Serum samples were analysed by an enzyme immunoassay for hormone determinations. In control group, there was a peak of testosterone (T) and dihydrotestosterone levels associated to the onset of puberty, at the third week. However, in low‐dose groups, the same peak was found at the fourth week (p < 0.05), indicating a delay in the onset of puberty in these groups. Moreover, high doses groups serum androgen levels were significantly lower (p < 0.05) than the control group from the first week until fifth week. This fact was supported by a epididymal histological analysis that indicate in low doses there were several content of spermatozoa at fourth week and in high doses there were few content of spermatozoa. Besides, corticosterone levels followed the same pattern of androgens in all groups. We can conclude that oral administration of isoflavones in male rats decreased the secretion of androgens and glucocorticoids causing a delay in the onset of puberty and may cause physiological and developmental problems. 相似文献
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Serum and Tissue Steroid Hormone Levels in Canine Mammary Tumours: Clinical and Prognostic Implications
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FL Queiroga D Pérez‐Alenza A González‐Gil G Silván L Peña JC Illera 《Reproduction in domestic animals》2015,50(5):858-865
Hormonal dependency of canine mammary tumours (CMT) has been studied over the last few decades. However, studies assessing the prognostic and predictive potential of serum and/or tissue steroid hormone levels are still scarce in CMT. To the best of our knowledge, this is the first report relating serum and tissue levels of steroid hormones and prognosis in dogs. Serum and tumour tissue from 45 female dogs with spontaneous CMT were included in the study. Moreover, serum and normal mammary tissue from 13 healthy female dogs were also included as controls. Steroid hormones were determined by competitive enzyme immunoassay. Overall, levels of steroid hormones in serum and tissue homogenates were significantly different between malignant and benign mammary tumours (p < 0.01), except for progesterone (P4) serum levels that revealed no statistical differences between groups. In malignant tumours, oestrone sulphate (SO4E1), dehydroepiandrosterone (DHEA), androstenedione (A4), testosterone (T) and P4 elevated tissue concentrations were significantly associated with tumour relapse and/or distant metastasis during follow‐up. A significant association was found between elevated tissue SO4E1 (p = 0.003), 17β‐oestradiol (E2) (p = 0.036), DHEA (p = 0.022), A4 (p = 0.001) and P4 (p = 0.013) concentrations and shorter disease‐free survival and overall survival in female dogs with malignant mammary tumours. The high levels of tissue steroids found in cases of poor prognosis open the possibility of additional new therapeutic approaches. Future clinical trials will be needed to clarify the usefulness of targeting steroid hormones in the treatment of this neoplastic disease. 相似文献
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Richarte F. Acasio Amado de los Santos Peter Vander Zaag 《American Journal of Potato Research》1986,63(3):162-170
Improper seed potato storage was considered to be a major constraint in the Philippine highlands. For this reason a program of introducing diffused light storage technology was launched in early 1978 to resolve the problem. Scattered reports indicated a rapid adoption of the technology by the farmers; however no follow-up had been done to determine the extent of adoption. Hence, a survey was conducted from July to December 1983 to assess the impact of the diffuse light storage (DLS) technology among potato farmers. Of the 1412 farmers interviewed 42% have adopted the DLS technology. Nearly all adopters have simply modified existing structures to permit diffuse light to enter and store tubers in thin layers. Only 1.5% have constructed simple storages. Generally the farmers who accepted the technology are close to the main access road and are the more progressive farmers. Most reported better quality seed and subsequent higher yields as a result of the technology. Conversely, 35% of the respondents, primarily in remote areas, were not even aware of the DLS technology. Another 27% of the respondents planned to accept the technology by improving their traditional storages. To increase the utilization of the technology, more extension effort needs to be put forth demonstrating the benefits of the DLS by improving existing storage structures found in remote areas where potato production is not well developed. 相似文献
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CASE HISTORY: A neonatal Thoroughbred foal was presented with rib fractures and left forelimb lameness secondary to dystocia. CLINICAL FINDINGS: The foal developed a head tilt, seizures and watery diarrhoea during hospitalisation and died at 7 days of age. Histological examination of the brain and spinal cord revealed a suppurative meningoencephalomyelitis with vasculitis, and numerous intralesional, gram-negative bacilli. Similar microscopic lesions were noted in the lungs, renal medullary interstitium, and umbilicus. Bacilli in the brain, spinal cord and umbilicus were identified immunohistochemically as Salmonella group B. Salmonella agona was isolated in pure culture from the brain, lung, liver, kidney, and intestine. CONCLUSION: This is the first report of meningoencephalomyelitis and septicaemia due to Salmonella infection in an equine neonate. 相似文献
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J Sarabia Fragoso M Pizarro Díaz JC Abad Moreno P Casanovas Infesta A Rodriguez‐Bertos K Barger 《Reproduction in domestic animals》2013,48(2):345-352
In a farm of grandparent broiler breeder chickens, we followed the development of 350 roosters from 6 to 55 weeks of age. Data collected and evaluated from these males included body weight, testicular weight, histologic and immunohistochemistry studies of the testes, hormone levels (testosterone, estradiol and corticosterone) and sperm production. The objective was to understand the factors that affect or influence hatch loss that is commonly observed after 45 weeks of age in breeder flocksare often correlated to broiler breeder male chickens. The results of this study showed that in conjunction with the weight of the rooster, the testicle weight increases quickly after the rooster receives light stimulation. At an older age, the study showed that there is a process of testicular shrinkage, and the same effect is seen in sperm production and testosterone levels in broiler breeder roosters. From the histology evaluation, we defined 5 histologic phases that illustrate the evolution of the testicular tissue: perinatal, infantile, puberty, adult and senile. We observed that the adult males with a body weight <3800 g were infertile or had subfertile levels and also had low levels of testosterone and high levels of corticosterone. In contrast, the heaviest males showed correct testicular vitality, high levels of testosterone and low levels of corticosterone. However, the roosters that had acquired this high body weight were also at risk of having less complete copulations because of their physical mass. The loss of uniformity of the males and the appearance of hierarchies within the flock accompany a decline in the percentages of hatches as a consequence of the poor confirmation of the males for copulation or the restriction to the access to the females. Results of this study show that the decrease in fertility from 45 weeks of age has been associated with a decline in testicular weight, sperm production and the testosterone levels in animals with a sub‐par weight. Likewise, decreasing hatch in older flocks may also result from a loss of conformation, and the lack of complete copulations is possible because of animals that are grossly overweight. 相似文献