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排序方式: 共有204条查询结果,搜索用时 62 毫秒
31.
I. García-Ispierto F. López-Gatius S. Almería J. Yániz P. Santolaria B. Serrano G. Bech-Sàbat C. Nogareda J. Sulon N.M. de Sousa J.F. Beckers 《Domestic animal endocrinology》2009
The aim of the present study was to investigate possible relationships between plasma concentrations of prolactin and the following factors throughout gestation in lactating dairy cows: photoperiod, season, milk production, Neospora caninum-seropositivity, twin pregnancy, and plasma concentrations of pregnancy associated glycoproteins-1 (PAG-1), progesterone and cortisol. Pregnancy was diagnosed by trans-rectal ultrasonography on Day 40 post-insemination and by palpation per rectum on Days 90, 120, 150, 180 and 210 or until abortion in aborting cows. Blood samples were collected from each animal immediately before each pregnancy diagnosis. The study population was comprised of 73 non-aborting (54 Neospora-seropositive cows) and 20 aborting cows (all Neospora-seropositive) cows. In non-aborting cows, GLM repeated measures of analysis of variance revealed that lactation number and days in milk had no effect on plasma prolactin concentrations throughout gestation, whereas high plasma prolactin concentrations were significantly associated with high plasma levels of cortisol and PAG-1, with Neospora-seropositivity, positive photoperiod (increasing day length), twin pregnancy, and with low plasma progesterone concentrations. An interaction among plasma prolactin, plasma cortisol and milk production was observed in that plasma prolactin concentrations differed significantly throughout gestation and were highest in high-producing cows with high cortisol levels. In Neospora-seropositive non-aborting versus aborting cows, mean prolactin concentrations failed to differ on Days 40, 90, 120, 150 and 180 of pregnancy, whereas prolactin values were significantly lower (P = 0.03) in aborting animals on Day 210 of pregnancy. Our results indicate that a positive photoperiod and Neospora-infection lead to increased plasma prolactin concentrations throughout gestation. Reduced prolactin concentrations detected in Neospora-seropositive aborting cows compared to non-aborting animals suggests a protective effect of prolactin in N. caninum infection. 相似文献
32.
B Serrano F López-Gatius P Santolaria S Almería I García-Ispierto G Bech-Sabat J Sulon NM de Sousa JF Beckers JL Yániz 《Reproduction in domestic animals》2009,44(4):600-605
This study was designed to establish the factors, if any, which could affect plasma pregnancy-associated glycoprotein-1 (PAG-1) expression in a study population of 87 pregnant, high-producing dairy cows. The factors examined were: semen providing breed (Holstein-Friesian vs Limousin), outcome of gestation (male vs female newborn, and singleton vs twin pregnancies), lactation number, milk production at pregnancy diagnosis, plasma progesterone concentration, season of gestation (warm period, March–November vs cool period, December–February), and day of gestation (40, 90, 120, 150, 180 and 210). Pregnancy was diagnosed by transrectal ultrasound on day 40 post-insemination and by palpation per rectum on days 90, 120, 150, 180 and 210. Blood samples were collected from each animal immediately before each pregnancy diagnosis. The relative contributions of the different factors on PAG-1 concentrations were evaluated by GLM repeated measures analysis of variance. No significant effects of the herd, foetal sex, milk production, lactation number and plasma progesterone concentrations were observed. In contrast, twin pregnancy, the use of Limousin semen and conception during the cool period were correlated with significantly increased plasma PAG-1 concentrations throughout gestation. Our data indicate that both cow well-being during early placental development, determined in our conditions by reduced heat stress when conception occurred in the cool season, and crossbreed pregnancies lead to improved PAG-1 production throughout the gestation period. 相似文献
33.
Serrano E Ferre I Osoro K Aduriz G Mateos-Sanz A Martínez A Atxaerandio R Hidalgo CO Ortega-Mora LM 《Veterinary parasitology》2006,135(3-4):197-203
Here, we studied the potential of Neospora caninum tachyzoites to infect heifers when administered in utero by artificial insemination via contaminated semen. Eighteen primiparous cyclic heifers were hormonally synchronized and artificially inseminated. Nine of them, which were inseminated with semen containing 10(7) live N. caninum NC-1 isolate-tachyzoites, reacted with seroconversion and a specific IFN-gamma response. Moreover, N. caninum DNA was demonstrated by a nested-PCR in the blood of all nine heifers and in brain, lungs, liver and uterine horn of several of them. In contrast, nine heifers inseminated with tachyzoite-free semen developed no antibody or IFN-gamma responses, and no parasite DNA was detected in blood or organs. At necropsy, viable embryos were detected in one and six of the infected and non-infected heifers, respectively. No specific Neospora DNA was detected in any of the embryos. This study provides evidence that intrauterine inoculation via contaminated semen cause N. caninum infection in cattle. 相似文献
34.
试验旨在研究饲粮中主要谷物和谷物的几何平均粒径(GMD)对20~48周龄罗曼褐壳蛋鸡生产性能与蛋品质的影响。试验选择960只罗曼褐壳蛋鸡,采用完全随机设计为6×2×3,共分6个处理组.谷物饲粮分别为玉米和小麦,谷物粉碎粒度分别为6、8、10mm。每个处理设8个重复,每个重复20只。所有的饲粮配方设计中包含50%的玉米或小麦。每4周记录生产性能结果,第48周龄时测量蛋品质。试验结果表明,GMD为10mm时鸡采食量显著高于GMD为6和8mm时(P〈0.05),说明粗糙的谷物粉碎粒度一定程度上有助于提高蛋鸡的采食量,而对蛋品质参数均没有显著影响。可以得出结论,谷物类型与谷物GMD除了影响早期罗曼褐壳蛋鸡采食量随谷物粉碎粒度的增加而增加外,其生产性能和蛋品质指标变化均不显著。 相似文献
35.
36.
Rodrigo BrionesLuis Serrano Rached Ben YounesIñaki Mondragon Jalel Labidi 《Industrial Crops and Products》2011,34(1):1035-1040
Polyol production from chemical modification of date seeds has been investigated through oxypropylation and liquefaction techniques (using organic solvents in the presence of a catalyst). The obtained products were characterized using infrared spectroscopy analysis, 1H NMR, thermogravimetric analysis and other parameters such as hydroxyl number (IOH) and viscosity. Results showed that 93% of the solid substance was converted into polyol in the oxypropylation reaction at the date seeds/propylene oxide ratio of 0.25 and 10% potassium hydroxide at 160 °C. The oxypropylated product has IOH of 779 mg KOH/g and viscosity of 6.9 Pa s. Regarding the liquefaction technique, results show that a yield of 95% was obtained at the date seeds/liquefying solvent ratio of 0.25 in 60 min of reaction at 160 °C. The liquefied product shows IOH of 336 mg KOH/g and viscosity of 0.9 Pa s. 相似文献
37.
Two Phytophthora species causing decline of wild olive (Olea europaea subsp. europaea var. sylvestris) 下载免费PDF全文
Since 2009, a severe decline leading to mortality has been observed affecting nearly 5 ha of a wild olive woodland of high ecological value in Seville, southern Spain. Phytophthora cryptogea and P. megasperma were consistently isolated from roots and rhizosphere of trees with symptoms sampled in 2009, 2011 and 2013. The isolates were identified on the basis of colony and reproductive structure morphology as well as temperature–growth relationships, and identification was further corroborated by their ITS and β‐tubulin sequences. Koch's postulates were demonstrated for both species on 1‐year‐old wild olives. Pathogenicity tests showed that both Phytophthora spp. are highly aggressive pathogens, although temperature–growth requirements for each species were distinct. As a consequence, the two species may be active in different seasons and their epidemiology may be differently influenced by global climate change, and they may show their active periods in different climatic scenarios. The climate change models for the Mediterranean Basin forecast a global temperature increase that favours the more thermophilic P. cryptogea. The high susceptibility to phytophthora root rot should not be disregarded in olive breeding programmes where wild olive is used as a source of resistance to verticillium wilt. 相似文献
38.
B. Serrano S. Almería I. García-Ispierto J.L. Yániz A. Abdelfattah-Hassan F. López-Gatius 《Research in veterinary science》2011,90(3):457-462
Pregnancy is characterized by transient changes in the maternal immune system, also evident at peripheral level. The present study analyzes the kinetics and possible factors affecting peripheral white blood cell populations throughout pregnancy in a herd of high-producing dairy cows chronically infected or not with Neospora caninum. We examined 54 pregnant parous cows: 29 Neospora-seronegative and 25 Neospora-seropositive cows. Blood samples were collected on Days 90, 120, 150, 180 and 210 of gestation. General Linear Model (GLM) repeated measures analysis of variance showed that the interaction Neospora-seropositivity × parity significantly affected total leukocyte, neutrophil and monocyte counts with lower levels of total leukocytes, lower neutrophil and higher monocyte counts recorded in primiparous Neospora-seropositive cows. In addition, N. caninum-seropositive cows had significantly increased monocyte counts on Day 180 of gestation compared to seronegative ones. Other factors significantly associated with changes in total and/or differential leukocyte profiles were period of pregnancy, season, twin pregnancy and milk production. In conclusion, a parity-associated effect of chronic N. caninum infection was observed on peripheral blood cell profiles in dairy cattle during gestation. 相似文献
39.
Nacira Muñoz Maria Eugenia Soria-Díaz Hamid Manyani Rocío Contreras Sánchez-Matamoros Antonio Gil Serrano Manuel Megías Ramiro Lascano 《Biology and Fertility of Soils》2014,50(2):207-215
The establishment of a symbiotic interaction involves a signal exchange between the host legume (flavonoids) and the nitrogen-fixing rhizobia (nodulation factors (NFs)). Likewise, abiotic stress conditions, such as salinity and drought, strongly reduce the nodulation process, possibly affecting also the signal exchange. In this work we characterized the structure and biological activity of NFs produced by Bradyrhizobium japonicum USDA 138 under control, salt, and osmotic stress conditions. This strain is the most widely used in Argentine soybean culture; under control conditions, it produces a mixture of four types of NFs (V(C16:0,MeFuc), V(C18:1,MeFuc), IV(C18:1), and V(C18:1,Ac,MeFuc)). Interestingly, under stress conditions, this strain produces new types of NFs, one common for both stress conditions (V(C16:1,MeFuc)) and another one only present under salt stress (IV(C18:1,MeFuc)). All mixtures of NFs, extracted from control, salt, and osmotic stress conditions, showed biological activity in soybean plants, such as root hair deformation, and the radical application of purified NFs induced systemic differences in dry matter accumulation. The inoculation of soybean with genistein-induced bacteria cultured under both control and stress conditions had a positive effect on the number of nodules formed and in some cases on dry matter accumulation. These responses are not related to changes in chlorophyll fluorescence or greenness index. 相似文献
40.