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871.
Joshi A Naqvi SM Bag S Dang AK Sharma RC Rawat PS Mittal JP 《Tropical animal health and production》2003,35(3):249-257
The Garole is a prolific but less well known and rare breed of small sheep found in the hot and humid Sunderban region of West Bengal. An ability to breed throughout the year and to graze in knee-deep water, resistance to foot rot and a strong mothering instinct are some of the special features of this breed. Garole rams could provide germplasm to incorporate prolificacy traits by artificial insemination of the nonprolific sheep breeds found in abundance in the semi-arid and arid tropical climates of India. The aim of the present study was to evaluate the semen production by Garole rams maintained in a semi-arid climate for three years and to objectively assess their semen quality by a computer-assisted sperm analysis technique. The donor rams were randomly selected each year from the original flock procured from their natural habitat or from the offspring born at the Institute farm. Semen was collected weekly for three weeks each autumn for three consecutive years from 8 rams each year. The overall means (SD) of the traits that did not differ significantly with age or year were volume, concentration, curvilinear velocity, average path velocity, amplitude of lateral head displacement, beat frequency, motility and the percentages of rapid motile sperms and of slow motile sperms. The age of the rams had a significant effect (p<0.05) on the straight-line velocity but this was not significantly affected by the length of exposure to the semi-arid climate. However, the age and year had significant effects (p<0.05) on linearity, straightness and the percentage of medium motile sperms. It was concluded that Garole rams are capable of producing good-quality semen even after a prolonged period of exposure to a semi-arid tropical climate. 相似文献
872.
采用测定生理指标,生长发育、繁殖率和生产指标的方法,对从澳大利亚引进的20只安哥拉山羊进行适应性研究。测定结果:这群安哥拉山羊四季的生理指标正常、体重稳定增长、产毛量高、马海毛质量合格;但母羊的繁殖率低,羔羊初生重和断奶重较低。分折研究结果认为,安哥拉山羊能适应陕北的气候条件,但必须充分满足其营养需要,特别是怀孕后期和泌乳期,才能充分发挥其生产性能。 相似文献
873.
采用RT-PCR技术从微小牛蜱饥饿幼蜱破解物中扩增到Bm86基因,将其与巴斯德毕赤酵母分泌型表达载体pPlC9K重组构建了重组表达载体pPIC9K-Bm86,测序正确后将其用SacⅠ内切酶线性化后采用电穿孔法转化巴斯德毕赤酵母菌Gs115,经G418抗性筛选高拷贝重组菌株后用甲醇诱导表达,SDSPAGE和Western-blotting分析结果表明,诱导表达的培养上清液中表达出具有反应活性的68ku重组Bm86蛋白,目的蛋白约占培养上清液中蛋白总量的32%以上,诱导96h目的蛋白的表达量为0.36mg/mL。 相似文献
874.
875.
A survey of manure management on pig farms in Northern Vietnam 总被引:1,自引:0,他引:1
Animal manure can provide nutrients for crop and fish production and input for biogas production but, if managed inappropriately, can also have a negative impact on the environment. The objective of this survey was to provide information about pig production and manure management practices in the Northern part of Vietnam in order to identify and prioritize research needs for future improvements in pig manure management. A survey was conducted by in-depth interviews on 54 pig farms in two Northern Vietnamese provinces, Thai Binh and Bac Giang. In addition to the survey, also key informant responses were obtained in the two provinces to help identify problems with existing manure management. The survey showed that large-scale pig producers (> 100 fatteners or 20 sows) had more pigs per hectare than medium-scale (19–99 fatteners, 5–19 sows) or small-scale (< 19 fatteners, < 5 sows) producers. Biogas was produced from 43% of the total manure produced on all surveyed farms, and was used for cooking. The proportion of total manure applied to crops was only 5% in Thai Binh and 35% in Bac Giang. Large-scale producers tended to operate smaller fishponds, and medium-scale farms operated larger ones. The farmers were of the opinion that fish in ponds fertilized with pig manure grew significantly faster than did fish in ponds supplied with other feed or types of fertilizer. Twenty percent of pig producers reported that they raised pigs just to provide manure to feed their pond fish. A large proportion (19%) of the total manure produced was discharged into public sewage systems, rivers and lakes. Of the 54 householders interviewed, 46 believed that animal manure caused serious damage to the environment. Farmers interviewed had little or no expertise in handling liquid manure, composting solid manure, or reducing contamination by means of microbial reduction of pollutants during manure management. In general, specialized pig production is seen as a commercial operation, while manure management remains non-commercial. The survey implied that more information to farmers, as well as stronger regulation of manure management, is needed in Vietnam. 相似文献
876.
为科学评估淄博市小反刍兽疫免疫效果,2018年6月采用横断面研究方法,对淄博市部分规模养殖场和自然村(散养户)的小反刍兽疫免疫情况进行评估。采用两阶段随机抽样方法结合部分便利抽样,共采集44个规模养殖场和81个自然村的2 350份羊血清样品,经检测发现,规模场群体合格率为95.45%(42/44),自然村群体合格率为91.36%(74/81),个体免疫抗体合格数为2 220份,个体合格率为94.47%,均高于国家和山东省的最低要求。评估结果表明,淄博市的小反刍兽疫总体免疫效果良好。 相似文献
877.
The effect of resveratrol on the developmental competence of porcine oocytes vitrified at germinal vesicle stage
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ECS Santos R Appeltant TQ Dang‐Nguyen J Noguchi H Kaneko K Kikuchi T Somfai 《Reproduction in domestic animals》2018,53(2):304-312
We tested the effects of resveratrol both as a pre‐treatment and as a recovery treatment after warming during in vitro maturation (IVM) on the viability and developmental competence of porcine oocytes vitrified at the germinal vesicle stage. Pre‐treatment before vitrification of oocytes for 3 hr with 2 μM resveratrol did not affect survival, oocyte maturation and embryo developmental competence to the blastocyst stage after parthenogenetic activation. However, supplementation of the medium with resveratrol during subsequent IVM after vitrification and warming significantly improved the ability of surviving oocytes to develop to the blastocyst stage, and this effect was observed only on vitrified, but not on non‐vitrified oocytes. The intracellular levels of glutathione and hydrogen peroxide in oocytes were not affected by vitrification and resveratrol treatment. Also, there was no significant difference in the occurrence of apoptosis measured by annexin V binding between vitrified and non‐vitrified oocytes, regardless of the resveratrol treatment. In conclusion, resveratrol did not prevent the cellular damages in immature porcine oocytes during vitrification; however, when added to the IVM medium, it specifically improved the developmental competence of vitrified oocytes. Further research will be necessary to clarify the mechanisms of action of resveratrol on the recovery of vitrified oocytes from vitrification‐related damages. 相似文献
878.
In order to quantify the WLED's impact on color of Chinese traditional calligraphy and painting, and explore the practical applicability of using WLED as display lighting, an experiment was carried out on the RYGB type of WLED irradiated models of calligraphy and painting. And the color parameters was tested periodically to make curve charts of color coordinate and luminance over time. The impact of the WLED on hue, saturation, brightness was quantified based on the carve to provide evidence of application of WLED. 相似文献
879.
Dang K. Nhan Le T. Phong Marc J.C. Verdegem Le T. Duong Roel H. Bosma David C. Little 《Agricultural Systems》2007
Promotion of integrated aquaculture with agriculture, including crops and livestock (IAA-farming), requires consideration of both bio-physical and socio-economic contexts. The major factors influencing the adoption of IAA-farming by households at three sites in the Mekong delta were identified. Special attention was given to the multiple roles ponds play in IAA-farming systems. Information was collected through semi-structured interviews and discussions with focus groups and key individuals. Data were analyzed using multivariate factor analysis, analysis of variance or participatory ranking methods. Three major IAA-systems were identified: (1) low-input fish farming integrated with intensive fruit production (system 1), (2) medium-input fish farming integrated with less intensive fruit production (system 2), and (3) high-input fish farming integrated with less intensive fruit production (system 3). System 1 was commonly practised in a rural fruit-dominated area with fertile soils, while systems 2 and 3 were more evident in peri-urban rice-dominated areas with less fertile soils. In the study area, only 6% of poor farmers adopted IAA-farming, while this was 42% for intermediate and 60% for rich households. Richer farmers tended to intensify fish farming and seek a more commercial orientation. The major factors why farmers did not start aquaculture were the inappropriateness of technology, insufficient land holding or poor access to extension services, limited farm management, and through a fear of conflicts associated with pesticide use on crops. The main motivations for practising IAA-farming included increased income and food for home consumption from the available farm resources while reducing environmental impacts. Further improvements to IAA-systems can be realized by strengthening nutrient recycling between different IAA-system components while enhancing farming output and safeguarding the environment. 相似文献
880.
运用机构运动的基本原理进行板簧疲劳试验机的特性参数分析,得出了结构参数变化对试验机特性的影响,同时得到功率匹配的基本计算方法及飞轮质量和位置对试验机的影响,为设计者提供参考. 相似文献