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101.
Conception of Jersey cattle in Turkey   总被引:1,自引:1,他引:0  
To determine the effects of insemination season (IS; dry: May through October and rainy: November through April), lactation number (LN; heifers, primiparous or multiparous) and their interaction on non-return rate (NRR), conception rate (CR) to first-service and pregnancy loss (PL) of Jersey cattle in Turkey, over 1468 lactation records from 510 Jersey dairy cows were used. There was an interaction between LN × IS on NRR, CR to first-service (p < 0.01) and PL (p < 0.05). The NRR and CR to first-service of heifers inseminated during dry season and of primiparous inseminated during rainy season were higher (p < 0.01) than that of multiparous inseminated during both season. The NRR and CR of heifers and primiparous were higher (p < 0.05) than that of multiparous cows. The insemination of heifers during rainy season and of primiparous and multiparous during dry season increased (p < 0.01) the PL compared to the inseminations of heifers during dry season and of primiparous during rainy season. The PL was lower (p < 0.05) in primiparous than multiparous cows. The results demonstrate that the heifers have high fertility than the lactating, especially multiparous and that IS appeared to have a measurable impact on traits relating to conception of Jersey cattle in the each LN.  相似文献   
102.
Thermal stress in cattle results in major decreases in dairy production and reproduction. A study was designed to evaluate the influence of temporary cooling on pregnancy rate in Holstein heifers during summer heat stress. Estrus was synchronized with two injections of prostaglandin (PG), administrated 11 d apart, and all heifers were housed in a shaded enclosed structure at the time of the second PG injection. After estrus detection, heifers were randomly divided into three groups: Control (C; n = 30), Sprinkler (S; n = 30) or Sprinkler and Fan (SF; n = 30). Rectal temperatures were measured 2.5 hours before AI, at the time of AI, and 1.5 and 3.5 hours after AI. Group C heifers receive no further treatment, but heifers in S and SF groups were exposed to short-term cooling from 2 hours before until 2 hours after AI with a sprinkler (S) or sprinkler and a fan (SF), respectively. Estrus detection and AI were performed by a single skilled technician; semen was from a bull of known fertility. Rectal temperature did not differ among groups 2.5 hours before AI, but at the time of AI was lower (P < 0.05) in SF group (39.3 ± 0.0°C) than in S (39.5 ± 0.0°C) and C (39.9 ± 0.1°C) groups which also differed (P < 0.05). At 1.5 and 3.5 hours after AI, rectal temperature remained lower in SF group (38.9 ± 0.0 and 38.7 ± 0.0°C, respectively) than in the S (39.4 ± 0.0 and 39.2 ± 0.0°C, respectively) and C (39.3 ± 0.0 and 39.3 ± 0.0°C, respectively) groups, which no longer differed. Pregnancy rate following AI was higher (P < 0.05) in SF group (56.7%) than in the C group (23.3%) with the S group (40%) intermediate and not different from either. The present study results indicate that cooling of dairy heifers for a short time before and after AI, especially with sprinkler and fan, can increase pregnancy rate during heat stress.  相似文献   
103.
PIateIet-activatingfact0r(PAFf1-O-aIkyI-2-acetyl-sn-glycer0-3-ph0sph0ch0Iine)wasdiscoveredasachemicaImediat0r,reIeasedfromsensitizedbas0-phiIs(Benvenisteetal1972),thatcausedpIateIetaggregati0n.SubsequentstudiesdemonstratedthatPAFwasproduceduponappropriatestimulation0favariety0fhumancells,includingneutrophils,e0sino-phils,mon0cytes,andend0thelialcells,andthisp0-tentlipidmediatorisinv0IvedinanumberOftheal-IergicandinfIammatoryresp0nses(Hanahan1986;BraquetetaI1987;WalIace1989IPresc0tte…  相似文献   
104.
运用免疫组化ABC法妊娠26~120d的奶山羊黄体中催产素免疫反应细胞的分布进行了观察。结果表明,奶山羊妊娠黄体中存在催产素(Oxytocin,OT)免疫反应阳性细胞。阳性细胞在形态上以卵圆形、圆形、棱形为主,还有一些具有明显的突起。根据阳性细胞胞质内反应颗粒着色的深浅,可把OT阳性细胞分为强阳性、中等阳性和弱阳性3种。在妊娠26~30d,阳性细胞数量最多,强阳性细胞主要分布于黄体的周边,中等阳性及弱阳性细胞则均匀分布于整个黄体组织中,妊娠31~60d,阳性细胞数量明显下降,弥散于整个黄体组织中;妊娠61~120d,阳性细胞的数量及逐渐增多,以中等阳性和弱阳性细胞为主,而强阳性细胞数量较少。连续切片HE染色的对照观察显示妊娠黄体中大、小黄体细胞均可出现OT免疫阳性反应。  相似文献   
105.
Birth weight is extensively investigated as an outcome of interacting with greenery in mothers’ living environment, because it is one of the major causes for neonatal and infant mortality, as well as a correlate of some adverse effects in childhood and beyond. Conversely, in modern urban-ecological systems the access to greenery is limited. The aim of this study was to answer the question whether green spaces and generally greenery in the living environment of pregnant women are associated with the birth weight of their infants and what the direction of that effect is. MEDLINE, EMBASE and the Internet were searched for relevant publications in English and Spanish. Eight studies were identified and included in the analyses (total n = 214 940). We report quality effects meta-analyses based on correlation and standardized regression coefficients as estimates of effect size. Neighbourhood greenness within 100-m buffer was weakly and positively associated with birth weight. The pooled correlation coefficient was 0.049 (95% CI: 0.039, 0.059) and the pooled standardized regression coefficient was 0.001 (95% CI: ?0.001, 0.003). There was, however, considerable heterogeneity between the studies. Using more sensitive measures for greenness and taking into account green space functionality and quality, adjusting for environmental exposures, and assessing individual attitudes towards nature, might yield clearer picture, higher statistical power and more precise results in future research. Our findings endorse the emphasis put on urban forestry and landscape management as closely related to public health and propose a more naturalistic, humanitarian and person-centered approach in future studies.  相似文献   
106.
实验猕猴早早孕诊断   总被引:1,自引:0,他引:1  
利用便携式B型超声仪检查诊断实验猕猴早早孕情况。结果表明B超检查妊娠10d、15d、20d猕猴的诊断准确率分别为53.1%(17/32)、76.0%(24/32)、100%(32/32)。  相似文献   
107.
This study was designed to compare embryo recovery rates and pregnancy rates of athletic and breeding Quarter Horse mares in a tropical warm climate. Thirty-nine barrel racing mares in training and 135 breeding mares as control donors were included. During the training period, the ambient temperature ranged from 31°C to 36°C and the average humidity from 70% to 90%. After the detection of a 35-mm follicle by ultrasound, ovulation was induced with 1 mg of deslorelin acetate (i.m), and insemination was performed 24 hours later with cooled and fresh semen from different fertile stallions. Embryos were collected on day 8 postovulation. The body temperature (rectal) was evaluated from eight athletic donor mares randomly selected from the same studied group. A total of 138 and 657 embryo collections were carried out on training and breeding mares, respectively, with a total of 105 (76%) and 466 (71%) embryos collected (P > .05). Similarly, no differences (P > .05) were observed for the pregnancy rates on day 15 (82/105, 78% vs. 370/466, 79%), and day 40 (73/105, 69% vs. 328/466, 70%) between the training and breeding donor mares. Just after training, the body temperature increased to an average of 39.4°C and the respiratory rate from 14.5 to 35.3 breaths per minute. The results of the present study showed that embryo production from appropriately trained donor mares in good condition were similar to non-athletic broodmares.  相似文献   
108.
提高牛冷冻胚胎成活率和移植受胎率的研究   总被引:3,自引:0,他引:3  
本文从冻前胚胎质量(等级)、胚胎的发育阶段、脱除冷冻保护剂的方法等对冷冻胚胎成活率的影响进行了比较系统的研究;从冻后胚胎质量(等级)、受体牛子宫及卵巢黄体生理状况,移植者技术水平对冷冻胚胎移植受胎率的影响进行了比较详细的研究。冻胚解冻成活率和移植受胎率分别达到76.2%(128/168)和46.6%(57/122),其中1995年的同项研究结果分别为84.4%(38/45)和55.6%(20/36),不仅达到实际应用水平,而且与国际先进水平相当。  相似文献   
109.
对妊娠毒血症小尾寒羊肝脏的大体结构、显微结构和超显微结构变化进行了观察,结果发现肝组织毛细血管充血、水肿,出血;肝细胞发生脂肪变性等脂肪肝的特征变化,细胞核浓缩,线粒体出现空泡化,细胞质内糖原颗粒增多.  相似文献   
110.
在广泛文献检索的基础上,对空青的种属、主要成分、药理、临床应用与注意事项等进行概述,为深入开发、利用提供科学资料.  相似文献   
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