如何缩短母猪空怀期

母猪的空怀时间长短决定着母猪的年产胎次,现代养猪生产围绕如何缩短非生产天数而努力,只有抓好空怀母猪管理才有可能实现。母猪空怀期的时间相对母猪整个生产循环来说是非常短暂的,母猪从断奶开始进入空怀期,理论上讲,在断奶后4~7天内大多数母猪发情配种,部分母猪在7~10天内也会发情配种,只有少数的母猪由于个别原因会     

ε-聚赖氨酸和乳酸链球菌素协同抑菌效应的研究

ε-聚赖氨酸和乳酸链球菌素属于天然的食品防腐剂.该研究以大肠杆菌和金黄色葡萄球菌为指示菌,探究ε-聚赖氨酸和乳酸链球菌素及其复配溶液的抑菌作用.结果表明:ε-聚赖氨酸(45μg/mL)和乳酸链球菌素(312.5μg/mL)复配溶液对大肠杆菌的抑制作用最佳;ε-聚赖氨酸(5μg/mL)和乳酸链球菌素(250μg/mL)复配溶液对金黄色葡萄球菌的抑制作用最佳.Checkerboard分析法表明,乳酸链球菌素和ε-聚赖氨酸抑菌作用具有叠加效应.研究结果可以为ε-聚赖氨酸和乳酸链球菌素在食品防腐中的应用提供理论依据.     

应用响应面法优化鲜核桃低温贮藏保鲜工艺北大核心CSCD

【Objective】In order to prevent the loss of nutrients and prolong the shelf life of fresh walnut during storage, the best preservation conditions of low temperature storage for fresh walnut were optimized. 【Methods】In this experiment, the fresh fruits of Qingxiang were selected as the test materias. Under the conditions of cold storage [temperature: (-1±0.5)℃, relative humidity: 70%-80%], the walnut kernel moisture content, seed coat color difference, peel color conversion index, peel browning index, fruit cracking rate and decay rate were evaluated, and the comprehensive indexes were calculated according to Hassan method. Then, single factor experiments were conducted on the number of 1-methylcyclopropene (1-MCP) preservative bags, the thickness of polyethylene (PE) bags, and the number of holes on the bags. 1-MCP was directly put into the PE bag. The response surface design was used to optimize the best preservation process parameters with the comprehensive scores as the response value. Finally, according to the best preservation process parameters, the fresh walnut fruits of Qingxiang were kept fresh for 90 days, and the comprehensive quality evaluation and sensory quality level were determined according to the consulting survey results of consumers (18-45 years old). The changes of fresh walnut flavor during the preservation period were analyzed by principal component analysis.【Results】 The best technology of low-temperature storage for 5 kg fresh walnut fruits was 1 bag (0.625 g) of 1-MCP, 40 μm PE and 1 holes on the bag (hole diameter 5 mm;fresh keeping bag 400 mm × 600 mm. The theoretical comprehensive score was 94.48. From the perspectives of sensory and flavor evaluation, the sensory quality level and comprehensive quality evaluation of fresh walnut stored at low temperature for 90 days under the best technology were less than grade 2, the color difference of seed coat could not be distinguished by naked eyes, and the flavor basically did not change, which indicated that the best technology of this experiment had a good preservation effect on fresh walnut.【Conclusion】 The results showed that the best low-temperature storage technology for 5 kg the Qingxiang fresh walnut is 1 bag of 1-MCP, 40 μm PE and 1 hole on the bag. The results of this study would provide a basis for low temperature storage of fresh walnut. © 2021, Office of Journal of the Fruit Science. All right reserved.     

一例猪传染性胃肠炎病毒与大肠杆菌混合感染的实验室诊断

四川某猪场发生10日龄内仔猪严重腹泻、呕吐疫情,发病率达80%,死亡率高达70%。为确诊病原,无菌采集腹泻致死仔猪的肝脏、十二指肠内容物及肠系膜淋巴结进行实验室检测。经分离、培养和鉴定,在十二指肠内容物中分离到大肠杆菌,致病性试验结果表明所分离大肠杆菌可在12小时左右致死小鼠。对提取的肠系膜淋巴结总RNA进行针对猪传染性胃肠炎（TGE）病毒的特异性RT-PCR检测,结果传染性胃肠炎病毒（TGEV）为阳性。根据临床症状、病理变化、病原检测综合判定本次疾病流行的主要病因为传染性胃肠炎病毒继发大肠杆菌感染。     

大同市奶牛业、牛奶市场问题突出亟待整顿

为了整顿和规范大同市奶牛业产销市场,保证上市牛奶符合国家卫生质量标准、保护消费者健康,根据山西省大同市政府、市长办公会议要求,大同市第一卫生防疫站受市政府的委托,于１９９９年４月１５－３０日对全市的牛奶产销情况进行了一次全面的调查,通过调查,为有关部门提供了可靠数据。大同市第一卫生防疫站于１９９９年４月以文件的形式向有关单位下发了《关于对全市鲜奶和消毒奶卫生质量情况调查的通知》之后,根据全市各奶牛场（厂）情况,抽调本站专业技术过硬、工作认真负责的同志组成调查组到各奶牛场（厂）,采取听汇报、看资料…     

可持续发展理念在澳大利亚职业技术教育中的渗透

可持续发展理念的核心思想是以人的发展为中心,实现“生态、经济、社会”3维复合系统的协调发展,而教育的可持续发展是社会可持续发展的核心和关键。解析其在澳大利亚职业技术教育及其保障体系、学生能力标准培养设计和教学实践及评价中的渗透,为我国目前快速发展的职业技术教育提供借鉴,更好地关注人的个体生命价值的全面开发,促进我国职业技术教育的良性循环和协调发展。